I couldn't let Joe have all the CNC glory here at LL, so I thought I'd come post some pics of my current project

This thing has been my off again on again project for the last few months and it's finally nearing completion.

The machine will have an overall cutting area of 50"x26". It is constructed almost entirely out of baltic birch plywood with MDF used in a few places. The tensile strength of plywood is much higher than MDF. This is a huge improvement over my first machine which was all MDF. I found out the hard way that MDF just can't give the kind of rigidity I needed. My design has lots of borrowed ideas from Steve(spalm) and Gerry(ger21) from cnczone.com. I've done my best to merge the best parts of both designs while trying to keep my build cost as low as possible.

Another improvement I've made over my first machine is a better use of space. If your gantry walls are 10" wide, and your bearings only fill 9" edge to edge, you're just throwing away stability. Another example of this is in the Z carriage. The walls of the carriage were designed with extra supporting material, as the lead screw nuts on the bottom would extend below the carriage anyway.

Here's a current model of the machine. I've made some significant changes to it based on suggestions from other CNCZone members after I started my build log in October.

Here's the pile of parts I started with. I originally intended to use sintered bushings on the .75" hardened rod, but opted for homemade UHMW PE bearings instead.

Here's the Z carriage. Credit for this portion goes in big part to Steve(spalm). It took him a bit of trial and error work to come up with his, which I modeled mine after.

And the backside of the Z carriage...

Here's a picture of the torsion box that supports the Y-axis rails. I based my torsion boxes off Gerry's (ger21). These are skinned by a 1/4" piece of baltic birch. The end result was extremely light weight and very strong.

Here's the entire gantry assembled. The base box is also a torsion box. The Air Force will no doubt be moving me every so often, so I've been very careful to build this machine so that it could be disassembled and transported with ease. Disassembled, the gantry takes up very little space.

I began gluing the table together earlier today, so pictures of that will be coming shortly

You have done very good work, i also had barrowed some ideas from the member you mentioned and also from you, and added a few of my own, that is what makes the these DIY projects great a collaboration of ideas for everyone to make a better end product.

Can't wait to see your end result. I have cut and recut parts to get it just the way i want mine, its an ongoing proccess.

Joe

Lookin' nice. What oz/in and size (mm) motors you using on that thing?

My current machine has 200 oz/in motors for x and y as well as an old 80 oz/in for z. I'll be moving these over to the new machine temporarily in order to route the PCB driver and break out boards. Then I'll be going with three of the 270 oz/in motors from automationdirect.

I'm not yet sure what I'll do with the old machine. I'm thinking I'll probably save the electric components and see if anyone is interested in the rest. If not, I'll strip the bearings and other hardware and have a nice toasty fire in the backyard

What boards are you going with and rated at what amperage I may take the same route I have the hobbycnc 4 axis board and 3 200oz. motors, I got the 4 axis because i like to have maybe an A Axis or double up on the Y Axis and slave the A Axis to it.

Joe

I'd like to go with PICStep boards, but they're a bit expensive to build, and you have the added hassle of having to program your PIC chips. Right now I'm planning on going with the 3977sed boards. I've got 3 3977 chips burried somewhere here on my desk I recieved as samples.

The only downside is you can only run them at 32V 2.5A. The automationdirect motors are rated for 2.8A, so I'll probably lose a little bit of power. I'm sure I'll eventually build at least one PICStep, maybe three. I can always sell my 3977 boards. But who knows... I may yet change my mind before all is done.

you can not run their motors on the hobby cnc board?

The automationdirect motors are bipolar, the hobbycnc board is unipolar. I'm unable to find nema23 unipolar motors with a torque greater than 200oz/in.

Some updates. I finished the table last week. Now I just need to make the end pieces for it.

I hooked up the 200oz hobbycnc motors from my current machine to the new gantry. It still needs some tweaking, but as is I'm very happy.

Here's a video of it in motion. The Y axis is running at 140ipm and the Z is running 100ipm. Sorry the video is crappy. I need to get a new digital camera.

http://www.comptonsoft.com/P1010005.MOV

Another of the gantry.

And one of the table. The little holes have 1/4-20 T-Nuts in them for holding work pieces to the table.

Very Nice work indeed, What settingsd are you using for the motor in mach3? vel. and accel. this is always eluding me, i need to sit down and watch the tutorials.

Joe

Sorry a bit OT , but just curious, where are you stationed now? I'm at Wright Pat.

Joe, I set accel to 2. I can't remember what all the fields were for, but I believe they are more intuitive than those in mach2.

Tovarishrob, I'm currently a 4th year ROTC cadet. My graduation is going to be slightly delayed, so I haven't yet recieved a job or base assignment. I'm just hoping I have shop space wherever I get sent.

That is some incredible work! I am very envious. I know what you mean about needing space... finally getting a garage in March. If you end up at WP let me know. Good luck finishing up your studies.

Thanks!

I haven't done much research into what base or even what field I'll be putting on my dream sheet. I'll probably put down comm or some sort of engineering classification.

I was at Tyndall 2 summers ago for field training. I think they had some sort of wood shop there for off hours tinkering. Hopefully wherever I go will have something similiar.

Haven't posted in a while. Thought I'd come back and share a pic of the completed router. Oddly enough, this thing is much larger than my JGRO machine, but it is also much lighter. I love working with MDF because of its uniformity, but the birch really worked out here for strength and weight.

Now I just need to paint it, finish the dust vac, and build a work bench.

looks great

what are the specs on your leadscrew and anti - backlash nut?

Thanks. I used 1/2-10 acme leadscrews with abnuts from dumpster on cnczone. The ab nuts are great. Dumpster claims 0 backlash. They fit nice, and the spring keeps the fit tight.

I thought I'd come back and post some updates for my machine.

I've gotten the assembly manual about 40% finished. You can find it here: http://www.comptonsoft.com/cnc/lc50man.pdf

For anyone interested in ordering a kit I installed a copy of oscommerce and set up a small shop here: http://www.comptonsoft.com/cnc/

The only one available for sale at the moment is my prototype kit. I'll just need to fabricate the router mounts for whoever buys it and it'll be ready to ship.

You can view the life of the project on my cnczone build log here: http://www.cnczone.com/forums/showthread.php?t=14331

Let me know if anyone has questions! I can be chatted via google talk username Pilotandy.