Seam Rippers that Won’t Roll

When I first started making seam rippers, I used a small Dritz ripper and glued the existing ripper into a turned handle. After I received some input from my wife, who is an accomplished seamstress, I experimented with a few where I left a square portion on the handle so the ripper would not roll when it is laid on the table.

Later I began using a commercial kit from Penn State Industries to make seam rippers. Of the three kits available, the most popular is the double-ended version. At a recent craft fair a lady told me she liked my seam rippers except for the fact that they roll when they are laid on the work table. SHe asked if there was anything I could do about that.

I took that as a challenge. First I put together a simple router jig for the lathe. It consists of two three-sided open boxes, one of which slides inside the other. On the narrower box (which goes on top), I drilled holes to mount my router. On the sides of the boxes are slits to allow adjustment up and down to fit various sizes of lathes, if that should be an option. On the bottom of the lower box is a guide block to fit between the ways of the lathe.

Next, I did something I said I would never do – I mounted a pen mandrel on my big lathe, I am using it because the lathe has a nice indexing system with 48 holes built into it.

This is pretty easy to use. First I place a glued-up seam ripper blank on the pen mandrel between bushings, and turn the blank until it is round, or almost round. I’ve learned that if the tube is glued off-center in the blank, I can leave a flat side on the blank.

Next, I place the router jig on the ways of the lathe and bring the tailstock back up to the mandrel. If there is a flat side already on the blank, I loosen the nut on the mandrel and turn it to the top side with the lathe spindle set to the Zero indexing mark.

I simply slide the jig along the ways with a large square bottom bit in the router.

After the first side is routed, I then turn the spindle the required number of indexing holes for the blank I am making. I have made 8-sided, 6-sided and 4-sided blanks. The 6-sided seems to be the optimum for not rolling and still comfortable in the hand.

Seam Ripper Handles before Finishing

After the sides are routed onto the seam ripper handle, I turn the ends. I try to place a small rise at the end for the user’s thumb to push against.

A caution – I check the tightness of the nut on the mandrel before every cut. In the picture above, the third handle down is round. This was a very hard wood (honey locust) and the vibrations from the router loosened the nut and allowed the barrel to turn on the mandrel.

Completed seam rippers with “won’t roll” handles.

How I set up the lathe to turn pens

There is nothing earth-shattering or new here – I wanted a place to post some pictures with text for a friend of mine.

Turning pens with the standard mandrel:

I use a mandrel to turn pens when they are “7 millimeter” size.  When they are larger than that I may or may not use a mandrel. There is a larger mandrel that is used for some larger pens from Berea hardwoods.

When I use a mandrel, I drive the mandrel with a 2MT collet.

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This collet requires a drawbar – I use a long 3/8-NC bolt. The complete setup looks like this:

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I turned the wooden knob to use with the lathe where this gets put on and taken off quite often.  The other lathe where I use this set-up is almost permanently set up. I use a bolt with nuts and washers for spacers and there is no knob on the hand wheel end of the headstock (below).

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I also use the MT2 collet to drive my three-wheel buffing setup, as well as my mandrel for bottle stoppers.

A few notes about the MT2 collets:

  1. you do need to tap them out with a hammer – I loosen the drawbar a few turns and tap it with a brass hammer.
  2. The collets don’t fit the mandrel “exactly” – the 1/4 inch fits the 0.246 (“7 MM”) mandrel pretty closely, but to fit the “B” mandrel (same size as an L drill bit), the 5/16 mandrel collapses considerably past its nominal size.

I also use a “mandrel saver” from PSI for the standard size mandrel.

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The complete set-up looks like this:

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Turning pens with barrel ID larger than the 0.246 mandrel:

I use a MT2 60-degree dead center in the headstock to drive the barrel and a 60-degree live center in the tailstock. These fit into the bushings for the pen barrel and center it better than a mandrel.

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(The bushings don’t match the finished barrel in the picture above – the bushings are for the Sierra Vista while the barrel is for a standard Sierra).

Then, to finish the barrel, I remove the bushings and drive the barrel directly with the 60-degree dead center. This eliminates bringing the gray sanding dust (iron) from the bushing onto the barrel.

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You will get a little slop-over of CA onto the end of the barrel – this can be sanded off, or even cut off  with a sharp knife if the CA is not set up too hard. (I use a knock-out punch mounted in a Jacobs chuck in my tailstock and a  purpose-built sanding disk that screws onto the 1×8 thread on the headstock.)

Bushing maintenance

People, even some “experienced” penturners forget that the bushing needs some maintenance from time-to time. Things to look for in order of descending importance:

1: CA (or other crud) build-up on the step of the bushing. This is the area indicated by the point of the knife blade in the picture below.

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2: CA (or other crud) build-up on the back of the bushing. This is the endof the bushing facing the camera in the photo below:

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If this area is not clean, and you are running the bushings back-to-back (like on a Cigar pen), the bushing can cock slightly and throw BOTH barrels out of round.

3: Condition of the hole in the center of the bushing. The bushing should slip easily over the mandrel if a mandrel is used. Use a letter D drill but to clean and re-size the hole.

If a mandrel is not used, the end of the bushing that fits over the 60-degree center must be round and perhaps have a slight chamfer. Clean it up with a countersink mounted in a wooden handle.

4: Buildup of CA on the bushing. This can fool the woodturner into thinking the pen barrel is turned to size, when in fact it is still too large.

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