BS-1 sector arms

[kmanuele]

I ordered a BS-1 clone indexing head, with 3-jaw chuck and tailstock. Disassembled for clean-up as most folks do and found the indexing head to be surprisingly clean. No issues there. Only problem I found was with the chuck - jaw motion was not smooth. Fixed by removing some debris and burrs inside, plus new grease. ok now.

The problem is with the sector arms. That spring clip holds them very tight against the dividing plate. Very difficult to move. I lapped the back sides -- didn't help much. The dividing plate has no burrs.

I know there needs to be some drag to keep the arms where you put them. Besides trying to adjust the spring, anyone have ideas or other solutions?

Thanks

 

[markba633csi]

I think I remember reading about a member who cut a plastic washer from a TV dinner tray and put that in
as a friction reducer- ? Don't recall where I saw it

Overall though you like the product? Did you buy it on Ebay? I've been tempted myself

 

[kmanuele]

I think I remember reading about a member who cut a plastic washer from a TV dinner tray and put that in
as a friction reducer- ? Don't recall where I saw it

Overall though you like the product? Did you buy it on Ebay? I've been tempted myself

Good idea. I have some thin sheets of UHMW plastic that might help.

I was able to compress the spring a bit to loosen the compression, plus some lube. Works better now, but not real smooth action sliding on the plate. Those arms are just die-cast. They aren't flat, and the locking screw tends to distort the assembly at various positions. The only negative in an otherwise good product.

If I get ambitious, might design and machine some.

So far, I am impressed with the quality, especially for the price (300 bucks including shipping). Besides the indexing head, it includes a 6" chuck, and an adjustable tailstock -- which also seems well made. Don't know how they do it for that price. BS-0 is even cheaper.

Ebay. I don't use Ebay much but have had good experiences with their vendors so far.

As far as I can tell from images, it seems to be exactly the same unit that other vendors sell with a brand name on it -- often at much higher prices, even within Ebay.

 

[bukwirm]

I had a similar problem with a different Chinese import dividing head. Actually, mine was even worse - there was only a ~0.020" gap for a spring stamped from ~0.040" material. I just milled 0.040" or so off the back of the sector arms.

 

[WobblyHand]

Good idea. I have some thin sheets of UHMW plastic that might help.

I was able to compress the spring a bit to loosen the compression, plus some lube. Works better now, but not real smooth action sliding on the plate. Those arms are just die-cast. They aren't flat, and the locking screw tends to distort the assembly at various positions. The only negative in an otherwise good product.

If I get ambitious, might design and machine some.

So far, I am impressed with the quality, especially for the price (300 bucks including shipping). Besides the indexing head, it includes a 6" chuck, and an adjustable tailstock -- which also seems well made. Don't know how they do it for that price. BS-0 is even cheaper.

Ebay. I don't use Ebay much but have had good experiences with their vendors so far.

As far as I can tell from images, it seems to be exactly the same unit that other vendors sell with a brand name on it -- often at much higher prices, even within Ebay.

My experience with these dividing heads is they often are made in the same factory, but the quality and finishing are different. I bought a cheap one off eBay and due to the inferior packaging the weight could easily shift. This caused the common carrier to drop the package on the ground right in front of my house. The cowardly driver positioned the package so the damage was concealed. Due to the way the package landed, I was concerned about hidden damage. After tear down I found hidden damage in the cast iron bearing sleeve, literally the only part of the entire assembly that was not available. It's custom ground to fit. And totally invisible without disassembly. It was cracked. After fighting with the vendor for several weeks eBay stepped in and forced a return and refund.

My second dividing head came from Precision Matthews. It cost more, but it was packaged so that no weight shift could occur. The foam was custom molded to the contents, unlike the first one, which was generic. It was double boxed as well. The head was nearly identical, but some of the details differed. The PM unit was a lot smoother, and required far fewer touch ups. The eBay unit engraving was so rough it would cut your fingers, the PM one was a little rough, but not dangerous.

Both were amazing units for their cost. Had the first not been dropped, it would have been ok, with some work. The PM unit is slightly more refined, and smoother turning, but basically, I paid for superior packaging and handling. I don't regret buying it at all. I really didn't need to do much to get the PM BS-0 to work. Anyways, sometimes you get lucky, and sometimes you get what you paid for.