Underpinner issue

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Rbtwo4

Rbtwo4

True Grumbler
Joined
Mar 17, 2022
Posts
51
Loc
Fort Lauderdale
Business
Father & Son Custom Framing
So I’m not sure what the problem is but my underpinner is pushing the molding up and the v nails isn’t going in fully. Then I found this (not sure what it’s called) and I can’t remember if it was from fletcher where I got it from. Any ideas what problem might be? Thank you
IMG_0462.webp
 
This from the Fletcher AMP underpinner parts might be it...
1737737908925.webp

my underpinner is pushing the molding up and the v nails isn’t going in fully
Click to expand...
This hints at a clamping issue. If the vertical clamp is not holding down the moulding properly, then the V-nail would be only partially driven into the moulding as it pops up.

Replacing this part may not solve your problem, because there shouldn't be anything under your v-nailer that could sever that part. I suggest you turn over your machine and compare what you see with the parts diagram for whatever model you have.
 
Underpinner Spares said:
Changing the plastic air silencer will not solve your issue as their only purpose is to quieten the air whilst it’s being discharged.

Without knowing what model you have the issue is hard to diagnose.
Click to expand...
Have an Alfa machine from Italy it’s a dinosaur
 
Jim Miller said:
This from the Fletcher AMP underpinner parts might be it...
View attachment 51023

This hints at a clamping issue. If the vertical clamp is not holding down the moulding properly, then the V-nail would be only partially driven into the moulding as it pops up.

Replacing this part may not solve your problem, because there shouldn't be anything under your v-nailer that could sever that part. I suggest you turn over your machine and compare what you see with the parts diagram for whatever model you have.
Click to expand...
Yeah def the clamp cus it’s not holding it down. Flipped it over and everything seems to be fine
 
There’s a lot going on in that photo - none of it good.

I guess someone has worked on this before as it’s a real mismatch of different spares, anyhow you need to check that the soft clamp regulator is working correctly as it only supplies an initial low top clamp pressure until the wedges are fired at which point it gives an air boost to the top clamp.

IMG_0055.webp
 
Underpinner Spares said:
There’s a lot going on in that photo - none of it good.

I guess someone has worked on this before as it’s a real mismatch of different spares, anyhow you need to check that the soft clamp regulator is working correctly as it only supplies an initial low top clamp pressure until the wedges are fired at which point it gives an air boost to the top clamp.

View attachment 51027
Click to expand...
 

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To test the soft clamp regulator:

Disconnect the pipe marked as (out)
Half press the foot pedal, low pressure (2 bar) air should come out of the disconnected side of the soft clamp.
Then fully depress the pedal, the air coming out should increase to a high pressure (8 bar)

If the air pressure doesn’t increase then it may be faulty, if it does increase then the part is not the cause of your issue.
 
Underpinner Spares said:
To test the soft clamp regulator:

Disconnect the pipe marked as (out)
Half press the foot pedal, low pressure (2 bar) air should come out of the disconnected side of the soft clamp.
Then fully depress the pedal, the air coming out should increase to a high pressure (8 bar)

If the air pressure doesn’t increase then it may be faulty, if it does increase then the part is not the cause of your issue.
Click to expand...
Ok so I did it and the air that comes out is strong and when I fully press down it’s weaker. So something is connected incorrectly?
 
How about moving the top clamp closer to the molding? Second, make sure you have lots of pressure.
 
Rbtwo4

That’s the opposite of what’s required which makes no logical sense to be honest.
Can you check that the activation pressure is working:
Reconnect the earlier disconnected pipe.
Disconnect the narrow 4mm pipe from the top of the soft clamp.
When you half press there should be no air coming from either the top of the now disconnected soft clamp nor from the 4mm pipe.
When you fully depressed the pedal air should come out of the 4mm pipe.
 
Underpinner Spares said:
Rbtwo4

That’s the opposite of what’s required which makes no logical sense to be honest.
Can you check that the activation pressure is working:
Reconnect the earlier disconnected pipe.
Disconnect the narrow 4mm pipe from the top of the soft clamp.
When you half press there should be no air coming from either the top of the now disconnected soft clamp nor from the 4mm pipe.
When you fully depressed the pedal air should come out of the 4mm pipe.
Click to expand...
So there’s some air coming out of the top and when I press half way there’s some air coming out of the top now when I press down fully air comes out of the 4mm
 
There should be absolutely no air at all coming from the top of the soft clamp regulator so it must be having issues.

There is a rubber diaphragm seal under the aluminium top section (and a coiled spring) if you are lucky it may just be the diaphragm that needs cleaning/oiling.

The air from the 4mm pipe when the pedal is depressed is working correctly.
 
Underpinner Spares said:
There should be absolutely no air at all coming from the top of the soft clamp regulator so it must be having issues.

There is a rubber diaphragm seal under the aluminium top section (and a coiled spring) if you are lucky it may just be the diaphragm that needs cleaning/oiling.

The air from the 4mm pipe when the pedal is depressed is working correctly.
Click to expand...
Ok had to run out and won’t be returning till Monday I will keep u posted. I really appreciate the help and walk through. Have a great weekend.
 
Underpinner Spares said:
There should be absolutely no air at all coming from the top of the soft clamp regulator so it must be having issues.

There is a rubber diaphragm seal under the aluminium top section (and a coiled spring) if you are lucky it may just be the diaphragm that needs cleaning/oiling.

The air from the 4mm pipe when the pedal is depressed is working correctly.
Click to expand...
 

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