Anyone taken a Walker Ceramax mag chuck apart?

Hi All:
I have a Walker Ceramax permanent mag chuck that has a worn out actuating mechanism and can no longer be turned on and off.

Have any of you ever had one of these apart?
Were you able to fix it?
Did it lose power when you had it back together?

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Walker sells a repair kit to fix the problem. The kit includes a new cam and a replacement sleeve bearing for the handle pivot in the base casting. The sleeve installation requires drilling/reaming a enlarged pivot hole.

The cam pivot hole on my chuck was worn.. I made a bronze sleeve to repair the damage. It fixed the problem.

Disassembly is straight forward. Some care is needed when separating the top plate from the bottom casting to avoid denting the sealing surfaces. No sealant is used to keep the gear oil from leaking out. As the top plate and magnetic slider are lifted out as a unit from the base the cam linkage attached to the slider will need to be disengaged. Two wood wedges will be useful as spacers along with a needle nose pliers to remove the cam.

Reassembly requires using wood spacers and sliding them out gradually to lower the top plate/magnet while not disturbing the engagement of the cam linkage. The position of the magnetic slider with respect to the top plate needs to be adjusted to insert the cam..

There are a pair of leaf springs that sit at the bottom of the base that may move out of position if the top plate is not lowered straight down.

It takes a few assembly trials to work out the details.

Here is a old thread providing more information:

https://www.practicalmachinist.com/...2-dissambly-337822/?highlight=walker+magnetic

The patent shows the details of the mechanism:
Magnetic chuck

There is no risk in demagnetizing the slider. Demagnetizing would require a very strong external reversing field.

Hi Robert R:
Thank you for that; it's exactly what I need to get started.
I owe you one!

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

There are some photos of a rebuild I did on mine here: https://groups.io/g/clausing-lathe-and-mill/album?id=142012. I also put a thread on PM sometime back in 2014, I think.

The relevant photos are titled "Ceramax...". I previously had a bit of write-up on the photo-share site where the photos were originally, but when that site decided they needed to charge a fee, we pulled our stuff off that site, and I only now have the photos. Robert R's description of process is just about what I went through. Note that the cam needs final shaping by the user to get the linkage operation correct (at least it seemed necessary in my case). Also, the replacement handle was made from scratch since the original was pretty worn out.

As already mentioned separating the magnet cluster from the top plate is the bear in this job. Mine was very rusted due to coolant leaking in over the decades. I made a rail around the top plate (wooden) then used long clamps to pull the magnet cluster off the top plate.

Great chuck but the cam design is crap.

Sliding the top off isn't bad, but no one tells you how to get it back on! I used a couple of small pieces of 1/4" plywood to keep them separated. When you have it exactly where you want it, slip them out carefully and watch your fingers. It helps if you take a photo or two before separating so you know where to park it.

specfab said:

There are some photos of a rebuild I did on mine here: https://groups.io/g/clausing-lathe-and-mill/album?id=142012. I also put a thread on PM sometime back in 2014, I think.

The relevant photos are titled "Ceramax...". I previously had a bit of write-up on the photo-share site where the photos were originally, but when that site decided they needed to charge a fee, we pulled our stuff off that site, and I only now have the photos.

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I had the same problem. One nice thing about PM is that it allows you to edit very old posts. I went back and added the photos using PM’s photo hosting.

There is a permanent mag chuck rebuild on YouTube. I just watched it a few days ago.

I think this is the one I watched
Mag Chuck Restoration - YouTube

rimcanyon said:

One nice thing about PM is that it allows you to edit very old posts.

Click to expand...

How do you do that? I can only edit posts for about 24 hours, then the "Edit" option disappears!

ballen said:

How do you do that? I can only edit posts for about 24 hours, then the "Edit" option disappears!

Click to expand...

You're right Bruce. I had forgotten. What I did was to ask the moderator to make the changes, which he did. Moderators can edit posts of any age.