The Framers Forum

Hello,
I have a Minigraf 4 underpinner that has served me well. Recently I changed the wedge hammer / piston unit because the old one was about ten years old. It was beginning to not drive wedges in fully. The new hammer is much better but the wedges are still not driving in fully. I have the bar pressure up to about 5.5 and don't want to go further in case of damaging the polycore moulding.
Does anyone have any advice to rectify this.
Thanks

Are the wedges definitely the correct type for polycore and are they in the correct way?
If the pressure is up that high and still not firing in fully something else is wrong.
Have you tried with some wood just to check?
I don't use plastic moulding so not sure what is different.

You might try ringing Will at lions? he's on their machinery team and could probably advise. He can tell you any parts you might need and if you cannot fix it over the phone you can send it to them in Birmingham to fix. They helped with my machine and were great.

Thanks both of you for your advice. The wedges are definitely the right way up. Pressure is at about 6 bar because polycore is not that hard.
Will ring Joe at Simon's.
Cheers

Joe doesn't work at Simons anymore!

My first thought is an air leak somewhere in the system. Have you tested for air leaks at all the connections? It is an easy test with soapy water and a brush.
An alternative idea is, had this machine had regular maintenance with "pneumatic lubrication oil" ? If not, there could be some sticking valves, possibly in the foot valve switch. The o-rings could also co bad without proper lubrication. Do noy use any other type of oil.

Thanks again