Messages

371

General Mach Discussion / Re: Encoders config

« on: October 06, 2012, 03:05:29 PM »

Is the error the same on all axes? Are the encoders the modular bearing-less type? If so, the accuracy would depend on the installation accuracy. If a modular encoder is not well aligned you could easily get 40 counts error over a one nominal 4000 counts revolution.

Dan

372

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: October 06, 2012, 02:52:53 PM »

I am curious what are you using for current control? Is it an Op Amp?

Also what do you mean by the frequency divider?

Dan

373

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

« on: October 06, 2012, 11:04:52 AM »

Yes, I have an Emco F1 bench top mill and it uses BT30 holders without the flats and the spring force is sufficient to hold the holders not allowing them to slip.

Dan

374

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

« on: October 06, 2012, 07:21:35 AM »

Hi Dave,

The BT holders have two flats at 180 degrees which engage with keys on the spindle. See photos earlier in this thread.  In this one you can see the seats for the keys on the spindle:

http://www.machsupport.com/forum/index.php/topic,22080.msg155852.html#msg155852

And this photos you can see the f;ats on the holder:

http://www.machsupport.com/forum/index.php/topic,22080.msg154764.html#msg154764

Dan

375

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: October 06, 2012, 02:13:55 AM »

Hi,

I think Tweakie has once mentioned this to me. But I still don't understand this, since as we know the current change rate on a coil is described by:

  i(t) = I₀^-(R/L)t

So only depends on the inductance...?

Dan

376

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: October 05, 2012, 02:22:36 PM »

Can you please clarify how the higher voltage helps in increasing the oscillating speed?

Dan

377

Show"N"Tell ( Your Machines) / Re: 1997 DYNA MYTE DM4800 VMC to Mach3 Conversion

« on: September 29, 2012, 01:13:05 AM »

Love watching your work!

Dan

378

Show"N"Tell ( Your Machines) / Re: Chiron FZ12 on its way sometime soon(ish)

« on: September 27, 2012, 04:47:18 AM »

I think you're right. Just wasn't willing to mess with the motors. But looks like it would be much cheaper and eliminate another electronic board in the chain, reducing chances to further troubles.

I too often find international postage prices being irrational. Sellers often work with a single freight company and aren't willing to check other options even when it's obvious that the price they are being quoted is way exaggerated.

However, I googled for commutation encoders and came up with a much cheaper one from US Digital with technical specs same as the Renco:

http://usdigital.com/products/encoders/incremental/rotary/kit/EC35

And it's priced almost half the Renco, at $161.

Dan

379

General Mach Discussion / Re: Allen Bradely drives to Sanyo denki motors ?

« on: September 26, 2012, 04:01:22 PM »

Using a scope to verify the phasing, like Hood suggested is the best way.

Dan

380

Show"N"Tell ( Your Machines) / Re: Chiron FZ12 on its way sometime soon(ish)

« on: September 26, 2012, 03:49:33 PM »

Hood,

On the previous subject of the resolvers on the motors, what is your opinion on using one of these:

http://www.vegacnc.com/html/vega2795502.htm

It's not cheap, but cheaper than replacing the motors I reckon. There are other vendors too offering such converters cheaper, but some have lower line count or miss the hall signals. This one has 8192 ppr, but from what you've shown, I am afraid that even this may not be sufficient to get good performance.

Dan