Using Calipers

[jttheclockman]

Tried turning a couple blanks yesterday and tried doing it without bushings and just using calipers. Found this not to be that easy. The reason I found this is first you have to start and stop the lathe a whole bunch more times than with bushings. The first thing might improve with repetions and or starting out with bushings and getting close and finishing up with out them. May try this.

Second thing is the accuracy as to how to measure these. The blank has a slight taper to it. I do not like straight bushing to bushing look. Like to have a wee bit of bulge. But unless I place the caliper on the utmost tip I am not sure how accurate that measurement is. I think I won't know for sure until I put the pen together and feel the joinging parts.

My question is: Is there any secrets for doing this method and is it worth it??? I am guessing a highend pen, perfection is the ultimate goal but is that obtainable??? Thanks for the replys.

 

[woody350ep]

How I do mine is this. I use the bushings, turn mandrel-less, and get the blank close with the bushings. I then take the calipers and measure the part that will be going where I am turning. For example, on a cigar I would measure the nib size and then use that number for my size on the blank, disregarding the size at the bushings. I make my measurements from the underside of the blank. What I mean by this is that I come from between the blank and the bed of the lathe with the calipers pointing up. This allows me to see quite well where the measurement is being taken from and I can move it to the very edge of the blank so as to make sure I get the measurement closest to the end as I can. I tighten down the calipers and then lower them straight down. This ensures I don't change the adjustment so the number remains accurate.

I don't take the bushings off the blank at all until I am done with the finish and everything. I do my CA finish with them on and just "snap" them off. It isn't hard to do, and I have never had a problem with it. If you know you are going to have to sand a bunch, or if you want to build up the CA a bit, you can turn or sand the blanks to slightly smaller than needed size and build up the finish from there.

One other thing I have found to be helpful is this. I created a chart that gives me all the sizes I need for whatever portion of the pen I am turning. They say not all pieces are the same on each pen, and while this is true, you will find that if you measure 10 parts from different kits of the same manufacturer, they are all going to be very very close. You can then average the number out and use that for your measurements. I can guarantee you that nobody will notice, especially being as close as it will be. You can have different numbers for different manufacturers, and I would recommend that, as that CAN make a difference. But, if you get all your kits from the same company, you shouldn't have any issues.

I would guess I stop my lathe probably an extra 10 times during the whole process, but this is well worth it for the perfect fit you gain from it. I bet it only adds another 5 minutes total to the pen.

A very small price to pay for extreme accuracy and that will make your pen that much better than the guy down the way who didn't care and went ahead and turned his OOR, under or overturned and put a shellawax finish on. You will be much more proud to show yours off when compared to his.