Best way to line up a ball crank for boring

[Torch]

Instead of a single jaw on either side, there's a row of spring-loaded mini-jaws down each side. When any one jawlet is fully compressed, the entire row is locked into their relative positions. The net effect is a jaw that conforms itself to the part shape.

Not at all "repeatable", but boy does it grip odd-shaped parts securely. With less muss and fuss or risk to the world's oceans than Spro's lead cloth.

[spro]

You say, I say and intelligent conversation rises. That is the point after all.

[ken572]

Good Morning Torch,

I was curious if you ever checked the (P.S.I. rating)

on the finger springs on that vise

That looks like it would come in pretty handy at times,

regardless if it gives repeatability or not.

Another item on my want list.

Ken.

[Torch]

No, I cannot say as I did. I can say you won't easily push one in with finger pressure, though! However, the springs do not directly control the maximum gripping force -- the springs just ensure the "jaw" conforms to the part shape. Once one of the jawlets (for lack of a better term?) hits the end of it's travel, the entire row is locked. The maximum gripping force is determined by how hard you crank down the movable "jaw" after they have locked.

I got mine at BusyBee a number of years ago, however, I can't seem to find it in their current catalog. Here's the manufacturer's page: http://www.shobha-india.com/precision-m ... -p1.html#1

Again, this vise has terrible repeatability by it's very nature. The body and frame are all ground square and straight, but the jaws are floating, after all. If accurately repeating the positioning of the workpiece (at a guess, I'd say +/- .005" or better) is important, you need to index off the part each and every time you clamp it down. It is not suitable for production work and I would not recommend this as a primary milling vise even for a hobbyist. But as a specialty tool, used as needed to grip an odd-shaped piece securely for one-off tasks, this is your baby.

In the case of the OP's ball crank, I would insert a shaft into the original hole, clamp it down using blocks or squares on the shaft, index centre of the bore and rebore it. The clamping pressure would be evenly distributed along the entire length, minimizing any distortion that might otherwise result from clamping the high-points with a regular milling vise. But if I had 50 of them to do, I'd make up some sort of repeatable jig instead.

[ken572]

No, I cannot say as I did. I can say you won't easily push one in with finger pressure, though! However, the springs do not directly control the maximum gripping force -- the springs just ensure the "jaw" conforms to the part shape. Once one of the jawlets (for lack of a better term?) hits the end of it's travel, the entire row is locked. The maximum gripping force is determined by how hard you crank down the movable "jaw" after they have locked.

I got mine at BusyBee a number of years ago, however, I can't seem to find it in their current catalog. Here's the manufacturer's page: http://www.shobha-india.com/precision-m ... -p1.html#1

Again, this vise has terrible repeatability by it's very nature. The body and frame are all ground square and straight, but the jaws are floating, after all. If accurately repeating the positioning of the workpiece (at a guess, I'd say +/- .005" or better) is important, you need to index off the part each and every time you clamp it down. It is not suitable for production work and I would not recommend this as a primary milling vise even for a hobbyist. But as a specialty tool, used as needed to grip an odd-shaped piece securely for one-off tasks, this is your baby.

In the case of the OP's ball crank, I would insert a shaft into the original hole, clamp it down using blocks or squares on the shaft, index centre of the bore and rebore it. The clamping pressure would be evenly distributed along the entire length, minimizing any distortion that might otherwise result from clamping the high-points with a regular milling vise. But if I had 50 of them to do, I'd make up some sort of repeatable jig instead.

Torch,

Thanks for sharing your vise, and the review etc.

Ken.

[Chuck K]

That looks pretty useful. If I understand what you saying....the jaws came with the vise and are fastened permanently to that vise? Or is it something that you slip between the existing jaws to "fixture" an odd part?

[Torch]

That looks pretty useful. If I understand what you saying....the jaws came with the vise and are fastened permanently to that vise?

Yup.