Shaper Spindle Replacements in Different Diameters

Customizing the spindle on your shaper could be a good investment. April 15, 2012

Can the 1" spindle in a Delta 43-379 shaper be replaced with a 3/4" spindle? I bought this shaper used and got a deal on it, but the 1" spindle is not one of the interchangeable ones.

Forum Responses
(Solid Wood Machining Forum)
From contributor K:
Yes, the whole cartridge is removed and replaced with one that has an inside taper that accepts 1/2" and 3/4" spindles. They come up on eBay once in a while.

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From contributor B:
You can also take the 1" spindle into any machine shop and they can turn it down to 3/4" for you. This may or may not be a good idea depending upon your future use of the machine.

I once had a spare 3/4" spindle for my SCMI T-110 shaper turned down to 1/2". That little bugger is just the ticket for an odd shaping situation every now and then.

From contributor D:

Those spindle cartridges are the handiest things ever. I have two that are turned to 3/4" o.d. and cut down in length, then countersunk and bored and threaded to take a recessed head screw. These will then take cope cutters (3 wing steel) and allow a long tenon to pass over the stub spindle. Or use a template with a fixed bearing point for curved cuts - even curved copes! And easy to replace bearings make it even better.

From the original questioner:
Thanks for the input. I dropped it off at a machine shop yesterday to have it cut down to 3/4. I really like the idea of cutting off a spindle and adapting it to let the long tenon pass over it. I will be looking for an extra spindle or two to modify. Are you using this system to produce long tenons on exterior/interior doors?

From contributor D:
We still use this type of tooling for a few odd cope and stick patterns, and yes, the tenon can protrude out and over the spindle and be of whatever length. The cope cutters are typically only about 1-1/2" in diameter 3 wing steel, standard Delta issue, or our regrinds. Delta used to offer a full line of these that were reversible cope and stick patterns back when the world knew about and made cope and stick joinery.

The beauty now is that this an easy way to do reproduction work without a $2,000 tooling bill for a door. We even use hand ground cutters and can modify them in a few minutes and be running.

From contributor R:
I am afraid you just destroyed about $200 worth of spindle. Those 1" solid spindle cartridges bring some fairly good money. I as well as a few other people would have gladly traded cartridges with you.

From contributor M:
Contributor R, I agree.

From contributor D:
The spindles are easily removed from the bearing cartridges for reworking. I have had machine shops make me a spindle for less than $100.00, and then put it into one of several cartridges I have. I find it easier to remove and insert the whole cartridge than to fiddle with the spindle in and out of the cartridge.

I assume these things are all harder to find now and that may drive pricing, but the basic spindle can still be easily made by a competent machine shop. At one time, you could trip over all the extra spindles and cartridges in two shops I worked in.

As for destroying, quite the contrary, those stub spindles have made hundreds of custom doors for less of my cost than anyone else could do them, so they paid for themselves many times over.

From contributor R:
I think the days of finding a machine shop to make a solid spindle for $100 are over. No competent machine shop that I know of would do it as a one-off job and do it right. I know what it takes to set the bearing preload and to maintain good runout (.001 or less) on a Delta cartridge. I have been rebuilding Delta cartridges for a number of years and it takes about an hour to replace the bearings and set the preload. Then to make a spindle on top of that? It just isn't possible for $100. Now if you want to make a few hundred, that is a different matter. Just setting the bearing preload requires machining parts to within +- .00025".

Finding interchangeable spindles for reasonable money is possible, as they do exist, but you have to look for them. Most, if not all, are reworked imports, but the quality is good. As a matter of fact, the imports are generally so good that they have less runout than original Delta spindles.

If someone came to me looking for a solid spindle conversion, I would have to charge something upwards of $400 to do it and maintain specs.

If someone wanted me to turn a 1" solid spindle down to 3/4" I suppose I could do it for about $100 but that is assuming they wanted common 60 degree V-threads at the top (mono-directional rotation only). If they wanted Acme threads (bi-directional rotation), I would have to charge at least $200 since that meant that I would have to make nuts as well. Making Acme nuts is not fun.

Delta still sells new interchangeable spindle cartridges for the HD shaper. They cost about $200 new.