[Magnum164]

I was cleaning up from a project I cut the other day and pick up a set of my parallels and noticed the did not lay flat on each other. After checking it seems all of my parallels in this set are not flat by about .03-.045. Then I remembered reading somewhere that parallels were intended to be parallel to diff tolerances, these to about .0003. So I guess I should only use these on their edges not across the width of the part.

[twocik]

Funny you write this, I just noticed the same thing on a few of mine (didn't check the other yet, thought I bent them). Hmmm now I'm going to check the rest of them That sucks

[mordantly]

why would you need to lie a parallel on its side?? just use a shorter set. as to being bent, it sounds like you are too rough on the thin sets! this reminds me of a bizarre case of a few different sizes from each set disappearing. we had standard and thin sets. one day i was emptying the chip cart from one of the mills and found a 1" size in the chips dumpster. on further investigation, they had been getting lost inside the machine and the swarf conveyor was spitting them out and burying them in AL chips.

[Magnum164]

why would you need to lie a parallel on its side?? just use a shorter set. as to being bent, it sounds like you are too rough on the thin sets! this reminds me of a bizarre case of a few different sizes from each set disappearing. we had standard and thin sets. one day i was emptying the chip cart from one of the mills and found a 1" size in the chips dumpster. on further investigation, they had been getting lost inside the machine and the swarf conveyor was spitting them out and burying them in AL chips.

I should have mentioned, this also applied to knew ones out of the box never used. Has nothing to do with being rough on them.

I lay them on the side for small parts to provide a smooth flat surface from time to time...

[Don Clement]

I don’t believe typical thin parallels are meant to be used on their sides as the specifications for thin parallels are typically only for one pair of sides. There are even parallels which are not flat at all on their sides called wavy parallels. http://www.1gg.com/html/parsteel.html Perhaps you need an assortment of shim stock instead of using thin parallels on their sides.

Don

[Magnum164]

@Don yes, wavy parallels are on my short list.... And now that I think about it, I was only using the parallels on the sides to hold small parts until my vise was shipped.. I was having to do a lot of odd holding in a 3 Jaw chuck to make cuts.

I guess I was considering them to be like 1-2-3 blocks and be square....

[Don Clement]

Also instead using of parallels with hard jaws, soft jaws for my 6” Vise can be machined in place to hold parts parallel or machined with special shapes such as is shown here to hold a series of 0.125” thick 3/8” diameter discs for tapping on edge:
http://s72.photobucket.com/albums/i1...6Procunier.mp4

Don

[Magnum164]

Funny you write this, I just noticed the same thing on a few of mine (didn't check the other yet, thought I bent them). Hmmm now I'm going to check the rest of them That sucks

If I can find that discussion I will post the link. At first I thought it was just cheap parallels. This can open up a whole can of worms on GDT & parallelism and flatness. Even though I laid them flat on a surface, would there be a situation where you may put a part between two parallels? If you do, then you are off by whatever the flatness of the parallel was which in my case could have been .05.

I guess if you want to check your parallels you should lay them on a granite surface and slide them under a DTI. I will do this later just for the curiosity factor and knowing they are in tolerance (not a cheap set). Also, will let me know what the flatness tolerance is. As a reminder I may mark the sides with a note "DO NOT LAY PART ON THIS SURFACE"

And as Don said, normally used in pairs.

[Magnum164]

Also instead using of parallels with hard jaws, soft jaws for my 6” Vise can be machined in place to hold parts parallel or machined with special shapes such as is shown here to hold a series of 0.125” thick 3/8” diameter discs for tapping on edge:
http://s72.photobucket.com/albums/i1...6Procunier.mp4

Don

I need to order some soft jaws or material to make some. Now that I have a vise:wave:

[mordantly]

i had made many sets of 6061-T651 jaw blanks for our Kurts. a lot of times it was more fun making the tooling than it was making the ridiculous tolerance part runs.

as to the roughness, i have seen many-a-set of 1/32" parallels die from roughing, milling, or crashes/clamping failures.

[Magnum164]

as to the roughness, i have seen many-a-set of 1/32" parallels die from roughing, milling, or crashes/clamping failures.

I can see where that can happen. I just wanted to clarify that the situation was with new out of the box parallels. These are also 1/8" parallels. I don't think I could trust myself with a set of 1/32".

[MichaelHenry]

I use step jaws quite a bit in my projects.

http://www.tormach.com/Product_PCNC_acc_vise.html

They are more convenient than parallels and can be placed on either side of the jaw plates.

Mike

[Magnum164]

I use step jaws quite a bit in my projects.

http://www.tormach.com/Product_PCNC_acc_vise.html

They are more convenient than parallels and can be placed on either side of the jaw plates.

Mike

I probably need to get a set as well. In hind sight some things I bought with my Tormach like collets I should have swapped with stuff like the stepped jaws...

[mordantly]

i can tell you machining the table, trunnion, or vise is not the most ideal situation!

also trick are the magnetic 3- and 4-jaw chuck stops...

[Magnum164]

i can tell you machining the table, trunnion, or vise is not the most ideal situation!

Well I definitely not planning to machine any of those any time soon. Not by design anyway.

[Don Clement]

There are soft jaws for 2 piece 3-jaw chucks. I make mine on the Tormach from 6061-T6 stock see: http://i72.photobucket.com/albums/i1...SoftJaws-1.jpg
The soft jaws are machined mounted in place on the chuck under load at the diameter of the part being held so runnout is negligible. In addition when machining the soft jaw a built in stop is machined so no magnetic stops are required.

Don

[R.DesJardin]

I too use 6061 soft jaws, I make them myself because it's cheap. I also machine steps in the so I don't have to use parallels. That way I can face a short part on both ends, just cut into the soft jaws. This really makes things easier.
Once you get used to these you'll love'm.

[Don Clement]

Also soft jaws called pie jaws that have an all around grip like a collet. see: http://www.usshoptools.com/current_y...pdf/PGS_40.pdf With Pie jaws there is no need for a six jaw chuck.

Don

[Magnum164]

I may buy some material this week to make some soft jaws.... I guess part of the fun is making the tools as well

[mordantly]

only annoying part of pie jaws is when you need to take them off...