Been using a couple of bits of wood as a clamp for ages, but I finally bit the bullet on a Tandy original pony when they had some on half price sale.
This one...
I was a bit disappointed though. The wingnut thing seemed a bit crude for the price and it spun - why couldn't they put a washer on it? Also, I wasn't keen on using the wooden block thing to open the clamp up ....and there seemed to be an awful lot of spring in the legs - it really didn't need a wingnut to keep it closed. So I started thinking what could I do to make it into the pony I was hoping it was going to be.
here it is in it's tarted up glory...
...mostly cosmetic. I added a couple of magnets up top, a holster for my pliers, shaped and shortened the leg and added a 'saddle', but the real functional mod and what I wanted to share, was what I did to the tensioning system.
As you can see I removed the bolt and wingnut and replaced it with a cam-clamp and spring system...
Much, much easier to use the cam-clamp than the wingnut, but the main addition that I havent seen before is the die compression spring. The spring works against the natural spring of the clamp and is in balance. Finding the right spring was tricky, but this is bang on. If I open the clamp up fully, the jaws open to about 3/4 of an inch under the force of the spring. At that point, the spring runs out of 'juice' fighting the clamp. I can open it up to about an inch and a quarter, but the spring needs a little help. But for everything I've done to date, 3/4 of an inch has been more than enough. I lift the lever, unwind, insert project, wind in the desired tension it's just a question of opening and closing the lever to move and re-clamp. You can set the clamping force to be like the brush of a butterflies wing, or about 200lbs and anything in between. That adjustment works exactly the same, regardless of the thickness of the project (up to the 3/4 inch mentioned, after that, the clamp starts to beat the spring a little). Overall, I'm super happy.
The little leather shield under the handle acts as a thread deflector, basically stops your thread from getting hooked under the arm of the clamp.
Clamp open...
closed...
Works like a charm. I'm sure I'm not the first to combine a compression spring with a cam clamp like this, but I havent seen it before so I thought I'd share. If someone has a Tandy pony and they fancy doing this mod, I can dig out the exact hardware specs I use, which would save some legwork. LMK if it's required.
Cheers,
Martyn.