Jacobs 3326 Drill Chuck Rebuild

[DLB]

If you have an older machine (Mark 5 or Model 10) it might have come with a Jacobs 3326 Drill Chuck. This is what my Greenie (1957) came with when I bought it used. I found that there are some ebay sellers selling new (NOS, it seems) 3326A chucks either with or without the key for very attractive prices. I paid $14 plus S&T for the deluxe version with a key. I was able to completely rebuild my 3326 using new parts from the 3326A. This was much less expensive than a rebuild kit from Jacobs and came with several more parts. I polished up the 3326 body while I had it apart, so my chuck is like new.

I don't have a Multi-Craft MC3326 chuck that also came with some early machines to compare. So I don't know if the same parts are interchangeable.

Note: Newer machines, I'd guess since the early 70's, have come with 'Jacobs-like' chucks, manufacturer(s) unknown. I would not expect the Jacobs parts to fit those chucks.

- David

[JPG]

What did you use to press the sleeve off/on the main body?

[DLB]

I used a large HF Bearing Splitter to press both off and on. Probably not necessary, but I used a 'bored board' between the collar and splitter to protect the gears while pressing together.

- David

[JPG]

Well that will not work on my 20N! Thanks.

[chapmanruss]

David,

I have to ask. Since you purchased a new 3326A chuck was there something about it that led you to taking the parts from it and using them in your original Jacobs 3326 Chuck.

As for the history of the Drill Chucks for the Shopsmith tools it dates back to the first Shopsmith the Model 10E which came with a Jacobs 33B Drill Chuck on an adapter. That was replaced by the Jacobs 3326 Drill Chuck which is essentially a 33B but with an extended back with a 5/8" smooth bore made to go directly on the 5/8" Spindle instead of the threaded bore of the 33B. The 3326 had two versions one with a 3/8" hole for the set screw and the second for the 5/16" set screw. The Jacobs Multi-Craft Chuck replaced the 3326 in the late 1950's. For a time was labeled MC3326 but later was MC8K26. I have seen 4 versions of the Multi-Craft Chuck, but I am not sure if all 4 versions came with Shopsmith's. 3 of them did. The Cushman Drill Chuck was the next one supplied with the Shopsmith Marks. I believe that change occurred in the 1970's. The current Drill Chuck and as you said manufacturer(s) unknown, has been around for several decades now and has had three different ways the Shopsmith logo was put on it. First engraved then two different etched logos.

The picture below has most of the Drill Chucks supplied with Shopsmith tools over the years. Starting on the bottom left is the Jacobs 33B with adapter. The middle three are the 3326 with the two versions and the middle one has the special 3/8" set screw which uses a 5/32" Allen Wrench. That special set screw was used when the Mark 5 first came out. The lower right is the Cushman Chuck. The Upper left two are Jacobs Multi-Craft Chucks. All of them look the same except the 4th version I have found but am not sure it was ever supplied with a Shopsmith. The upper middle to right Chucks are the most recent with the one on the right being the current one. Like 3 of the 4 Multi-Craft Chucks they vary only in the labeling on them.

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Drill Chucks unlabeled.jpg (131.36 KiB) Viewed 11456 times

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Below is that 4th version of the Multi-Craft Chuck that is different than the other 3. Notice the very shallow taper on the end of the main body.

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Multi-Craft Chuck V-4 a.jpg (225.48 KiB) Viewed 11456 times

[DLB]

Well that will not work on my 20N! Thanks.

A large shaft (aka stop) collar combined with a wheel puller comes to mind. What is the ID and OD of the collar and the OD of the body? I have a 2-3/4" shaft collar for my stand-alone OAR, so they are available in large sizes. Throw in a bit of heat if needed. I'm not sure if I would break out a hammer on these, they look pretty stout but are also pricey. A press is preferred, of course.

- David

[DLB]

David,

I have to ask. Since you purchased a new 3326A chuck was there something about it that led you to taking the parts from it and using them in your original Jacobs 3326 Chuck...

The 3326A is listed as "5/8" Bore Plain Bearing." I originally bought it because it was inexpensive and I thought I could add a setscrew if that was needed. That didn't work out, I think I put the setscrew too close to the mounting end without realizing that the bore had a slight step and is over-sized there. But I had disassembled it because the lubrication had dried out and to drill/tap a setscrew hole. The 5/8" mounting hole is about 1" deep, but the first 5/16" or so is over-sized. Long story short, my first attempt did not work out as I had a ton of runout.

But I was able to use the parts I had removed from the 3326A to replace six of the seven parts of my old 3326, which was a good solution for me. Plus, the new key is nicer than the old one. I prefer the Jacobs 3326 to its successors, though the modern ones with Shopsmith logo can use a slightly smaller bit. (Jacobs 3326 has a 5/64" minimum due to the gripping features in the jaws.)

- David

[chapmanruss]

David,

Thanks for the information about the Jacobs 3326A Chuck. I have not seen one before. It appears to be something to be aware of when shopping for a replacement Jacobs 3326 Drill Chuck, so the buyer doesn't get something unexpected.

[JPG]

"What is the ID and OD of the collar and the OD of the body?"

I do not have it handy, but I doubt you would believe the answers.

Realize the max jaw capacity of a 20N Jacobs chuck is 1.0 inch.