Chinese Mini Lathe

Just a shot in the dark ,but.

has anyone any experience with the Mossfits on the PCB. The ones that are used are listed as discontinued and no data sheets are available to cross reference .

Thanks for any info,

Bob

Bob

If you say which make and model of lathe and the markings on the MOSFETs I might have a chance at helping you.

Hi Bob,
If you give some more information there is more chance that you will get help. What is the part number of the mosfets (Are you sure that they are mosfets ?) What is the part number of the board or post a picture of the board.

Les.

Bob,

The typical Sieg pcb that is mosfet based uses IRFP450 mosfets.

Ebay is a typical source for new ones...

Edited By John Rudd on 20/09/2013 14:42:10

Hi guys,

sorry for the delay in posting a reply. I couldn't find my camera.

I have posted some photos of the offending board so you can see the parts and numbers.

The board has been tested and the other componants seem to be fine just thes mossfets. I can't find any data sheets so as to cross ref .So in the dark really unless you have any ideas. Its the two mossfets on the left that are causing the problem A69108 .But a alternative for all would be great.

Thanks for your time

Bob

Errr, what makes you think that they're MOSFETs? The ref idents seem to be SCR1 and SCR2, which rather implies that they're SCRs.

Regards,

Andrew

Hi,

They are SCRs, S8020L might be a suitable alternative (Farnell etc)

Regards,

John

As does a google search on "A69108 equivalent".

That looks like a US controller board, the chinese boards shipped in the UK output nearer to a scary 350V DC and look completely different.

The fault may be elsewhere if you are testing SCRs expecting them to be mosfets.

Neil

Hi Bob,
This information on these speed controllers suggest that the power devices are SCR's (As others suspect.) not MOSFETS as you suspect. The info in the link suggests that these devices are S8010L or S8020L both of which are available from Farnell.

Les.

If you google the model number thats on the motor KBLC-240D you will find a lot of information about it, I suspect that the board is from a mini lathe, if so which one? Best regards Pat

Just found on Amadeal's site new boards at £85.00 if all else fails, regards Pat

KB controls are scr based, not MOSFET. On mine when it recently stalled, the fuse blew. Are you sure it isn't just a fuse?

Just to add, the scr's used are 'isolated tab' take this inot account if you need to change them..........

Which in my experience is unusual for them to blow (as long as the fuses are not changed for incorrect values) and I've repaired many of these boards...

Whoops...

Sorry guys .......senior moment me thinks (some daft buggers about aint there)

You were correct they are SCRs ,but still causing problems .All this only happened because the speed sensor was diconected and reconnected ( power off   As soon as it was powered up it blew the fuse and this is where I've ended up. Will check to see the replacements are isolated and see how we go.

Thanks to everyone for their replies , will try and get it right next time

Thanks again,

Bob

Hi Packmule,

Suggest you make a simple SCR tester, if you don't possess one.

Otherwise its all guesswork.

Regards, Bear..

I've just taken delivery of a brand new Warco Super Mini Lathe. This reply is therefore not really related to the above but is by way of a warning. Maybe the Forum Master should move this to another topic or use it to start a new one.

The unit was unpacked this morning and would have been set up except that the "instruction" booklet, if you could call it that, was for the old Warco Mini so the switch layout etc. was nothing like the Super Mini. In any case, the content was so meagre that it would have been difficlut to have used the booklet even on the old design.

I rang Warco asking for an decent instruction book for the Super Mini. The response was "there isn't one". So, I now have a nice new lathe (nice for the price anyway) and a load of ancillaries (gear wheels etc) with no way of knowing what goes where to achieve which, except by trial and error.

In addition, the arbor supplied for the tail stock chuck had a tang which meant that over an inch of the scale on the travel was lost, or the arbor was ejected! Did they have an arbor for the job? No they didn't - I ground off the tang.

I am less than impressed with Warco UK as you may imagine. So please beware of buying their products unless you're sure you know more than the UK supplier appears to.

Finally, has anyone any idea where I can get sensible instructions for this lathe? If not then I'll try writing some as I gain information and post the result. I'm used to a 1927 4 ¹/₂ ^“ Southbend lathe for which I have a complete and comprehensive set of manuals.

ARC

ARC...sorry can't help you myself.

but I suggest starting new thread..perhaps referencing you lathe make/model in the title..

just so it doesn't get overlooked.

Hello ARC. Good morning.

I do not know if it is useful for you, but I suggest you to take a look at the manual from LittleMachineShop you can found by visiting the following **LINK** .
It's apparently intended for the same machine with another badge and another color.

Best regards
Dias Costa

Hi ARC

A manual for a similar model can be found here at Grizzly. I think you will find that quite a few of the UK suppliers, not just Warco, of these small machines tend to offer only very cut down manuals with their machines. It seems to have been a gripe for many years but it would seem to be one of the ways they use to keep costs down but all same it is very frustrating.

Welcome to the forum and I hope you enjoy using your new acquisition.

Martin W

Thanks to those who responded so quickly to my plea for a manual for the Warco Super Mini Lathe. Both the above suggested sources gave very useful info.

This thread, or should I say "sub-thread" has also woken Warco up and they are sending another manual. I will report on whether this is better than their last attempt.

Only one further problem has been spotted and that relates to the collar scale on the tail-stock drive. I ordered an imperial version of the lathe and largely received one with the exception of this collar where the scale is metric.

My former QA managerial resposibilities lead me to believe that Warco are hardly up to aerospace standars in that department!

Thanks again to the responders.

ARC (Bob Clare)