HobbyCNC 3 axis board build and review

[Jay C]

Update:

My cable arrived the moring (WOW to FedEx Ground!) so I set my Vrefs all for .5A, wired one of my surplus/unknown steppers (a little dinky one that someone gave me out of whatever) about the size of two cdrom motors stacked. I installed Mach1 just for the ease of install and jogging but the OCX driver didn't install. So I downlaoded the instructions and Art says that Win2K needs a manual install. I uninstalled the driver, replaced it with the alternate driver Art provides, rebooted, and viola Mach1 can take over my timer

Ok, some simple configs like picking the axis that are used, confirming the parallel port pin configs, and setting my hot keys for the axis, and I was steppin' . I played in the motor tuning screen trying to get more torque but the motor is too weak. SO I connected the Japan Servo 80oz-in I bought from Dave. Now we are talking! The 80 sings though ... and it's an annoying tune to my ears.

Off to the garage to complete my lead screw ... I'm thinking I may have to find a bigger motor than I have for my X (the cross slide) but the Z will be fine with the 80oz-in no doubt.

Dave's board works as advertised, but requires attention to detail when assembling/configuring it. I would recommend it to anyone that has soldered before and has some knowledge of electric circuits (especially for the linear power supply).

That's it for my review, it a shame about the hijacking but what can you do

Jay

[CNCadmin]

Jayc can you add your review here - http://www.cnczone.com/reviews/showp...7/cat/3/page/1 in summary.

[Jay C]

Posted.

[Lewis Riley]

Hi Jay C. Lew Riley here. I have just bought a 4 axis driver from Hobby CNC and am looking forward to putting it together. I was glad to see your words of encouragement. I was wondering though. It says in the instructions that you cannot run less than .5 amps. Your small motor wouldn't draw that, would it. Also , I am planning on buying the 200 oz in, motors. I have a good supply of motors , but nothing that matches. Can you mix and match? Thanks , Lew

[Lewis Riley]

I am going to go a little heavy on the Medium sized machine , small , but over kill. Do you think the 200 oz. in. motors would be enough? I haven't a lot of experience at this but really want to get one going. I have lots of stuff for building a big machine, but not much to build a small one.So I thought I would start with a heavy medium. I see Dave from Hobby CNC is on line too. Thanks Dave , I will be back in touch . Lew

[Jay C]

Originally Posted by Lewis Riley Hi Jay C. Lew Riley here. I have just bought a 4 axis driver from Hobby CNC and am looking forward to putting it together. I was glad to see your words of encouragement. I was wondering though. It says in the instructions that you cannot run less than .5 amps.

The Vref can go below .103V which sets the current limit to .5A This doesn't mean the motor will use the whole .5, it just means it won't see any higher than that.

Your small motor wouldn't draw that, would it. Also , I am planning on buying the 200 oz in, motors. I have a good supply of motors , but nothing that matches. Can you mix and match? Thanks , Lew

Yes, each axis has its own chip and it's own Vref. In fact, I ran two surplus/unknowns on X and Z, and the Japan Servo stepper on Y each with it's own Vref ... I jogged them around a bit independently, then hit the 0,0,0 button in Mach1 and it ran the X,Y back first then the Z. The only thing I didn't like about the "bigger" 80oz-in is that it "sings" ... and it hurts my ears. I don't know if it's be worse with an even bigger one

Jay

[Jay C]

Originally Posted by Lewis Riley I am going to go a little heavy on the Medium sized machine , small , but over kill. Do you think the 200 oz. in. motors would be enough?

Lew, I have to admit that I was impressed with the raw torque of the 80oz-in at "low" speed. When I revved up the speed, it got worse. So my practical knowledge leads me to think that the "bigger" motors allow more torque at higher speeds. In my case, my traverse won't be that far so high IPM wasn't a major factor ... size is. Besides, when you are cutting metal you can't go that fast anywy, and the mechanical advantage of a leadscrew is going to icrease your torque as well. I can't answer directly, becaue I've never tried a 200oz-in.

I haven't a lot of experience at this but really want to get one going. I have lots of stuff for building a big machine, but not much to build a small one.So I thought I would start with a heavy medium. I see Dave from Hobby CNC is on line too. Thanks Dave , I will be back in touch . Lew

I sometimes wonder if he ever sleeps ... I sent him an email at 12AM on a Thursday ... he replied at 4AM the same day

Jay

[Jay C]

Lew, I just read your post on HOBBYCNC yahoo group

I am planning to build a medium sized machine. Apx. 4'6" by 2'. But , I am going on the heavy side. Do you think the 200 in. oz. motors will work for this?

Um, what do you consider small if that's medium? What spindle are you going with? Sounds like 200oz-in is what you'll want just to get good IPM traverses. Is this a design you came up with or a scaled up version of a plan?

Good luck,
Jay