View Full Version : 3X3 Gantry router/mill project

07-07-2004, 06:44 AM
Entry post:
Some photos of parts and materials collection process.

This will be the Yaxis Gantry with modifications for end support

These will be the x axis glide for the gantry.

This, with modifications will serve as the Z axis

07-07-2004, 09:20 AM
Thats looking to be a nice collection of parts.
Since you are only doing a 4 x4 table I am wondering if you should use belts.
I only suggested belts so as to make it cheap. But you could use lead screws for that size.
I guess all have their pros and cons. With screws you wont need as much down gearing as with belts.

I think belts are only an alternative for long axis where you want to keep the cost down.

07-07-2004, 09:51 AM
I'm wondering about those belts and drive ratios.... the motors I have are strong..those E712s. running with the higher encoders will reduce the speed maybe without being prone to faulting. And if I run them with lower voltage, I am thinking maybe their strength will offset the possible overheating. ....Pretty sure the Z axis will be screw though.... I still need a much clearer understanding of how all those elements play with each other. Otherwise, yes, I want to avoid all the pulley reduction setups if possible....maybe some properly ratioed gear motors will come along at a "can't pass up" price....
In any event, over the months I've got now somethin' to work with that fits together relatively nice.

07-07-2004, 10:24 AM
Staying under 48", belts will work BUT, you may want to look into lead screws (I agree with ynneb). You can pick up NOOK leads with .003/ft. precision fairly cheap and all the potential (again I said potential) problems with the belts will be eliminated. If you have another $50 (or less) to spend you will see so much gain later on. Plus you can save the belts for future projects or sell them! You have made some very good purchases up till now and most likely things will be just fine. Hey, can I hire you to make purchases for me? I have been trying to pick up a set of rails like that (for that price) but never seem to get what I want. I usually buy new for my resale machines and there are plenty of great deals out there if you know where to look.

07-07-2004, 12:38 PM
Subscribed! Mate, if thing turns out like your last project, I will be watching every step of the way:D
Now a few questions!
Just wondering what you mean when you say higher count encoders will slow it down? Is this due to the 45Khz limit in Mach2? If so, then surely this will increase the likelyhood of a fault, since the geckos will only bear (bare?) a 128 pulse error before faulting, then 128 pulses could end up being a fraction of a degree - please excuse me if I am barking up the wrong tree, I have no idea what encoders you have, or even if you are using geckos:confused:
Anyhow, I would love to see this machine run off of balscrews too, don't forget that Reid Tool will export from the USA for an extra $25 admin fee. Again, I have no experience with belts, but I think they are better suited to longer beds than 4 foot since ballscrews should still be affordable.
Anyhow, don't let me put you off, it's gonna be great either way:)

07-07-2004, 09:36 PM
I've got Gecko 320's in the control station. Adapters are available for multipliers which might quell the ppr issue. The computer and power supply will be castered from the Shoptask to the router and reconnected. Multiple configurations can be saved to enable easy transition. But, I Have considered the Rutex drives....and another power supply.....just not for a while yet....$$.
Noticing that the y axis(gantry) is already belt driven, I intend to experiment with this motion first. A static mount with the full 24 inch Z axis rails(don't want to cut them down yet) will be put together and numerous tests will ensue.
Remembering that this is a hobby, the intent is not to simply build the machine, but to explore the multiple variations available. This will facilitate a better understanding of "the way things work". Hopefully I won't dawdle too much. Being a factotum, there is usually little time 'til winter. Going there has to be as rewarding as being there.
Hmmm.....I reserve the right to alter my philosophical sensibilities at any time:)

07-07-2004, 10:07 PM
Bloy... You've got one major advantage that a lot of us don't... You've got a kick ass Mill/Lathe to work with...

You can mill your own parts... Bearing blocks, spacers, Turn your leadscrews, make couplings...yada... yada.. yada...

01-20-2005, 02:33 PM

01-20-2005, 03:48 PM

Welcome to the router club :) We haven't talked in sometime. Call me if you want to talk about your project.

05-09-2005, 09:02 PM
Geeesh it took months to get this far. And it's on top of another project that has to be completed first for my "work".

But this is the basic configuration: raise it up about 2.5 feet (table and all) under a square metal tube frame. I'd like to do sculpting and have a secondary table insert for more stressful operations so the Z axis won't be "reaching " and have less flex while not extended so far.

I feel lucky that I got most of these parts months (year?) ago because now the bidding on Ebay always goes way over MY budget.

05-09-2005, 09:31 PM
It's nice to know I'm not the only one taking forever to finish a router. :) I was going to ask you about this after seeing that post on Yahoo about it.

05-09-2005, 09:36 PM
I like the raised design you have going. Like you said, Z clearance will be more flexible. One question: Are you going to run dual screws on either side of the X axis? Or do you plan on just one side being powered? If you go with dual screws, how does everything get syncronized?(SP?) Through the software, or wiring or something else?


05-09-2005, 10:18 PM
yes, I plan on using two Geckos and Mach3 to "Slave" both sides with rack and pinion (not shown in pics) . Mach3 will do this and Art has several customers that are using this feature successfully. the X axis rails are really WAY stronger than the open bearing y and Z, but In time I'm sure I will find a way to retrofit THK rails and use the Thomson bearings for another project....but for now (and forever probably :confused: ) I'm going with what I have.

Also, the Y axis is belt driven and am "in the process" of upgrading the belt. The old one seems of lessor quality and has more "stretch" than a good quality belt. I just lost out on a 4 ft ballscrew and nut on Ebay as it skyrocketed to more than what I could put out.

Most of the sculpting done with the z axis extended will be of an artistic nature where tolerances won't be critical. And, I don't intend to be cutting much more than multiple passes in aluminum with the table insert and the Z axis retracted.

05-10-2005, 12:03 AM
I have (2) 12:1 gearheads and "made for" servo motors rated at 60V/Krpm (as seen in above pictures).
I "Plywood-boarded" a power supply giving 95.6VDC and
found the output shaft rotates at 132.8rpm. The motor shaft
therefore rotates at 1,593.6rpm (12 X 132.8).

Wanting to use an existing Gecko320 which cannot exceed 80VDC, I
will apply 75VDC to the motor. In theory, this would bring the motor
rpm down to 1,250rpm and gearhead shaft output at 104.16rpm (1250
divided by 12).

With direct drive, travel per 1 rotation of output shaft is 3.92857
inches. Hence, 1 inch of travel will equal .254545 of 1 rotation.
Multiplying this by 12 (gearhead reduction) yields 3.05454rpi
(Revolutions of motor Per Inch of travel).

If using a 500cpr (Counts Per Revolution) quadrature encoder, this
translates to 2000ppr (Pulses Per Revolution). Multiplying this by
the motor shaft rpi (Revolutions Per Inch) gives 6,109.08 pulses per
inch of travel (2000ppr X 3.05454rpi).

Changing the 1,250rpm of motor to revolutions per second yields
20.8333rps (Revolutions Per Second). With 2000ppr encoder, total
pulses per second equals 41666.67 (2000 X 20.8333).

Mach3's max ppr is 45,000 so as figured this configuration should
work with motor tuning setup at maximum velocity given ample power
of motor.

Inches Per Minute of travel (ipm) would be 409.2269 (1250rpm divided
by 3.05454rpi)

Assuming the motor has the power or the machine mass is within means,
this all should work

Originally the $30 per motor/reducer ebay buy was intended for only the gearheads, but
the motors came with them and are in pristine unused shape.


05-10-2005, 12:30 AM
the USDIGITAL E7MS was chosen (had no choice really) because it was the only size that fit the recess on the motor's back plate....a nice match.

05-10-2005, 04:54 AM
Wow, you have found some nice stuff at ebay. This is going to be one slick router. would it be difficult to convert the Yaxis to rack and pinion instead of upgrading the belt?


05-10-2005, 08:56 AM

The more I think about this design, the more I like it. I keep imagining a seperate actuation for the table that allows it to be infinitely adjusted relative to the Z axis (to keep Z cantilevering to a minimum). The only concern might be accuracy of alignment (i.e. how to keep the table truly perpendicular to the Z). Alternately, I can imagine the table being comprised of a base on wheels that can be removed for clearance of larger work. Just dreamin' here...

BTW, I'm including an image of a commercial design similar to yours (uptime.ca - now out of business?). They used a ballscrew on only one side of the X, which never conviced me... Also they seemed to skimp in using only 1 rail on the Y, but they swore by it.

05-10-2005, 11:03 AM
You say that the business is no longer? I wonder if it had to do with the design of their machine. But I DO detect from the picture that both sides of the Xaxis seem to be driven by Ballscrews...just above the rail bearings.
On the router I'm building (eventually), those side supports for the X axis will be integrated to the floor stand. I'm thinking of having each side modular and mount to the table module with gussets underneath, adjustable to achieve proper alignment along with floor pads to remove unevenness of floor variations.
If I don't do this the machine will never make it out of the basement without doing some home reconstruction!
Thanks for that Picture!

05-10-2005, 11:13 AM
Here is the Ballscrew assembly I used for the Z axis. I got one from ebay "lisa_ctrsurplus" but the balls had not been circulating and the screw was useless. But I called them up, they said "keep that one..we'll send you another". Well, the second was in Dandy shape! And, I got an extra set of mounting blocks, thrust bearings and hardware from the first. To mount this I milled off the "tongue" of the ballnut bracket and tapped into the remaining smaller flange. the end blocks were shaved here and there and retapped to fit clearances behind the Thomson bearings. That "clutch" and the extra screw shaft were cut off. Also I shortened the Zaxis rail assembly by six inches to accomodate the ballscrew assembly.

05-10-2005, 01:08 PM
...But I DO detect from the picture that both sides of the Xaxis seem to be driven by Ballscrews...just above the rail bearings.

You're right...I need to think before I type :o

I think they are out of business because they lacked marketing skills (see K2CNC for tips on how to do this :rolleyes: ) (aren't smilies FUN?)

05-10-2005, 03:15 PM
LOL .....I'm still wondering how the single rail of the Y axis of that "uptime.ca" machine can maintain any accuracy when under load....especially with the Z's longer reach. Although my Thomson open bearings aren't much better when the Xaxis is going negative and "pulling" the tool into the material. Forces are then against the "open" portion of the lower pillow blocks.

This is what delays me I think. I really want to "rip" the Y axis rail back-plate into two separate supported rails. Then remount turning the rails 90 degrees so the open pillows are opposed to one another....and wider apart. A sturdy "U" bracket could be made for the mounting of the pillows. The same for the Zaxis rails. With this configuration, I've thought of going horizontal for the Y axis rails and dropping the Z down in between. I'd lose some X and Y axis travel doing so.

05-10-2005, 04:13 PM
yep a lot of long levers with short fulcrums on that one.

05-10-2005, 05:13 PM
LOL .....I'm still wondering how the single rail of the Y axis of that "uptime.ca" machine can maintain any accuracy when under load....

I said the same thing to the guy at Uptime.ca. He assured me that one rail was enough because the trucks are preloaded to withstand heavy loads. Heck, he claimed his machine could cut STEEL, and hold .003 repeatability while doing so. Still, he admitted that many potential customers had the same reservation that I did, and offered to put 2 rails in there "if it would make me feel better".

He had a "nobody understands me" attitude regarding his design which probably didn't help his business. Bottom line for me: two rails are better than one. :p

05-24-2005, 12:19 PM
here are some changes made to the existing parts for the Thomson bearing orientation. Loading on the bearings will now be more evenly distributed through the solid portion of the "open" pillows. There will be a loss to the X and Y travels...but not much considering the increase of the strength of the new working area.

Geeesh....it was hard (emotionally) to take those existing rail units and "rip" them down.
I will be using that plate "cardboard" for mounting a ballscrew nut. Same on other side without ballscrew drive.
Now...have some more aluminum plate on order....the pillows on the Z will be farther apart (the cardboard is only a representation) with a new travel of the Z at 9.5".

05-24-2005, 01:01 PM
That's pretty slick looking. Good to see you're still making progress! ;)

05-24-2005, 01:20 PM
Looks sweet. It's nerve racking knowing that you have to cut something apart that is in good working order and create something else that you have to make it work.

05-24-2005, 01:36 PM
I don't have a Y ballscrew yet and could kick myself..... the other day a 52" "new" 20mm one came up on ebay for $80-buy now. I recorded it and delayed for a minute....came back and it was gone..drat... then another the same came up as bidding with six days left and it is already up to $80....

oh well...I'm still thinking of going with a rack and pinion and using the unused space/plate on the back of the Z axis for the motor mount/pinion and adding an angle length along one Y rail support for the rack.

06-23-2005, 11:03 AM
....Photos of latest progress...

No, that isn't the spindle motor I will be using...the one pictured has bearing sleeves that rattle unless kept full of heavy lubricant:)

This is just a working table...the actual table will be about 8" lower. the X axis glides and pinion drive motor/reducer will be the same as pictured in relation to the Y axis and will rest on a 4" by 2" steel tube supported on verticles. I'm thinking of calling the gantry slides the "X" axis as the operator will be at the open end of the table. Thus while in operation, the view will be : side rails move away or closer (Y), the gantry slides move across (X), and the Z....as usual.

This X/Z axis unit is Very rigid (as is), yet glides nicely!

A ballscrew/nut has been obtained with the nut being mounted to one side of the X/Z unit. A stiffener plate(with small gussets) will be added to the open side of the unit and the spindle will drop down through the created "box" frame.

06-23-2005, 05:58 PM
...just a note...
extra holes were added and tapped on the sides of the Z pillow blocks and secured to the back plate, making the pillows themselves gussets. Since they are "square", they do a nice job of making the XY unit(keeping the standard configuration) Very rigid. But under loads with the ballscrew driving one side, I want to enclose the Z frame by adding that "stiffener plate" with gussets across the lower "open" portion (near the front Y pillows as pictured) to ensure the unit can't rack. I don't have the actual spindle motor yet so I am undecided how to size the gussets without cramping the through-way for the spindle motor/router.

The Y rail opposite the one with the mounted ballscrew will probably be used for the cable tracking chain....or sumpthin'.. :)

06-23-2005, 06:36 PM
As it turns out, there will be 34" of Y travel (gantry glides)with a few inches to accomodate a larger workpiece, and 42" of X travel (side rails).

The dual x axis drive motors are centered on each end (one shown above) with the pinion extending down between the THK truck bearings with the rack mounted very near the trucks. A spring-loaded secondary plate for the motor mounts will pivot upon the main gantry load plate to keep the pinion engaged with the rack, and an adjustable stop will prevent too much pressure (or too little) between the racks and pinions...i.e. backlash adjustments. The picture only shows a mock setup with a scrap part to rest the motor on.
I went to the steel supplier today for the base/side frame materials but he closed up shop early for a trip to a nearby town..Green Bay, so I have until tommorow to change my mind over how I intend to construct and tie in the gantry with the side rails. :)

07-06-2005, 07:31 AM
Some work done...the main X bearing plate will be "rabbeted" to accept the gantry end plate and the gantry side supports. This will make the whole gantry mount on the X rails rigid.
...sure wish I had "rounding over" mill bits... with a toolchange after milling the profiles, many of the hard edges would have a softer feel.

My Shoptask is certainly up to the task (pun intended)...some of the parts didn't fit in the envelope so I mounted them at a 45 degree angle and rotated the G-code....that extra gain worked. Also, I found out that the machine is trammed well. after tightening the Z axis and running the edges of the gantry end plates, they came out right on parallel to .0009 to match the rail support dimensions....that is if I read my caliper correctly :)

07-27-2005, 07:47 AM
The steel frame is being cut from the supplier. The rail supports will be 4"X1.5" channel with 3"X2" verticals (three on each side) with 1"X1" square tube for the rack support/riser. The pictures show a 1"x1" wood filler for now.

The motor mount/pinion tension adjuster also has a stop bolt inside the spring to allow a little adjustable play but prevents the pinion from backing away from the rack. It may need to be modified, but with the leverage generated from the distance to the pivot, it MAY be adequate.

That black anodized gantry rail support material (aluminum) is some tuff stuff, but I have a couple of 1/2"X42" aluminum strips to attach for added angular support if there is any flex under extreme loading.

The motors are 60V/KRPMs with a 12:1 reduction gearhead..will run them slaved at 75V with plenty of amps using Gecko 320's....a total of four drives including the Y znd Z.

07-27-2005, 07:51 AM
This is really coming on nice :) Should certainly be a solid machine once it is finnished.

07-27-2005, 08:02 AM
Thanks Kong,

It is very rigid, yet glides nicely....
The rails are parallel as it sits now, with the truck bearing fastener holes a smidgen oversize for square alignment.
Heh...Like you Kong, I'm doing a bunch of other things in between trying to get this contraption together!

P.S. That CNC'd shoptask (and Mach3) is working well...many holes, all in alignment. In fact, yesterday I found a way to further reduce backlash on the Y axis thrust bearing mount block.....the block that holds the bearings was flexing under load due to distance of block fasteners from ballscrew.

07-27-2005, 10:04 AM
Here is one of the two motor mount plates...FUN making!

....generated with BobCad...

08-17-2005, 08:28 AM
Here is where I'm at now.
...tested the drive motors with a 18V tool battery and they WORK! the Rack is so neat gliding back and forth (although rather slowly at only 18VDC). The Z going down will lift the mass easily as it bottoms on the temporary table.
Still need to do the Y-axis screw.
The Base is level and held with temporary cross bracing 'till all the angulations are added. It comes apart...each side removable from the center sections (in case or when it needs to be taken out of the basement). Some steel I puchased, and other I had laying around. Many pieces are from salvaged bed frames often given away at yard sales.
.....so much grinding! You know, to hide the bad looking welds!

On the rack mount angle, I centered the screw holes to secure it to the channel...not thinking....they should have been just out enough to clear the rack. Now it is difficult to get a wrench on the screws without hitting the rack to adjust. A ball-end hex wrench will work but I don't like it.
The base will also provide storage of heavy objects after a platform is added to the bottom frame. Hopefully this will add in stability.

08-17-2005, 02:26 PM
Actually, because I did a lot of tacking and short stitching when welding up the base, the welds were not smooth. Hence, the grinding to even out the beads.
The one end framing of the base will be removed and the table that the gantry is sitting on will roll into the base. After positioning the gantry on the base, the table can be rolled out and the frame reassembled. THEN the alignment of the rail/rack channel before final welds.

08-19-2005, 08:03 PM

The more I think about this design, the more I like it. I keep imagining a seperate actuation for the table that allows it to be infinitely adjusted relative to the Z axis (to keep Z cantilevering to a minimum). The only concern might be accuracy of alignment (i.e. how to keep the table truly perpendicular to the Z). Alternately, I can imagine the table being comprised of a base on wheels that can be removed for clearance of larger work. Just dreamin' here...


You know, Carlo, I'm not sure you are still reading this thread, but that idea of a height adjustable table is starting to look real. I took apart a trash compactor and it lowered the ram with three large screws tied together with sprockets and roller chain and to the drive motor. I'm starting to envision four screws near the corners of the table....something on the line of a knee mill, the four screws adjusting all at once. The four (or six) glides could be short thk rails riding on the side of the frame. I have several extra inches of clearance after the travel of the spindle on the y axis ends.

08-19-2005, 08:41 PM
more pictures of the table frame. the pieces will all be on one plane when cut to size.
....oh, and a pic of a cramped shop...

08-19-2005, 11:32 PM
Gee..after looking at the pictures again, maybe I could convince my wife that I need a plasma cutter too.....with THC no less.

08-24-2005, 11:08 AM
Rails are shimmed and racks adjusted... all glide smoothly with 18VDC tool battery (seen on gantry). the platform for storage is temporary...will fit as time becomes available.

If I DID add a plasma device, the storage area would be reduced and a "hopper" type chute would be added under the table to direct the debris from cutting into the center where it would fall through to a pan on the floor....I think this would work...will cross that bridge if or when.....

08-24-2005, 11:36 AM
One thing I don't have incorporated is a "quick release" for the rack and pinion engagement. Although they CAN be disengaged by backing off the stop screw and pressing in on the tension spring while tightening the pivot screw, this is very inconvenient. This was done to test the travel with the 18VDC battery, driving one end of the gantry at a time. Hopefully, when all is said and done, and the machine is fully CNC functional (with auto aligning home/limit switches), the need to disengage the racks and pinions will not arise very often.


08-26-2005, 12:40 AM
testing different configurations for power supply and driver parts

Mike F
08-27-2005, 04:12 PM

Your control box looks just like mine at the moment - a load of bits spread out waiting for somewhere to go :) :)

I bet you get yours finished before me!!


08-27-2005, 04:37 PM
Hi Mike,
Well, at this moment...er just before sitting down over here at the computer... I am fitting it for best case location under the sub table of the machine. Prior, all the screw tabs for the box lid were ground off and a latch will be fitted. I don't want the box sticking out, but I want access to it for any reason. After the location is decided upon, then the out and in connector locations will be established. There are two slides here from a trash compactor drawer that was taken apart. I was inititially going to have the box slide out for maintenance, but then the cables would have to be longer for the extension as the box rolled out. I'll post a picture when I have its location on the machine set.


Mike F
08-27-2005, 04:58 PM

:idea: I like the idea of the box being on slides, for easy access, and I think a little extra cabling will be well worth the effort. - Mmmmm, thinks, I can use that idea myself.

I see no extra cooling for the Geckos - are you just relying on the one, large fan to cool the whole of the box? I have opted for individual, CPU coolers on my Geckos and will probably also have a larger, extractor fan mounted at the back of the box. Maybe overkill, I just don't know :confused:


08-27-2005, 06:00 PM
I've got a bunch of fans of various sizes from scrapped devices over the years....just didn't get them all out yet.
One that is 5"X5" (like in computers only bigger), runs at 240VAC with high "wind". I put 120VAC through it and I like the velocity now. It will do I think, with a filter to screen out debris. There will probaly be an internal one (seen in picture) against the heatsinks for the geckos alone....And then a smaller exhaust fan.
The box has a seal around the door so I don't have to worry too much about keeping it pressurized....there will be alot of "watching what happens" after installation. But it would be nice to get it right the first time.
So, with the supply working with 120VAC input, this should hook up nicely.....just WHERE yet I'm still deciding on.


08-27-2005, 07:53 PM
OOooops..another delay...knocked off the bench a three part bin with 10,8,and 6 washers. So now the floor is covered with small flat washers to be sorted. Geeesh and I had a lot of those... :(

09-08-2005, 07:26 AM
Here's a series of pictures of the power supply/drive assembly....

The transformer was origunally 96VDC single secondary. I unwound some loops to make it 73VDC and added a second secondary for 50VDC. The two secondaries have individual rectifiers.

The three caps (one for the 50VDC and two for the 73VDC) are mounted as a module and the whole unit installs into the box. Fuse holders were salvaged from discarded equipment.

The fan is under the cabinet blowing into the fins of the gecko heatsinks.

09-08-2005, 07:34 AM
almost ready to add cabling...

The shield is installed to protect from accidental electrocution while adjusting the gecko tuning pots. I'll need a big "CAUTION" sticker to attach to the shield :)
Material used for the shield was the chassis cover from an old VCR, reshaped to fit.

The drawer glides are from a domestic trash compactor scrapped for parts.
They are very sturdy.

09-08-2005, 08:57 AM
It works!

09-08-2005, 09:37 AM
Do big Caps like laying on the sides?

09-08-2005, 09:41 AM
Gee ...I don't know! Good Question! They didn't fit vertically in the box so I just mounted them for best fit.
AL? input...

09-08-2005, 10:47 AM
No worries, you can place a cap anyway you like.


09-08-2005, 10:58 AM
Nice machine by the way. Looks very professional.

09-08-2005, 11:40 AM

Where did you get the cabinet for your powersupply?


09-08-2005, 11:46 AM
The electrical cabinet came off of Ebay...I can't offhand recall the sellor, but it was a pretty fair price. It has a seal around the lid and had seven screwdown brackets spot-welded around the box for securing the lid (except the hinged side). I ground them off and installed a keyed latch that came off of my old floppy disk case.

09-08-2005, 11:58 AM
I tried doing a history of my Paypal account to find the actual purchase information, but Paypal can't do it at this time...."try again later"..it says.

John (Bloy)

09-08-2005, 01:43 PM

Thanks anyway,


09-11-2005, 11:29 AM
Cable guide chain is sure fun to work with....I think I got carried away!
Half the wiring will go down each side to meet in the lower middle electrical box. This helps keep some of the wires shorter...besides, all the wires won't fit into one chain track.

I got the E-Chain on Ebay for total $44 from Michael Blackburn (CNCZone member Fair451)....Thanks Mike!

Some of the brackets that came with the chain didn't work out, but modifications brought it together.

09-11-2005, 11:46 AM
Sooner or later I'm going to have to tackle machining the ballscrew system for the X axis.

09-17-2005, 03:02 AM
Some more visuals of progress...

Still working on the ballscrew nut mount....

The connectors to the Z and X axis motors are four pin microphone plugs....available here...
Hmmm..The price went up a buck since I got them a year ago...

The pins are relatively hefty, but two pins were doubled up for each motor connection.
The plastic nut/strain reliefs seen on the motors were cut flush and reamed to fit the female microphone jack. The jack was then re-wired inside the motors.

I've been able to get 328 ipm on the gantry rack and pinions with smooth operation. I think I can get more with lower acceleration. The Z bobs up and down nicely with a busy Gcode. ....We'll see how it performs under load....

I was surprized how smooth the rack and pinions were...

For the Yaxis (slaved rack and pinions) motors I plan to make a block to mount on the motor where the wire comes out and place XLR sockets for the motor power, and more four pin microphone jacks for the encoders.

There's still room for home/limit/alignment switch wires in the track, but they for the most part will not be in the track. Only the X and Z limit/home....and the spindle (router at this time) power.

09-17-2005, 10:04 AM
This morning, after over viewing the pictures I see that some of them are redundant.. I'll fix that...
The Ballscrew looks exposed and have a plan for a cover to enclose it and protect from dust/debris. This is what I'm considering as I fabricate the ballscrew nut mount bracket.
Which brings up vacuum.... from above, a larger hose, Y'd(split) with two smaller tubes dropping down through the Z axis "box" on either side of the drive motor and spindle. This might work as I've held in place the smaller tubes. But I may need more volume as opposed to velocity. If that's the case, then it (the vacuum hose) will come in from the rear and float with the gantry.
Also, since I have air, I would also like to incorporate small jets on the gantry that occasionally spray the rack as the gantry glides.
...this whole project is FUN!!

Mike F
09-17-2005, 01:43 PM

Excellent photos. They show good detail of construction.

A question if I may, how did you fix your pulleys to both the motor and ballscrews? It looks like grub screws. I am in the process of working out how to attach mine and doubted that grub screws would take the continual back and forth movement. Jeff of HomeCNC recommends drilling through the pulley hub and shaft and putting a pin all the way through. Any thoughts?


09-17-2005, 01:59 PM
Yes, I agree that the grubs might not do... The Z axis has a keyway... and the motor shafts have a flat that matches the pulley flat with two screws that squeeze the flat. http://www.cnczone.com/gallery/data/500/medium/pulley_on_motor_shaft.JPG
I'm thinking of attempting to do a keyway in the long ballscrew and the pulley. Otherwise, on the Shoptask, I ground a convex? spot on the motor shaft...so the grub always sought the lowest spot and could only tighten further if the shaft shifted. Have had no problems... even after turning down the ballscrew and threading the end at the bearing block...or rather Mach3 did the threading. I'm sure I didn't do everything right as I finished off the last couple thou of the shaft with emery cloth to get rid of the roughness.

That size pulley only came with a 5/16" bore without a keyway, so as impatient as I can sometimes be, I just bored it to 1/2" (actually reamed at .499) and quickly mounted it.
The whole machine is coming apart for painting at some point so by then I'll have figured what route to go.
By the way...I like Jeff's advice to pin the pulley, but that leaves no room for lateral adjustment should the need arise.

I'll do some testing and watch what happens....though I'd kinda like to learn the process of making keyways.

Below...some extra pictures of Ebay Ballscrew used in project.

specs on Ballscrew and nut...
0750-0500 SRT
Lead Accuracy: ±0.004 in./ft.
Double Start
0.750" Ball Circle Diameter
0.500" Lead
0.602" Root Diameter
0.141" Nominal Ball Diameter
1.22" Screw Weight (lbs./ft.)
SBN Double Circuit Ball Nut 78 ball bearings per circuit - 156 total per nut
Dynamic Load (lbs.) 2,723
Static Load (lbs.) 17,425
Torque to Raise 1 lb. (in.-lb.) .088
Nut Weight (lbs.) .8
Ball Nut Number SBN7500

09-18-2005, 08:40 AM
here's the cutoff from the bearing block end of the Ballscrew...
I definitely have to get a cutoff tool that fits the tool post. :)
This end was chucked and the ballscrew was held in the Shopmaster's 3-point steady rest (part of the tailstock). The operations were performed and then the end was hacked off...

09-18-2005, 08:43 AM
This is the progress on the connector block for the slaved Y axis motors

09-19-2005, 09:47 AM
Connector blocks complete and wired...
The two missing screws securing the blocks?...need a trip to the hardware store.

09-21-2005, 11:09 PM
What a lot of fiddlin'...
Now have all three axes functional. Here are pics of the x axis nut mount.
The idea is to enable a full cover protecting the screw & nut with a slot where the mount bracket passes through. I was a bit leery of the thin bracket, but I used that "T" iron found in old garage door opener tracks. Its hard metal and with a good weld, the bracket is pretty solid.

Oh....I cut off two inches on each end of the racks ... this causes the pinions to run off the racks when the outer bearing truck just protrudes past the end of the rail. I was ready to get a big pad to "catch" the gantry if it ran away and sent itself off the end.....since I was having so much fun zipping it back and forth.

09-29-2005, 06:04 PM
The Z axis switches are covered with the outer chassis from an old computer power supply....bent and cut to fit. The switches are those little micros from Radio shack. One is as shown, the other two are with rollers (they had a smideon more reach). the connector block is from a 30mm square rod that came in a mechanism from Ebay.

09-29-2005, 10:05 PM
The repeatability of the Z axis switches is .0001 slowly and .0003 rapidly moving to the home.

Edit this..... after repeating numerous times, suddenly the readout was in the .001.... found a particle resting on the trip bracket....
This design has limitations....definately need a occasional small jet of air to clear these surfaces... and a traveling one to clear the racks....especially if lubricant is used. Using air if available can be VERY beneficial.

09-29-2005, 10:08 PM
Thanks for adding that last pic. I figured the switch was under there. :)
.0001's not too bad.

10-04-2005, 12:31 AM
Here is the trip for the limit/home switches... the shoulder bolts are from an old old copy machine (incandescent light), and the nylon spacers are from the local hardware. they work well, but I plan to make some steel (or brass) wheels as replacement.

Also... a day of inspired painting (mostly in taping and cleanup-what a mess)...later on, the sides, front and back, along with the inner sides of the table area will be paneled with access doors for the lower level-light blue-as the power supply box from previous post. Hopefully these panels with edging will be the first project on the router.

There will be a 2to 3 inch space on the upper level under the table for misc flat piece fixtures etc. storage.

10-08-2005, 07:57 AM
A couple steps further

All the limits are wired in series.
The homing switches are separate
Total five inputs plus ground all come together in the box, the gounds are combined, the series connections established, and a six pin connector sends the wires to the drive box.
With Mach3, input pins 10,11,12,13,and 15 are used. 10 being the shared series limits.

The router motor power wire is run through the e-chain using 18awg 4wire(shielded) with two wires each combined for the AC neutral and hot. A solid state relay (shown) will be used for Mach3 "on/off" control.

As seen, there are two parallel port connections for future needed inputs/ outputs.

If there is anything anyone wants to see specifically, please mention here, or PM, or E-mail and I will grab some pictures and post.

10-08-2005, 04:03 PM
Looking really good... I'm starting to think that you enjoy building these machines and making them look nice more than you enjoy using them though. ;)

10-08-2005, 04:30 PM
Hi Nathan,
Well, I sure used the Shoptask extensively for the construct of this machine. And, Yah! that was fun too!
There's one thing that really bothers me (er at least one) ....and that is rushing a project through and never getting back (or taking apart) to redo a portion or detail that forever remains blatant in my eyes as a sore.

For example:
The Z axis box frame has a side plate of aluminum with markings from the supplier still visible(see post 74 or 62-closeup of Z axis). But to properly resurface the plate just about ALL the Z axis has to be disassembled (again!), and then tediously aligned in reassembly. Fortunately, the Box Z will glide off the rails after removing an end plate of the gantry.
But I will probably do it in time. :)

10-13-2005, 12:52 AM
I needed something 2.5" X 2.5" X roughly 44". I Was thinking of welding metal strips or thin angles to shape...then discovered something at the local hardware.

It's a section of square downspout for rain water control... pretty heavy plastic. It was run through a fine toothed blade on the table saw to make the slot for the ballnut bracket. It needed to be heated after "ripping" to reduce the stress and shape it to a near perfect square.
There may still be a need for a flexible "sweep" to reduce the slot opening....something like those found at the bottom of storm doors.

10-19-2005, 02:16 AM
Some pics of table addition and a quick "stick it down" board using carpet tape with a "write" wizard (by German Bravo) script Included in Mach3. Notice i'm keeping my wife involved.... ;)

Using a regular router two edge carbide "v" bit, the spindle speed was 8,000 and the feedrate was a conservative 80ipm first pass and 120ipm second pass. I sanded the surface of the lettering to give a slightly soft edge. ....Much more testing will be done to find comfortable speeds and feeds for many various materials.

That monitor was a $15 buy at a yard sale. :banana:

10-22-2005, 01:09 PM
I've added a second port and the 110VAC outlet controlled by the SSRs. I found a small 110 socket from salvaged components that I mounted to hold the "walwart" (white object) for the 5VDC to the breakout boards. I'm sure after time I will be utilizing those free pins:)

10-22-2005, 02:13 PM
Sorry John, I have been putting off reading this due to the time required to take it all in! Had time today though, just got through it all from page1 and WOW. Your work is always top notch, and I am always amazed by the time you spend making sure it looks the part to. Good work, you gotta be happy :)

10-22-2005, 02:57 PM
http://www.techsavvy.com/industry/menu/03tm2.html?starturl=industry this is a manufacturer of liner guides and ways and ball screws ... they are out of charlotte north carolina ... STAR LINER SYSTEMS .. check it out

11-25-2005, 01:19 AM
Sorry John, I have been putting off reading this due to the time required to take it all in! Had time today though, just got through it all from page1 and WOW. Your work is always top notch, and I am always amazed by the time you spend making sure it looks the part to. Good work, you gotta be happy :)

Thanks Kong,
Lately its been under a sheet as I take care of other responsibilities. I've been researching a fourth axis for routing spindles and such. I hope to be able to set the device onto the table and get about 2 to 3 feet of travel with it. Also have determined what I will be doing for the spindle vacuum skirt.
Now just to be able to get back at it for some winter production.....(yeah- right) :)

John (Bloy)

03-10-2006, 06:25 PM
Just thought I'd post a pic of one of the pieces I'm making with this router...

03-10-2006, 08:17 PM
looks really nice!

03-11-2006, 06:00 PM
very nice bloy2004, did you have any difficulties with the dual ballscrews? You did a nice job.

03-11-2006, 09:26 PM
Hi Jimbo,
The machine actually has dual rack and pinions for the "Y" axis. The "X" and "Z" axes use the standard single ballscrew. The picture below shows one side of the dual "Y" axis rack.

03-11-2006, 10:47 PM
sorry, thats what I meant. I was curious about any synch issues with the slaved motors, either physical or software.

03-11-2006, 11:35 PM
The dual "slaved" "Y" axes are working just fine. AM running Mach3 at 75Khz and get 318 ipm on the dual "Y" setup.....More on the "X" and "Z".
I have 500 quad(2000) encoders on all motors.

Of course, I can't run that fast cutting with a small .125 two flute finish cut. But the rapids really make the machine shift around on it's soft casters. This was intended as the frame is made such a way that is doesn't flex with all its cross angles to make a rigid table. Actually this is easier on the operation during rapids ....like shock absorbers....the gantry moves one way suddenly, but the frame cushions the move as it recoils a bit oppositely. When it's cutting at full capacity, the whole machine is softly moving about minutely within a small footprint as the bit finds its way to its designated position.

In short, I am quite pleased with the performance.

03-12-2006, 12:07 AM
looks really nice!