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aslatte2
03-23-2010, 02:03 PM
Hello. I want to make a multi-purpose 4 axis foam cutter. This cutter will cut R/C airplane wings and skimboard foam core (a small surf board). I want use a Gecko 540 driver. As for steppers I want to use, NEMA 23 Vexta PK266-02A Bipolar 160 oz-in. Does this sound legit?

I also wanted to know if a Lead screw will work with a 65"x35" XxY setup with out shaking?

And would it be stupid of me to use "HI-LEAD 1/2- .250 in./rev 2 start" instaed of "ACME 1/2 - 10 1 start"?

or ACME 3/4-5 instead of ACME 3/4-10?

Thanks,

Alex

aslatte2
03-24-2010, 01:08 AM
.

aslatte2
03-24-2010, 11:25 PM
come on anyone have any input? Please! :wave:

szastoupil
03-30-2010, 05:28 PM
Alex,

This isn't as big as you are looking for, but here is some motivation that comes close to the hardware you described. I just finished it last weekend and learning how to use it. I am extremely happy on how tight the system is using drawer slides. Going through the effort to put the X-axis slides vertical should reduce a lot of slope that would otherwise show up in the cut.

I'm using the same Vexta motors you mentioned, G540, 3/8" ACME lead screws 12TPI, and delrin nuts from ebay. I used 24" slides on X and 14" on Y. Most of my use will be 10" and 2" respectively. Around center of the slides is where they are the most slope free (if any).

I'm still trying to figure everything else out and starting the "packing peanut" stage. (Where the outcomes of all my cuts are being donated to the shredder at my local UPS Store). :)

Scott

szastoupil
03-30-2010, 05:36 PM
I forgot to add my observations on the ACME screws is that they have a little wiggle in them. But it appears all the wiggle is from using crude hose and clamps as motor couplers. The far end is supported by 3/8" ID pressfit bearings from the local ACE hardware. The ACME screws where ~$8ea from ENCO. I prepped them by removing a handful of burs by lightly touching up with a file, light sanding, cleaned with alcohol, and waxed with a cotton string and Johnson's Paste Wax. I only need to run my cutter at 5-8in/min for cutting, and 15-20in/min for moving.

THend
04-06-2010, 12:57 PM
I would ask the rod question over in the mechanical design area..

There are so many considerations..

65 inch run is pretty long, so a good stout and straight rod will be important, and I would take 2 start over single start if I were to do it all over again.

I really recommend reading through the Mach3 manual and gleaning from it what you can.

The thread pitch, number of starts, steps per rev, full/half/quarter/eighth step mode, what speed to you really need..... it all adds up to performance.

After having a foam cutter for 8 years, and designing a new one, I will say this...

You want to be able to hit the "Go" button and not feel like you HAVE to watch the machine every second...

Good luck.