Re: [CAD_CAM_EDM_DRO] 20 questions - long

I wouldn't use the all-thread. It is very inefficient at transferring
power to the moving axis. I know you wouldn't think so, but it is.
Between all-thread (cheap) and ball screws (expensive) is Acme threaded
rod. That's what I would use. You can get low backlash nuts for it too,
if I'm not mistaken, or make your own. it also comes in a variety of
thread pitches, and even multi-lead.

As for the linear components, you might look into roundways and linear
recirculating ball bearings. They're pricey, but you can't beat the
convenience. (Wish I'd held out for those myself.) Thompson makes good
parts that last a long time.

For structural components, someone posted this link earlier today
http://www.tslots.com/ looks like interesting stuff. They also make
linear components, but I'm not sure they would be suitable for
machining applications.

Gecko makes really good motor driver electronics.
http://www.geckodrive.com They also have good support here on this
list, and elsewhere. Check their support section for lots of info on
steppers, power supplies, etc.

The controller you provided the link to below is a unipolar driver.
You'll get /much/ better performance with a bipolar chopper drive. I
used a unipolar drive on my machine to mill the circuit boards for a
bipolar chopper drive. The performance increase is phenomenal. I'm
using my own L297/L298 driver design, but there are a lot of designs on
the web.

Regards,
JJ

On Thursday, Oct 9, 2003, at 18:37 US/Eastern, morgantechnical wrote:

> I am planning on building 2 xyz tables this winter. One will be a
> small one (12x18)for drilling circuit boards and routing 1/4 inch
> acrylic/plastic auto tags (can you believe they asked me almost
> 11,000 for a commercial one that was basic). For the smaller table,
> where the z axis is not critical, will a piece of all thread do the
> job ok? I plan on using this controller at the link below.
>
> http://www.electronics-lab.com/projects/pc/008/
>
> does anyone see a problem with this board or is there a better route?
>
> what stepper motors would you recommended for the small one(in/oz)
> (brand)?
>
> what router motor would be good?
>
> I can handle the power supply end (finally something i can do)
>
> On the large unit, i would like to make it 48x96 workable area
> and put a router in it to mainly work up to 2 inch wood. Could all-
> thread be used on the z axis here as the weight of the router would
> seem to me to control the backlash ? Anyone have good working
> combination similar to this please let me know.
>
> Oh yes, and software. Can anyone steer me as to what they would
> recommend on this type of configuration?
>
> In case someone is wondering, i would like to stay in a 2k budget on
> all of this. From some of the sites i have seen on the web i may be
> better buying some item pre-made. Suggestions?
>
> Sorry my ? button is stuck. but all i have managed to do is throw
> away a bunch of big boat anchor printers with good steppers in them.
>
>
> I have browsed the web and seemed to come full circle and i am not
> much better on hardware
>
> I have experience in electronics/computers, a smithy 3 in 1 lathe
> (yes, i would like to convert this to cnc later) and a roland vinyl
> cutter that i think runs something like hpgl or some proprietary
> language with an interpreter on the board.
>
> I just have hardly any experience in this area. THe last thing i ran
> was an IBM 7535 and 7545 radial arm :)
>
>
>
>
>
>
>
>
>
>
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