X Sorby dent calipers

[Mark J]

OK, I am sure that Robert Sorby makes some excellent tools, but 40 bucks for the double calipers is a bit over the top.  I see them on Amazon for 30 bucks, but still.  https://www.amazon.com/Sorby-Calipers-Double-Ended/dp/B000OY6CFO

Somebody must make something similar.  I am sure I could cut something out of plastic or even aluminum.  

What do you folks do?

[Marmotjr]

I have a variety of calipers of various sizes.  I can't speak to the price, as they were all hand me downs, but they're all either steel or brass.   On the rare occasion I have felt the need for double calipers, but have made use of other methods, usually just my fingers gauging the wall thickness.  Not nearly as accurate, but it works.  I'm not a fan of the uber thin walls anyways, unless I'm making a light fixture or something that needs to be thin.  I don't want to accidentally put a finger through a bowl trying to pick it up. 

For $30-$40, I'd be more tempted to just use some 1/4" mdf and double it up to cut out the curves on the bandsaw, drill it, flip the top piece, and add a bolt.  Sand off the tips on one end so both ends touch at the same time.  A quarter sheet of mdf for like $10 would get you a whole set of double calipers. 

 

Well, now I'm resigned happy that you mentioned this, as now I have yet another shop project to do. 

[thatCharlieDude]

Here are the Sorby ones on Amazon for 20 bucks https://www.amazon.com/Robert-Sorby-Double-Turners-Calipers/dp/B001ENVE70/ref=sr_1_2?ie=UTF8&qid=1502752365&sr=8-2&keywords=Double-Ended+Calipers

[Mark J]

24 minutes ago, thatCharlieDude said:

Here are the Sorby ones on Amazon for 20 bucks

Alas the 4 inch size.

[thatCharlieDude]

Oh no! I didn't even notice that, sorry!

[Marmotjr]

If I'm buying a pair, I'd want at least 10-12" of depth.  I'd actually want to get a full set of sizes, but now we're talking big bucks (relatively speaking).  (Sorry to harp on this idea) If I were to make a set, I could make them custom to the bowl I was turning.  If I was doing a long narrow hollow form, ala umbrella stand-ish, then my calipers would also have to be long and narrow.  I could cut the pieces as I see fit.   They wouldn't need a lot of mouth opening, in fact a big sweeping jaw would prevent it from getting into such a form.  It might be a one - two trick pony, but the rest of the board could have other shapes made from it.   Then again, a set of mdf calipers wouldn't have that much longevity to it, but these types aren't really used for much like a regular set would, they aren't intended to hold a size, they're supposed to go in, measure the thickness using the opposite end to read it, and then be opened back up for removal.  (Again, sorry for beating this almost dead horse, this project is sitting on my mind tonight).

Another option would be to use a large set of the regular calipers you already have.  Insert the calipers into the bowl, and adjust themm to the wall thickness.  Then use another set of digital calipers, measure the opening size at the threaded rod.  Remove the big calipers, and reset them to the size you just measured, and then you will see the wall thickness.  Kind of a PITA, but in the short term, it'd work if you're worried about it.

But sometimes, you just gotta bite the bullet and get a commercially made tool.  Went digging through my list of turning suppliers, and was somewhat surprised to see that if they are selling double calipers, they are usually sorby brand.   Penn State does have an 8" set for $25 https://www.pennstateind.com/store/LBCAL.html

 

[Mark J]

I agree with you.  Its easy to get intrigued with the idea of making your own.  Anything thin and stiff would work like MDF Lexan or aluminum and you should be able to cut any of them on a bandsaw.  

But at 25 bucks (nice find by the way) I would be inclined to buy the ready made.  

[Mark J]

I bought Penn State calipers and a set of three dividers for another 18 bucks.

They'll need a litle judicious bending.

Dividers look OK.