Optimum Mill electrical problem

My Optimum BF16 vario went besirk.

The miller was running at mid speed on poti i redused the speed and bang the fuse blew, i replaced the 10A fuse and switch the machine back on, this time the machine only runs at to speed now and does not react to the poti.

Anyone have any idea what may be wrong, or better still how i can cure this problem.

Regards

Ray

Had the same thing on my lathe though the fuse did not go the pot only gave off or full speed and that was what had gone, £5 for a new pot and its been as good as gold since

Hello Jason

The pot was the first thing i checked it still read 4K7 - 0 but this picture made me think,

Ray

.

Now, that does not look a happy little trim-pot.

MichaelG.

Hello Michael

Now that was my thought exactly, but why

Ray

From the foto, it looks like the speed control board is similar to the American KB units.....

I'd be checking the thyristors to see if one or both are shorted, that would cause the full speed symptom....

why the the little trim is burnt? Hmmm strange but possible....if it's the min or max speed adjustment then they are both in series with the normal speed pot, stepped across a fixed supply rail.....if the voltage is higher(much higher than normal) then the current flowing maybe the cause of the burn up.....this is all supposition of course.....and I could be completely wrong......

A better foto of the board would help.....

How are your electronic repair skills?

Thank you John

my electronic repair skills are very limited. here is another pic.

Ok,

The board is very much like I thought.....

Firstly, is the machine under warranty?

Secondly, if not, then you need to have the motor tested/inspected.....I suspect the motor may have damaged the controller....

Once the motor is deemed ok, then decide on a course of action to repair/replace the controller......

Over to you.....

OK John

The trimmer and fuse blew as i turned the pot to reduce speed, after replaceing the fuse 10A the motor ran but only at top speed, i couldn't controll it with the pot any more, i thought the motor would be OK.

No warranty but where can i get such a controller, i'v searched ebay but no luck, i thought of the makers Optimum but could not find any spare parts.

Ray

Ray,

Maybe an email to them...?

Here In the UK, Amadeal sell a similar machine, maybe worth an email......?

I'm not sure but I think EXCEL at Coventry re-badge Optimum mills as their own brand.

Worth a look. ??

http://www.excelmachinetools.co.uk/manual-mills/4/light-duty-drill-mill/148/index.html

Edited By Dave Daniels on 31/05/2015 19:19:53

John

Email sent to Optimum in Germany.

Dave

Tthanks for the link but EXEL start at the next size up BF20 Vario

Thank you both

Ray