Messages

441

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: July 26, 2012, 01:02:58 PM »

Hey Steve. Interesting new project to follow. Always nice to see your work and the way you present it.

Dan

P.S.
If you could resize a bit your photos it would make it easier to watch them as they are too wide to fit on the screen.

442

Show"N"Tell ( Your Machines) / Re: 9x20 Chinese Lathe Conversion

« on: July 23, 2012, 04:27:39 AM »

That's an interesting controller. I was not aware of it. Will be interesting to see how it works for you. Found the introductory thread for this controller and your last question is back from May and was not addressed, which makes me wonder if they still work on it and all issues have been sorted.

Dan

443

Show"N"Tell ( Your Machines) / Re: 9x20 Chinese Lathe Conversion

« on: July 22, 2012, 01:02:39 PM »

We'll have to keep waiting for Greg to fix this then

Dan

444

Show"N"Tell ( Your Machines) / Re: 9x20 Chinese Lathe Conversion

« on: July 22, 2012, 03:45:31 AM »

Hood,

Thanks for the doc. The Ultra 5000 has a somewhat different tuning screen, but I think I can try implementing some of the recommendations, like the scope setup. Wonder if they could provide a similar doc for the 5000 if I asked.

I emailed you the plugin. Please let know how it works for you.

Dan

445

Show"N"Tell ( Your Machines) / Re: 9x20 Chinese Lathe Conversion

« on: July 21, 2012, 03:02:42 PM »

Hi Hood,

I was not able to tune the spindle Just looks like the Ultra 5000 has the wrong parameters for tuning a servo. Can't get it hold position and be stiff at the same time. Either can get it position tuned or be stiff. Put in an AMT programmable encoder instead of the original 1000 ppr one the other day. Set it to 2048 ppr and tried to tune it. Had only less than an hour to play with it, but it didn't feel any better. In fact may be even worse, but I am not sure. The belt, although pretty tight, starts behaving as a musical instrument string when I try to increase the position gain. And in the same time I get overshoot on position. The point when I am happy with the position gain and there is no overshoot, the spindle loses stiffness completely.

Regarding the plugin, yes, Greg sent me a version with quadrature signal for the spindle, but he said he didn't think it would solve the problem we were experiencing, but it would be nice if it did in some way. If you like to play with I can send it to you. It works very well here, and in spite of what Greg said I haven't been able yet to get any symptoms of the problem we were seeing with the spindle. SRO seems to be working fine as well as CSS. But I only had a few minutes to play with it.

Dan

Dan

446

General Mach Discussion / Re: Minor Threading Problem

« on: July 15, 2012, 02:47:28 PM »

Hi John,

The number you arrived at seems to be right based on the mathematical formula for a 60°: DOC = 0.5 x Pitch x tan60° ≈ 0.866 x Pitch ≈ 1.3

Dan

447

General Mach Discussion / Re: Minor Threading Problem

« on: July 15, 2012, 12:47:53 PM »

Hood, I think it would depend on the tool tip radius. John's probably sharper (smaller radius) than yours.

Dan

448

Show"N"Tell ( Your Machines) / Re: 9x20 Chinese Lathe Conversion

« on: July 13, 2012, 01:48:50 PM »

Thank you for sharing, Joe.

Dan

449

Show"N"Tell ( Your Machines) / Re: 9x20 Chinese Lathe Conversion

« on: July 13, 2012, 03:41:25 AM »

Just watched your videos. You have one huge workshop there... and it looks so clean in the same time... I liked it. The lathe looks good too. In my opinion, with the Chinese stepper drivers, the motors or louder as compared to Gecko. And speaking of this, I would love to try out Granite Devices drives with stepper motors. They claim that they drive the stepper with a sine wave and I think it would make the motor run quieter and smoother. However, their drives are a bit expensive.

Dan

450

Show"N"Tell ( Your Machines) / Re: O3N250

« on: July 10, 2012, 03:18:16 AM »

You did a good work with screen set, Peter. I like the look.

Dan