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underpinner identification help, please
Posted: Wed 20 Dec, 2023 8:17 pm
by NKP1962
Just aquired this underpinner, and was wondering if any of you good people would be able to identify it, thanks, as i need a manual and parts list for it to overhaul it!.
Re: underpinner identification help, please
Posted: Wed 20 Dec, 2023 8:50 pm
by Not your average framer
The foot pedal is the clue here. If I am not mistaken, that is a Thorpe international underpinner. They were sold through Origin Framing Supplies who were based in Croyden. It's a very long time ago, but I remember seeing one being demostrated at the Spring Fair during the 1990's. This was a very long time before I had even begun to be a framer at all.
Re: underpinner identification help, please
Posted: Wed 20 Dec, 2023 11:48 pm
by prospero
The head mechanism looks very like the old Euro range, so I suspect it's a derivative of one of those.
I do have some experience of them and they are basic but tough machines so I may be able to help with
any probs.
Re: underpinner identification help, please
Posted: Thu 21 Dec, 2023 7:17 am
by NTG999
This does look similar to my old machine that I need to sell, the images might be helpful
Re: underpinner identification help, please
Posted: Thu 21 Dec, 2023 9:16 am
by NKP1962
NTG999 wrote: ↑Thu 21 Dec, 2023 7:17 am
This does look similar to my old machine that I need to sell, the images might be helpful
That looks identical - just need the manual(s) now to see how it works, and how to overhaul it. Many thanks
Re: underpinner identification help, please
Posted: Thu 21 Dec, 2023 11:26 am
by prospero
A major shortcoming with these machines is the top pressure pad. It can dent certain mouldings. On my Euro
model I made a triangle from ½" thick wood and faced it with cork (polyurethane is better if you can get a bit).
This is to spread the load and is placed over the corner when joining.
To set the pressure you wind the pad up and press the pedal until the pad arm reaches a point where it stops going down.
Then, hold it at this point and screw down the pad onto the moulding until it is firmly seated on the moulding. Now if you
press all the way down a v-nail will be inserted. It's important to keep the v-nail feed chute clear of debris and accumulated
glue, particularly where the v-nails mate against the end. If the hammer runs smoothly when you press the pedal then the only
lubrication you need is maybe a squirt of WD-40 in the hammer channel.
Re: underpinner identification help, please
Posted: Thu 21 Dec, 2023 7:06 pm
by NKP1962
prospero wrote: ↑Thu 21 Dec, 2023 11:26 am
A major shortcoming with these machines is the top pressure pad. It can dent certain mouldings. On my Euro
model I made a triangle from ½" thick wood and faced it with cork (polyurethane is better if you can get a bit).
This is to spread the load and is placed over the corner when joining.
To set the pressure you wind the pad up and press the pedal until the pad arm reaches a point where it stops going down.
Then, hold it at this point and screw down the pad onto the moulding until it is firmly seated on the moulding. Now if you
press all the way down a v-nail will be inserted. It's important to keep the v-nail feed chute clear of debris and accumulated
glue, particularly where the v-nails mate against the end. If the hammer runs smoothly when you press the pedal then the only
lubrication you need is maybe a squirt of WD-40 in the hammer channel.
Thanks for the input - I was going to fabricate a pad of some sort for the top pressure pad, and I'm going to strip it down to clean everything & lubricate it
Re: underpinner identification help, please
Posted: Thu 21 Dec, 2023 7:09 pm
by NKP1962
Thanks to everyone for their help - I've been advised by Charnwood that it is an SF Strapit and about 35 years old. It works, but will need some cleaning, etc. but seems in good condition - better than I looked at 35