PR751 – Double impression answer
Q: We are having an issue with our PR751 Slide-A-Mark making a double impression. Is there an adjustment to correct this?
Shorten the dwell timer.
Tighten / or screw in 1/4 turn at a time until your double hit stops.
To provide more clarification. Here is the system and what too look for on the Air Gauge.
Video confirms it appears to be a the pressure adjustment was changed (lowered) so the dwell timer needs to be opened up.
The lower Ram force air pressure setting travels through the timer slower.
By turning the RED knob counter clockwise you can allow more air through faster thus shortening the time on the back of the internal Ram marking hammer which causes the double ghost hit.
I usually open about a ¼ of a turn and test util the marker doesn’t advance and collapse the preload spring then turn it is a little until it does.
It is very easy and fast just be sure to tighten the lock nut and retest (sometimes when tightening the lock nut we move the adjustment knob).
If you look at the pressure regulator we apply a “GREEN ZONE” factory setting.
Which in your case looks like middle is 80psi (60psi min to 100psi max)
The machine appears in the video to be about 45psi.
This is fine, and the machine is adjustable from 30psi to 100, but when you lower the PSI you need to open up which shortens the machines dwell time.
Like wise should you Raise the Ram force PSI you need to close the timer (turn clockwise) to reduce the air flow a bit.
Remember just turn it out until it doesn’t reach the part then turn in a little at a time until you get a mark.