alien_squirrel's JGRO build

[alien_squirrel]

Well, I've learned quite a bit from reading these forums over the past few months and I've finally started building. The main purpose of this machine is cut out parts for a Joe's 2006, so appearances aren't all that important. So far I've bought the following:

Hobbycnc 4 axis kit /w 305 oz/in steppers
CNC4PC breakout board
Skate bearings
Gas pipe, mdf, angle aluminum, and hardware
computer case
6 pin molex connectors

The hobbycnc kit was very easy to assemble but I haven't tested it yet. I wish the fan output was 12v instead of 24v to make it more easily compatible with computer fans. I'm probably going to assemble the machine with coarse thread pan head screws that I have from another project. These were originally used for mounting large speakers in mdf cabinets and they seem to have significantly greater holding power than the 1/4-20 bolts recommended in the plans.

I haven't decided what leadscrews, anti-backlash nuts, etc. I'm going to use so I am open to suggestions. I am leaning towards the precision 1/2-10 acme threaded rod form mcmaster.com but it is several times more expensive than the ordinary acme threaded rod from enco. Is there any significant advantage to using the more expensive stuff?

Here's what I've done so far.

[txcowdog]

I have the Enco 1/2-10 and I love it. Not only is it very smooth but it is also on sale for half price. A 6' length is only$7 and if your order totals $50 you can get free shipping thru Sept 30th if you enter a promo code during checkout. You will want the free shipping because the shipping tube is 6' long and VERY heavy if you buy several lengths of rod so you know UPS will stick it to you for such a long and heavy package. With all this, I would definitely go with Enco.

[matt888]

I'm pretty much in your exact spot right now. Sorry for hijacking your thread, but I'd like to follow your build since I believe I'm ultimately shooting for the same end product as you.

I've just completed soldering the Hobby CNC kit and tested it with a 12V powers supply. Got 5.05V at the check point... going to throw the chips on today. I'm also going to make a real simple MDF case that I'll probably make more custom once the machine is running well one day.

My plan is to use wood screws, not threaded bolts. Are you planning on making the table longer to cut all of the Joe2000 pieces?

I have a jig saw, circle saw, and small table saw(10"). Any pointers on how I can get perfectly straight cuts for this project? I was thinking about clamping a 2x4 down across the MDF sheets and using it as a guide for the circle saw or jig saw?

Alien_Squirrel, are you going to use the "Cutlist" program to optimize your MDF waste on the sheets?

Matt

[pntbllrsprky]

matt for doing the big pieces, trying using a ruler or a long piece of metal as a guide. a 2x4 may not be straight enough. It could be slightly warped

[matt888]

Originally Posted by pntbllrsprky matt for doing the big pieces, trying using a ruler or a long piece of metal as a guide. a 2x4 may not be straight enough. It could be slightly warped

Gotcha. Thanks!

[alien_squirrel]

Are you planning on making the table longer to cut all of the Joe2000 pieces?

Yes, I was planning to make the table longer.

Alien_Squirrel, are you going to use the "Cutlist" program to optimize your MDF waste on the sheets?

I tried the Cutlist program and it is definitely a nice piece of software. Unfortunately the 2x4 "handy panels" I got from HD are not perfectly square so I can't always fit all the pieces.

I finished cutting the bearing blocks and angle aluminum today. I'll post more pics soon.

[alien_squirrel]

Sorry I haven't posted anything in a while. I had to re-cut some of the bearing support blocks because edges where splitting off where the density changes in the mdf. Originally I had cut them so the angle aluminum fit snugly between the outside edges of the notches. The new ones have the angle aluminum resting on the inside edges. I also had to buy a new set of titanium plated drill bits because the old ones were simply to dull to handle the aluminum.

I bought some 3/4" and 1/2" HDPE from a local plastic supplier to make the adjustment blocks and anti-backlash nuts. I was planning to cut these on the table saw but I don't know if it's okay to use a 40 tooth blade with HDPE or if I should get an 80 tooth blade. Any suggestions?

The first picture is just the dust I vacuumed up.

[voltsandbolts]

Looks like your build is going great. I too built a jgro stile cnc to cut parts for a Joe 2000.
I’ll most likely start on the Joe 2000 after the snow hits the ground here in New England.

Don’t worry about the waste, in fact you want some waste, that way when you get the machine up and running you have something to practice cutting on. The Scraps!

Enjoy your build and have fun,

P.S. I used the ¼-20 rod, and I plan to up grade to the ½-10 Acme. I don’t think the machine it’s self is ridged enough to get any real benefit in use the precision acme on. I’d go with the regular stuff, but that’s just my humble opinion.

[alien_squirrel]

Things have been going kind of slow because the water heater started leaking onto the garage floor(none of the mdf pieces were damaged), but I've almost got the z axis done. I modified the antibacklash nut design a bit to better accomadate the 1/2 inch threaded rod but I still need to tap them.

P.S. I used the ¼-20 rod, and I plan to up grade to the ½-10 Acme. I don’t think the machine it’s self is ridged enough to get any real benefit in use the precision acme on. I’d go with the regular stuff, but that’s just my humble opinion.

Yeah, I'm just going to get the cheap stuff from enco and use the extra money to buy a real acme tap.

[alien_squirrel]

I finally made the router mounts for my Dewalt router (the basic design is the same as the joe's 2006 router mounts), so the z axis is basically done. The y axis (x in the plans) is almost done, just have to drill a few more holes and bolt everything together. All the bearings, lovejoy couplers, etc. have arrived so I should be able to assemble some stuff and see if everything moves smoothly. The paint on the gas pipe kind of bumpy so I will probably try and spin it with the drill and remove the paint. I'm not quite sure what abrasive to use, any suggestions?

[alien_squirrel]

I was able to get the paint cleaned of of the 1/2 inch gas pipes using emmery cloth and a dremel for the particularly stubborn parts. I think they turned out pretty well, but the cheap black and decker drill that I used to turn them has started making a faint grinding sound, kind of like the bearings are wearing out. Hopefully it will last long enough to finish the 1 inch pipe.

[alien_squirrel]

I finally got the the y and z axis assembled. Everything moves smoothly and all the bearings touch the gas pipe. It has been raining quite a bit lately so some parts that fit together fine a couple of weeks ago require a lot of force to assemble.