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Author Topic: Any idea why my PDC is doing this?  (Read 1519 times)

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Offline bwehman

  • Posts: 151
Any idea why my PDC is doing this?
« on: March 28, 2022, 11:06 PM »
Super strange behavior from my PDC - coincidentally as the TPC launches... - where it's randomly running VERY slowly in 4th gear, almost like it's in 1st. But then, you can see in the video, if I change the torque setting, sometimes it'll just ramp back up to full speed. Sometimes back down. Up, down, up, down. Full battery, tried multiple different batteries - no luck.

VIDEO:https://youtu.be/7Ya6dM2ekg8
« Last Edit: March 28, 2022, 11:09 PM by bwehman »

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Offline jonnyrocket

  • Posts: 95
Re: Any idea why my PDC is doing this?
« Reply #1 on: March 29, 2022, 05:36 PM »
I believe what you’re seeing is normal. The torque limit is there to get consistency in your work across multiple wholes, wether that be driving screws or other tasks. But for Drilling, if you want the full RPM of the tool, leave the switch in Drill Mode.  It helps that there is a drill mode on either side of the torque limit scale.

Offline mino

  • Posts: 1046
Re: Any idea why my PDC is doing this?
« Reply #2 on: March 29, 2022, 06:31 PM »
Correct. When the torque limiter is set, the drill limits the top speed to avoid the momentum of the drill + gearbox to over-tighten the screws by itself from too-high speed.

The torque is set to no-limit at both the begin and end of the torque slide. Do test in those two positions if you see the behavior. If not, then mystery solved.

If you see a problem even at the no-limiter config, I would continue looking - a repair may be in order. May be the torque limiter knob too dirty inside ... or anything else.
When The Machine has no brains, use yours.

Offline bwehman

  • Posts: 151
Re: Any idea why my PDC is doing this?
« Reply #3 on: March 30, 2022, 11:28 AM »
I believe what you’re seeing is normal. The torque limit is there to get consistency in your work across multiple wholes, wether that be driving screws or other tasks. But for Drilling, if you want the full RPM of the tool, leave the switch in Drill Mode.  It helps that there is a drill mode on either side of the torque limit scale.

Then in that case, it's been working incorrectly since 2017 and only now started working the way it should. haha.

Offline bwehman

  • Posts: 151
Re: Any idea why my PDC is doing this?
« Reply #4 on: April 08, 2022, 07:06 PM »
Heard back from Festool today. Two issues were the cause: gearbox with sheared gears, and the circuit board fried.

Offline mino

  • Posts: 1046
Re: Any idea why my PDC is doing this?
« Reply #5 on: April 08, 2022, 10:06 PM »
Heard back from Festool today. Two issues were the cause: gearbox with sheared gears, and the circuit board fried.
Pretty sure the CB having fired part of it was the real culprit for this specific problem. The sheared gears were just found while at it - and still need to be fixed.

I played with my DRC a bit today and you are right.

The C12 I have does this "reduce speed based on torque setting" while the DRC does not.

Mental image I guess where I equated this also for the DRC while it was not the case there. I rarely use the torque limiter on the DRC as do most screwing with the C12.
When The Machine has no brains, use yours.

Offline bwehman

  • Posts: 151
Re: Any idea why my PDC is doing this?
« Reply #6 on: April 10, 2022, 11:20 AM »
The real surprise is the sheared gears assessment. I have a CXS and T18 that see 90% of my drilling usage. A T12 before that, and a BHC for masonry. This PDC was used about two dozen days over the five years I've had it, and I don't recall ever experience some kind of catastrophe that would've stripped gears out. ¯\_(ツ)_/¯

Offline mino

  • Posts: 1046
Re: Any idea why my PDC is doing this?
« Reply #7 on: April 11, 2022, 06:40 AM »
The real surprise is the sheared gears assessment. I have a CXS and T18 that see 90% of my drilling usage. A T12 before that, and a BHC for masonry. This PDC was used about two dozen days over the five years I've had it, and I don't recall ever experience some kind of catastrophe that would've stripped gears out. ¯\_(ツ)_/¯

The only thing coming to mind is the 2nd and 3rd speeds do not have "sure" selections, so could be damaged inadvertantly.

But IMO the more likely "issue" would be the Festool inspection threshold for an "OK" gearbox state. They are known to be kinda  overzealous in fixing pretty much anything that is not "up to spec" when maintaining a tool. From what I gather, a tool going out of their service is expected to be "functionally as new" ..
When The Machine has no brains, use yours.