Jgro build... a few questions..

[Noone]

Hi... during the summer armed with a second hand triton saw bench, £20 worth of MDF I embarked on the Jgro build... With leaks in my workshop, and from the water tank I have been spending ages cleaning up tools which have rusted and fixing the holes It has been put on hold for a while.

Anyhow Starting up again but I have a few questions...

Firstly would mild steel tube be fine for the rails? How important is it that is super shiny and friction free?

Secondly, I bought some motors before the new year the same as these http://cgi.ebay.co.uk/4x-NEMA-23-Ste...item27af6fc5f2

I was wondering a) are they suitable and b) what power supply do I require for using 3 motors? i.e current and voltage...

There a few nice switching power supply on ebay going quite cheap so it would be ncie to ry and get my order in soon..

Finally what limit switches if any do I require?


As you can tell I am a complete CNC newbie and doing this build so I can practice the machining first and start making some stuff in the hope of int he near future making a far better quicker and more accurate machine...

Also using M10 leadscrew what sort of accuracy can I expect from this machine??

Thankyou in advance,

[MrWild]

they might work, but I wouldn't expect much. For my Z I'm using a a motor with 3NM (425in.oz.) and X, Y have 2.2NM (285in.oz.) The motors you bought have 1NM (130in.oz,). While not abysmal, you will be stuck with slow rapids, and if you push things too hard while cutting, you'll suffer lost steps. Will they work? Sure, but when you move on, you will not be taking them to the next build.

What power supply is dependant on what drives you use. If you go with the cheap chinese 65~~ multi axis board, you will be stuck with a 24v maximum as the "36v, 2.5A" they quote is a "die at" level. 24v 6A power supply is about it for those drives, but they will work with your motors.

You don't *require* limit switches, and those motors won't cause much if any damage if they over travel. Some set "soft limits" in the software and the router won't go past them when told to. The computer sets the limits in this case. Because I'm using more powerful motors, I'm using micro switches with metal feelers. $10 will get you half a dozen when you need them. You won't need them with your motors. Slow enough for you to hit the E stop which you DO need.

On the rails and tubing, if the tubes are as stiff as gas or water pipe, sure, they will work. However, many of the tubes I've seen aren't as stiff. The gantry isn't light when complete, and thin wall tubing will sway and swoop no matter how shiney and slick it might appear to be.