Tell me of 5C collets, collet blocks and spin indexers

[RJSakowski]

One difference between 5C and ER collets is the grip range, In order to cover the entire range of diameters with 5C , you need collets in increments of 1/32" and preferably 1/64". A workaround is to use a thin shim around the circumference of the work to build up to a standard diameter.

 

[cg285]

Ok, so these all definitely have a use but it appears I can get by with just the blocks for now.

i suspect you will find frequent uses for the collet blocks (and angle plates) while a spin indexer will spend most if it's time on a shelf next to the rotary table.

 

[Herk]

5C collets are also threaded internally and can accept a work depth stop which can be handy.

 

[Aaron_W]

Thanks, I can see that the 5C collets have their own advantages, but can probably wait until I have a need or find a really good deal. They were the most expensive aspect of the blocks which finding a set of ER blocks avoids for now. It seems like one of the major advantages of these blocks comes into play when doing repetitive work.

One thing to keep in mind is that when using collet blocks vertically in a milling vise, especially a tiny vise like a Sherline vise, you have only a small gripping surface to hold the collet block. The rear nut on a 5C block eats up that height so the chances of the block slipping under milling pressure is higher. The ER blocks have no rear nut so are more solidly held; just so you know.

This is a good thing to know. After I ordered the ER blocks I found an ER 5C adapter and was wondering if I may have been better off buying a set of 5C collet blocks with the adapter. I can see that there will still be an advantage to having actual ER blocks even if if I do later get a set of 5C blocks. They will be complementary not duplication.