Dewalt mystery solved

Timbuck

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My Dewalt cordless drill has been acting up..slipping as if the torque setting was at zero. :( I stripped it down and cleaned all the parts but no fault was evident I examined the planetary gears and the clutch and all seemed ok :confused:...Then as I was reassembling it I put the end of a screwdriver on the pinion gear at the end of the armature to help guide it into gearbox and I noticed it moved a bit..now that shouldn't happen its supposed to be fixed solid on the shaft..When I removed the gear (which I shouldn't be able to do normally) I noticed a hairline crack running from the centre...Eureka! problem solved...Replacement part from dealer 36 UKP luckily I found one on Ebay 10 UKP All up and running again.
 
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How does that gear stay fixed to the shaft?

Is there a set-screw or some kind of protruding 'fin' on the shaft that dovetails into a slot on the gear?

I had a really nice Sears cordless drill that was a workhorse for over 20 yrs, and then finally the NiCad batteries would no longer hold a charge, and when I went to replace them, found that Sears stopped making them, and never found any 3rd-party replacements. I was very upset.

Same thing happened with it's replacement a 'Black & Decker' unit, but in only 5 yrs as they went from 12v battery packs to 18v, and those were Lithium Ion batteries.

I wonder if there is a brand (maybe DeWalt?) that keeps the same battery pack attachment and form factor, even if/when they upgrade the internals?

The typical rotor/stator and clutch type motor of a drill has not changed much in decades, but lots of these manufacturers love to force obsolescence by simply altering the way a battery pack attaches to the handle.

I find this infuriating.

Sorry for the off-topic rant.

Ken, I am glad yours is a simple repair. Thanks for sharing this info and photos.
 
There are other options. I repacked the battery pack on my 14.4volt ryobi and chanded from NiCad to NiMH.You can even get them pre packed in the right layout for many drills. I just bought the right number of SubC cells and soldered them together so they looke like the old one. Just make sure it is not the charger at fault
 
There are other options. I repacked the battery pack on my 14.4volt ryobi and chanded from NiCad to NiMH.You can even get them pre packed in the right layout for many drills. I just bought the right number of SubC cells and soldered them together so they looke like the old one. Just make sure it is not the charger at fault

Thanks for the info Ian.

I will look into this again.

At one time I found the proper Lithium Ion batteries that would fit the pack (I think they were either 18350 or 18340), and a charge-controller board (needed to prevent overheating and overcharging, as the chemistry of these batts is more volatile than NiCd or NiMh but has greater energy density), but I need to find out if the factory charger that came with the drill is sound, and can charge the Lithium Ion chemistry at the proper current without causing problems (like a fire).

I am well versed in the Lithium Ion NCR, ICR and IMR chemistry batteries since I use them in my own electronics hobby projects (lots of items are 5v USB-powered nowadays and 18650 batteries do well with a nominal 4.7v DC), but rebuilding a battery pack requires finesse and if a new charger is needed or some other MacGuyver solution, the whole project has the potential to exceed the cost of a newer, cheaper pre-made drill kit, since Ideally you'd want 2 battery packs...


I struggle with this often, because I despise the throw-away nature of the way lots of things are manufactured, and when the cost of a proper rebuild, which nearly always guarantees my ability to keep things alive & working for a very long time since I can DIY any future repairs after the rebuild, when the cost exceeds the price of new, once you factor in your time and effort, in addition to the parts, sometimes it seems hopeless.

However, when I have done this type of life-extension-of & DIY for things, it always teaches me something, and advances my confidence to fix things, for which I am always proud of these projects, and of course as you probably know well, sometimes our failures teach us more than our successes.
 
@ Booli.

In answer to your question in #2 I suspect that the gear is a friction or press fit onto the shaft. (The hole in the gear would be very slightly smaller than the diameter of the shaft, when the gear is placed onto the shaft it has to expand slightly and so there are tensile forces in the gear which pull it onto the shaft. Push a ring onto a slightly bigger finger than it’s sized for and you’ll see what I mean.)

In answer to your final and excellent point in #4 I see stigma and cultural aversion towards allowing failure to ever happen, certainly to the point of choosing not to attempting things unless you’re condifent that you will succeed. Sometimes our failures do teach us more than our successes; however the willingness to both learn and to risk learning in such a way is certainly a difficult change of mindset for many - sadly work in progress for me too.

@Timbuck. Thanks for sharing, another interesting post to learn from.
 
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For those interested in this sort of thing, there is a channel on you tube, AvE, who takes apart stuff like this and comments on their manufacture and failure points. Also does a lot of messing around trying other things.
You may not like his language, but I find it interesting.
Here's his teardown of a Dewalt drill.
https://www.youtube.com/watch?v=NHCS7JXfuv0
h
 
I'm surprised Mrs. Timms lets you work on tools on the good table cloth :eek:
 
I use electric tools infrequently these days and have given up on cordless tools. They are great if you use frequently, but in my case batteries always dead and progress to not holding a charge better off with the corded versions for infrequent use.
 
For those interested in this sort of thing, there is a channel on you tube, AvE, who takes apart stuff like this and comments on their manufacture and failure points. Also does a lot of messing around trying other things.
You may not like his language, but I find it interesting.
Here's his teardown of a Dewalt drill.
https://www.youtube.com/watch?v=NHCS7JXfuv0
h

Very interesting videos. I just wasted a couple hours watching a guy take apart and assemble a drill. I laughed out loud a few times. Learned a lot. Powdered metal gears? Who knew. Total tool nerddom. Enjoyed it. Thanks for the link. As for the language, I thought it was totally appropriate. This is language of the shop.
 
New armature arrived this morning....Fitted it into the drill and it's working again just like new. :music:
The downside is that while fitting it back together I dropped a screw on the floor bent down to pick it up and put my back out.:uhoh:
 
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New armature arrived this morning....Fitted it into the drill and it's working again just like new. :music:

I'm glad to hear that the repair was an easy fix with just that part. :)
 
Ken,
Let me know if you find a place for a replacement back!
H
 
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