[pilot001]

Hi !

We had a periodic problem with VMC 4020Ht.

One of the AMPs (AMP-0021 glentek) sometimes just stopped (stopped the whole cnc aswell).
We had not had any idea what is wrong. I had enough of that. I began to look for a replacement. Some clicks later, i realised that the available replacements are not cheap. Prices ranging from 495 to 1500 USD. And the cheapest is in the States. (postal fee and costums would increase the price)
Thats not good... specially for us (we aint got a big enterprise).

But wait a sec ! This is only a DC servo brushed and with tachograph loopback to the AMPlifier. Hmm there has to be at least one alternative sollution !

So i started to look around (ebay), and asked around on the Hungarian Hobby CNC forum . One guy told me that with this parameters (DC bus 150V and tach + analoge input + 20A - 40A peak) he can sell me an AMP.

I looked up the device on the net : MAXI MAESTRO 200X 25/50

It can be used from 3ph 220V or DC bus ,
25A cont. and 50A peak. + built in FAN
Thats some amp !
Quickly i searched the web to find one (and check the price).
Guy told me that i could get it from him for only 15000 HUF (around 60USD).
Holy S**iT ! Thats pocket money compeared to the cheapest 495USD AMP.

2 days later i have put it in.

Took some reading and head scraching, but finally it works as good as glentek or AMC's AMP.

Some effords were made to fit this amp into place but it looks good...a tight fit !
The connctors are not compatible so i had to make a "converter" piece to do the job.

[pilot001]

Hi all !

Of course, this sollution applies for all other CNCs with this kind of a system (DC BRUHSED servo + tacho + analoge signals) so other fadals (NON AC servos) can be fitted with the same type of AMP. (but i guess u already know this)

Bye !

[Al_The_Man]

Also there are Aerotech, A-M-C and Copley Controls that could be used in a pinch, and the BLDC versions can be used with DC brushed just as well, this is nice if deciding to go with BLDC motors later, the amp is in place already.
Al.