All posts by Dave

Chuck Sizing Guides – Upgraded

I have updated my Chuck Sizing Guides. The “new” shape is simpler to use.

These are not marking gauges – that is, I don’t use them to mark the blank. Instead I use them to check my marks. So first, I guess at the right diameter and mark the blank. Then I check it with the gauge and re-mark. Usually that’s all it takes, but a third adjustment will get me there in any case.

I have never liked holding metal calipers against spinning wood. These seem safer, easy to use, and I don’t have to remember or look up numbers to set the calipers.

I cut guides for each of my chuck jaws from scrap 1/4″ plywood. There is a point on one end and a flat on the other. From the point to one corner of the flat is the right size to start a tenon, to the other corner is for a recess.

Getting the measurements right took a bit of trial-and-error. The measurement I wanted was where I start cutting the tenon or recess. The diameter where you start cutting ends up on the inside of the jaws when you’re done.

So to get the measurements, I removed two jaw segments from the chuck and placed them in their perfect-round diameter (where the gap between the segments is about 3/16″). That makes a half-circle and I can measure between the jaws, near the bottom.

For the recess, the starting point can not be any smaller than with the jaws fully closed, otherwise you won’t get the jaws into the recess. That turns out to be about the right diameter when you expand the jaws.

I made a guide for one of my jaws, and tested it out by making a tenon. Then I tweaked the guide to get it just right. I used that “tweak” to help me know how best to measure for the other jaws. I feel this is important, as the guides have to match my style and how I use them.

I marked the measurements I ended up with on the guide, so I can re-make it if it breaks. They are painted blue so I can see them amongst the chips when I drop them.

The guides also have a small slot cut on the side to indicate the maximum chuck jaw depth.

Low-Speed Mod for my PM3520B

I added a 150 ohm resistor to the ground-side of the speed control potentiometer. I had done some measurements and that was the right resistance to let the lathe run at its lowest speed (48 RPM on the low pulley) when the speed control is all the way down. It used to stop the motor.

When I needed to run the lathe really slow, it was tricky to find the spot with the speed knob.

I may someday want to be able to turn the motor off with the speed control again. If that is the case, I’ll get a switched potentiometer to replace the original one. Then I can turn it down all the way to get low speed, and just click the knob to switch it off.

Headstock Tool Rack

I made a rack to sit on the headstock and hold my chuck keys, allen wrenches, and a few other tools I want to have nearby.

It’s simple: A chunk of scrap wood, with a lip routed out to fit the headstock, and 3 rare-earth magnets to hold it on. Looking at the pictures, it appears I cut out for the headstock and glued on another piece for the top. Whatever works.

The magnets aren’t enough to hold up the weight of the chuck allen keys, but adding the lip over the top of the headstock does the trick.

I drilled holes for the wrenches and things so that the shorter ones are in the middle, and don’t interfere with the spindle handwheel.

Dust Collection

I discovered that 3″ PVC pipe couplers are the same size as 4″ dust collector hose.

I cut a length of 3″ pipe, added a coupler and am using that rather than the large hood I had been using.

I think the pipe collects sanding dust better. Also, since the pipe is longer than the hood is, the stand can be farther back and out of the way. I was always bumping it with the banjo and had to walk around the lathe to move it around.

I added a pipe clamp where the two sections slide together to do the height adjustment, so it will stay at the correct height but can rotate. Now I can just swing the pipe out of the way without having to move the stand around.

Drilling Tenons

I make goblets, and use a very shallow (1/16″ to 1/8″) tenon to align the stem to the bowl and base.

To drill these tenons, I use a 1/4″ straight router bit. These make flat-bottomed holes, which is important when the hole is only 1/16″ deep. A regular twist drill makes a pointy hole, and a brad-point bit has a point that will go too deep (and through the bottom of the goblet’s base).

I drill these on the lathe, with a Jacobs chuck in the tailstock. The quill on my lathe (Powermatic 3520B) has 16 TPI (threads per inch) pitch. That means that one revolution of the handle will move the quill 1/16″. I use this fact to measure the hole depth – advance the quill till the bit just starts to cut, then one revolution more is 1/16″ deep. Two gives me 1/8″, or 1 1/2 turns would be 3/32″, etc.

Corian Bandsaw inserts

I needed some inserts for my “new” (1968) 20″ Rockwell bandsaw. I had some squares of Corian countertop material sitting around, and it was just right.

I turned the inserts to the correct size, being careful about the diameter and thickness so they would sit just right in the saw table.

After cutting a slot for the blade, I marked where the slot in the table was, and super-glued a tab there to keep the insert aligned.

The one insert with the round hole is for wet wood, to help the chips clear through the table and (hopefully) get to the dust collector.

Sanding Disk Storage

This is how I store sanding disks, in PVC pipe end caps.

They are in a drawer so they stay clean of chips and sawdust. And Velcro-up so I can pick them up one at a time using the mandrel on my sander.

I don’t rely on the PVC to align the disk on the mandrel. I haven’t had any problems aligning the disks by hand.

Fixed my Wolverine Vari-Grind Arm

I got a new spindle gouge, and discovered that it bumps on the huge “pocket” on the end of the Wolverine arm.

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bump

I’ve never really completely liked the huge V-pocket in that arm anyway.

I found a scrap of plastic (I think it’s Delrin, but it really doesn’t matter).  I sanded an angle on one end and used a countersink bit to drill a pocket.

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Screwed that to the back of the arm with sheet-metal screws.

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And now my gouges don’t bump the arm. Also, I think this pocket works much better than the original.

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One screw goes thru the tube, and I ground off the other one (the lower one in these photos) so it won’t interfere with the existing pocket. I don’t plan to use that pocket, but I do loan my grinder to the club’s symposium and having the “expected” setup is probably useful for demonstrators.

Wolverine makes that pocket huge like that so you can drop the butt end of a tool handle in there.  Same reason the square bar comes so excessively long (I cut about a foot off of mine).  All the Wolverine advertisements show skews and roughing gouges being sharpened like that.  I think it’s a terrible idea – way too easy to have a gouge dig into the wheel and cause alot of damage (to the operator, the grinder wheel, and the gouge). Also, every time you sharpen, the tool gets shorter, which changes that angle.  Just get a platform and make some angle-setting jigs.  Much safer and pretty easy.