Use of aftermarket ER20 collet nuts. My machine seems to be a different spindle thread than the 25mm 1.5mm standard. The OEM nut fits perfectly and seems to be 24mm x 1.5. Anyway it’s a full 1 MM smaller than the standard.
It may be just my machine but, I certainly don’t want anyone to get hurt or damage their spindle threads.
I did not see this problem till it was brought to my attention by AlexW. You would never know it unless you put it on the spindle without a collet inserted.
There’s two types of commercially available ER20 collet nuts- one comes with M24x1.0 threads and the other comes with M25x1.5 threads.
When we were designing the MR-1 spindles we accidentally spec’ed an M24x1.5 thread on the drawing. By the time spindle shafts were in production, it was too late. The only option we had available was to customize the collet nut threads to be M24x1.5 to match.
We’ve got a good supply of these collet nuts now so we’ll make them available for purchase on the website.
Anyone who has a machine in their shop that takes a ER20A collet nut can have 14 brand new nuts. Just pay me for shipping and they are yours. Due to the fact that they don’t fit my MR1, they are of no use to me. They are all brand new in the boxes. You can email me or just respond to the forum. jmessar2166@gmail.com
You clearly have those nuts for a reason (although sized wrong). What is your operating philosophy that uses a bunch of nuts. This is all new to me so I am not getting it.
Thanks,
I set up all my often used collets with the nut attached.
My thought was it would speed up the process. I was wrong. The time saved was not worth the effort.
I like to blow out the taper inside the collet nut each time I install a new collet. Otherwise chips can get in there and cause runout. So, for me, having more than one collet nut wouldn’t be a benefit for me either.
On a prior machine with an ER spindle I found it helpful to keep nuts setup with tools and collets inserted. It allowed for faster tool changes and I could keep them all labeled with the tool numbers so that I quickly knew what to grab when doing a tool change.
I’ll probably buy a few of them when they are listed. On the MR-1 it would be nice to have a dedicated collet nut and collet for the probe since I use it so frequently.
As a fellow design engineer, it makes me feel better that I’m not the only one that encounters these kinds of mistakes; bet that was a bad day. I love the honesty, thanks!