Robert Bailey published a new build:

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yep, I got 4 to test with , then replaced all the load bearing wheels with the extreme wheels. I just used the regular wheels on the bottom to lock every thing together. also used the regular wheels for the Z axis.

 

if anyone is wondering about the holes across the bottom of the gantry, the plan is to run a 80mm piece across and tie the gantries together to make it more rigid .

 

Had my cad guy get me a picture out of solidworks so you could see what the end result will look like. our current gantry plates are nothing like the picture but the holes for the wheels are in the same location.
we started out to make a set of plates the could be used with belts or lead screws. I just chose to use the c-beam an not drill all the extra holes. I plan on putting an 80mm across the bottom to make the gantry
stronger just haven't got to that yet. as you can see on the gantry plates we but 5mm holes down the back and across the bottom for good measure, never know what you might need. we will make no plates with
the router when it is running, we are brain storming on doing a Z gantry to get back some lost Y length.

we ran some tests yesterday with a g-code test file ,the alien, with a pen taped to the router. I had to bring the max velocity and feed down to 2000. will most likely have to go slower when cutting. I have the TinyG
hooked up to a 24VDC 10 amp supply I got off ebay. I hooked it up to a lab PS I bowered from work and it show about 1.5 amp draw when drawing the alien.

Fell free to ask questions or point things out, this is the first build and we keep seeing things to change all the time.
Robert

 

Yep I have the motor step rate on 1/8. i think my problem was trying to push this monster faster than the motors could go and one would get out of sync. the problem with screws is the deflection when there isn't any support. I think the 1000mm C-Beam is about as long as you will be able to push without a lot
of deflection especially on the small 8mm screw. would love to do a rack and pinion system, but this is what my learning budget can handle for the moment. going to post a few more pics tomorrow. cutting the cross
members tonight and assembling it tomorrow morning.

 

Got the 40mm and the 80mm attached to the gantry this morning. the 40mm will be used for the cable chain and the 80mm just ties the bottom of the gantry together. I also pimped it out with a little
red in a few slots. I also did another test run, this time with the smiley face. might get it to cut something next week, headed out of town for a couple of days so it will have to wait.
Robert

 

Thanks guys, been busy at work so haven't had a lot of time to work on it. we did get to cut the first test. it is an adapter plate for a speaker for a piece of equipment we build where I work.
now that we are all back from vacations I hope to take the next step and make it out of .032 aluminum. hopefully today.

Here is the CNC in action on one of its test cuts.

 

here is some more pictures, haven't had much time to work on it. Getting ready to drill the main board with 5/16 holes for alignment dowels and 1/4 threaded inserts for hold downs.
added side shields to deflect stuff from getting into the tracks. after putting the lexan on I figured I could have put some angle aluminum to cover the wheels and track. Still testing software to get code
into the tinyG. Don't want to use the chillipepper stuff, want this to be offline to the internet. going to test grblgru tomorrow..

 

forgot to add this, I have bench tested my SSR's and they switch on at less than 1.5 volts so the tinyG can turn on the router and another device, like a vacuum. all I have left is to make a few final connections
and test it out.

 

my coworker has gone for the day but I can get them, they are in solidworks. I had him make me a 1:1 pdf that I printed out to make the plates. did the cuts on my dewalt chopsaw and drilled the holes on
my drill press. as soon as I get my machine fully tested I am going to have it make new plates that are more precise. here is what I had on my pc. I included an end plate that we came up with, but was going to cost
$500 at a local shop to have made.

 

My coworker "Brad" lives 8 hours a day in solidworks did the drawings. we took the OX plates and did some mods. we are working on some new ones which will reverse the top channel an add a couple of inches of 'Y' travel. I'll talked to him Friday and he will post the files. I build it all with the 1000mm beams, if you follow my build then you will not but the bundles. did some more work on it Saturday, put a new work surface on it and drilled 5/16 peg holes and 1/4-20 threaded inserts, wont have any problem holding down projects. the spoil board will be drilled to allow the pins and bolts to go through and lock into the work surface. as soon as I get that drill and verified I will post it also, it is 24"x24" but could be made to fit the entire work surface.

 

I ma using 1000mm beams all around, the gantry is very stiff but this week I notices several thousands wiggle in the x and z axis, we tore it all apart and found
the black wheels wiggle. we made sure the shims were in between the bearings but couldn't get it to go away. most of them the bearings just feel out, so their fit is loose. luckily I had ordered extra
extreme wheels so I had 4 to put on the top and bottom of the Z axis, and that seems to have fixed it. might be something mark need to look into. going up tomorrow to drill out the spoil board, then redo some measurements and start making better
plates and brackets. I will post more drawings as soon as we finish the design. think we are going to flip the X axis to make it easier to work on the X and Z. right now you have to dissemble the Z to replace
the X screw block.

 

finished the spoil board today, lines up great with the main work surface, been working on a tinyg gcode sender. modeled after the grbl panel, but writing in C#. I am learning to program again, but
I have several programmers in the office that guide me when I get stuck. and the working area is about 32x32

 

Please don't use my gantry plates, we found an error that causes problems. somewhere we got solidworks drawings that weren't correct or something. the wheel spacing
is off about 1-1.5 mm, we have redrawn them and are in the process of drilling and will test them out over the next couple of days. I deleted the pdf file, if you have it delete it. I will post new ones as soon as we verify that the new ones work.

 

Haven't gotten as far as I would like, have worked on the user interface mostly, I haven't got any serial stuff written yet. we have had several set backs with the machine. wheels loose, flex in the Z axis.
we redesigned the X gantry and the Z assembly to make it more stable. so far I have broken several end mills all 1/8", including 2 'O' flutes from toolstoday.com , cannot seem to find a happy spot with the
speed and feeds. anything over 1/64 DOC and 10-15 IPM snaps the bits. 1/4 bits run faster and don't seem to clog up. Just added a air system to clear chips, will have a mist system designed next week. I will try to add pictures after the holiday.

As far as the software goes, any suggestions for options and features would help. I already have edit and save of controller settings, Z probe, working on program stops and tool change, automatic change of units based on Gcode file, manual commands. If someone wants the source I will provide it as long as they give their source back to the community. I am not a programmer so it is most likely not the best way to do things.

 

done a lot of work on the machine this month, we are having issues with the rigidity of the Z-axis in the Y direction. we made new X plates and added a 4th wheel on both sides and added 2 sets on the back
to try and make it more ridged, but it still rocks. we have concluded that the open face of the C-beam is flexing along with the wheels/bearings and screws. anything more than one IPS plunge and the Z-axis
cants outward several 1000's of an inch. we are trying to decide on getting rid of the c-beam on the X or to try and flip it around. I also cant seem to mill 6061-t6 worth a crap. Plastic and thin aluminum
seems to do ok, 5-10 IPS and 4-5 on the router speed. made a lot of difference when we added the air blower to it. I just got the mister, just have to make a bracket to attach it. the small aluminum bracket
is a switch mount that my office needed, the one on the left is what we have made singles are $160, $450 for 11 of them. took me and the cad guy 30 minutes to cad/cam it um and mill them, another 30 min and I had
a total of 5 made. I am also trying my hand at making a TinyG Gcode sender, it is posted under the control software, far from finished.

 

I'm getting flex in both directions, we put a digital dial indicator on the X direction of the Z and got it to move a couple 1000's by squeezing the open area of the C-beam, which we think is adding to the issue.
If we do a plunge rate of 1 IPM and a 1/64th DOC it seems to be able to handle it without walking, but an rpm of 15-18k with a loose fixture that end mill grows a pair of legs doing 6061 aluminum.