[JFII]

I have an old skill 1825 router where a few months ago I put a bit in it to do some work but never got back to it. When I tried to take the bit out I could not turn the collet nut to loosen.

The collet lock started to slip so I ground down a regular wrench to fit and that started to slip. It still would not budge. Finally I put the router on its side and supported the collet nut with some wood block then gave each side of the nut a whack with a hammer. This loosened up the nut and the armature shaft. I am a bit confused by the terminology (see image) and would think the armature shaft is what the collet screws onto. There are no obvious cracks or splits in any of the parts. I figure if I did crack or split something it would open up when I tightened the parts down. Anyway it is threaded for both the collet nut and the motor shaft, which is also threaded for it (at first i did think i broke something) My question is how do I tighten it (collet) onto the motor shaft. I'm thinking i need to disassemble the router further but what can I grip to keep the motor shaft (armature shaft?) locked and from spinning as i tighten the collet to it. I also thought of sticking a screw driver through the case into the fan but I did not want to bend anything considering it spins at 25k or so and thought it much wiser to ask before I have shrapnel everywhere including me.

 

[jw2170]

That shaft appears to have a flat side on it to take a spanner?

 

[old55]

Welcome to the forum.

 

[TenGees]

Don't use the fan! I think that James is right... There's flats on the armature shaft (very top of the diagram) just above the threads. In case you don't speak Australian a spanner is a wrench. Use a wrench that fits well, you don't want to strip those flats.

 

[JFII]

I have an old skill 1825 router where a few months ago I put a bit in it to do some work but never got back to it. When I tried to take the bit out I could not turn the collet nut to loosen.

The collet lock started to slip so I ground down a regular wrench to fit and that started to slip. It still would not budge. Finally I put the router on its side and supported the collet nut with some wood block then gave each side of the nut a whack with a hammer. This loosened up the nut and the armature shaft. I am a bit confused by the terminology (see image) and would think the armature shaft is what the collet screws onto. There are no obvious cracks or splits in any of the parts. I figure if I did crack or split something it would open up when I tightened the parts down. Anyway it is threaded for both the collet nut and the motor shaft, which is also threaded for it (at first i did think i broke something) My question is how do I tighten it (collet) onto the motor shaft. I'm thinking i need to disassemble the router further but what can I grip to keep the motor shaft (armature shaft?) locked and from spinning as i tighten the collet to it. I also thought of sticking a screw driver through the case into the fan but I did not want to bend anything considering it spins at 25k or so and thought it much wiser to ask before I have shrapnel everywhere including me.


View attachment 399325

Thank you for your responses.

As i wrote but here is more detail
What I did was lay the collet nut on a piece of 2"x4" so it was slightly supporting the router and gave 3 sides a whack with a hammer. Nothing. So I went a little harder after the 4th or 5th whack it was loose. I found the no damage to any of the parts.
I took the router apart. taking pictures as i opened it. All the face screws need to come out and only the bottom screws that go to the top side of the cover (I took them all out ) be careful of the small piece and spring that are part of the lock on mechanism. it will jump out and hide if you let it. I blew out with compressed air. I checked the brushes and they were fine. (did not disassemble the brush mounts i used a magnifying glass to inspect them)
I could not find anywhere on the armature shaft the had any place for a wrench so i reassembled the router.
Before I put the collet and nut back on i dialed down the speed to its slowest plugged it and and pulled the trigger. It seemed to spin up fine so i slowly dialed up the speed and there weren't any vibrations.
I unplugged the router and screwed on the collet and shoved a long thin screwdriver onto the fan blades and tightened. Here i was making a guess that when the collet nut is tightened onto a bit it it also tightens the collet onto the shaft. reasoning - The threads for the shaft were under the threads for the collet nut. When a bit bottoms out it is bottoming out on the shaft. I put the collet nut on LOOSLY and mounted the router into its table (I did this in case i had cracked the collet nut and when I spun it up it was going to fail an throw itself and the bit free the table would offer some protection) put a small 1/2" bit in and tightened the collet with its its wrench holding the collet in place with the wrench i had made when trying to remove it (I did not put the built in lock back on because i had damaged the hole where the screw goes to hole down the lock ) turned on the router at its slowest slowly turning up the speed - no vibrations so i cut about 3 feet of of scrap. all seemed fine.
I left the bit in and turned out the lights - just kidding.

 

[JFII]

The shaft is round and is threaded at the top the part marked in the picture is the collet? screws onto the armature shaft of the router. Yes the collet has 2 flat sides and is where the built in lock would slide onto.

 

[old55]

Welcome to the forum.

 

[JFII]

Please correct me. Logically I don't think they would machine a collet right onto the armature shaft of the device.
The armature shaft being defined as the single solid shaft the motor spins on. is this correct? The picture should look more like this one

 

[JFII]

Welcome to the forum.

thanks ross

 

[TenGees]

Some routers (my old Craftsman for instance) use the shaft as part of the collet. The part labeled 'Collet' is the end of the armature.

I wonder if you can fix the screw hole somehow. Maybe drill it out a hair, to accommodate a slightly bigger screw, so that you can use the lock. Or if you can get at the 'flats' on the shaft, put a wrench on those to hold the shaft as you tighten the collet with a second wrench. If your collet isn't properly tightened - it could be very dangerous to operate! They spin about 20,000 RPM and if the bit comes out, it can ricochet around like a bullet. A previous member of the forum had just a piece of carbide come off of a bit and it damaged his ear quite badly... needed fancy surgery to repair. Imagine if that was an eye.

 

[JFII]

The lock would slide over the the flat sides of the collet and started to slip. The wrench I ground down both in thickness and width fits perfectly without my needing to hold it when adding or removing a bit. Before it was awkward to hold the spring loaded lock and turn the wrench on the collet nut while the router was in the table now its much easier.
The steel for an armature shaft and collet are heat treat differently and usually a different metal or alloy all together is used. This is before the part is machined. How old is this sears router?

 

[TenGees]

I think the Craftsman is late 70s. It can only take 1/4" bits. The locking lever on it engages into a square notch, not flats.