Under pinner Issues

[DaGeo Art]

I have both a manual and pnumatic underpinner and having issues with both. For the Grizzly (manual) one, I am waiting on Tech support to advise as they no longer sell them (purchased new 6/2020). The pnumatic underpinner makes the frame jump up and the nails (2) go through the frame. This does not always happen but extremely frustrating. I gently press the pedal allowing for the knob to come down just a bit and then press all the way down. What am I doing wrong? If someone can PLEASE call me, I'd greatly appreciate it. 850-603-9668

 

[Rick Granick]

What model is the pneumatic one?

 

[DaGeo Art]

PPFE 1000

 

[alacrity8]

PPFE 1000

I am unfamiliar with either brand.
The PPFE does not look too dissimilar to an AMP machine.
Do you have a Manual that you can share?
The only time I've accidentally fired 2 stacked nails is if I had a misfire on the previous attempt.
Are you noticing any issue immediately before the double stack of nails goes through the frame?

 

[alacrity8]

I am unfamiliar with either brand.
The PPFE does not look too dissimilar to an AMP machine.
Do you have a Manual that you can share?
The only time I've accidentally fired 2 stacked nails is if I had a misfire on the previous attempt.
Are you noticing any issue immediately before the double stack of nails goes through the frame?

I see that there is a user manual in the Manuals Library for the PPFE 1000:

https://www.thegrumble.com/data/manuals/PPFE_1000_Underpinner.pdf

It shows nothing about the inner workings of the machine.
The only thing I could suggest as a possible problem is that 2 nails may get loaded into the chamber, and 1 nail fires.
On the next firing of the joiner, the one nail in the chamber is forced into the frame by the firing of a new nail.
If this is the case, it is possibly a problem with the Drive Head. It may need adjusting or replacing.
You also may be having this problem due to nails not specifically designed for your machine.
The exact shape of the V-Nails seem to vary from manufacturer to manufacturer.