Alpha Underpinner

[DCS]

I have an Alpha foot operated underpinner that is doing my top in.
Every time I try to join a frame it seperates the mitre rather than joining it together? I amat a loss as to the problem.
I pull the back stop up tight, the front bit is in tight and the clamp is as tight as I can get it but still the same problem.

Any tips appreciated

Thanks

[prospero]

Never used this machine, but 99 times out of 100 this problem is caused by insufficient pressure on the top of the join. This results in the two halfs lifting and separating before the wedge gets a chance to bite. Especially important with harder woods.


The other 1% is having the wedges loaded blunt side up.

[The Jolly Good Framer #1]

I dont have an Alpha but I do have the same problem with hard wood moulding if there's a build up of glue on the hammer (the bit that pushes the wedge up)

[DCS]

Thanks for the info, now I think about it the moulding clamp is a pig to tighten onto the moulding, I'llhave a play tomorrow.

[Steve Goodall]

Failing that - call Flavio at Alpha - their technical guru!!! I spent a week in India with him earlier this month & he is "the man"!!!

Also his English is much better than my Italian!!!

[DCS]

The problem was the moulding clamp which I have now replaced with a new one from Lion.
The old shaft on the clamp was pitted to hell and wasn't travelling as far down as I thought.

Thanks for input everyone.