Summa D140 Cuts not closing

[pstrwks]

I have been having a problem with my summa D140 where the cuts are not closing, or so I thought. Turns out that they were not starting on time. So for those of you who find this thread. The rather undocumented fix is in the coil setup. This setting seems to control the landing force of the blade (and the max and min force of the cut pressure). Increasing the DRAGL value by 2 made the cut start on time.

 

[cornholio]

The old Summas show such a behaviour when they get old. (10-15 years)
There is a small round piece of "rubbery foam" inside the solenoid, that stops the upward movement of the tool. Over time, this piece of foam gets compressed and there is a delay, when the tool starts the movement downwards. Since this down movement is only controlled over time(not adjustable, AFAIK), the only official remedy is a replacement of the tool head.
The landing parameter is the current through the solenoid, when the tool touches the cutting strip. Increasing it may help for a while, but isn't the final solution.
I have "refurbished" a couple of these heads over time, by installing new dampers into the solenoid. It's a bit tricky, because you need to remove "debris" out of a very strong magnet and the coil needs to be centered nicely, when put together again.