Making your own calipers

you can make calipers out of wood, a machine screw, two washers and a wing nut. it will take you a couple of hours and be half as good as the hceap $10 calipers. You can upgrade the wood to baltic plywood, spend more time to make them nice and have them half as good as a used Starrett caliper bought for about the same $$ on e-bay.

I'm in the process of putting together directions for making what is the best caliper for faceplate turning that I have ever used. If you buy them from a catalog they cost $50 plus shipping. There is a guy on Woodturning Central that has come up with something similar that goes for $70 plus shipping. If you make my type it costs about $5 if you use brass rod and $3 if you use steel rod. Plus you can modify the plan to make it especially suited for very wide flatter turnings (big plates & platters) or very deep narrow turnings with small openings (hollow forms). You can make it as big or small as you want. Also, it takes less than a half hour to put together.

I'm planning on taking the pictures and putting the text together today. As soon as I get it done I'll re-post where it can be found. I'm thinking that the easiest way for people to get it, pictures and all, would be to post it on Woodturning Central rather than emailing it as a Word document. I'll let you know in a few hours (or at least by tonight).

Hi S. It's actually fairly easy to make wood calipers. I made a set

7-8 years ago just because I was doing a fairly deep project and the normal calipers were too small and I needed them right then. Any scrap 1/4" plywood will work fine. Just draw out the shape on the plywood, tape a second piece to it and jig them both out at the same time. Drill a hole in the center of both. (again at the same time) Flip one and bolt them together. A nylock nut works well here. There not starrett but they work just fine. The beauty of this is you can make any size you want when you need them if you have the scrap plywood. Bob

Much appreciated!

S.

I just posted the instructions and pictures on Woodturning Central (6:53 EST). The intro post title is DIY - faceplate caliper - cheap & best I've used and the next 7 posts are the step by step instructions and pictures. I hope I put everything into logical sets of operations. Hope this helps you out.

Where is Woodturning Central?

Thanks,

S.

Here's the link:

Larry, I have only one problem with your otherwise innovation. I didn't think of it!

I am generally against using eponyms for tools, but this one is for one of our own. As it becomes widely made and used, I hope it will come to be known as the "ebd Caliper". Let's all start referring to it as such.

Turn to Safety, Arch Fortiter

Arch,

You crack me up!!! Actually I plagerized the idea. I saw one similar in a catalog for $50. I said to myself "I'm not spending that, but it DOES look good". I went to the hardware store and wandered the aisles untill I found some parts that I thought would work. End of story. I hardly think that it rates designating them ebd calipers...although (see bottom of post for a never before given revelation)

I will be posting in the near future some Cole jaw extension that I designed and had made. Maybe those should be ebd extensions (LOL).

Perhaps it's time to come clean. I work under the name Eskimo Blue Day otherwise ebd. Why? Long ago Jefferson Airplane had a tune by that name. Featured strongly in every course are words that I like to keep in mind whenever I work wood. Every course of the song ends "It doesn't mean shit to a tree". I want to remember to be humble and do the best I can with the wood because a tree died to supply it. But no matter how good I get, It doesn't mean shit to a tree.

Conceptually it is nice, but I would be real concerned that it isn't sufficiently rigid to be accurate. All that thin wire; wouldn't take much to push it an eight off. Presumably that hasn't been your experience?

Not my experience at all. I admit you need to be aware not to put a lot of pressure on them but in test measurements on flat stock of metal and wood the accuracy is to the 1/32".

I think Larry's innovation is his idea of combining a 50 cent cable ferrule with thin rod. It's using a cheap, but durable metal ferrule that makes it different.

I have used bent malleable wire and have used a pair of right angled coat hanger wires, but I prefer to measure thickness directly instead of by mentally subtracting a space or trying to get a fixed caliper out of a narrow orifice.

The ebd measure can be viewed along the rod, of course, but maybe someone could in some way add an inexpensive way to open the ebd for easy removal from inside a vessel and close it again outside the vessel to the measured dimension. ie. for observing or measuring a wall or bottom thickness when the caliper is outside the vessel like the more expensive calipers that can be sprung open for easy removal and returned to the measurement set by a knurled nut.

Why bother, you ask. Because! :)

Turn to Safety, Arch Fortiter

What kind of calipers?

A vernier style might not be too hard if you're good with a mill, but a dial caliper is going to need a jeweler's lathe and a digital would require some serious electrical skills.

In any case, calipers are a real bargin at $10. They're even a bargin at $150- there's a lot of tiny, fussy stuff involved in making a pair- and you need a good one to make one in the first place.

The real sticking points in making a good pair one's self are the long, tiny rack and the gear that meshes with it, and the knob for your thumb- in a good senario, it should be able to move the slide, but slip when it is tight. It's also not a trivial task to etch or otherwise mark your lines. The easiest way (which is not all that easy) short of using a CNC engraver or etching laser would be to draw your scale large, and then use a photoresisting chemical to print it on the metal at the right size and etch it in an acid bath. I know the broad outline of how that's done, but not the specifics.

No matter how you do it, it's going to cost more than $10 if you want any kind of accuracy in one you've made.

That's not to discourage you from making some, of course- it's a great idea if you just want to make your own calipers. But if you're doing it as a way to get a pair for less than $10, I think you'll find it's not going to happen unless you've already got some precision machinery.

Ermm... ahem... *mumble*

It just occured to me that you might be talking about bow calipers for turning rather than precision measurement calipers.

If you're just using them for transferring dimensions and not measuring per se, that's not too tough, really.

Depending on what you've got, you could make a fairly nice metal set with a bench vise and a drill press. Just clamp the metal in the vise and bend it by hand, drill a hole through the top of each arm for a pivot, and put a bolt or rivet through it with a washer between the arms, and drill through the side of the arms to slide a bolt through. A nut on that bolt would allow you to adjust the gap pretty easily, and a spring over the bolt would keep the arms spread apart.

Apologies, if I had the wrong thing in mind- I use a dial caliper every day, and that's the first thing that comes to mind when I hear the word.

Thanks everyone for the input. I'm making a bunch of wood calipers to copy table legs, putting the leg and a caliper for each depth on a peg board in front of me as I work. Buying the copper wingnuts and bolts is a lot cheaper than buying the 10 dollar metal ones.

S.

Tap brads into sticks, mark depths, part until reached. Talk about cheap! Keep your story stick in front of you to remember what each groove means.

Hey, I like this idea.

S.

If you use sturdier stuff than soft steel nails you can clip them and use the rough ends to cut your grooves. Drywall screws ground flat should do if the project's not too complicated.

Personally, I think calipers have their use, but not for what you're doing..

IMHO, you need to make hardboard or even card board templates for each of the points/measurements along the leg...

They can be as simple as a piece of cardboard carved out with a box cutter so that the cutout section fits over your turning... Easy to make, you can write on them and if you screw on up all you've wanted is a piece of cardboard..

If you want to be really precise, make 2 or more templates for each depth, maybe one too big, one too small and one that" "just right".....lol Sort of like doing "go-no-go" with a spark plug gauge..

mac

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