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nuplowboy
01-23-2005, 08:08 PM
At long last, I've begun the contruction of my first CNC router/dremel!

After giving it some thought and thanks to some folks from the zone, I've decided to slap together jgro's design for my first attempt. I can then use that machine to make patterns for aluminum castings to make a more durable version with potentially more range. It'll also let me experiment so I better know what the Aluminum machine should be. (what size steppers, lead screw pitch, spindle type, etc)

Work began on Saturday as I hacked up the MDF into pieces roughly the sizes shown in the plans. I say roughly because Home Depot did some of the cuts and let's just say I'll have to adjust a few dimensions... :( That's just one more reason to upgrade to a big-ol' cabinet table saw someday...

Today I slept in, then went to work. I was able to get the base and bed torsion boxes glued up. Then, I ran out of Gorilla glue. And, I got hungry. I'd post pics, but we've all seen MDF boxes!

More to come, I've got money in this thing, I'm committed now!

nuplowboy
01-24-2005, 11:13 PM
Due to other commitments (work, basketball league) Nothing was done on the cnc project today. However, this is fortunate, because the quality of the work was poor.

With any luck, progress will happen tomorrow afternoon.

I do have a couple of questions...

1. What is the most economical (cheap) software for converting 3D CAD models (STL, etc) to G-code? I have found a couple and the best bet so far is MeshCAM (~$100) Are there others out there I have not run across?

2. Does anyone have a supplier/part# for a good, simple N.C. home/limit switch they've had good luck with? Again, since I'm...err "thrifty", I'm looking for low-buck but decent.

Thanks! More to come and pictures whenever I get something that looks less like a pile of MDF!

ger21
01-24-2005, 11:17 PM
1. What is the most economical (cheap) software for converting 3D CAD models (STL, etc) to G-code? I have found a couple and the best bet so far is MeshCAM (~$100) Are there others out there I have not run across?



There site was down when I just checked, but STLWork was on sale for $75. Not sure if it still is, though. http://www.cadcamcadcam.com/ I believe there is a demo you can try.

Almost forgot. FreeMill. http://www.cncportal.com
It's free, but a pain to use due to the almost nonexistant options. Depends what you're making, though.

nuplowboy
01-26-2005, 11:26 PM
Well, tonight there was some progress. All adjustment blocks are drilled and tapped. I also dug out the router to start on the dados in some of the parts for the Y and Z. MDF is a real pain in the rear. Oh well. Progress is pretty slow since after getting home I have to fire up the heater in the shop and let that go for an hour so it gets up to a decent temp.

Ger21... I downloaded FreeMill last night, and checked out the other. Thanks for the links, they look promising. The price for FreeMill is definitely in my price range :rolleyes: although I will probably upgrade to MeshCAM or STLwork later.

A question about FreeMill. I was playing around with it today and it has bunches of options for postprocessing. I've been figuring on running TurboCNC or a similar program to feed the 3-axis controller from HobbyCNC. My question is, which postprocessing option in FreeMill gives me the G-code or whatever that works (best) with TurboCNC?

nuplowboy
01-30-2005, 09:44 PM
Things are starting to look like a machine. After a couple half-days of workin' on it this weekend, I have the base, table, and gantry pretty close to ready. Below are pics of the base/table and gantry as they were last night. Today I finished up some of the gantry glue-up. I also painted the table and the underside of the base (hammered black on most, silver/grey for the working table surface) and started drilling parts for the X axis carriage. That work's about 75% ready for glue.

Also bought the ready-rod and pipe this afternoon, Will have the gantry on the base rails as soon as I machine the angle-iron to hold the skate bearings. I'm using steel for the bearing supports instead of Aluminum. This is partly for strength and rigidity. The other reason is laziness, I can cut steel easier with my chop saw and I can always weld the excess into some other project!

stevec
01-31-2005, 08:31 AM
nuplowboy,
Looks Great so far!

You are building alot faster than I did. I am building the same machine for my first build and the mdf cutting and building is now done, now I am working on the smaller stuff like the backlash-nuts. It's intresting to know that someone else is working on the same project at the same time and going through the same pains. I will take a photo of mine today and post it here for your viewing. We may be able to help each other in getting these up and running. I am still unsure about software, motors and a controller. I was thinking about using the hobbyCNC kit. What do you plan to use?

Steve

dwwright
01-31-2005, 09:32 AM
I built the same machine about a month ago. I used the hobbycnc board and 80 oz/in. motors, but I'd recommend either the 127 or 200 oz/in that he sells now. I started out with a AT power supply but soon upgraded to a 24 V that I found on ebay. I'm now looking at modifying a amp power supply to get 35 to 40 volts out of. JGRO's design has plenty of adjustment built in to make it accurate. I thought about doing the steel angle iron myself, but I found that the aluminum was much easier to mill with the wood equipment I have. By the way, I didn't install home/limit switches as I haven't found that I need them. I may wire a emergency stop switch eventually to the limit switch. Other than that, most of the stuff I mill is within the table limits and it doesn't move fast enough (10-15 ipm) to cause much concern.

Darren

stevec
01-31-2005, 01:09 PM
dwwright,

Do you recommend getting the hobbycnc chopper driver kit for $79.00 or should I get the package kit for $120.00. It's a $41.00 difference and not sure if it's a savings or get the other parts locally. Also, should I look to ebay for the stepper motors or get them at hobbycnc as well? And where do I get the power suppy.

Thanks
Steve

dwwright
01-31-2005, 01:33 PM
dwwright,

Do you recommend getting the hobbycnc chopper driver kit for $79.00 or should I get the package kit for $120.00. It's a $41.00 difference and not sure if it's a savings or get the other parts locally. Also, should I look to ebay for the stepper motors or get them at hobbycnc as well? And where do I get the power suppy.

Thanks
Steve

Looks like the kit is a good value. I spent $30 for wire alone, fans are usually around $10 - $15, not to mention the other power supply parts. However Old stereos (with high output) and old amplifiers are good sources for power supplies and you can sometimes find them at antique stores for a good price. Check around at an office park to see if they have any old telephone equipment, they usually have some 24v power supplies with them that would work also. I guess it depends on how resourceful you are and if you want to build the power supply. Dave's price for the motors w/the board are a good value and he would probably be more likely to support them, but he's pretty helpful otherwise too.

Additionally, the next time around I'll do the 4-axis board. I regret not buying it the first time as I'd like to setup for spinning some table legs and such. Although you can add another motor and plug it in place of the x or y axis.

Just my thoughts and ramblings....Hope this helps

Darren

nuplowboy
01-31-2005, 06:42 PM
I already have a hobbyCNC kit with the 80 oz steppers from about a year ago when I got semi-serious about building a machine. I got as far as to build the controller and PC power supply and attempt the first aluminum casting. That casting failed back in August/September and sort of took the wind out of my sails. I got motivated again and with the weather, figured the MDF plan was the best for a first run.

As far as build speed, I'm not being nearly as picky with details as I would normally be. I figure a CNC router with bad accuracy (bad for CNC) is still way better/easier than me cutting out patterns, etc by hand. You can build a pretty decent piece of furniture with 0.031 accuracy! The next machine will be much more rigid (all aluminum) and stronger and will be built with better precision. I'll probably upgrade to bigger steppers for the next one too, so I can tackle the occasional aluminum part or go faster in wood.

stevec
01-31-2005, 07:50 PM
Here is a few shots of my jgro special. The last photo is a cheap cutting board I got at Walmart (.99). I am building the anti-backlash nuts (try) with it. Not sure if it will work, I read someone on this board say it will.

Steve

nuplowboy
02-01-2005, 11:14 PM
No progress Monday, very little today. I did paint the top of the base. I started fab on the angle iron bearing supports for the Y axis. As I mentioned, I went with steel. Drilling the holes was no problem, but then I got to the spot faces to recess the cap screw heads. Using a file wasn't very appealing (laziness kicked in) and I hated to take the grinder to it and get a less-than flat surface. Then, a solution hit me (chair). I know plan to weld the head of the cap screw to the inside of the angle iron. This will leave the outside ridge clean and eliminate the need to hold the head of the screw while tightening/adjusting. I tacked one in place to test the plan before retiring to the couch for Biker Buildoff. (Darn Discovery Channel really cuts into my hobby time!, American Chopper, American HotRod...) Problem solved...

nuplowboy
02-06-2005, 05:23 PM
More progress on the router. The X-axis carriage is now in primer and should be black by this evening, maybe later with the Super Bowl and all... :D I have the pipes in the base and one of them is trued up sqaure to the base and ready for the gantry, which is also in primer and ready for paint. The other day, I tossed the parts together and had the gantry rolling pretty smooth and tight, even without spending any time on getting the rails square first. With a little more effort and Jgro's advice from the thread in the downloads section, The gantry should end up pretty good.

Pics attached: base painted with galvanized pipes, gantry primed, X-axis primed, and y-axis bearing supports primed.

nuplowboy
02-06-2005, 11:57 PM
Gantry, X-axis, and Y-axis bearing angle iron in hammered black...

nuplowboy
02-08-2005, 10:35 PM
With the gantry painted up, I installed the bearings to the angle iron, using a scrap piece of steel angle as a flat to set the bearings pretty well flush with the angle iron so they start out fairly consistant. I placed the whole works in on the Y-axis rails and paralleled up the one rail I removed to install the gantry. The gantry rolled pretty nice, with a little more resistance at the ends of its travel. At first it felt pretty slop-free, but then I noticed that in the middle 2/3 of travel, the gantry could be rocked a bit. I do need to work on the adjustments more to fine tune, but I'm beginning to wonder if 1" pipe can be found in 4' pieces that are straight... I pulled the rails out and put them against the edge of my 4' level (machined edges). There does seem to be a slight bow to the pipes (maybe 1/16" over the length)

A question for the group: any preferences/suggestions for dealing with less-than straight pipe (not bad, straighest pieces out of two stores). I've thought of a couple possibilities:

1. Orient the pipes bowed inboard so it results in more bearing preload in the middle of the travel rather than slop in the middle.

2. (this one's more work and $/time) Install a piece of channel iron or similar beam on the outside of the base assembly. Then use setscrews to push in on the rails (and maybe pull) in places to try to hold the rail straighter.

3. ($) I had thought about buying some cold rolled solid bars in 1 1/4" from a local steel house. I need to look at the standards for cold rolled bar to see what the allowable straightness tolerance is for that size. The diameter would be pretty dead-on, but it might not be much straighter than what I've got, depending on the piece I get...

Like I said, I do still need to work on the adjustments I have and see how good I can get it. I might be able to live with the arch in the pipes once it's all set up, but I thought I'd pick your brains about ways to work with it.

Thanks in advance for the ideas...

yukonho
02-08-2005, 11:28 PM
I would choose door number 1.
My guess is that this will have the desired effects. The truth is though that 4 feet of unsupported 1.25" anything will bow, especially with that heavy gantry. Consider going with a shorter X axis, or supporting the tube/bar at least in the middle.
colin

nuplowboy
02-09-2005, 12:32 AM
Thanks Yukonho. I was sort of leaning that way, mostly due to laziness! :rolleyes:

I'm not too worried about vertical deflections due to the gantry. It's not very heavy and I don't think it'll get too heavy with the other 2 axis in there. The 1" pipe (or a close approximation for calculations sake) will only deflect about 1/32" each beam with a 100lb gantry and the 41"-ish span I actually have, and I don't expect it to get that heavy. Solid 1 1/4" cuts the deflection by about half that if it comes down to that. The biggest problem is the pre-bowed pipe, which I can make work for this first machine. Worst case, I'll have to "persuade" the pipes to be straigter :devious: Let's see, if I hooked it under that plate, and slid a cheater pipe over.... Well, let's hope it doesn't come to that!

nuplowboy
02-12-2005, 11:20 AM
I have officially hit my first semi-major setback. The other night while working to dial in the gantry on it's rails, the adjustment blocks for the pipes basically gave up. A few had stripped out the 1/4" threads, which I half expected. I had installed threaded inserts for wood with pretty big flutes in those spots that stripped. Then, on of those pulled out of the MDF! So, I "quietly" turned off the heater, turned off the lights and went inside.

Now, on to plan A.2! I am about to head into town to get some foam. From that foam, I will make adjustment blocks. This of course, sounds insane untill I stick those blocks in some sand and pour aluminum into them. A little drilling and tapping, and I'll have some stout blocks to remount the pipes in and try adjusting the gantry over. It was getting frustrating when I'd measure and remeasure everything nice and square, then tighten up the bearings and have it roll about once then start rocking and/or racking. I'll eliminate the give from the ends of the pipe and see where I get with the middle!

Off to Home Depot, or Lowes, or Menards... depends on which one's the easiest to get to based on the traffic today!

mvaughn
02-12-2005, 11:42 AM
Making alignment blocks out of aluminum will definitely solve your issue.

What I did was to put T-nuts in my MDF blocks. It doesn't rely on MDFs ability to hold a thread. As long as the block doesn't break in half it should be just fine.

Just my $.02

Here is a pic:

nuplowboy
02-12-2005, 05:19 PM
Got some foam and cast the adjustment blocks this afternoon. Actually, they're still cooling down. A little grinding, some holes, some threads, and I'll be back on track.

The castings didn't turn out perfect. There are some voids and shrinks on the back sides of the blocks, but I started with 1 1/2" foam, and they are solid and full for at least 1" of that, so there's plenty of metal to hold a couple pipes! Normally, I'd be upset about the quality, but this was a quickie pour with runners and sprues that were poorly thought out and poorly executed. Then I poured too slowly.

"Huskerplowboy Foundry: Specializing in small, poor quality castings."

Disclaimer:
By the way, metal casting is dangerous and shouldn't be done by anyone, anywhere, at any time. Just because I'm an idiot and play with very hot fire and metal, doesn't mean it's safe or smart. I cannot be held responsible for anyone trying casting themselves. (flame2)

TinkerDJ
02-12-2005, 05:44 PM
I was going to do the exact same thing and cast those blocks out of aluminum. I have been trying to cut the foam with the holes already in them so all i have to do is drill them a little bit then tap the holes. Have you thought about casting bearing supports as well. I am trying to work on a holder for 3 bearings so that they can be preloaded and not have the problems only 2 bearings have.

Your not the only idiot playing with molten aluminum. :D
There's nothing better then sitting back watching aluminum melt in your crucible in anticipation of a good pour, when a piece of magnizium in the mix flares to life. (flame2)

nuplowboy
02-12-2005, 07:05 PM
I have thought about casting nearly the whole machine, including bearing supports. I know a couple folks with small mills who could true up the angles. In fact, the machine I started to build before deciding on the Jgro express for a starter had this Z-axis design... I actually poured one attempt this fall for the Z-axis part that would have the 45's for the bearings, but the casting didn't turn out and the project lost momentum. Come to think of it, I should've melted down that failure while I had the furnace hot....

TinkerDJ
02-13-2005, 02:21 PM
I was basically of the same opinion but Jgro's design is laid out so well and some of the results have been great, i figured i'd build one then go from there. I have a smaller router already built but my z axis is not working well so after i design a new z axis for the smaller one i can start milling pcb's. But i will still build Jgro's design for doing wood, as well one thing i would like to do is modify it slightly so i can use it as a plotter of sorts. I have most of the metal parts at home now and all i need to do is get a nice week of weather (have to do all my cutting outside i no longer have a garage) and i'll be off to putting the whole thing together.

nuplowboy
02-13-2005, 06:15 PM
I think these will hold the rails... Turned out ok, but I wish I'd spent a bit more time on the castings so they'd be nicer. The two on the other end got cut down to 1" thick due to bigger casting defects. Monday I restart the Y axis adjustment process...

nuplowboy
02-23-2005, 10:38 PM
I now have a 1-axis CNC machine! Last night, with hopes of renewing my motivation, I tackled the task of making this monster move. I installed the x-axis lead screw and stepper, wired up a plug for the motor leads, dug the old pentium 166 out of the other room in the shop, set it up on a piece of plywood on top of a carboard box, and fired up TurboCNC. Nothing... Well, then I realized that I had no idea what the parallel port pinouts were for the Hobby CNC board I have. (I have that info now thanks to Dave via his Yahoo support zone) However, I noticed that when I hit the arrow keys to jog the Y, (stepper hooked up to X, but I was in hit all the buttons mode), one direction did cause a single step from the motor. I eventually figured out that pin 2 was the X direction and pin 3 was the step pin. After slowing the max speed WAAAAAYYYYYYY down (Boy steppers make weird noises when they miss about 20 rev's worth of steps!).. I had the gantry crawling back and forth. :banana: That felt good. The 80 oz steppers with 1/4-20 allthread are SLOW, but it won't be too bad to start out. I should be able to pretty easily switch to 5/16-18 or 3/8-16 allthread and gain a little speed, but that's for later. Now, I need to focus on casting a pile of adjustment blocks for the Y and Z axis.

There's still some work to do on the X before I move on. I want to give alignment 1 more shot and I need to align the lead nut with the motor and tail bearing. It would have been pretty dead-on, but when the home depot cut down the MDF, the gantry back ended up a bit shorter than spec. Then, to get the bearings back to the proper width, I had to add a 1/4" piece of poplar under one of the bearing supports, shifting the gantry centerline over 1/8"+. No biggie, just more work... At least it moves under it's own power!

tbenefi33
02-24-2005, 02:36 AM
Hi newbee here also thinking of building the same machine what kind of stepper motor would yall reccamend ?

nuplowboy
03-13-2005, 12:38 PM
No, I haven't dropped off the face of the earth. Back on the 26th of Feb, I sprained my ankle pretty hard playing basketball. (chair) It's been just within the last few days that I could really put any weight on it. Needless to say, just about every project I have's been neglected, alot. I can limp around on it without crutches now, so just as soon as I clean up this pig stye of a house and catch up on the laundry (it's tough to carry that basket using crutches!) I'll be back to work on the hobby stuff. And, not a moment too soon! A feller can only watch so much TV. With all the Dukes of Hazard reruns on, I've been getting a strange urge to paint my cnc router orange with a big '01' on the side and a flag on the top! I'm just not sure how well it'll jump the creek... :rolleyes:

hotrodtom
03-13-2005, 05:30 PM
What A Great Forum. Got The Cnc Bug Somewhere, When I Saw Jgro Plans I Couldn't Stop Studying Them So I Bought A Sheet Of Mdf. Yesterday Cut Most Of Pieces.
Last Week Bought A Bar Oh Uhmw, Plan On Using It For Pipe Supports, Anti Lash Blocks & Lead Screw Bearings.
Also I Don't Remember Where I Found The Plans But Lucky I Printed Them Then, Can Anyone Refresh Me.
The Woodworking Part Is Not A Problem For Me, But Getting The Rest Will Be A Challenge. I Will Continue Reading Post And Web Surfing.
Also Have A Weakness For American Hot Rod And American Chopper.

Have A Good Day
Tom In Indiana

nuplowboy
03-20-2005, 09:58 PM
Well, I finally got rid of the crutches and got the house back to "average bachelor pad" so back to the shop I went. I cast some adjustment blocks for the Y axis today. Actually, I intended to cast all 8 of the small adjustment blocks, but as usual, I screwed up the pour and only got 4 usable blocks out of it. Could've been worse, I'm surprised I didn't get 3 good ones and have to pour again just to get going! I have most of the cleanup and drilling done for the 4 I did get and should have them finished up tomorrow. Then as soon as I fab the bearing holders, I'll be up to a 2-axis machine! That would be much more useful than my current 1-axis machine. I'm just not good at looking at the CAD drawing and moving the sheet of foam around while the gantry crawls back and forth! Just for motivation, and to make it look like I've accomplished something so far, I've included a couple pics. One of the machine with the table mocked up a few weeks ago, the other of one of the new Y-axis adjustment blocks. Oooo Ahhh! :cool:

nuplowboy
03-22-2005, 09:54 PM
Well, my luck's caught up with me again. I completed the Y axis adjustment blocks and the bearing holders tonight. But, when I went to mock up the bearings and see how the y-axis looks, I noticed a problem... The rails are too far apart! Actually, I somehow managed to build the Y axis assembly with the pieces that hold the angle iron bearing supports 1/4" too close together. I have no idea how I managed to do that since it requires at least 2 pieces to be made wrong! The dados in the main plate of the assembly are apparently too close to each other by 1/4", which should mean that the nut support also had to be made too short by 1/4" That assembly fit up real nice when I glued it. Amazing... (nuts)

At this point I can't bear to think about building another Y-axis (even though that'd be the right way to fix this). The other options, none good, are to space the bearing supports off their MDF pieces (not attractive, since I welded the bolts to the bearing supports and they might quickly become too short, plus the alignment grooves become useless...) or to slot the attachment points for the rail adjustment blocks so that one or both can be mounted closer together. I am leaning that direction...With the aluminum rail blocks, I might be able to make "8" shaped holes if I can drill a hole right next to the others, that'd help keep it from shifting too. Some JB weld could also backfill the slots to make them holes again...

:withstupi Any thoughts?

tbenefi33
04-02-2005, 12:40 AM
hello well i just about got all my parts and ready to start building will have more pics in the my gallery

japoni
04-04-2005, 11:31 PM
nuplowboy - I noticed in jgro's design he used 1/4-20 bolts to hold the upper and lower plates on the Z-Axis. It looks like you used #8 Screws, if so do you notice any flex.

I to am using this porition of jgro's design, and was just wondering before I attach them together.

nuplowboy
04-05-2005, 07:44 PM
On the part your refering to, I used 4 or 5 course drywall screws along with Gorrilla polyurethane glue in the joints. The screws most likely add very little strength once the glue sets. They're used more to hold the joint tight while the poly glue expands and hardens. The assembly feels pretty rigid. It'll be a while before I get back to adjusting for my mistakes and get it mounted though...

nuplowboy
09-17-2005, 11:32 PM
After a long break, I got back to working on the router today. I quickly (and sloppily) cut out new parts for the Z axis (I think the originals ended up as kindling sometime this summer (flame2) ) and glued them up. Not my best work, but I need to get this thing together and cutting stuff. After all, I really just want it to mill shapes out of foam so I can cast them in Aluminum.

After clamping up the Z for the night, I turned to figuring out what I messed up on the X axis to make it not fit tight enough between the rails. I measured and consulted the fresh copy of plans I printed... Well, to my amazement (and frustration), all of the MDF parts checked out right on. But, still no go. The only parts that seem to be off are the bearing supports. The holes seem to be a tad too far from the corner of the angle iron, setting the bearings back from the edge a little (nuts) . It doesn't seem like enough to cause all the slop, but the skate bearing on pipe setup is pretty touchy, coming at a round pipe with bearings at 90 degrees...any little difference in the bearing placement makes a significant swing in rail-to-rail distance... So, tomorrow, I will have to run to town (again) and pick up some more 1 1/4" angle iron (or angle aluminum) so I can remake the bearing supports to get the bearings closer to the edge. We'll have to see how that works out. If it gets things close, I figure I can shim the angles in their supports a little to close a gap...

nuplowboy
09-19-2005, 10:53 PM
I now officially have a 2-axis machine! Sunday I drilled out the bearing holders for the X axis and got that thing to fit right. Tonight I was able to rough out a drive nut (no tensioner yet, couldn't find my #10 tap!) and hook up the X axis and stepper. I fired up TurboCNC and started by reexperimenting with start and max speeds to avoid whistling steppers. Once I had the directions squared away, I stuck a piece of dowel in the X carriage and taped a sharpie to it (not quite tight enough, but ok for a test. I found a piece of foam-cored poster board in the shop and put it on the machine's table.

Using a G-code file generated by spalm's awesome program from this thread: http://www.cnczone.com/forums/showthread.php?t=13277&page=2&pp=15

I set the machine in motion and a while later (longer than it should've taken, I had the start speed set too low so it tried to accelerate and deccelerate for each line of code...), I had a pretty picture... It almost came back to the start point, came pretty close. The not-quite-tight tape on the sharpie and the fact that I didn't tape down the poster board could've caused the error. I need to spend a little time to square the X to the Y, but I was pretty psyched about the results... Just enough to keep me going :)

It's good to see my old P1-166 computer doing something useful (if you call a computer making a pile of MDF draw a doodle "useful") :rolleyes:

spalm
09-19-2005, 11:49 PM
Fantastic. Aint it fun? My first cut was with a sharpie. Actually it was the second cut as I drove the first shapie into the table breaking the tip.

You are on the road,
Steve

Jason Marsha
09-20-2005, 11:47 AM
Congrats. Try that design with a v-bit in a trim router, it should look great.


Jason

Zoriander
09-20-2005, 12:26 PM
which ballscrews did you use?
the project looks really nice

:p I am da leet-zoriander

nuplowboy
09-20-2005, 09:46 PM
Thanks Zoriander. I really like that hammered finish paint, covers up all the goofs, or at least most of them! The aluminum adjustment blocks look good against the black too. Thanks to all the folks for the encouragement and advice!

For now, it uses 1/4"-20 allthread per Jgro's plans. I may experiment with some 5/16 or 3/8"-16 allthread at some point, but for now, it'll work. The next machine will require much, much larger steppers and will likely be able to use fewer threads per inch on the lead screws. So far, I'm pretty happy with the machine, all things considered. As long as I don't have to carve the foam patterns by hand, I don't mind it cutting on them for hours! I've got plenty of other projects to keep me busy!

nuplowboy
09-20-2005, 11:38 PM
Question:

Does anyone have some good sources to get 6-conductor cable? The stuff that came with the HobbyCNC kit is 6wire-22 gauge. I don't know for sure if it's shielded, or if it needs to be. Heavier gauge wire would be ok too, cut down on resistance for the long runs.

Some other things I'd like to find are some good connectors for the stepper wires (6 prong) and those flexible cable tracks.

Thanks

randyf1965
09-21-2005, 12:48 PM
http://pr3.pacrad.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=25977&prmenbr=126&lastcat=1505

$.42 per foot less than 100'.. over 100' $.34




Question:

Does anyone have some good sources to get 6-conductor cable? The stuff that came with the HobbyCNC kit is 6wire-22 gauge. I don't know for sure if it's shielded, or if it needs to be. Heavier gauge wire would be ok too, cut down on resistance for the long runs.

Some other things I'd like to find are some good connectors for the stepper wires (6 prong) and those flexible cable tracks.

Thanks

nuplowboy
09-22-2005, 09:03 PM
Howdy,

A little more progress and some fun with fire. Tonight I cast the adjustment blocks for the Z axis. With the help of some process improvements in my castings, I actually got a useable part from all of the patterns this time! :wee: Actually, they all look pretty good, even without hitting them with the flap wheel. I will, of course, take the wheel to them, because I like shiny things! With any luck, I'll be up to 3 axis by the end of the weekend. Then, I can see what I can break!

Randyf1965, thanks for the link for stepper wire... Have you done much business with them? Are they a good company to do business with?

randyf1965
09-22-2005, 11:11 PM
wow! nice looking castings.. what improvements have you made? My new furnace should be ready to fire this weekend.

Sorry haven't ordered from them, yet.

ViperTX
09-22-2005, 11:46 PM
nuplowboy....you castings are absolutely amazing!

My approach would be to pull out a piece of jig plate and cut the parts from it.

Jimmy Southern
09-23-2005, 12:34 PM
nuplowboy,

Just had a thought. Go to your local parts store and pick up a couple of the 6 conductor trailer plugs & recepticles. You may also be able to get 6 conductor cable there also. It's a fairly heavy gauge wire 14 I think.

For cable guides go to ebay and search for Igus e-chain or e-track or cable carrier.

Hope this helps
Jimmy Southern

nuplowboy
09-25-2005, 10:25 PM
randyf1965 and ViperTX, thanks for the compliments.

Randy, The biggest improvement lately was building a KHPT (see my page http://www.geocities.com/mkollath/cncbuild7.html) I saw it on this site: http://www.buildyouridea.com/foundry/lost_foam_howto/lost_foam_howto.html Basically, it's a piece of pipe cut in two and hinged. It provides an easier target for pouring and a riser to provide pressure to fill the mold. I've used it once, but oh, what an improvement!

Viper, I like the castings because of the price. I haven't had too many donations of plate aluminum, but I have gotten quite a few free lawnmower engines! In fact, that's what this last batch of adjustment blocks was, a donated lawn mower engine, or part of it.

Update on progress: The adjustment blocks have been cleaned up, drilled, tapped, and installed on the Z axis. The Z rails have been cut, deburred and installed. The Z bearning holders were fabricated today and are ready for skate bearings, just as soon as I find that other package of them... For these bearing holders, I did the mounting a little different than the X and Y. Instead of welding bolts to the angle iron, I welded coupling nuts for 1/4" allthread, using a hole through the corner and a bolt to anchor them while I welded. They went together a little more smoothly than the previous ones, and leave much less hardware poking into the tunnel for the leadscrew, which is fairly tight on the Z. I hope to get the Z moving on Monday and will post some update pics then.

nuplowboy
09-26-2005, 10:45 PM
Well, There was little progress today. It stopped raining this morning, so after work I had to play catch up on the mowing. I've kind of let the lawn go for a week or more while fiddling with CNC. :rolleyes:

Anyhow, I was able to get a little done on the Z axis today. I installed the bearings on the angle iron and mounted the Z on it's rails. I even managed to get the rails pretty darn near close to square with the table, which is a plus. The carriage glides pretty well. I then installed the lead screw nut and allthread and stepper.

There was a setback. The old dremel I planned to use doesn't seem to run anymore. I'll fiddle with it some, but I may have to purchase a new item for a spindle. So much for the cast cradle I made over a year ago to hold the dremel!

nuplowboy
09-27-2005, 11:45 PM
At long last! The machine has cut something!!!!

Turns out the Dremel was ok, just needed to be kicked hard. Actually, a couple of the housing screws were loose causing the motor to bind. That fixed, I strapped it onto the cast cradle and wired up the Z axis stepper. Then, the moment of truth:

First cut (and first 2 pictures) was in insulation foam, since that's the primary goal for this machine. The spirograph was cut at about 1/8" deep (couldv'e gone deeper) and as fast as the little steppers could push it (around 7.5 ipm according to TurboCNC). Talk about nice cuts! The 1/8" 2-flute carbide ball mill I used does an outstanding job with the foam.

Second cut, just to push it, was the same spiro in MDF. Same cutter, same feeds, approx same depth. The dremel sounded like it had to work a bit, but kept up just fine. There was some fuzzy tearout at the surface, but then MDF is just thick cardboard.

On both cuts, the machine hit where it started, which is awesome. Later this week I will have to play with cutting some squares to make sure the X and Y are perpendicular...

pen25
09-28-2005, 02:14 AM
good job. have been following this thread for a while now.

nuplowboy
10-03-2005, 10:13 PM
The machine has officially done what it was built to do. Over the weekend, I machined two handwheels out of foam (the first one had a nasty mismatch between the top and bottom sides). Despite the Y axis shelling out an IC on the driver during the finish pass of the second part (and gouging it), they patterns were mostly usable and tonight I cast them. I think the Al was a little too cold (didn't look cold) becuase the wheels had a couple of spots that were almost cold shuts. They'll work, but could've been better. I'm just happy to see this thing making 3D foam shapes that I can cast, just like I planned! A little machining and I'll have cool wheels to watch spin while the machine cuts for hours!