Re: [CAD_CAM_EDM_DRO] Re: Big servo motors drive recommendations

>>That was my thoughts Patrick about 12 months ago. I looked at the old
>>analogue servo cards covered in oil and crude and decided to look at digital
>>cards, the cheap hobby ones. I believed all the BS I was told. There are
>>some digital ones that are OK, ELMO do some, but they are £2500 each, Ouch.

Thats my general impression too. They are not quite made for these 'big'
machines.

>>The biggest problem I have found with all the DIY ones is it seems the
>>designers don't understand how the requirements change as the motor gets
>>bigger to keep some viable dynamic range, and if you mantion dynamic range
>>they will say it's OK the PID takes care of it. They all say it will be OK
>>you just have to drop the acceleration and speed a bit. They design their
>>cards so that the error signal gives a fixed ON time to the PWM signal.

>That's the problem of expecting Ferrari performance from a Mini.
>It seems to be becoming a trend these days for companies to expect that.
>I've seen lots of examples over the groups lately from people knocking
>"hobby" products because they demand "commercial" performance for a cut
>down price.
>Short of doing it yourself, or spending commercial money you'll continue
>to be disappointed.
>Steve Blackmore

Well, time is money and money is time. If converting is sucha a pita ill hold on
to this machine a year longer bleeding $$$ for repairs and then buy a new or
fairly new instead of messing for countless hours to convert it into something
slow and sensitive. Rapids in my machine are 12000mm/s, 10000mm/s and
7000mm/s. And I need to be able to cut in 400mm/s.

Loooking at my 20+ years old analouge servo drives they dont look that
complicated. Its a powerboard with few components and a signalboard with
more components, but not that many. Wonder why none of the DIY-guys just
dont copy these. I have all the schematics. Judging from the parts they are soo
overpriced at $1500 for an exchange unit. Prolly not worth the effort if one
could get a few of those £250 Chinese analogue drives. If those could be
turned into a drop-in-replacement to mine...

I'd like to take a look at those, no URL ?