cheap leadscrews :s

[Zoriander]

Hi all,
I am a total newbie, but I want to make a jgro cnc by myself.
I think I am going to buy 3* 640 oz/inch stepper motors from www.homeshopcnc.com.

For the leadscrews I wonder if these ones are ok, because they are really cheap http://gonebowlin.com/dumpsterCNC/ can somebody give me some advise?

And also for the driver boards, I still don't know which I should buy, The geckos of www.homeshopcnc.com are a little bit expensive...

My budget is sort of small, I want to spend less then 1500 euros. But I want a cnc from 1.5*1*0.3 metres workspace. And if possible I want to be able to cut metal with it.

I hope somebody can help me

tnx a lot

Toon

[buscht]

Toon, those are not ball screws. They are ACME screws and I think that they are just selling the nuts, not the screw itself.

With that large of a stepper motor, 640 oz-in, I don't know of any cheaper driver solution. If you use the 270 oz-in motors, you have lots more options for lower cost drivers.

[phantomcow2]

First of all, those are not ballscrews, just antibacklash nuts for ACME leadscrews. But thankyou for that link, i've been trying to get back to that website but have not been able to remember the URL or name!
Ballscrews for a person on a budget is tough, i would go for some ACME screws from McMaster Carr or some place of the like.
640oz/in seems like a lot for a router. Even my milling machine is using 127oz motors, and that cuts metal almost always. I think the intelitek at school uses even smaller motors and uses cuts metal fine. THis will greatly reduce your cost.
And like the above poster said, going with smaller motors leads to other low cost solutions for a driver board. Gecko's are expensive, no doubt about it.
But I got my driver board from HobbyCNC, i had a difficult time getting to go but thats probably because of my crappy soldering skills *and it was the first time i had done it*.
The board seems pretty good, it supports microstepping and the owner can troubleshoot like none other!

[Zoriander]

tnx for the replies, Ithink I will go for the 270 oz/inch model.
But will it be able to cut over such a distance, or doesn't that mather?

Can you give me a good link for suitable driver boards?

tnx a lot
Toon

[buscht]

Here's what I use. http://www.xylotex.com/
He used to sell the cable between the motor and the driver, but I don't see it anymore.

Here's a great source for stepper motors and cables.
http://web2.automationdirect.com/adc...ors_-z-_Cables

[phantomcow2]

Http://www.hobbycnc.com
You can get the 3 axis board for 80. Keep in mind you need unipolar motors with this board!

[Zoriander]

is it a big deal if it is unipolar or bipolar?
Because I don't think that's a real big problem

but can you also tell me that my workspace is to large for 274 oz/ inch stepper motors?

tnx
Toon

[phantomcow2]

Unipolar or bipolar is a big deal, that dictates which type of driver board you want.
So the HObbyCNC board will work only with unipolar. If your a bipolar fan i believe Xylotex makes their boards for bipolar.
I dont think that workspace dictates how much torque you need, but more what you want to do and heft of the machine, like how much load there is to move. Obviously if your machine is 100% cast iron you want beefier motor. BUt for a router which is probably MDF and aluminum, 274 is more than enough i think

[exester]

Hello Toon,
Try www.damencnc.nl for cheap steppermotors and electronics and always helpfull with any problem you might have.

Arjan

[Zoriander]

tnx for the link arjan,
He lives at about 100 km from my home

Toon

[lucas]

There's also this one in Holland:
www.stappenmotor.nl
Quality and prices look better.

[ger21]

Originally Posted by phantomcow2 BUt for a router which is probably MDF and aluminum, 274 is more than enough i think

It depends how fast you want to cut too. using leadscrews, 270oz-in is going to give you a maximum speed of around 100-125ipm, on a smaller size machine (24x36). And you'd most likely need Gecko's to get that kind of speed (48V or higher). You may be able to get more speed with the same size motors by going to rack and pinion drive. But if you want to cut at 200 or more ipm, you'll need bigger motors (with high lead screws).