Dewalt 625E Mystery

[Trevanion]

So following on from Craig Salisbury's thread the other day about wanting a new router to replace his Dewalt 625E, he sent me the Dewalt 625E to have a look at.

The router has been kept immaculately and is almost like new having obviously done very little work in its life. It's a 2018 Type 7 model so it's not that old.



From Craig's footage it was obvious that the end of the armature was bent so I got to task getting it out, I must say that the Dewalt (and I would assume the Trend T10 and T11 also) is an absolute pig to get the armature out of, the machine has to be completely dismantled to its base components. I would recommend a drink to smooth over the experience a bit.



Once I had the armature out I chucked it up in the lathe and got it running true to the bearing surface near the collet end, then I checked it with the dial on the inside of the taper (you might want to watch it on youtube as it looks rather small here).

[youtubessl]K2RcaEGqiPU[/youtubessl]

So from the bearing surface to the collet taper it is out 25 thousands of an inch which is about 0.6mm in metric. I doubt that it is possible to straighten it without a decent setup for such work.

Once I took it out of the chuck I noticed this on the armature:



Well, obviously it's not supposed to look like that, I'm not sure how that could've possibly happened in a totally enclosed machine unless it was a manufacturing defect from new. The field doesn't seem to have any obvious marks from a collision but there is a slight blackish mark where it was run:



Now, I know the machine does run fine as I've run it myself before taking it apart, I don't believe there's been any serious damage anywhere, but I'm not sure how that could've happened to the armature internally. Since I barely know what I'm doing I kind of want a second opinion before buying a new armature whether it's actually worth doing or if the field is toast and it's not worth the effort.

As a side note, if it is worth doing I think I'll change the bearings while it's apart as these seem to be a common failure item on both the Dewalt and Trend routers, interestingly they use an Italian SKF 6005 C3 bearing on the routing end but I do wonder if it's a lower quality SKF bearing as it's not like others I've used already shedding its grease though the top seal which I would guess has happened because of its use in a router table, although it does have a high-speed phenolic cage inside.





They use a cheap unbranded Chinese 608 bearing on the top end of the armature.





I think swapping them for decent NSK DDU bearings or non-contact SKFs would be a good idea.

 

[Trevanion]

No one? Not a single opinion?

 

[AJB Temple]

To have opinions we need knowledge. You have more than most of us.

To me this is a good money after bad tool, and I would scrap it. Consuming time. Valuable commodity.

 

[9fingers]

Are you looking for applause? :lol:

I've rebuilt a T10 and T11 with new standard bearings. Both had been used in a table and the labyrinth seal had packed solid with dust, burned and seized the spindles. They came from a commercial workshop where no dust extraction was used and they were run into the ground.
I gave one to Steve Maskery when all his gear got nicked and I use the other 110v one here. Virtually all parts are the same as on your DW but quite often with price differences so worth checking
Your bent spindle looks like a classic result of something catching a the job getting thrown across the room. The collet socket takes the worst of the damage but also puts a small bend in the armature and makes it rub on the field lams.
The rear bearing does little work and need not be at all special as long as it is smooth.
Armatures look to be £120 ish by the time you have bearings too its looking a bit of an uneconomic repair certainly if you are thinking of selling on

Bob

 

[Trevanion]

Are you looking for applause? :lol:

No, I'm looking for someone to tell me whether this is a boat anchor or not! :lol:

I'm mostly just curious as to how that chunk of laminations on the armature getting damaged could've happened, I wouldn't have thought it happened when the collet taper got bent as you have a decent amount of bearing support that you would think would prevent it, but I might be wrong.

As you say, it's probably not worth repairing, but it seems a shame to scrap it. If the armature was £60 I wouldn't think twice about doing it but £120 seems rather steep! I can pick up a Type 6 armature for just under £80 but I have no idea if that is compatible with the Type 7.

 

[Eric the Viking]

Have you worked out how far along the shaft the bend is ?

The photo you posted of the rotor damage makes it appear as though the shaft is bent close to the end of the rotor, although that might just be a "trick of the light". I'm wondering if there is some manufacturing flaw in the shaff that's hidden under the windings and laquer.

Worth repairing? I would. The stator doesn't look badly damaged, and what you should then have is a known quantity. And if it is to be used in a table, you might even be able to install a better bearing for that orientation.

 

[Trevanion]

Have you worked out how far along the shaft the bend is ?

The photo you posted of the rotor damage makes it appear as though the shaft is bent close to the end of the rotor, although that might just be a "trick of the light". I'm wondering if there is some manufacturing flaw in the shaff that's hidden under the windings and laquer.

As in the video I gently chucked onto the rotor and got the bearing surface running within half a thousandth and it seemed most of the bend was at the collet taper, but I know the way I’ve done it isn’t the best, ideally I should’ve had a centre in the back of the spindle and then a fixed steady holding the bearing surface true but I don’t have a fixed steady for my CVA unfortunately.

Worth repairing? I would. The stator doesn't look badly damaged, and what you should then have is a known quantity. And if it is to be used in a table, you might even be able to install a better bearing for that orientation.

That’s what I was thinking, if it’s completely refurbished with a new armature and upgraded (or at least, a better quality than the originals) bearings it should be as good or possibly better than new. I didn’t want to go ahead with buying all the bits and someone say “Oh, that field is toast” :lol:

Having shopped around it seems the best price for an armature is £116, the bearings a further £15 or so.

 

[9fingers]

If you put the armature between centres in a lathe you can clock it at various places along its length. I reckon you will find it will have an S shape along its axis.

Type 6 and Type 7 armatures have different part nos on both part suppliers and DW own website suggesting that they are different but I would be very surprised if they would re-design a complex part from a well established design. A phone call to one of the spare parts dealers claiming you don't know which type router you have due to missing label etc will possibly elicit the answer.
Miles tools have been helpful to me in the past - just depends who answers the phone.

Bob

 

[Eric the Viking]

+1 for Miles Tools from here.

 

[Trevanion]

Type 6 and Type 7 armatures have different part nos on both part suppliers and DW own website suggesting that they are different but I would be very surprised if they would re-design a complex part from a well established design

I figured out the difference, the Type 6 Router uses a 6201 bearing on the top on the armature while the Type 7 uses a 608, quite the downgrade!

You can see in this video the older type Dewalt router top bearings at about 4:30

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Though, there is a metal bushing around the 608 bearing in the plastic housing, I wonder by removing this it will allow for a 6201 bearing, will report back :eusa-think:

 

[9fingers]

Well spotted Dan.
Those two bearings have differences in every dimension. I guess the change to a smaller bearing might have been on the grounds of cost and trivial change to the armature stub diameter. A size reducing bush in the plastic moulding also makes sense when compare to the cost of re-tooling a very complex injection mould for the body.

If for some reason you cant get a 6201 (32mm OD) to fit then maybe you could bush it for a 6000 (26mm OD) which should also fit directly onto a type 6 armature?

Bob

 

[Trevanion]

My only concern with the Type 6 armature is that it looks like the laminations (less spacing around the diameter, hard to explain what I’m talking about) are slightly wider from the photos than the Type 7, would that make any difference to its running? It also raises the question of whether the armature is wider or narrower and whether it will fit in the field properly or not.

 

[9fingers]

My only concern with the Type 6 armature is that it looks like the laminations (less spacing around the diameter, hard to explain what I’m talking about) are slightly wider from the photos than the Type 7, would that make any difference to its running? It also raises the question of whether the armature is wider or narrower and whether it will fit in the field properly or not.

It does need to be a reasonable fit in the field say a sub mm gap

 

[Trevanion]

So I had a look at the bushing, it appears it's a 25mm to 22mm bushing, if I wanted to put a larger bearing in I'd have to bore it out which would be a task!

I think at this point I'll just knock it on the head, at the cost of over £110 for a new armature alone it becomes a very unviable repair, especially when these routers seem to be selling in good condition with all the accompanying parts in its box for about £150 secondhand.

It's been an interesting dissection none the less.

 

[Lurker]

I for one have enjoyed your probings.

:shock: just realised how that sounds

 

[9fingers]

Dan, I think yours is a wise decision. Either chuck all the bits in a box for spares or if you don't have the space/inclination, I'd take out the speed controller, its knob and the magnet as known good working items of some value to put on Ebay.
The magnets have been known to fall off into the "coffee grinder", speed knobs get broken and controllers fail.
It is very rare to get trouble with router field coils but they might be saleable too.

Bob