PDA

View Full Version : Building my second cnc router



balsaman
05-19-2003, 11:43 PM
Hey guys,

I am currently working on my second cnc machine. This one will have a 24"x36"x5" cutting volume.

Here are the plans. They make use of 80/20 extruded aluminum channel and THK linear rail and bearings.

Base is purple, gantry is black/white, rail is red, bearings are blue.

Eric

balsaman
05-19-2003, 11:45 PM
closeup of gantry

balsaman
05-19-2003, 11:47 PM
Sides of gantry will be 1/2" aluminum plate. I started cutting the aluminum channel for the hardware on my other cnc. (pockets)

balsaman
05-19-2003, 11:53 PM
Here are the first few parts. The four standoffs between the bases. I had my machine cut the pockets then cut the part off the longer lenght.

I have hardware that fits into the pockets to fix two 80/20 parts together at right angles.

paulried
05-20-2003, 12:03 AM
Man that looks sweet! I sure wish I was 2% as good at cad as you guys are. I am currently fighting the uphill learning battle.

I love that you are using generation #1 to build #2.

balsaman
05-20-2003, 12:23 AM
Paul,

I took two courses at a local college. Best thing I ever did. Trying to self learn is frustrating. I am trying to teach myself 3d...very frustrating....:)

Eric

chuckknigh
05-20-2003, 12:48 AM
Where can I find extrusion like this? I don't have the slightest idea where, even, to look!

Although, knowing this crowd, it's probably available at McMaster/Carr.

-- Chuck Knight

balsaman
05-20-2003, 12:51 AM
www.8020.net

www.tslot.com

Max
05-20-2003, 01:13 AM
80/20 sent me a cd along with their catalog that has useful files and drawings.
Only problem is that the Auto Quoter program relies on AutoCAD R12 to work.
I wish it would work with any generic cad program that I could afford.
If anything, just having their catalog is a useful reference.

Zephrant
05-20-2003, 11:54 AM
Very cool- What kind of drive are you going to use? Single ball/screw for the X?

Zeph

HomeCNC
05-21-2003, 12:32 PM
Have you purchased the THK rails and bearings yet? That should set you back some. :) Or are you the guy that gets these rails and things for free from your company???

balsaman
05-21-2003, 08:32 PM
I don't have the rails/bearings yet. I keep a look out at work for some being tossed or as machines become obsolete/replaced. There is a posibility I can get some from an obsolete die in the next week or two.

I am planning to use 3/4"-6 of 7/8"-5 acme rod and delrin nuts driven by Geckos and dc servo motors. I have the three brushed motors so far....:) They are 1.1 amp 110 VDC motors. I know I can only run the Geckos at 80 volts.

Eric

HomeCNC
05-22-2003, 01:43 PM
I wish I knew more about electronics. It is interesting that your motors are higher on voltage but lower on amps than my servo motors. My motors are only 36 volts but are 5 amps. I wonder what is better, more voltage or more amps?

ToyMaker
05-22-2003, 03:55 PM
Which is better, volts or amps?

It depends :) , One way to look at it is by power.

Here's some arithmetic;
Eric's motor: 110Vdc @ 1.1A, R=E/I, Ohms = 110/1.1 = 100 Ohms
Current at 80V, I=E/R, Amps = 80/100 = 0.8 Amps
Power P=E*I, Watts = 80 * 0.8 = 64 Watts
Horsepower 1 hp = 746W, 64W = 0.08 hp

Jeff's motor: 36Vdc @ 5A
Power P=E*I, Watts = 36 & 5 = 180 Watts
Horsepower 1 hp = 746W, 180W = 0.24 hp

So... under full rated load Jeff's motor is going to put more "rubber on the road" so to speak. I think that Eric's motors will deliver a higher no-load speed because of the higher drive voltage (the motor has to turn faster to build up the counter emf).

robotic regards,

Tom

balsaman
05-22-2003, 04:41 PM
Tom, correct me if I am wrong. The motor will draw something less than the rated current when not loaded. Loading the motor will make it draw more current. If that is true, i will be able to make it draw 1.1 amps at 80 volts (the gecko's have a max current trim pot), so watts is 88, and the HP is .117 in, something less out, as the motor isn't 100% efficient.

I think both motors will work fine (I hope). Probably Jeff's are better.

Eric

ToyMaker
05-22-2003, 06:20 PM
Eric:
You are right. Your motor will draw a lot less than rated amps when not loaded. In fact it will draw just enough power to overcome the friction in the bearings.
But that is not the whole story. I think the Gecko drives are choppers. That means there is the frequency of the chop signal and the inductance of the motor coils to take into account too (it's a never ending story :) ).

robotic regards,

Tom

balsaman
05-22-2003, 10:08 PM
I will find out I guess. I know those motors will have lots more torque and speed than the steppers!

I managed an hour or two in the shop today. I got the base of the machine done. I am glad I won't have to paint this one. I hate paint!

This thing is rather large. How come it always looks smaller on my computer screen? :)

Eric

paulried
05-22-2003, 10:17 PM
Because you need to get a bigger computer screen! :D

I want one that has a sticker on it that says "Images shown on this screen may be larger than real life" like the mirror on my car!

HomeCNC
05-22-2003, 10:47 PM
Well knowing you, your motors were most likely FREE!!!! And free always beats most anything. :D

balsaman
05-26-2003, 10:47 PM
Hi everyone.

Today I cut the gantry sides out of 6061 aluminum plate. I cut it 1/8" oversize on a bandsaw then used my wood router to clean up the sides and cut the pockets in for the extruded aluminum. My wood router doesn't like the aluminum too much but it's fine if the feed rate is kept down. This was all done at 3" per minute up to 9" for some lighter cuts. Turned out pretty good.

here is a pic of the router cutting aluminum...lots of chips. The dust collector was going but most of the chips stayed behind.

balsaman
05-26-2003, 10:49 PM
Finished parts. Pockets are .125" deep. They keep the aluminum channel from turning with just one bolt in the middle. I will also add some triangle gussets to keep things rigid/square.

balsaman
05-26-2003, 10:50 PM
Trial fit. It's going to work!

balsaman
05-26-2003, 10:50 PM
One more....

HomeCNC
05-26-2003, 11:15 PM
Alright Balsaman, another aluminum built router on the way. You will be able to do much more with this router than cut balsa. YOur going to half to change your name! :D

balsaman
05-26-2003, 11:24 PM
Jeff,

Even my wooden router can cut aluminum. I am really looking forward to seeing what this one will do. I will need a larger spindle router, as somethimes that's what's limiting me on the one I have now.

:)

Eric

boxwood
05-26-2003, 11:33 PM
Hi Eric
Nice looking design you are starting on there, thought you might be interested in this, MSC has precision acme threaded rod, if I had it to do over I would go with the 1/2- 2, they also have the non percision rod very cheap too I got that in a 3/8-8 $10 for 6 ft
and made some delrin nuts today with a homemade tap saw that on a pic you posted thanks for the post they help keep me motivated.
Ray

http://www.mscdirect.com/PDF.process?pdf=3580&Section_Id=451

georgebarr
05-27-2003, 02:06 AM
Balsaman,
How does your thk bearings screw into the side of your aluminum extrusion? I plan on building my first cnc frame using aluminum extrusion and need some tips. Also, did you get any discount from 80/20 or tslots and how did you ask them for the discounts and how much of a discount?

Thanks,

balsaman
05-27-2003, 09:14 PM
Boxwood, thanks for the link.

George,

I haven't decided yet how to fasten the rail to the aluminum. I was thinking about drilling and tapping the holes in a lenght of 1/2"x1/4" flat bar, then sliding it into the t slot in the extrusion. One could also drill and tap the center section of the extrusion...

I got all my aluminum extrusion surplus...so yes..a big discount. (it was being scrapped at work) It was very dirty, as it was guarding on some eqiupment.

Eric

balsaman
05-28-2003, 06:13 PM
Assembled the gantry bridge today to see how it fits. It's going to work.

balsaman
05-28-2003, 06:18 PM
I got some linear rail. It's a bunch of not so gently used stuff from some obsolete equipment. It will work tho. One of the lenghts shown is bent, and part of the bearing "Race" is broken out (like the bearing phisically was torn off of it). I will cut out the bad section. I also got a whack of the matching bearings. All are dirty and some aren't usable. I need to sort thru them to get as many working as I can.

The price was right, and I am sure I will have enough good stuff for this project.

Eric

balsaman
05-31-2003, 09:56 PM
I got my gantry rolling today. It works great! Y and Z tomorrow I hope.

Eric

WOODKNACK
05-31-2003, 09:59 PM
Balsaman,
Looks real good! I got my catolog from T slots. That aluminum extrution is neat. looks like there is a ton of things you can build with it! Nice job on your router table....:banana:

balsaman
05-31-2003, 10:04 PM
Just how do you post those darn bananas anyways?

Thanks for you nice comments.

Eric

georgebarr
05-31-2003, 10:11 PM
I have some questions. What is the overall size of your gantry? Also, how thick is your aluminum plate (the one that holds the y axis)? What is your expected Z axis travel? I am putting together my extrusion gantry using autocad.

WOODKNACK
05-31-2003, 10:12 PM
I would tell you but then Id have to kill ya!(flame2)

LOL

balsaman
06-01-2003, 09:21 AM
Cutting volume of 24x36x5"
1/2" plate
Gantry bridge is 8" wide by 20" tall

balsaman
06-05-2003, 10:44 PM
Y and Z are sliding effortlessly. Motors, leadscrews, and nuts are next.

Eric:cheers: :cheers:

balsaman
06-05-2003, 11:04 PM
The cool thing is I once again used my other cnc for the y and z parts. I laid out the linear bearings and plates in cad and had my cnc start all the holes with a center drill .050 deep. Then it was just a matter of drilling a c-boring the holes the right sizes. It all fit great!

I wish I had better tools. I have a crappy drill press and my other cnc. It's hard to cut the aluminum accuratly with a hack saw or my cheap tablesaw. I need a milling machine. Still, it's going well.

Eric

cbcnc
06-05-2003, 11:25 PM
Balsaman,

Yup, bigger leads to even bigger. Once you see where your boundries are then you start looking over the fence.

Chris

HomeCNC
06-06-2003, 12:00 AM
Pretty soon you will need to see how square you are. I had to slot the holes on the top Y axis way to get the Z perpendicular to the gantry. How close are you wanting to get? or willing to accept?

Zephrant
06-06-2003, 12:26 AM
BM- Did you order the aluminum pre-cut with the end jointing hardware, or did you do that yourself?

For getting true on the Z axis, can you shim between the Z sled and the bearings to help true it up in the X-Z plane, and adjust the router bracket for the Y-Z plane if needed?

Edit- Nevermind, I re-read and found your pocketing picture earlier. ;)

But while I'm here:

Did you draw it up in full 3D, or just 2D?

Did you get "tooling plate" for the sides, or just standard plate? 6061-T6?

Zeph

balsaman
06-06-2003, 08:20 AM
So far it's pretty square, but I can only measure using a square. The machine itself will be out a bit here and there but I hope some stuff I can square up by loosening, adjusting, and retightening. Other area's may need shimming. Once it's built, I will use a dial indicator to get it as close as I can, and cut a couple squares and check that the right angles are right...:) I am willing to accept it as good as it comes out. I mostly cut airplane parts, so 10 thousands here and there won't matter. Still, I hope to get it better than that. We will see.

I used 6061-T6 aluminum. I drew it up in 2D.

anoel
06-06-2003, 09:42 AM
How rigid does it feel right now. How's the motor mount going to be done for the Z? From the picture it doesn't look like a lot of clearance for a leadscrew (but then again picures have a tendancy to compress space. Are you going to use gear reduction on the servos?

balsaman
06-06-2003, 09:57 AM
There is about 1.25" in there for the lead screw/nut. I am just cutting that stuff now on my other cnc. It feels nice and rigid, but we will see when we make heavy cuts/crash :). I am planning direct drive for the servo's onto 3/4-6 acme lead screws.

Eric

anoel
06-06-2003, 10:15 AM
How about your cutting table are you going to go with a T-Slotted aluminum table or a wooden sacraficial table?

(I ask these questions because I see a servo driven Aluminum macine in my not so distant future...)

balsaman
06-06-2003, 12:17 PM
MDF with holes drilled every inch with threaded inserts in the holes, like my last one.

Here are my end/thrust bearing in thier delrin holders. The delrin in pocketed so the open end goes against the aluminum. The other end has a shoulder to keep the bearing in there. A shoulder on the leadscrew goes aganst the inner race, and a nut on the other side.

Also see a loose bearing and one of the tapped delrin nuts.

Eric

balsaman
06-06-2003, 12:21 PM
the other side of the bearing holder.

cbcnc
06-06-2003, 12:31 PM
Eric,

Looks good!
That is the way I have done my bearings. I have used a aluminum holder though. The holes that attach the holders are oversize so there is some play for adjustment. Also, if they are on the backside of the frame and the hole that the leadscrew goes through is smaller than the bearing, you don't need the lip.

Chris

balsaman
06-06-2003, 12:37 PM
You still need the lip to keep the bearing from pushing out. The aluminum holds it on one side, with the hole being smaller than the bearing OD, and the lip holds the other side.

Once the machine is running, If I feel the delrin won't stand up, I will make some aluminum ones.

Eric

cbcnc
06-06-2003, 12:49 PM
You're right about the lip. On my x axis I have supported the leadscrew on both ends so the locknuts and washers hold the bearings in. My other two axes will have one bearing each and the lip.

Chris

anoel
06-06-2003, 01:49 PM
Here's a pic of the bearing block that I used on the Y axis of my big machine. Is' just made from 1/2" PVC and Clamps around the bearing. The Skate bearing fit nice and tight and after clamping, doesn't slip .

balsaman
06-11-2003, 01:47 PM
Ok so I got a little paranoid about the plastic nuts for this machine, so I made some new ones out of Inconel. It's tough as nails, I just hope not too tough that it wears my leadscrew. The 3/4" x 6 acme screw I am getting is only $15.00 per 6' length so no biggie.

balsaman
06-11-2003, 01:55 PM
Cut the pocket and drilled holes in my side plate for the y axis motor. I found a severe feed rate issue with arcs in turbocnc so after I broke a 1/8" bit I went with a square pocket. It seems the feedrate is ignored while cutting arcs so the feedrate went a wee (double at least) over the F3 I specified. I never noticed this before as I usually am impatient and my feed rates are way up there when cutting wood anyways. I am waiting to hear from the turbocnc guru's if it's just me or not...:D

anyways here is the pocket.

Let me know if I am boring you all.

anoel
06-11-2003, 02:07 PM
A little lube should keep the wear down. (a little telfon spray now and then, perhaps)

What is Inconel? Looks like a bronze derivitive from the photo.
How hard was it to tap? I know that tapping the 1/2" 10tpi holes in UHMW was pretty tough. I cringe to think what it'd be like in metal.

balsaman
06-11-2003, 02:09 PM
I am not tool maker but yes it's some sort of bronze material. It taps ok, the shavings come out in little chips so that's nice.

Here is the motor mounted for now.

Zephrant
06-11-2003, 07:48 PM
Looks great- Keep the info coming.

Zeph

balsaman
06-13-2003, 01:59 AM
Sorry guys, that material for the nuts is not Inconel (which is like stainless steel) but Amco, which is a sort of bronze material. I got that mixed up in the above posts.

Eric

anoel
06-13-2003, 10:53 AM
So when do you expect to be spinning motors? Were you able to decide upon a router motor?

balsaman
06-13-2003, 11:11 AM
I need to buy the gecko's yet, and I am waiting for the lead screws...I little while yet.

Eric

keithorr
06-13-2003, 01:08 PM
Originally posted by balsaman
Sorry guys, that material for the nuts is not Inconel (which is like stainless steel) but Amco, which is a sort of bronze material. I got that mixed up in the above posts.

Eric

Glad you caught that. I started to write a response the other night questioning you about that but decided to let it go. You would have had a hard time cutting threads that easily in inconel. "Shavings" ha!;)

balsaman
06-13-2003, 01:25 PM
yes inconel is very very hard. :) I am just an electrician, what do I know.

Eric

balsaman
06-14-2003, 08:59 PM
I made all the aluminum motor mounting plates, and bearing mounts. Once again used a centre drill on my cnc to get all the holes in the right spots. I also took out the four short corner posts and replaced them with aluminum plate bolted on the ends. This gave me 3" more cutting area without the machine getting any bigger..:)

Here is a shot with the motors mounted. I ordered the screws, they will be in next week.

I am hoping for a surprise for fathers day tomorrow...

Eric

Zephrant
06-14-2003, 11:05 PM
Originally posted by balsaman
I am hoping for a surprise for fathers day tomorrow...


Ooo look! Another Tie! Surprise! ;)

Zeph

balsaman
06-15-2003, 05:13 PM
yep, I got a tie...


I also got this! I am not sure if it's the same as yours Jeff. I liked it because it's going to be easy to mount. It's 1.75 HP. Model 690LR, 11 amps.

Eric (Lucky Dad)

balsaman
06-15-2003, 05:14 PM
another

balsaman
06-15-2003, 05:58 PM
Nope,

Jeff, looking back I see you got the bigger router. I like the mounts you made. I think it will make some mounts from delrin, since it's hard for me to make them from aluminum with my CNC (read slow).

Eric

cbcnc
06-15-2003, 08:56 PM
Nice router! I know that you won't dissappointed in it in any case.
Happy Father's Day!

Chris

HomeCNC
06-15-2003, 11:58 PM
I also have the 690 router for doing my woodworking with. It is a very nice dependable machine.

jakk100
06-17-2003, 01:33 AM
Balsaman,
What size motors are you using for X,Y and Z?
Oz torque?
Servo?
RPM?

Thanks,
Jakk

balsaman
06-17-2003, 12:33 PM
I don't know. They are off old wire feeders(for mig welding). They are 115 volt DC and 1.1 amps. They say 1/8 HP on them. If they don't work, I will get some servo's from Jeff. (or maybe I will win some...:)

Eric

HomeCNC
06-17-2003, 01:20 PM
Eric, You guessed June 21 !! with 975 users now I think you have a very good chance to win!

balsaman
06-17-2003, 01:41 PM
My fingers hurt I have them crossed so hard..:) That would be the first thing I have won in my life!

Eric(nuts)

balsaman
06-20-2003, 12:44 PM
Well it is a bit of a sad day for me today as I sold my trusty cnc machine (first one). I am now cncless until I get this one going. That should motivate me!

On a brighter note I can now order my Gecko's! Which i will do in about 5 minutes!
:cheers:

Stay tuned! (unless your tired of me) :)

Eric

balsaman
06-21-2003, 03:48 PM
Guys,

I got my Acme rod. I need to turn the ends down at my buddies next week. In the mean time I ordered the gecko 320's. I also mounted the 3 encoders. The z is on top of the motor, x and y on the oposite ends of the lead screw. Not as neat and pretty as Jeffs servo setup but functional I hope. Maybe someday I will order some "real" servos.

Eric

HuFlungDung
06-21-2003, 03:59 PM
For what its worth, I'd suggest that you can make your machine a lot stiffer if you can find a way to sneak in a few braces that break up your rectangular "framing", so to speak. As you may know, triangles cannot be deformed without stretching or compressing one side, so this takes the onus off of the joints to be so "smokin' tight" on any rectangular frame.

Disclaimer: no insult intended, as you may already have planned to do this, or perhaps it is impossible to fit them in :)

balsaman
06-21-2003, 04:44 PM
Hu,

Yes, That is my intentions. There will be triangular bracing in there. I didn't want them to interfere with anything mechanical, so I have left them off untill it's all moving under it's own power. Once that is accomplished, I will put bracing in as required. I was also thinking perhaps steel cables in an x with turnbuckles, if it's practical. I want the screws etc in first for ease or assembly, so I don't have to fight with the extra bracing.

Eric

kong
06-23-2003, 05:14 AM
Could you give me some info on your motor setup please Balsaman, you say they are not "proper" servos, so I am assuming ordinary brushed servo motors, with seperate encoders? Just curious coz I found something similar on ebay which may work. Thanks.

balsaman
06-23-2003, 07:20 AM
Yes, they are ordinary brushed DC motors with seperate encoders. They come out of MIG welder wire feeders. Once I get my gecko's I will let you know how it all works.

Eric

balsaman
06-24-2003, 10:04 PM
Well I got my acme rod turned down yesterday so I started assembling that part today. Got the x and y sorted out. Perhaps the z tomorrow. I ran the dc motors on a dc drive just to try it out. Got up to 200" per minute before the rod shakes real bad so at least that part won't be a limiting factor. I am not sure about the torque tho. Those motors slow down badly when I leaned into the axis. Time will tell I guess. Do the geckos just keep raising the voltage as the load increases to compensate? Iguess thats how they work. Probably till they reach thier current limit?

Anyways, here is a picture.

balsaman
06-24-2003, 10:05 PM
Another

TRC1
06-25-2003, 01:32 AM
Very Impressive!!!!

HuFlungDung
06-25-2003, 01:47 AM
Balsaman,

If you are using encoder feedback, your motor performance should improve a tremendous amount when you get them hooked up, and the tuning done. There is no way to slow down a servo on a closed loop, either it runs at the commanded speed, or it trips the breaker trying to do it :)

anoel
06-26-2003, 11:24 AM
Got those Geckos in yet? I'm getting pretty antsy myself waiting to see this thing cut. :)

balsaman
07-01-2003, 07:10 PM
They took my money on Friday (visa). I hope that means they shipped them. :)

I just noticed that the 90 volt DC drive I was using to supply the motor for testing is only puting out 45 volts. I think one of the SCR's is cooked. Took them both off the board and they test funny...I will replace them both and try again. I am planning to use this drive as a powersupply along with some caps to smooth it out. In any case this is probably why I was worried about the motor torque in the above post. My motors are 110 volts.

I still need to tie up some loose ends mechanically as well.

I am considereing mounting this machine at about a 75 degree angle when its done so it fits in my shop better. Any comments on this? I have seen a few commercial machines this way as well as the odd home made one. All are larger than mine.

Eric

balsaman
07-01-2003, 07:14 PM
Anyone know the formula for the proper cap required for a rectified AC?

anoel
07-01-2003, 08:07 PM
Download this. You'll be able to model your Power Supply with it and see just how much ripple you'll end up with.

http://www.duncanamps.com/psud2/index.html

balsaman
07-01-2003, 10:04 PM
Thanks, but that won't install properly on my computer. I would prefer it if someone had the formula. Anyone?

rcrabb
07-01-2003, 10:35 PM
I have rectifeid DC on my power supplies I'm running between 50 and 60 volts. If it helps I can tell you what I have

abasir
07-01-2003, 11:04 PM
Extract from paper at Gecko website.
Is this what you are after?

HomeCNC
07-02-2003, 12:16 AM
The full paper is on the FTP site here.

balsaman
07-02-2003, 09:02 AM
Yeah, that's what I am after, thanks all.

Eric

balsaman
07-03-2003, 12:53 PM
Hey gang,

After doing some reading I am wondering if I need to go belt drive with my servo setup. (shoulda doen my reading before I got this far I guess).

Any thoughts on this?

ger21
07-03-2003, 03:33 PM
Everything I've read says around 2 to 1 reduction, is that what your thinking? But I have no experience myself.

Gerry

balsaman
07-03-2003, 04:19 PM
Yeah that's what I have been seeing. My servos 2300 RMP. At 1000 RPM I will be getting 166 inches a minute, so I doubt I will ever go over that....Since I have gone this far, and my gecko's should be here soon, I will try it direct drive. If it doesn't work, or my motors heat up, I will have to look at some other options.

Eric

balsaman
07-04-2003, 12:41 PM
I got the z axis all set. I have been also putting in all the bolts now and tightening stuff down. Up till now I have been "dry" fitting all the parts. It's coming out quite stiff even without cross pieces.

Here is a photo of the z. The router/holder needs to get bolted to this plate.

balsaman
07-04-2003, 12:45 PM
X axis endoder setup. Even if I go to a belt drive, I am pretty sure I can leave the encoder on the leadscrew shaft. I have plenty of resolution.

balsaman
07-04-2003, 12:49 PM
Here is the Y axis encoder. This one I changed the cable exit so I can get the machine closer to the wall. Like I said once I am all done I may mount the machine at some odd angle to save some space. Also I think it may make it easier to reach the corners and load larger stock. Time will tell. Maybe the machine won't even go.

I am getting some deflection on the gantry if I push hard on the ends. I hope some cross bracing will keep things a little stiffer.

balsaman
07-04-2003, 12:53 PM
here is a shot of the solid couplings I used. The screws are turned down to .375 (same as motor shafts) and the couplings have setscrews. It works, but there is a slight misalignment causing the screw to wobble a bit. These will be changed to flexible couplings of some sort. I went to Princess Auto to pick some up yesterday but they were sold out of the size I needed.

Eric

balsaman
07-04-2003, 01:46 PM
Hey, the delivery guy came and brought my Gecko's! I even got a little gecko beanie baby with it, which my daughter has claimed aleady. Maybe I will hook one up and spin a motor! Someone warned me never to spin the motors because If I do I won't finish the machine. I didn't spin any on my first machine but I think I am safe and I will indeed finish. I will let you all know how it all works out.

Eric

balsaman
07-04-2003, 01:47 PM
Forgot the obligatory picture.

kong
07-04-2003, 02:05 PM
This machine is gonna be great Balsaman, i can't wait to see it running. Nice work!:wee:

HomeCNC
07-04-2003, 04:53 PM
Hey! is that a stuffed Gecko? I got a refrigerator magnet Gecko when I ordered my drives. :D

balsaman
07-04-2003, 05:41 PM
Yep, its a stuffed one. They must have run out of fridge magnets.(wedge) . I hooked up one gecko and I was a motor spinner big time! I was amazed at the power, even tho I was just using a 24v power supply. Once I get my 80 volt supply working it will have plenty of power.

Jeff, I used the TurboCNC computer's +5 volts to supply the gecko step/dir common. I read somewhere that you used a wallwart. Is that true? Where did you hook the wallwart 0V? to the Gecko main power supply negative terminal?

I am so excited, this thing may actually work!:banana:

Eric

balsaman
07-04-2003, 11:44 PM
Hey guys, I hooked the gecko up to an axis (X) and am getting rapids of 60 inches a minute on 24 volts. This is on 110 volt motors. Tomorow I will see about a 75-80 volt supply. I am happy so far.

Eric

balsaman
07-05-2003, 02:44 PM
Gang,

On 65 volts I get 150 inches a minute. I can live with that! I want to try 80 volts but my PS is putting out 80.8 volts. I don't want to let the smoke out. I am waithing to hear from the gecko people first. The gecko's are rated at 80 volts max. Some stuff is rated conservatively, some stuff is rated at the very max. I want to be sure about the gecko's. Even at 80 volts, I won't increase the rapids, but the little extra power will be nice for when I crash this thing..:)

Eric

ToyMaker
07-05-2003, 06:10 PM
Eric:
If those drives can't take a 1% over-voltage something is extremely wrong. But wait for an official answer anyway :)

robotic regards,

Tom
= = = = =
Contentment makes poor men rich; discontent makes rich men poor.

balsaman
07-05-2003, 06:26 PM
The official answer is it would be ok, but he said that since the PS is unregulated, it may vary 15% up and down with the line suppy. On the high end I could get 93 volts. That would be bad. I will leave it at 65 volts for now until I get a 80 volt regulated supply. I still may use the DC drive I have, which is variable from 0-90 volts, but I need to replace an SCR first. As is, it's working great on 65 volts.

Eric

ToyMaker
07-05-2003, 10:38 PM
You could add protection (and regulation) to you power supply. Digikey have a 82V 5W zener diode that might do the trick.

robotic regards,

Tom
= = = = =
If we attend continually and promptly to the little that we can do, we shall long be surprised to find out how little remains that we cannot do.
- Samuel Butler

balsaman
07-06-2003, 03:56 PM
I am sticking with 65 volts for now. I got two axis running now so I could run a gcode file. I imagined the z axis going up and down for now. :). It's very funny to watch the gcode go. Just for fun I upped the feed rate to 100 ipm since I am not cutting anything anyways.

I have been playing with the settings in Tcnc. I have left it at 150 ipm rapids which is plenty. The gecko's and servo's are capable of violent accel settings without faulting. I have the max step set at 18000, accel at 100,000 and max start at 1000. My encoders are 1200 lines. With that setting it accels to 150 ipm in about .17 seconds if I remember right. Even more violence can be obtained but I worry about the limits of my machine mechanically and really there is no need.

So far I am really happy with how this is all coming together. I just can wait to cut a part.

Actally my first parts will be new nuts probaby as I am sure I won't be happy with the amco nuts I made. Too hard. I will see if I can locate some delrin at least 1.5" thick for some heavy duty delrin nuts. The first nuts I made were 3/4" thick and switch to amco because I didn't think they could hack it.

Stay tuned.

Eric

HomeCNC
07-06-2003, 10:37 PM
Alright! Balsaman!!

Welcome to servo power :D

You asked me about using the wall wart. I used a 12 VDC one because of the Axxus board I used. It needs this input so it can supply power for Relays, Limit/home switches, and Gecko power.

cbcnc
07-06-2003, 11:23 PM
Actally my first parts will be new nuts probaby as I am sure I won't be happy with the amco nuts I made. Too hard. I will see if I can locate some delrin at least 1.5" thick for some heavy duty delrin nuts. The first nuts I made were 3/4" thick and switch to amco because I didn't think they could hack it.
Eric,

I have been using some 2" dia. solid Delrin rod that you can cut lengths off of. I bore thru the face, tap it and mill a flat for mounting. I didn't think that 1/2" thk material was enough for leadnuts and this was a way to get more thickness easily.
You machine is really looking good.

Chris

MikeA
07-07-2003, 09:54 AM
Great job, but more important the whole project and the manner in which you are presenting it is very interesting and imformative. My question is, as obviously you have spent a lot of hours and are not totally against spending a little cash, why not ball screws?

balsaman
07-07-2003, 08:37 PM
I am against spending cash! The most expensive part so far is the gecko's. Most of the stuff you see I got from the dumpster. The acme rod was only $15.00 per length. I used it on my last machine and was very happy. At some time if I want I can replace the acme with ball screws. My idea is to get it going. This is my first try with a heavier machine and servo's. My last machine made me money. If this one does, I can justify ballscrews if I think it's needed....I doubt it.

Thanks for the compliments on the thread. I sometimes think I may be posting too much. Sometimes I figure I am talking to myself! Sometimes I think it must be boring. I am glad some people like it!

More to come!

Eric

Lanny
07-08-2003, 08:11 AM
Balsaman, don't think for even one second that's it's boring or that you're talking to yourself. I for one am captivated and look forward to your updates.

Keep 'em coming!!

CAMmando
07-08-2003, 12:11 PM
Balsa Man,

I have been following closely.

Keep it up.

Dave

tsalaf
07-08-2003, 04:09 PM
We’re here to benefit from each other’s successes and mistakes. None of us can benefit if we don’t post

balsaman
07-09-2003, 12:41 AM
Hi Gang.

I spent the last few hours switching to new delrin nuts. I am getting an awful resonance now as the screw whips inside the nut. I may have to go back to the amco nuts. I am thinking of incorperating some kind of antibacklash into the nuts if I can. perhaps ballscrews are the answer for larger machines. My long screw is 48". I will work it out.

On a brighter note, I installed the cross bracing on the gantry. This went well and has stiffened up the machine nicely.

I was having some trouble with alignment/binding on the z axis. I got that fixed up for the most part. It's been a rather frustrating evening.

Oh, and my shop is a mess! I need to clean it up. :)
Eric

cbcnc
07-09-2003, 03:04 AM
Balsaman,

A quick fix could be to sink a couple of large diameter woodscrews into the nut close to the leadscrew threads. The delrin will flex and tighten up on the threads.

Chris

balsaman
07-09-2003, 09:45 PM
Acme nuts try 3. Here is the latest acme nut. I went back to the amco but split them so I could take the backlash out. I put in 2 setcsrews(you can see the holes) on either side of the mounting hole. The setscrews are only half way thru, so they push against the other half. This limits the "squish" so I can dial out the play. I tried it on my long axis and it seems pretty good.

Eric

sshelge
07-09-2003, 11:17 PM
balsaman
I have been folllowing your posts from the ezone up to here, i wan to thank all the knowledge that you share with us in an unconditional way, and congratulate for your achievements. I think your next goal will be a laser cut, tha same stuff, steppers , cad's, g code, but with a concentrated beam directed into 3 mirrors that ends in a cutting nozzle, just take a look to this site
www.emissiontechnologies.com

Helge

balsaman
07-10-2003, 12:08 AM
Hey I am glad you like the machines. Build one you will love it. A laser would be cool but expensive. It takes an entirely different machine. It can be built very lightly because there is no cutting pressure like with a router. I also think you need to go around 300" per minute. Great link you provided. Thanks.

Eric

balsaman
07-10-2003, 05:12 PM
I got all 3 axis going yesterday. Wires are everywhere! The gecko's are on the bench still, everything is temporarily wired (and ugly).

I made a breakout board as an interface between the PC and the gecko's. JCK helped me with how inputs and outputs are done. The board includes 3 outputs and 4 inputs, and terminal stips for connecting everything. I need to add the Parallel port connector yet.

I plan on working on the machine cabling ASAP to clean it all up a little (a lot). I will also make a control box to mount everything in.

Oh and I need to buy a sheet of 3/4" MDF as a sacrificial table.

Eric

treemagnet
07-12-2003, 12:44 AM
Looks great Balsaman I plan on making one as well this winter. Panzypoof has cut more wood in the last six months than i have in the last 10 years. I tought panzypoof cad and how to use master cam and now I think I created a monster. Keep up the good work and pictures comming. hope to see you at some of the fun flies this year.

Tom

balsaman
07-14-2003, 10:19 PM
Gang,

I was away for the weekend but found some time today to add the "cat track" to the x and y axis. This allows me to start cleaning up the cabling. The cables go thru the tracking and it follows the axis nicely.

Eric

balsaman
07-14-2003, 10:20 PM
Here is a poor shot of the track that follows the gantry. It will have the cables for the y and z axis in it.

balsaman
07-14-2003, 10:25 PM
TreeMagnet, good to see you here! I am glad Denis is having fun on his 7th Sojourn! He builds nice planes! I hope I can make it to some funflies this year! Maybe the Flying Dutchman's Scale Rally in Kitchener?

Eric

treemagnet
07-14-2003, 11:19 PM
So how do you like servo motors i am thinking on using them on my router. if I can find them cheappppp.
when is the Flying Dutchman's Scale Rally maybe denis and i might go.

Tom

ToyMaker
07-15-2003, 08:55 AM
Eric:
Great work. I hope someday to follow a similar path.
Your cross bracing will be even more effective (and your machine more rigid) if you bolt through the cross arms where they meet.

robotic regards,

Tom
= = = = =
Doesn't expecting the unexpected make the unexpected become the expected?

kong
07-15-2003, 09:15 AM
I seriously love those cat-tracks. The biggest problem I have on my machine is the sheer amount of cabling on the z-y axis. What kind of prices the those type of things start at aver there?

balsaman
07-15-2003, 09:39 AM
Tom, (treemagnet). I looked at my calender. I hope to be able to go to this funfly:

September 6th, 2003 — Richmond Hill Electric Fun Fly hosted by the Electric Model Flyers of Southern Ontario and the Richmond Hill Model Club, at Nineteenth Ave. at Bayview Ave. MAAC or AMA required. Contact Robert Pike 416-724-7615 or www.emfso.org for directions.

Other than that, my summer is booked!

The servo's work great! Lots of speed and great power. You will like it except the price! It's not as bad if you can find some used servos.

Eric

balsaman
07-15-2003, 09:41 AM
Tom, (Toymaker)

That's a good idea. I will do that.

Eric

balsaman
07-15-2003, 06:41 PM
kong,

check your PM.

Eric

treemagnet
07-15-2003, 11:03 PM
Ya I am not so sure that I really want to look at the price for servo motors but I think I will sink a little money in to this project ahhhhh better start saving :( if I am going to do it I might as well do it right

Tom

rcrabb
07-16-2003, 05:28 PM
Balsaman, I think I remember you posting that your motors were from some surplus wire feeders. If that's true, How are they working for you?

balsaman
07-16-2003, 05:51 PM
They work great! Very smooth and so far very cool. Once I start cutting something, I will let you know.

Eric

rcrabb
07-16-2003, 06:07 PM
I have a huge pile of surplus parts. I think I can come up with a few dc motors. I did find 3 encoders.

balsaman
07-17-2003, 10:03 PM
Gang,

Today was limit switch day. I was trying to figure out have to get all those switches in there. I didn't bother with the over travel switches on my last machine (just home switches) but since this one is servo driven I figured it would be safer with them. The problem is it's hard to get the home switch close to the end of the axis travel and still have room for the over travel switch. I went with the two switches back to back. I also wanted to set it up so that over shooting any switch will not destroy the switch. In other words I didn't want the axis to bump into the switch. I set it up so the axis travels over the switches to activate them.

Here are some images of the setup.

balsaman
07-17-2003, 10:08 PM
The chunk of aluminum angle is filed at the edges that activate the swithes at a 45 degree angle. Like a wedge shape. As the wedge hits the home switch, it pushes it in but can carry on past it to the overtravel switch. The overtravel switch will disable the drive and notify the software.

The other end just has an overtravel. This is the y axis, the above picture was the x axis.

balsaman
07-17-2003, 10:09 PM
The other end of the y axis is here. Z axis isn't sorted out yet.

CAMmando
07-18-2003, 12:17 AM
Balsaman,

Could you make a spacer block to mount one of the switches overlap the body of the 2 switches some. You might need to extend the actuating surface a bit.

Keep posting cause you are really helping me. I just bought some limit switches today. Came across them and I couldnt resist (even though I wont need them for a few months :) ).

Do the switches just wire into the Geckos ?

jimini
07-18-2003, 01:30 AM
I think you have an excellent idea with your home\limit switches.
Makes a nice clean setup, shows who the pros are.:cheers:

balsaman
07-18-2003, 10:20 AM
You could overlap them. As is there is only about 3/8" - 1/2" between home and O.T., so I can live with that.

Unfortunately, the Gecko's don't provide anything for limit switches or outputs, or home switches. I made a stand alone breakout board to interface between the gecko's and parallel cable. I added 4 inputs and 3 outputs there.

Eric

balsaman
07-18-2003, 02:29 PM
Today I mounted the router in place on the Z axis. I am trying really hard to get it ALL done before I start cutting parts out. I know once I am cutting it will be hard to get motivated to get those last few details done. I ran out of wire for the limit switches so that's on hold for now. I plan on having this thing done next week so stay tuned for some parts. (There will be about 30 more pictures between then as now as I finish it up...LOL

Eric

anoel
07-18-2003, 02:47 PM
R U going to do a dust collector on this one?

tsalaf
07-18-2003, 02:49 PM
Eric,

How about a pic of your breakout board and a source for parts for us electrically challenged?

HuFlungDung
07-18-2003, 02:54 PM
A word of caution, as I don't know if this is common knowledge that has already been posted, but there is a serious danger of a runaway servomotor when it comes time to test run. This is due simply to an inverted hookup of the encoders and is easy to fix by interchanging some leads. But, do not have your servos hooked to the screws until you've checked that they behave when you've got everything nearly done. A runaway on your light duty machines could destroy something before you can blink.

balsaman
07-18-2003, 03:06 PM
I will put the dust collector from my last machine on this one.

I have included a picture of the breakout board with the parallel plug on there. I don't have an electrical drawing because I did it on the fly. Stay tuned and I will show some drawings of how to do inputs and outputs. The step and dir pins basically just go straight to the terminal strip to be connected to the gecko's.

Hu,

The gecko's simply fault out if wired to run backwards. It is expecting the pulses in a certain order from the encoder and if it doesn't get them it shuts down. Changing the motor leads (or encoder leads) makes it work. The gecko's are very impressive and a no brainer to hook up safely.

Eric

balsaman
07-18-2003, 03:26 PM
Here are examples of inputs and outputs from/to your parallel port. What I did was figure out which pins I had available in Turbocnc for inputs and outputs, and then soldered the board accordingly when I made it up. Now when I get everything wired, I will be able to go from the breakout board terminal strip to the drives, inputs (limit switches), and outputs (relays for spindle, dust collector).

there is a typo in the drawing, the input shoud read TO COMPUTER INPUT.

Eric

mbogucki
07-19-2003, 03:06 AM
Hi Eric,

First off, thanks for the info with regards to the
xylotex controller. I'll probably be ordering one next week.

Secondly, your mill is very VERY impressive!!

I was looking at your relay schematic. I'm sure your aware of this but I just had to stick my nose in on this. You might want to add a diode across that relay so you spare your npn transistor from a horrible death. :D

I can't wait to see more pictures of your mill.

Very inspiring!!!

--Mike

balsaman
07-19-2003, 09:34 AM
Well, it's one of those opto-isolated solid state relays, so I think it should be ok. ie. no coil.

Thanks for the comments. I am having fun!

Eric

balsaman
07-19-2003, 10:11 AM
Also it was pointed out to me that if it's a powertransistor (which it is), it has a built in diode, and is designed for use with inductive loads. I didn't even know that. But then, I am no electonics guy at all, and all the information on the inputs and outputs was passed on to me by others anyways.

Eric

balsaman
07-21-2003, 11:24 PM
Hi Gang,

it seems this home made cnc stuff isn't for sissies. I got around 25 hours in the control box alone. On a brighter not I have my machine all working again. Still have a few loose ends electricaly to tie up yet.

On the picture you see the gecko's mounted on the door. This is so I could still adjust the gain, etc easily. This way I can also mount a heatsink on the oposite side if required.

Next to the gecko's is the router speed control. I am having some trouble with this unit, as it's not controlling the speed for some reason....

In the box you see the two home made circuits. The one on the left is my breakout/input/output board which is working perfectly. On the right is the gecko enable/fault/overtravel/estop manager. This is supposed to monitor the gecko fault terminal, overtravel switches, the state of the estop, and enable/reset the drives via a reset pushbutton. It also notifies the computer in case anything goes wrong. There are still a few issues with this circuit I need to work out. It's very close...

You can see in the top right the 3 output relays for spindle, and exhaust fan, and ?(future use).

Believe it or not I worked very hard to make it nice and neat! Unfortunately, the wires really add up and the box could be a little bigger. Oh well it's functional. I worked hard also at trying to prevent any noise getting into the encoder cabling. All the cables are shielded and grounded, and I tried to route them away from the motor cables. (alto they run all in the same cat track!)

balsaman
07-21-2003, 11:28 PM
This is my "operator console" that will reside at the front of the machine. It has the estop button, spindle override switch, spindle speed control, gecko reset button, and 3 leds indicating the state of the 3 geckodrives.(on is drive enabled/ready, off is drive faulted)

Eric

balsaman
07-22-2003, 05:15 PM
I made a part! Those who know me will have seen this part before. I have made it on my other machine. Well, this machine has made this one! It came out great! I cut it from 3/8 MDF at 50 inches a minute with a 1/8" carbide. It was cut in 5 minutes! It's about 6" in diameter. I also cut a rectangle, to see how square the machine is. I have a little work to do there. Should be a matter of loostening a few bolts, tweak the gantry, and retighten. I am very happy!

Eric

HomeCNC
07-23-2003, 02:23 AM
That is great Balsaman! Tell me, How did you wire your fault led's that are on your front panel to the drives?

CAMmando
07-23-2003, 10:17 AM
+1 on the LED's

BTW, how long did that same piece take on the old machine ?

balsaman
07-23-2003, 01:06 PM
Jeff,

How do you implement the err/res terminal on your gecko's? I love the drives but the err/res isn't too handy. Did you just tie the err/res pins together, and use one input to the computer? Or did you just jumper them to the enc+ terminal? I made an entire board just to handle the drive reset and drive fault circuitly, which is mostly relays and a few transistors, oh and I stuck a overtravel relay on there too so If there is an estop, overtravel, or drive fault, a signal goes to an input on the computer (I used the overtravel input in Tcnc). My LED's are not hooked up yet but will be soon. When I get a minute I will drav up the circuit in cad quickly so you can see how I did it. I have some chicken scrathes on paper right now.\

You can buy a ready made circuit to handle all this (and more) as well for $85.00. I will post the link when I am on my other 'puter.

BTW, I got my fault / reset circuit working now minus the OT limits and estop part. I also fixed my spindle control, it was a wiring error on my part (as usual).

The part took 15 mins on my other machine as far as I remember.

I got my gantry squared up very close now too. :) I need some methed of fine tuning it, so I can get it exact. For now I will keep cutting a square, adjust, cut a square, adjust. I am within about .010 in 6" now.

Eric

balsaman
07-23-2003, 01:40 PM
For the first time since I started building this thing, it actually looks like a cnc router. It finally looked right after I added the wodden base/table. Since I am setting it up /calibrating, I put a scrap piece of wafer board on for now. That way I can screw materal down to it with wood screws. Once I get the x,y perpendicular, I will put a 3/4" sheet of MDF down properly, and try and calibrate the Z with a dial indicator. Then I will have the machine drill a hole every inch square for clamps etc.

Eric

balsaman
07-23-2003, 08:44 PM
Jeff and others,

Here is the link to the guy who made his own err/res manager.

http://www.sfu.ca/~alan/gecko/

Eric

balsaman
07-24-2003, 12:34 AM
Jeff, here is how I did the err/res on the geckos. When I power up the machine a 6 second timer resets the drives. The drive is then able to drive the transistor on it's own via the err/res pin which is +5 when all is well, which holds the xfr (x fault relay) and the external LED on. I didnt show yfr and zfr but they are done the same. If the drive faults the err/res pin goes to ground which turns off the transistor which turns off the fault relay, and the LED. Once the fault relay turns off, it breaks the rung bellow all that stuff to the computer input. Not shown in that rung is contacts from the estop and from the overtravel relay (which is wired to the overtravel switches). If a drive faults they can all be reset by hitting the drive reset button, which starts the timer again allowing the six second reset one shot.

Clear as mud?

Eric

EDIT: Septhember 7, 2003. This cicuit does not work correctly. Look further in the thread for a working circuit.

balsaman
08-06-2003, 01:43 PM
Hi guys,

I am still here. I have been cutting stuff instead of finishing up the limit switches :rolleyes:. Have a look at this cool part. I traced over a logo I found on the net. Took a while..:) Cut it .1" deep with a 1/16" endmill, then switch to a 1/8" endmill (thanks to CAMmando for getting the tool change in my post working) to cut the profile out. Took 31 minutes. That's a nickle beside it for size. It's 3/4" oak.

Eric

tsalaf
08-06-2003, 01:59 PM
Eric,

Nice work. Looks like those limit switches will never get finished now.

Steve
www.tac-pro.com

balsaman
08-06-2003, 02:15 PM
Actually, they are all wired up, but I need to wire them to the breakout board, that's all! (and the home switches are working). It's just too much fun to cut stuff. I will finish it up in the next few weeks. Oh and the dust collector too...honest!

Eric

kong
08-06-2003, 02:30 PM
I bet that was 31 minutes of shear joy. Glad to see it's almost complete, it is now time for you to "play":D

balsaman
08-06-2003, 02:57 PM
31 minutes of ear splitting noisy joy. I use earplugs everytime.

Eric

CAMmando
08-06-2003, 06:20 PM
Balsaman = Oakman :D

kong
08-22-2003, 09:45 AM
Balsaman, just wondering how stiff you find that 80/20 frame? I am coming close to finalising a design based around it and some big 'ol supported shafting. And, if you don't mind all the questions, are the fasteners you used "proper" ones from 80/20, or could I just use a long bolt and tap the centre of the square? We don't seem to have 80/20 over here, but Bosch-Rexroth make a virtually identical product in 45mm x 45mm.

balsaman
08-22-2003, 09:50 AM
I used proper hardware in places and I also tapped the center hole in places. Both work great. Its quite rigid, but I have not tried to cut anything heavy.

Eric

anoel
08-22-2003, 10:25 AM
Here's a challenge to prove your machine's salt....

Try to come up with a simple design for a small CNC machine with about a 6"X12"X1.5" work area that uses only MDF and steel shaft and Oilite bushings and threaded rod and steppers and Delrin/UHMW nuts. And can be cut entirely from the CNC machine (i.e. no hand made parts.) Not that it's a test for heavy cuts unless you replace the MDF with Aluminum. But would be something very slick to try. And you could end up with a slick little PCB mill for cheap and easy. (Oh, and of course you've got to mill your own controller with your CNC as well.)

You'd end up with something that you could sell as a kit, finished product or plans for. (Tempting?)

balsaman
08-22-2003, 11:01 PM
I have thought about that. Looks like the guy from cheapcnc.com is doing it.

Eric

balsaman
08-22-2003, 11:04 PM
Guys,

I spent some time tweaking the drives and software today. I am now going 200 inches a minute on x and y, and 150 (plenty) on z. I can go 225 but 200 gets the job done. :) :) :)

I need to calibrate it yet with a dial indicator but I am too busy cutting stuff.

Eric

iregan
08-23-2003, 03:10 AM
Eric,
I'm curious, what are the speeds your cutting at?
I'm figuring on my rapids being around 200" a minute, I could go higher but would probably sacrifice accuracy and the more performance the more tweaking, right?
I hope my machine ends up as nice as yours :)
Regan

balsaman
08-23-2003, 10:04 AM
So far I have been cutting mostly around 20-30" per minute. Some small stuff maybe around 60" I usually set the feedrate around 30 and then use feed override to fine tune it.

For rapids you don't lose any accuracy (at least with servos) by going faster. When cutting maybe you do if your machine bends due to the force of the cut or acceleration. I know my machine doesn't cut as smooth at a high feed rate on arcs that are made of many tiny lines because turbocnc doesn't have "look ahead" so the machine literally shakes as it accels/decels for every little line.

Eric

balsaman
08-23-2003, 06:32 PM
Ok Guys,

Being the boner that I am this afternoon I accidentally hooked 12 volts to the gecko encoder +5 and err/res pins. :( The 12 volts and encoder +5 terminals are next to each other on the drive/fault/reset circuit board I made. I blew the drive and the encoder. I had another encoder so no biggie there. I emailed Mariss of geckodrive and he told me to send the drive back to him.

I guess I am down for the next while :(

Eric

boxwood
08-23-2003, 07:43 PM
ah man bummer, sorry that happened. but Im sure you,ll be back up soon. No worries mate

iregan
08-25-2003, 12:28 AM
Thanks for the info, and sorry about your mishap, I'm going to have to watch out for that when I get to connecting it all together.
The extra tweaking I was talking about was more to do with the actual building. I haven't decided if I'll run my motors at direct drive with a 10tpi screw or belt drive and change the ratio for more speed. My motors max rpm is 3000 so I was thinking to keep them happy at around 2k-2.3k I'll be running 800oz/inch servos so I don't think direct drive would be a problem and I would imagine it would be easier on a machine than going for a coarser thread. I could run two of motors at max with a transformer I have here, but I'm not sure if its worth the effort.
Regan

balsaman
09-04-2003, 07:21 PM
Guys.

I got word from Geckodrive that my drive is repaired and on it's way back! I order another drive as well so stay tuned for a 4th axis. I also redesigned my error/reset, overtravel manager circuit board, so I will post a circuit in the next few days for anyone who cares.

Eric

JIMMY
09-04-2003, 08:29 PM
We all care

kong
09-05-2003, 09:21 AM
Originally posted by JIMMY
We all care
I'll second that!
Cant wait to see a fourth axis. Are you gonna have enough clearance under your gantry though?!

anoel
09-05-2003, 10:51 AM
Originally posted by balsaman
Guys.

I got word from Geckodrive that my drive is repaired and on it's way back! I order another drive as well so stay tuned for a 4th axis. I also redesigned my error/reset, overtravel manager circuit board, so I will post a circuit in the next few days for anyone who cares.

Eric

Are you going to mod an existing rotary table for the 4th axis or are you going to build your own from gears and scrap?

I'm wiring up my Gecko control box right now and hope to be finished with it by middle of next week. I'd like to check out your revised err/res manager, if you would.

balsaman
09-05-2003, 04:48 PM
I will try and post it tonight. The other one I posted had some "issues" (lets say). It worked for reseting the drive but not as I intended for the faults and I never did hook up the output from it to the input to the computer. I had some stuff backwards with the transistors and such. This next one has been tested with the two drives I have and will work.

I am going to build a rotary table from a DC motor/gearbox. I need to fit a plate of some sort so I can attach a chuck or something. It's still early in the design stage. I have 5" of space under the z axis so short parts will fit, or when in "lathe mode" I can do some longer parts by using some kind of tailstock.

Eric

Mr.Chips
09-05-2003, 07:53 PM
I have really enjoyed reading this thread, there is so much information here. I'm in the Research stage of my CNC.
I have a question about the extruded alum construction. In the long run will all the bolted joints loosen? Seems they would as there should be quite a bit of torque and viberation. Or am I too concerned. I am leaning to the bolted alum plates with dowel pin construction.
Thanks

balsaman
09-05-2003, 09:23 PM
In the long run will all the bolted joints loosen? Seems they would as there should be quite a bit of torque and viberation.

That is possible I suppose. So far everything on mine is still tight. Perhaps I have 5 hours on it or so. I will use some blue locktight on the bolts if it's a problem. I don't think it generates enough vibration to come loose tho. I will let you know how it stands up in the long run.

Eric

balsaman
09-05-2003, 10:33 PM
Here is the err/res circuit and it also handles the limit switches. Shown are for two axis but for more just add more of the same.

What happens is the operator (that's me) pushes the reset button for one second which closes the relay contacts for 1 second. The err/res pin on the drives go to 5 volts to reset the drives. Once the drives are reset they stay at 5 volts on the err/res pins happily unless they fault. As long as the drives are happy the transistors are on which means the collector is at 0 volts. If all the drives are happy (ignoring the limits for now) the transistor on the top right is off and the line to the computer will be at 5 volts.

If a drive faults, the err/res pin goes to 0 volts. This turns off it's transistor and the collector will go to +5 volts and the transistor on the top right will turn on causing the line to the computer to go to 0 volts which will tell the software something is bad.

Similarly, if all the limit switches are closed then the transistor connected to them will be on and it's collector will be at 0 volts. It works just like the drives circuit.

I included LED's on all the drives (2 drives shown, 4 in real life on my circuit) so we call tell what drive faulted. When the drive is ok, the LED is on.

Clear as mud?

Eric

balsaman
09-09-2003, 10:19 PM
Guys,

I got my gecko drive back all fixed up. Thank you to Mariss of gecko Drive! They fixed it for free even tho it was 100% my stupidity that it broke. They are a top notch outfit for sure!

I also got another drive from them for my indexer. I have a question. The motor/gearbox I have for the 4th axis is of the straight thru design, as in the motor and the output shaft are inline, and not at 90 degrees from each other. What that means is I won't be able to place the indexer face up. Will that piss me off? What aplications would I need to have the indexer face up? As far as I can see I won't need to anyways. Advice from the guys who know would be great.

Thanks!

Eric

balsaman
09-14-2003, 09:40 PM
Ok here is the beginning of my newest axis: An old DC motor/gearbox. The gearbox is 16.71 :1 (or something). The motor is 115 volts, 1/8 HP. I have a 500 line encoder for it (pictured). I will add a backplate and this chuck: (item b)

http://www.leevalley.com/images/item/woodworking/turning/03j7040g1.jpg

It's a 3", 4 jaw chuck.

I hope I will be able to figure out how to program this thing.

Eric

cbcnc
09-15-2003, 06:42 PM
Eric,

I saw this site where he has a dividing head in the works. It might be worth a look.
Here (http://www.tejasdragon.com/)

Chris

balsaman
09-16-2003, 08:00 AM
He has a pretty cool 4th axis there too. Thanks.

Eric

balsaman
09-18-2003, 11:06 PM
Hey guys,

I got my router limit switches wired up through my err/res manager board a while back. I ran a 2 hour long program today and I was getting nuisance trips of the limits causing the program to stop (axis no where near the limits). Think it could be noise? Vibration? Anyone else having this?

Eric

kong
09-22-2003, 03:42 PM
Sorry to go back to an old subject Balsaman, but I was wondering what nuts you are using now? Upon reading the thread (again!), I see you switched back to squished Amco nuts. I am in the process of making some from Delrin, about 2" in length, but wonder if I am wasting my time. I have some phosphor bronze knocking around, but am difficulty tapping it with the home-made tap. Your thoughts would be appreciated!

High Seas
09-22-2003, 05:28 PM
Re post # 12

Delrin Nuts on Acme threaded rod. OK -- there is a plan I'd like to try too. Who will you have cut the nuts?
I've got 2 acme threaded rods and nuts off eBay but am unhappy with the tollerances. Was considering casting (re-enforced resin) a tighter set, but less hassle if you can source someone to tap'em.

Cheers mate!

balsaman
09-22-2003, 06:02 PM
Still using the split amco nuts. Delrin works well when the speed is moderate and when tapped with a chunk of acme rod. The acme taps are too large, causing backlash.

Eric

balsaman
09-23-2003, 10:34 PM
I made an adapter from oak to adapt my encoder to the motor. I tried machining a plastic one but I had meltage on the deeper cuts. I guess the plastic chips can't get out of the way.

Anyway, here is is:

balsaman
09-23-2003, 10:34 PM
Assembled:

kong
09-24-2003, 08:24 AM
Nice one Balsaman, you just solved another puzzle for me! I have encoders that have a shaft, and was wondering the best way to mount them to my motors secondary shaft.:D

balsaman
09-24-2003, 12:13 PM
rubber hose makes a great coupler if you dan't have any helical couplings. The torque required to turn an encoder is zero.

Eric

balsaman
09-28-2003, 03:43 PM
I finally :rolleyes: got around to putting the permanent 3/4" MDF table on my machine and getting the machine to drill the 925 holes in it. In about 700 of the holes are 10-24 t-nuts (blind nuts) for clamping and such. That's every other hole and all the holes around the outside.

I also made a table/stand for it from left over 8020 aluminium extrusion. So now it's sitting in it's own spot and off my work bench. There is a shelf under it for the computer and the control box and possibly soon a wet-vac for dustcollector. The keyboard is sitting on a retractable tray inder the machine.

Also shown is the cute little 3" 4 jaw chuck that will soon be a part of the 4th axis. A friend of mine is building a tail stock for me so I can put some longer stuff in the 4th axis.

I got a copy of mastercam 9 tutorial book from a tool and die maker friend so I will read up on it to get more familiar with Mastercam. I will need it for 4th axis work as I have no idea how to get this thing going once it's up and going.

Eric

Mr.Ed
09-28-2003, 05:29 PM
Balsaman, wise man...

I was a bit afraid about lesson 7. Any tips on constructing a "dust enclosure" ?

Ed.

balsaman
09-28-2003, 06:47 PM
A dust enclosure is a posibility, but getting the dust at the source would be better. This is what I did on my first machine and it was pretty good, getting about 95% of the dust.

This new machine is a bit more challenging because it's got a much larger work envelope. Getting the hose to follow the router without getting wrapped around an axis is not easy. I think I have it worked out and will post a few pics once I get that far.

I do know that a router is much more enjoyable when you can control the dust. Most of the time I don't feel like cutting anything because of the mess it will make. This is pushing the dust collector to the front burner for me at this time.

I will be out of town for a week on training for work so it will have to wait a little longer.

Eric

keithorr
09-28-2003, 08:09 PM
I use my router to shape graphite. No dust collector in the world can keep up with that stuff.

I placed the router in a corner of the shop and built two walls and a roof around it. Placed a large plexi viewing window in one side, a hollow core door in the other, lights in the ceiling, and a dryer vent hose from the ceiling to the router motor (Porter Cable) so the spindle can breathe fresh air.

Hook up a dual filtered shop vac with good cfm to keep the interior pressure down, otherwise graphite dust finds its way out through any little cracks. Yes, everything is caulked and weather stripped.

Note the custom z axis motor dust boot.

kdoney
09-29-2003, 09:43 AM
What type of bit do you use? What is the feed and speed and how thick is this granite? I would like to try that myself.

balsaman
09-29-2003, 04:19 PM
He is cutting graphite, not granite.

Eric

agilityrun
09-29-2003, 09:16 PM
I'd be real interested in how you're cutting the graphite , your max depth of cut and how small a cutter you can use. I've been looking at an alternative at work for cutting graphite electrodes. Currently using a do all saw modified to cnc.

Mr.Ed
10-09-2003, 06:24 AM
Balsaman,

I've read your thread a couple of times now and must say it's a real eye-opener. :)

I'm looking to buy some Linear slides like yours. First started out on ebay in the Netherlands, but if you do a search on THK there are no entries found. As i stated somewhere before, ebay in the NL is a real joke. :p

Anyway, at ebay on the other side of the big pond, i find "lots" :rolleyes: of THK linear slides, in all sizes and types. If i import a set of those i better get the right ones in one try! First, if i buy them for let's say 20 dollars, they will add like 20 dollars or so for shipment. :eek: So things i buy in such a pricerange are double more expensive for me then for you guys. :(

Could you (would you :) ) please shed some light on the type and size of slides you found in the dumpster, and using now? Did you find any print on those bearing blocks?

Secondly, what do you think, is the total length / amount of 8020 extrusion that you used?

I'm overall impressed by your project sofar, and the whole community here on cnczone. Great job.

Mr.Ed

kong
10-11-2003, 01:05 PM
Balsaman, just reading through your err/res manager post, and I have a couple questions for you (no surprise there then!). I understand the basics of how it works, but under the 1k ohm resistor for the LED, there is another symbol that looks like another led, what is this please. Also, the way I see it, you are using normally open switches for your limits, I have a preference for NC, so how coiuld I modify the circuit to use these instead? I figure on using a seperate 5v supply, where you have indicated enc+, and also using a momentary switch instead of relays, I take it this will be ok? These may sound like daft questions, but don't want to blow anything up!

Mr.Ed
10-12-2003, 11:25 AM
I'm first ! :D

I think Balsaman has a lot on his mind right now. I think he underestimated the amount of response on his thread just a little bit ! :p

Ed.

balsaman
10-12-2003, 01:35 PM
Hi guys, sorry was away for a few days. I will answer your questions tonight when I have some more time. :)

Eric

balsaman
10-12-2003, 05:56 PM
Originally posted by Mr.Ed
Balsaman,

I've read your thread a couple of times now and must say it's a real eye-opener. :)

I'm looking to buy some Linear slides like yours. First started out on ebay in the Netherlands, but if you do a search on THK there are no entries found. As i stated somewhere before, ebay in the NL is a real joke. :p

Anyway, at ebay on the other side of the big pond, i find "lots" :rolleyes: of THK linear slides, in all sizes and types. If i import a set of those i better get the right ones in one try! First, if i buy them for let's say 20 dollars, they will add like 20 dollars or so for shipment. :eek: So things i buy in such a pricerange are double more expensive for me then for you guys. :(

Could you (would you :) ) please shed some light on the type and size of slides you found in the dumpster, and using now? Did you find any print on those bearing blocks?

Secondly, what do you think, is the total length / amount of 8020 extrusion that you used?

I'm overall impressed by your project sofar, and the whole community here on cnczone. Great job.

Mr.Ed

My bearing blocks say THK HSR20 on them, so I assume that means they fit on 20 mm rail.

I used about 36 feet of 8020 extrusion not including the table it sits on. Basically 4-48" and 4-30" parts for the base, and 4-30" parts for the trolley.

Eric

balsaman
10-12-2003, 06:11 PM
Originally posted by kong
Balsaman, just reading through your err/res manager post, and I have a couple questions for you (no surprise there then!). I understand the basics of how it works, but under the 1k ohm resistor for the LED, there is another symbol that looks like another led, what is this please. Also, the way I see it, you are using normally open switches for your limits, I have a preference for NC, so how coiuld I modify the circuit to use these instead? I figure on using a seperate 5v supply, where you have indicated enc+, and also using a momentary switch instead of relays, I take it this will be ok? These may sound like daft questions, but don't want to blow anything up!

The drawing on the bottom of this page is the working ERR/res manager that I am currently using.

Under and to the right of the 1 k resistor is a diode. This is to prevent the happy drives LED's from turning off when an unhappy drive faults.

I am using NC limit switches.

Basically, if the base of the transistor is getting 5 volts (from a drive pin 5 or the O.T. switches, the transistor is on and the collector is at 0V. When this is true the LED is on and we are happy. if a drive faults, or a O.T. switch opens, the base goes to 0V, and the transistor turns off. The collector goes to +5V and the LED for that drive (or the O.T circuit) turns off. The happy drives LED's stay on because the diodes. Once any of the transistors collectors go to +5, the last transistor turns on and it's collector goes to 0V, whick tells the 'puter something bad has happened.

Eric

balsaman
10-12-2003, 07:42 PM
Kong,

You NEED to use the enc+ for the +5 volts (at least according to mariss of geckodrive).

I am still quietly working on my 4th axis. I added the 4th drive, top right hand corner. Almost like I planned it to fit there (I didn't).

balsaman
10-12-2003, 07:44 PM
My good tool and die maker buddy Chris made me an adapter for my 4 jaw chuck so it will fit my gearbox. Here it is holding a jar of putty! I will be turning a round chunk of wood tomorrow sometime! (I hope)

Eric

kong
10-13-2003, 07:35 AM
Thanks very much Balsaman, I understand it now. I found a nice e-stop circuit posted by Mariss too, over on the cad_cam_edm_dro groups. I'm not the most electronically minded of people, so hope I don't screw-up!
You'll to get hold of a video camera now and get some film of the fourth axis in action:D

turkgeltz
10-27-2003, 02:32 PM
Your cutting graphite interests me. I am curious on how thick it is and what you use to cut it with. Do you use real small carbide cutters?

kong
11-04-2003, 11:51 AM
Firstly, an appology. I have been reading the cad_cam yahoo group, and noticed a few posts about using an external 5v to reset the drives. I know it is contrary to what you have said, but I posted on their asking for confirmation, hope you don't take offence:D
Now, more stupid questions. If I end up using the enc+ to reset the drives, are you using each enc+ to reset each drive, or when you press the reset button, does a single enc+ reset all the drives at once? Secondly, due to my lack of electronics knowledge, I was thinking of adding diodes in place of the relays on your circuit, then to the momentary reset switch, but I can't quite work out if this will keep each circuit isolated, or will it be the equivalent of daisy-chaining the err/res terminals together, therefore rendering your circuit useless. Your advice would be appreciated, Jason.

balsaman
11-04-2003, 12:16 PM
No offence taken.

I have found the whole err/res thing very elusive myself. I emailed Mariss some of the questions you are asking. Marriss told me it needs to be the 5 v from the enc+. Why? I don't know. I also asked if I can use just one enc+ to reset all the drives and got no answer. Because I hate the smoke, i decided to play it safe, thus the relay.
I suppose the diodes would work, if you are using the enc+ from one drive to reset all the drives. Let me know what you find out at CAD CAM...

Eric

kong
11-05-2003, 08:23 AM
Well, the reply I got was concerning connecting all the drives err/res together to reset them all at once, and it seems this may create a lot of interference causing one or more of the drives to shut down. No reply on the external power supply yet though. I think I will play it safe, and do as you have done. Relays, and use the enc+ to reset it's own drive. Thanks for the help, I'm looking to get some piccies up in the next couple of weeks:D

HomeCNC
11-05-2003, 11:45 AM
I have always used one enc+ to reset all the drives and I have never had any problems at all.

kong
11-07-2003, 08:58 AM
Darn it, I thought I had enough spare switches to go individually, but I don't. So, HomeCNC, to confirm, I can go from one enc+ terminal to a push switch, then from the switch I can go straight to each err/res terminal? As long as there are no other components needed to prevent smoke, I will wire it in this afternoon. Thanks for the help guys!

HomeCNC
11-13-2003, 12:38 PM
Kong,

Go to my web site and look for the servo controller box wiring drawing. Look at how my two position switch turns on/off the Gecko's.

kong
11-13-2003, 12:43 PM
Thanks HomeCNC, it is done now. I realised that if I wire the err/res terms together to one enc+ it would render Balsmans cicuit useless:rolleyes: so I got hold of some more switches, and now have each err/res to it's own enc+.

sturner
11-14-2003, 02:42 PM
Futura Industries provides a line of extruded aluminum channels called "TSLOTS". They are manufactured by an aluminum extruder and sold through distributors. The advantage of these channels is that they don't have grooves in them, they have a smooth finish. The smooth finish will help you to keep your CNC router clean. Price should be more competitive also.

cncadmin
11-14-2003, 02:45 PM
I checked out the website the stuff looks good, I guess one could get a catalog mailed? Here is a link (http://www.tslots.com/CATALOGDOWNLOAD.HTML) to their on-line catalog.

balsaman
11-27-2003, 12:55 AM
Well, I finally spent some time calibrating my machine. I was having so much fun cutting stuff I didn't bother. When I started cutting finer stuff like the pictures with meshcam with z depth in the .030" range I noticed the z wasn't running perfectly true to the table. I spent 4 hours today with a dial indicator tweaking things. The travel across the gantry was out by 40 thousands from one end to the other! I got it to within about 007" now, and the long axis is within 004". That's as close as I could get it. Now I will get some kind of fly cutter and skim the table to bring it closer than I will need it.

Been playing with Mach2 also. It works GREAT! I need to free up $150.00 to register it. The fact that it has Look Ahead (CVC) makes my machine move much smoother.

I found two 1.125" diameter, 1 pitch, 4 start ballscrews and nuts at work. They were cleaning up and going to pitch them. I might retrofit my machine for them. I will need some timing belts and a hefty ratio to make 'em work. I like the idea of the screws only turning 100 rpm to go 100" per minute. It will eliminate that nasty screw whip and make things oh so smooooooth.

Eric

Mr.Chips
11-27-2003, 01:06 AM
Eric,
Isn't there an electronic leveling capability. Thought I rember reading where you could touch the z in the four corners and it would record the uneveness and make automatic allounces for it.

Hager

balsaman
11-27-2003, 08:35 AM
Maybe, but it's not just the corners you need to worry about. The rails needed to be adjusted at every attachment point. They were "wavey" so to speak.

Eric

Mr.Chips
11-27-2003, 12:36 PM
Gotcha.
Flycutting is the way to go, to align to table plane.

Hager

HomeCNC
11-27-2003, 03:25 PM
Flycutting is what I also did with my aluminum table top on my CNC router.

xairflyer
11-29-2003, 07:07 AM
What do you guys do about wear on the table, do cut on a second replacable one fixed to the main table, or do you just use it until it has that many tracks and scores you replace it.

balsaman
11-29-2003, 10:23 AM
Replace it when it has too many tracks. The best is where you don't cut through the material your cutting but just skim the surface of the table...easier said than done.

Eric

HomeCNC
11-29-2003, 01:49 PM
I don't cut on my finished aluminum table. I put a scrap wood under the piece to cut for that purpose. My aluminum table is the same as a milling machines table. It has T slots in it for hold down nuts.

balsaman
01-04-2004, 09:53 PM
Ok guys I borrowed my buddies camera and made a video of my machine cutting the electric airplane motor mounts I sell on ebay. It's a big file. 8 megs. Have a look. I got some more video but I need to edit them as they are too big.

here is the file: www.e-zflight.com/files/cnc.avi Looks like you need to right click and choose Save Target as...?

Here is a picture of the resulting part.

Mr.Chips
01-04-2004, 10:42 PM
Eric,

Thats a neat video. Now the questions for the newbies.
What is the inches per min on this machine?
I don't see any dust and the cutouts disappear immediately. Are you using a vacuum table?
How and when do you cut the little tabs that are left holding the part when the cutting is complete?

Hager

balsaman
01-04-2004, 10:57 PM
Hagar,

The speed you see there is 40" per minute cutting, 120" per minute for rapid or "air" moves.

Yes, I am using a vacuum table, but there is dust, just the camera doesn't pick it up, also it's being blown away by the fan on the router. I removed the dust collector shroud for the video, so you can see the cutter. Thre is only one "cutout" per part, as the rest of the holes are cut away completely. The center cutout flies away if you look carefully.

The parts are being held in by little tabs about .075" long. This was done at the CAD stage when I drew the part up. I just put in 4 little gaps in my outer circles (or squares).

Here is another video, this one is ~6 MB. I edited this one.

www.e-zflight.com/files/cnc.mpg

Eric

Mr.Chips
01-04-2004, 11:10 PM
Thanks for taping the various running machine parts, that's as interesting as the cutting.

So how do you cut the 0.075" long tabs, by hand? Or clamp the part and have the machine cut it.

Hager

balsaman
01-04-2004, 11:13 PM
I just cut them with a utility knife. It's only 1/16" aircraft plywood. I then hit it with a sanding block, and touch the top while I am at it to knock off the fuzz. The sanding takes about 5 seconds per part.

Eric

Mr.Chips
01-04-2004, 11:17 PM
I see you are using Acme thread on the X axis and it looks like a ball screw on the Z axis.
What's the reason for using the ball screw on the Z and not an Acme thread?
Thanks
Hager

balsaman
01-04-2004, 11:22 PM
It's all 3/4-6 acme. No ballscrews. I just adjust the backlash out now and then. (mostly then).

Eric

kong
01-05-2004, 08:28 AM
Nice work, that vacuum table looks pretty good;)

owhite
01-19-2004, 10:06 PM
Eric,

I am absolutely marveling at this entire thread, but I'm most amazed to hear that its possible for a CNC router to mill aluminum. Were most of your aluminum plates made for this table done by milling the parts yourself? Could you describe the method? Interested in feed rates, cutting tools, other advice you have.

Owen

dlenox
01-20-2004, 06:20 PM
Balsaman,

Your input is valued by all of us newbees. Thank you!

Is there a reason that you put the X axis linear rails on
the side of the base, rather than standing uppright?
I assume it was to simplify the attachment of the bearing
blocks to the verticle uprights...

Seeing that this is your second machine built, what would
any lessons learned be or in hind-sight what design changes
would you implement?

balsaman
01-20-2004, 07:30 PM
I cut the aluminum on a band saw to rough shape, then used my cnc to clean it up and center drill all the holes for bearing blocks etc. I cut them with a 1/4" carbide endmill, 3 passes at about 3 or 4 ipm if I remember correctly. I also pocketed the gantry sides, same endmill, same speeds, just one pass.

The rails were put on the sides to simplify things. If I did it again I would put them under the extrusions, to protect them from the dust. I might also make my z axis longer/more travel, so there would be more room for a 4th axis, and for access for tool changes.

I am glad you like it. I do too. :)

Eric

balsaman
01-20-2004, 08:24 PM
I should add that cutting aluminum was not all that fun, and my machine didn't really like it that much. The machine did it because it was fairly small (thus rigid even tho it was MDF) and used THK linear bearings, rails.

Eric

dlenox
01-20-2004, 08:31 PM
can the linear rails on the X axis be hung up-side-down?
this would definately help with dust/chips...

balsaman
01-20-2004, 09:46 PM
Yes, If I did it again, that is how I would do it. Not that I am having a problem now, as the bearings have seals that seem to just push the dust along, but over time maybe...and some dust gets in the bolt holes in the rail, which can contaminate the bearings. I know you can buy the little plastic plugs, but I havent done that yet.

Eric

Hobbiest
01-21-2004, 01:55 AM
Why not just suirt a little caulking compound, or wood glue into the holes? That way you can just pry it right out when you need to get to the screws.

xairflyer
01-21-2004, 06:48 AM
Have you looked at replacing the bearing itself with these new frelon types called simplicity bearings available from pacific.

I visited a company that build various production line machines, and they now use these is preference, due to the higher load capacity and longer life.

http://www.pacific-bearing.com/products/viewProduct.cfm?ID=1

Just realised you are using rails rather than shaft !!

Oh well somebody might find it useful.

anoel
01-21-2004, 08:22 AM
Xairflyer, I'm using the Frelon bearings on my Z axis. Very nice...

limbo
01-21-2004, 09:13 AM
Balsaman,

Did you use coolant or lubrication for cutting aluminium?

John

balsaman
01-21-2004, 09:58 PM
No, but you should. Tough on an MDF machine tho. Some folks spray a little WD40 on the part.


Eric

Mr.Chips
02-23-2004, 02:28 PM
Eric,

I see in this posting that you removed the extruded pieces between the upper and lower frame and replaced them with alum plate.
Post #197

http://www.cnczone.com/showthread.php?s=&threadid=646&perpage=25&pagenumber=8

Was there too much flex in the connection?
Hager

balsaman
02-23-2004, 06:26 PM
No, that was done very early in constuction. It was to get me an extra 3" of travel in the x direction.

Eric

Mr.Chips
02-23-2004, 09:56 PM
I see, it makes sense now.
Hager

ballendo
02-24-2004, 09:37 AM
Hello,

Higher load and longer life, but not for pre-loaded applications...

At least that's what every "plastic" bearing mfr has told me so far. They all want a thou or so for clearance, so that as the plastic expands when iut heats up due to friction, there is somewhere for it to go... Tests are continuing:)

Ballendo



Originally posted by xairflyer
Have you looked at replacing the bearing itself with these new frelon types called simplicity bearings available from pacific.

I visited a company that build various production line machines, and they now use these is preference, due to the higher load capacity and longer life.

http://www.pacific-bearing.com/products/viewProduct.cfm?ID=1

Just realised you are using rails rather than shaft !!

Oh well somebody might find it useful.

fyffe555
02-24-2004, 06:12 PM
Hi Ballendo, what does 'pre-loaded' actually mean?

I thought it refered to preloading ball race linear bearings to remove play in the bearing- which wouldn't apply to the plastic stuff?

sentra52
02-26-2004, 09:55 AM
I'm a newbie to CNC, I read this entire post last night well after I should have been asleep. My questions: will you be posting a complete set of your design? Will the plans be up for sale?

balsaman
03-03-2004, 08:44 PM
No.

I have no plans to offer plans. Making plans that are of a quality that can be offered for sale takes longer than making the machine.

E

Gus_452000
03-17-2004, 07:03 AM
Balsaman,
sorry for proberbly asking questions that you will have already answered to others but here goes.
What software are you using, and I mean form design to controlling the steppers!
There is so much out there some for free and some for $k000.00 I think if I know what works for someone I can try and may or may not change as and when I need to.
Sorry for daft questions but I need to start somewhere (started cutting MDF today and have got 100oz steppers and a 1850watt router) so have to start thinking further ahead.
Gus

InventIt
03-18-2004, 03:16 PM
Balsaman,
Ever get your 4th axis up and running? If so, what have you made with it?

Gus_452000
03-25-2004, 02:49 AM
Balsaman,
Hows that table coming on?
Any chance of a few pics?

Gus

balsaman
03-27-2004, 06:36 PM
Originally posted by Gus_452000
Balsaman,
sorry for proberbly asking questions that you will have already answered to others but here goes.
What software are you using, and I mean form design to controlling the steppers!
There is so much out there some for free and some for $k000.00 I think if I know what works for someone I can try and may or may not change as and when I need to.
Sorry for daft questions but I need to start somewhere (started cutting MDF today and have got 100oz steppers and a 1850watt router) so have to start thinking further ahead.
Gus

I use AutoCad, AceConverter for CAM, Also MasterCam when I am at work.

I use Turbocnc to control the motors.

Rotary axis is still in the works. I have it working but haven't done any significant work on it because I am waiting for a friend to finish building me a tail stock. He seems to have lost interest....

No "new" pictures right now. The vacuum table is working like a charm, alto my machine has been idle for a month or so now.

Eric

balsaman
03-27-2004, 06:37 PM
BTW, I have a bunch of aluminum 8020 extrusion left over which is for sale in the clasified section here: http://cnczone.com/modules.php?s=&name=Classifieds&op=detail&cat=17&de=11

Eric

mikburts
04-13-2004, 01:05 PM
Material info--
The 80/20 aluminum extrusions are used in the glass industry where they install store front glass.

Mike

Domenicxx
06-30-2004, 01:19 AM
Hi Eric

I see you are using 8020. Have you thought of using the 8020 Linear motion guides that they make.

What do you think will they work ?

http://www.8020linearmotion.com/profileindex.asp

regards
Domenixx

( Sydney Australia)

balsaman
07-01-2004, 06:32 PM
I have seen those. For them to be slop free they have a lot of friction because they have no bearings and a lot of contact area. They usually have adjustment screws to dial out the play. I have not tried them.

Eric

balsaman
10-11-2004, 01:38 PM
This machine is for sale. if interested have a look at the clasified section here: http://www.cnczone.com/classifieds/showproduct.php?product=97

Eric

kong
10-11-2004, 02:37 PM
Hope everythings ok Eric, you getting into metal working now?

balsaman
10-11-2004, 03:03 PM
Everything is great. Yes metal working. I want to convert a mill and possibly my lathe.

Eric

kong
10-11-2004, 03:15 PM
Yay, now you're talking! I have taken the same route myself if you will pardon the pun :)