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oldhat
07-24-2012, 10:37 AM
The Parallels in the box are in sets of two I read that are ground in sets of 2 how true is this for low cost Parallels i see no marking to keep sets together.

did a search no info.

Bill;)

Void
07-24-2012, 10:47 AM
I don't know the answer to that. Simple check would be to check them with a micrometer or on a surface plate with a DTI and a surface gage. All of mine are parallel to within 0.0001". If I need better I will pay more or make my own.

-DU-

oldtiffie
07-24-2012, 10:49 AM
Try Littlemachineshop.com

http://littlemachineshop.com/products/product_view.php?ProductID=1893&category=

oldhat
07-24-2012, 10:54 AM
you hit the target got them from Littlemachineshop

thanks all

Bill

rowbare
07-24-2012, 10:55 AM
The Parallels in the box are in sets of two I read that are ground in sets of 2 how true is this for low cost Parallels i see no marking to keep sets together.

did a search no info.

Bill;)I imagine even the cheap sets are ground together as pairs. As for keeping them together, each pair in a set is a different height...

bob

loply
07-24-2012, 11:22 AM
I bought a cheap(ish) set a while ago and whilst they are definitely acceptable for my usage many of them are bent/curved.

I can't say exactly how much because my digital DI which indicates to 0.001mm fluctuates so much it's unclear, but a quick check on the surface plate reveals they are indeed slightly banana shaped. It's less than 0.01mm though.

Point being even if they are ground together it doesn't matter that much because for whatever reason they came out wonky.

Dr Stan
07-24-2012, 12:56 PM
[QUOTE=loply;786091Point being even if they are ground together it doesn't matter that much because for whatever reason they came out wonky.[/QUOTE]

They were ground with the mag set on full which pulled them flat and as soon as it was released the parallels sprung back to their original shape (warped). To get them flat you need to grind the first side with the mag on residual, held down with double sided tape & the mag off, or held in a vise up off the mag. Even then you can get warped parallels due to stress relieving from the grinding operation. It takes time and experience to get something flat and parallel, not just parallel. Something you cannot expect from a cheap mass produced parallel.

J Tiers
07-24-2012, 11:45 PM
No telling if the cheap labor in India or china knows, or cares, to keep the two together......... they all look pretty much alike once ground.... I'd bet on them being ground together, possibly in groups of dozen even, but I wouldn't bet much on the group all getting paired up correctly.

Dan Dubeau
07-25-2012, 11:10 AM
My cheap Chinese set were ground as pairs, and nearly dead nuts parallel. I mic'd them all, and engraved the actual size on the side. I've had to regrind a few due to wear, and dings and such, and I just re-engraved the size on the side. This allows quicker setups on the CNC where I set all my tools to the table, and add up the z offsets for my G54 z value. It's really handy to know the sizes without having to grab a mic all the time.