It is not unusual for shaft mounted encoders to have some strain relief
rather than a hard connection. see link.
https://www.shopcross.com/zo-.25bore-200ppr?msclkid=0c56646795e81faf9ef104ab7e98b74f&utm_source=bing&utm_medium=cpc&utm_campaign=(ROI)%20Shopping%20-%20No%20Numbers&utm_term=4586406598964502&utm_content=Everything%20Else
YMMV
Dave
On 6/18/21 11:04 AM, Gregg Eshelman via Emc-users wrote:
Reamers can be some fun stuff. I hand reamed the spindle on a 1913 Sears Expert (made by South Bend, an
"Old, reliable" manufacturer that was all of 4 years old back then) 14" metal lathe out to
just over 3/4". The ends of the spindle bore were just a hair over 3/4" but in between was smaller
and pretty rough. I wanted to have it able to pass a 3/4" diameter bar all the way through, so I made it
happen, one small increment at a time.
On Friday, June 18, 2021, 11:07:09 AM MDT, Gerrit Visser <gerr...@psgv.ca>
wrote:
Reamers don't work well in nominal size holes. So always leave enough meat ofr it to do its work. The attached link gives good info on that topic.
Machine reamers cut on the leading edge only, there is no taper. Hand reamers
have a taper, and won't cut to a shoulder.
If concentricity is the key goal, then drill well under size, bore to reamer
alloance and then ream.
https://www.fltechnical.com/news/reamer-guide-basic-technical-information-for-reamers
Gerrit
-----Original Message-----
From: John Dammeyer <jo...@autoartisans.com>
Sent: June 18, 2021 11:49 AM
To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net>
Subject: [Emc-users] Machining question
This isn't as much a LinuxCNC question but more of an approach to how to
machine something.
The attached photo shows a coupler from a 3/8" encoder to 14mm Servo Motor so I can test on the bench the Pi4 closed loop encoder behavior.
This one didn't turn out very well. I drilled all the way through and then used a reamer to bring it to 3/8". It's a firm sliding fit on the encoder shaft. Without removing it from the chuck I then drilled halfway to 13mm and then used a 14mm reamer to bring it to size, testing with the motor shaft.
Problem was the reamer was slightly tapered at the front so it did a poor job. I finished it up with the boring tool but maybe a few thou too large. However the wobble seems much worse than that.
I'm thinking the better approach would be to drill all the way through undersize 3/8" and then drill half way with 13mm. Then only use the boring tool to bring the back half up to 3/8" and the front up to 14mm. This way if the initial hole wasn't concentric with rotation the boring tool would ensure it is.
Make sense? Or is there a better way?
Thanks
John
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