Will Home Made Spindle Washers Cause Run Out?

If you've been woodturning for awhile and use scroll chucks then you've probably had a chuck that seized on the threads and is difficult to remove. Grease or oil will not prevent stuck chuck but there are anti-seize compounds based on copper or graphite that can help. Another way is a plastic washer, called a spindle washer, that prevents the chuck from getting super tight. These washers can be purchased commercially or made in the shop.

I tend to pack rat jars and containers for various uses. One day a plastic jar lid caught my eye and I decided to make a spindle washer. After some experimentation I found that larger, thicker, lids like those from peanut butter, peanuts, mayonnaise, etc. made better washers. Pass on any lids with writing or other decoration. My method is simple, drill a 1" hole in the center of the lid (use whatever size matches your spindle), mount it on the lathe held in place with a faceplate or chuck and use a parting tool to remove the outside rim. It doesn't have to be perfect. You can make them any size you want. Most of the time I can remove a chuck using only my hand, occasionally after a long turning session I need a little leverage but the washer still prevents the chuck from seizing up tight.

A common concern is that plastic lids are not made with any precision and will cause excessive run-out which expresses itself as vibration. I decided to test a homemade spindle washer and find out how much runout it introduced.

First I measured a washer using an iGaging digital caliper accurate to 0.001" and with a resolution of 0.0005". Now I don't remember from what kind of lid this washer was made, I've had it for more than a year. But measuring various points around the washer, the deviation was never more than 0.0005" so the total variation is withing 0.001" which I found quite impressive.

Next I chucked the largest Forstner bit I own into my Nova G3 and tested runout using a dial indicator against the shank. The results were surprising. The very first test was after turning a handle for a beater chisel and I did not clean the threads beforehand, consequently it had the greatest runout of any test. Really, that test should be thrown out but I included it. The three remaining tests were done with clean threads.

The runout will be magnified as you move away from the center so if my test piece were 2" in diameter, the measured runout would be approximately doubled. Testing shows the washers introduce some runout but less than what the chuck itself introduces. So claims they introduce wobble are valid, however; the chuck introduces even more wobble so how much is acceptable to you. At the end of the day these are wood lathes and I'm not attempting to make precision parts so for me the washer is an acceptable trade off.

Nova G3 vs. Nova Precision Midi lathe chucks

I've been using a Nova Midi chuck but wanted an upgrade. So when I spied an open box G3 on Amazon Warehouse with 2 sets of jaws for $124 shipped, I bit. The G3 was supposed to be direct threaded for 1x8 threads but instead mine was threaded for 1-1/4x8. No problem, I ring Amazon on the blower (opened a chat with customer service) and told them I would keep it if they gave me credit to buy the proper insert. No problem says Amazon and within 2 days my insert had arrived.

G3 (left) and Precision Midi (right)

The Midi was purchased used and came with 2" and 1" jaws, a woodworm screw, allen keys, and tommy bars for around $50; not a bad deal. The G3 also came with 2" and 1" jaws, a woodworm screw, allen keys, and the wrench doohickey; for a little less than $124. My lathe is still not 100% operational so I haven't turned with the G3 yet so this is not a proper review although I don't believe a review is really necessary. [Update: I have used the G3 a good bit and it performs equal to the Midi although I prefer it since I can scroll the jaws one handed.] The G3 is among the most popular lathe chucks sold and Teknatool makes high quality chucks. What I am doing is comparing size and heft of the two chucks since the G3 looks considerably bigger so you'd expect it to be beefier, but is it?

G3 (left) and Precision Midi (right)

So in about every way, the G3 dwarfs the Midi so you'd expect it to be a heavier duty chuck. But as you can see in the pictures above, the G3 is mostly hollow. Placed on the scale, the G3 weighs in at 55 oz., or 1.56 kg.; the Midi weighs 53 oz. or 1.50 kg. The 2 oz. difference is the G3 has a threaded insert, the Midi is direct threaded for 1x8. They are essentially the same weight.

Precision Midi

Nova G3

One advantage the Midi has over the G3, and it's pretty significant to owners of gap bed lathes, is that being shorter it allows more room for turning platters. The G3 is so long it renders the gap on my Delta 46-111 useless. Of course the main advantage of the G3 and why I wanted to upgrade was that you can open or close the jaws one handed while using the other hand to steady the wood blank or bowl. The Midi chuck requires 3 hands unless your lathe comes with a spindle lock. So was the G3 really an upgrade? It's sounding less and less so, but the G3 also has set screws on the spindle threads so it can be reversed. The Midi has no set screws and if you reversed the lathe it would spin itself right off the spindle.

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