I submit you are overly-optimistic on the amount of "daylight" you'll actually save with your initial faceplate + clamps approach.
A faceplate needs to be stout enough to manage the clamping stresses, after all. Read, "deep, ribbed, or both". Then your clamps are fully atop it, not embedded.
No. Not at all. It isn't subject to optimism. It's a matter of numbers. An average 8" scroll chuck will be an average of 5.5" - 5.75" tall/thick/what-have-you. For all intents and purposes, assume that it will be mounted with its back to a table, so I refer to the dimension as "height". There is approximately 8" of envelope space/height. Losing 5.75" of that 8" is undesirable to me.
A face plate can
EASILY be 0.750" and clamps 2.5" would mean I save/regain/avoid consuming 2.50". That's a 43% savings. And a big deal.
It is entirely possible that we could even get away with a 0.50" thick face plate. And, if we consider the "jaws" that I modeled being 2.0" tall, we save
SIGNIFICANT amount of work envelope.
Zahnrad,
Pic links fixed, let me know if you still have a problem.
Thanks. I have clamps like that. They would be
great if they could be made to work, correctly. I am curious/dubious/cautious that the sliding wedge type jaws would hold a shaft well enough to prevent movement
while also doing so accurately enough as well as not causing misalignment...
Hey, Zahnrad.
With a few different length socket cap screws and a couple of jaw designs...
For inside clamping, the screws could push out if the jaws were counter bored from the inside (there is already a hole for wrench access) or have a set tapped and pull from the outside.
Of course this is too much work if you can buy something.
thin.jpg photo - David photos at pbase.com
thin.jpg photo - David photos at pbase.com
Best regards,
--david
edit: After reading your post #16 (Should have read it sooner) I realize this isn't what you're are looking for. Removing as much material as you dare from the front (and back mounting surface) of an existing chuck (steel if you can get one) sounds like your best option.
Thanks. Your design is not too far from what I had designed. I'm not fully happy with the "jaws" yet, but I am very much considering purchasing an independent jaw chuck and machining it as much as possible to see just what we can obtain...
The reason for the 8" was the through hole. But by using an independent jaw chuck, we can use a 6" chuck and bore out the ID to the desired clearance diameter. The slightly smaller jaws are an added benefit, too. And, if we can get it down to a small enough height, it might just work. I remain cautious, though.
Thanks, all. I appreciate the input. Still looking and evaluating.