FINALLY!...Build start

[Ursine]

Life keeps getting in the way of my CNC build. As you can see, I've started the torsion box. I went with 1/2" cabinet grade (birtch) ply instead of MDF. For the last week it rained everyday and both the temp and humidity level have hovered near 90. Not the best environment for MDF. We're also in our hurricane season (Florida), so we can count on more storms thru the summer.

I also made a miter sled to make my cuts square. Works like a charm. I'll get the 3/4 sheets in the next couple of days and start on that.
Feels good to finally get the ball rolling on this.

Dave

[CJL5585]

FINALLY!...Build start

Glad to see you have started on your project. Building a CNC is a lot of work, but it is worth it in the end.

Keep posting.
Jerry

[ignatz]

Nice start! What type of finish are you planning on using?

[Ursine]

As for the finish, I'm not a woodworker, so I'm not sure. I't's nice looking ply so maybe a Varathane stain to seal it.

Dave

[Ursine]

I picked up some 3/4 birch ply and cut the end supports. Spend the extra money and get a forstner bit for the pipe holes if you can. Using a hole saw with my gutless drill press was no picnic.
As for finishing, I'm thinking along the lines of a polyurathane.
I've got a question...how do you attach the supports ends to the torsion box. Right now they're just sitting in place, posing for the picture.

Dave

[ignatz]

Hi Dave, I had the same questions as far as connecting the pieces goes.

I layed out the center and locations for four bolts on the support bed (both sides). I marked the center of the support rails. I lined up the support rails center marks with the support bed's center marks and clamped the rails to the bed. I transfered the marks for the bolts from the bed to the rails and then drilled the holes (8 total) big enough for a 2.5" 1/4"-20 bolt to pass through. I was able to put the bolts in by sliding the clamped assembly off of the edge of my work table and reaching under the support bed to tighten a 1/4 washer and nut.

Check this link for Larry's complete answer including a method for connecting the table to the support rails.

I hope this helps.

[Ursine]

Worked all day on getting the Y axis done. Although it still needs a few things, I'm cautiously optimistic at it's outcome. With the end pieces only clamped in place, I set the gantry on the pipes. Somehow the gantry was 1/4 inch too thin so I had to shim the bearing blocks. With that done, It moved smoothly from one end to the other. The bearing bolts have yet to be adjusted, but it looks like it might work.
Can't wait til next week when the AC guy comes to drop a vent in the garage.

[Ursine]

Well, I found out why my gantry measurements were off. While my birch ply was labeled as 3/4 inch it's really about .690. I revised all my measurements when building the x-axis and everything went together nicely. I just placed an order for some anti-backlash nuts. I've got a 4 day weekend coming up, and hope to get everything except electronics done during that time.

Dave

[Ursine]

Today I put the 1/2 -10 acme lead in place. I'm using dumpsterCNC's anti-backlash nuts. The thrust bearing adjustment was something I saw on this site. Good thing I did because I need a few 16's worth of adjustment already. I spun it with a drill and it moves nice and smooth.

Dave

[joecnc2006]

Glad to see someone was able to use my idea on making those adjustable.

http://www.cnczone.com/forums/showpo...4&postcount=53

I use a different type now on my second machine since i do not need any adjustability, it is sandwich'd between two HDPE pieces...

http://www.cnczone.com/forums/showpo...1&postcount=48

Joe

[Ursine]

Almost there! I just ordered the 3 axis kit from HobbyCNC. Also put in an order for the recommended 30VAC PS. I'm waiting until I get the steppers installed before I finalize placement of the anti-backlash nuts and glue/screw everything together. Due to the fact I'm using birch ply with a slight warp in it, I'm taking no chances.
One of my students is a machinist and I've been talking to him about a possible 2nd machine in aluminum (after the 1st one is built and proven of course). I'll see about a local shop turning the ends of my 1/2 leads down to 1/4.

Dave

[Ursine]

All thats left is steppers and leadscrews. I had a machinist turn down the end of my 1/2-10 screws to 1/4 inch. I'll start building the HobbyCNC board tomorrow. I got an old P3 800 that should work for running Mach2. Hopefully I'll be making dust by Sunday.

Dave