Joe2006 Build

[joecnc2006]

Originally Posted by pminmo yes If your gantry is 10" wide, put one one each side so you don't limit your travel.

Yes i would say it should work, I did think about doing the same thing, but mine runs at 80ipm with very little whipping, also your leadscrew could have a slight bow in it which will contribute to whipping, I had to replace mine once because of this. Just make the larger portion of the antibacklash nut and place a nut into it will not allow the nut to spin and move distance wise in relation to the distance from the anti-backlash nut.

Here is the DWG file for the anti backlash nut incase you need it, to make a part, try it with 3/4" MDF, the nut stepdown is 0.4" and see how it works..

rename the .txt file to .tap



Joe

[dighsx]

Well I promised some pictures so here we go. First is the gantry put together? Then there's a shot of the adjustment box on the gantry. I had to machine the parts for the box, but it wasn't a big deal. Pic 3 is the torsion box before after painting. Pic 4 is a cool shot of me cutting the rails for the X-axis. Looks like I know what I'm doing don't it? Pic 5 is the machine put together before I installed the motors and lead screws.

More pics to come in the next post.

Joe, where did you buy your lead screws? I got my from Enco and they seemed pretty good but I must have some bend in the one cuz I get the whip at the end.

[dighsx]

Ok this next set shows the making of my cutting bed. I got two chunks of 3/4 inch MDF and glued them up. Then grooved it for the T-Track. To attach the T-Track I bored 1/2 inch holes on the bottom so I could attach nuts to the screws.

And the last pic is a shot of the whole thing together.

I ordered bigger motors over the weekend (762 oz NEMA 34's). Today I'm going to machine the extra anti-backlash nuts and try and get them installed.

[sdantonio]

Hi Jay,

I'm a bit confused about your ppower supply (but then there are people out here who will tell you I am easily and possibly permanently confused anyway). You have the sysmotech, which I assume is supplying 5VDC and 55VDC. So what is the need for what looks like a big torroidal tranny and the capacitor in the corner. Or is the sysmotech just supplying the 5VDDC and the 55 comes from the torroidal tranny?

It's a nicely set up box.

When you get to the point in the thread, please spend a little extra time when you describe your limit and e-stop switches with plenty of pictures.

Thanks

[sdantonio]

here is a stupid question regarding whip.

Are you pre-loading your lead screw? This will often cut the whipping down a bit.

[pminmo]

Wow, nice job!!!

[dighsx]

Steven, The torroidal outputs 39Vac at 20amps it then goes into the big capacitor and from there to a bridge rectifier which turns it into 55Vdc at 15amps. I get my 5Vdc from an old power supply I had laying around which is behind the jacks.

I preloaded my lead screws (or at least I think I did) how much should you preload them. I.E. how tight is too tight?

I'm starting to look around for switches to use as limit switches but I'm not totally sure what I should use. I'm open for suggestions. And when I install them I'll post pictures.

Phil, Thanks.

[Jason Marsha]

Great pics Jay. Those 762 motors should allow you to blaze through any material.

Jason

[joecnc2006]

Wow, it is looking really good, I like the top you put on it with slotted channels, you have pleanty of room in the Z Axis for it, and it also will allow you to do any shimming if needed at all to plane the surface.

Looking forward to the larger motors..

[sdantonio]

hi Jay,

Hubbard CNC has some switches made by "Micro Switch". a set of 3 switches is $1.99 (enough for 1 axis - 2 limits and a home). I picked up enough to do 6 axis for $14 including shipping

It was suggested to me to preload with 2, 1/2 inch beleville washers facing opposite directions to supply the tension. Cranking down on the nut squishes the belevilles and loads the screw.

Attached is how I was told to do it. The spacer can simply be a stack of flat washers or you can get fancy and cut one custom. Doing it this way would mean cutting 2 lead screw bearing HDPE blocks and mounting them back to back (the spacers take up the space inbetween for the motor end (upper diagram), only one required on the distal end (lower diagram).

This was any longitudinal forces on the screw are localized inside the machine where they belong. The only force the motor sees in the torque to turn the screw, so it is isolated from the other forces.

[sdantonio]

OK, now that I look closer the sysmotech is just a plackard. I was thinking it was the actual PS. But it is cool.

[sdantonio]

wow, I'm forgetting lots of stuff here. Hubbard CNC is a ebay seller