Mill refusing to power up

Just reporting back on the outcome of this.

Apparently, and this is a known issue, the board in this machine is the KB Speed Controller which seems to be in use in a bewildering array of these Chinese Origin machines. There is a good reason replacements are freely available.

Anyhow, Chester repaired it within the week and even though the machine was technically out of warranty and no longer their problem they asked only for a very, very modest "contribution". I think I paid for the biscuits in the canteen today. Can't fault them really, it was right after an annual shutdown and they really didn't have to do the work for (almost) free and after another very frustrating day with an EX-supplier I am pleased I bought this particular brand of machine and I will be buying more of their kit in future.

Just as well really as my workshop is full of Chester Kit

graham.

Nice to hear a happy ending.......glad you got sorted.

strange that it was working one minute and then not working....

i have mill from Chester with the same board and never missed a beat.....(having said that am I'm tempting providence?) good job I have spare boards.....

Edited By John Rudd on 13/01/2014 19:18:59

It was John, the only explanation I have is that when I switched the motor on that little bit of surge was enough for some component to call it a day.

You have spare boards.. veeery interresting Doktor

I was really surprised to find the number of machines these are installed to. And then to discover "Oh yes, they do that". So matter of fact! But you know, Chester have worked hard to address the needs of the "less spendy" customer and I really believe they are getting there. Their Open Days are a step in the right direction and there is no doubt whatsoever I will be at their next one. I bought a machine vice at a terrific discount last one and I am eyeing up one of their more industrial sized polishing machines for a specific job.

graham.

I read somewhere you were advised to turn these variable speed Chinese machines down to zero revs when switching off

This might be useful sometime.

MichaelG.

Michael,

I contacted KB directly and got an official copy of the KB series circuit diagrams....

Was a long time ago and I think they don't supply anymore...

Also have a copy of the install/setup manual

These docs have really been useful in my repair work for these boards....

Incidently, the Sieg X3 mill uses a very similar circuit for its speed control.....

Michael,

I contacted KB directly and got an official copy of the KB series circuit diagrams....

Was a long time ago and I think they don't supply anymore...

Also have a copy of the install/setup manual

These docs have really been useful in my repair work for these boards....

Incidently, the Sieg X3 mill uses a very similar circuit for its speed control.....

Just worth pointing out that my understanding is that the KB boards are marketed as 'made in the USA' ,. although many importers fit them to Chinese machines.

I have had two failures of Chinese speed controllers, neither being the fault of the board itself. One was shorted out by a loose controller box screw and replaced under warranty, the other was shorted out by along thread of swarf that reached all the way into the controller box.

Neil

Good thing you weren't hanging on to the other end by the sound of it!

There are orig KB boards as fitted to some machines and then there the Chinese clones.......

the clones come I two flavours...the early ones used thru hole components while the later versions use smd technology.....in both cases the circuit is exactly the same.......