Working on my DIY Tool Post Grinder-Ugh

[Janderso]

Your more persnickety than me. I would just run a center punch around the i.d. and smack the bearing in. Mike

Oh believe me I’ve considered it.

 

[Janderso]

I found this video that I remember watching a while back.
I’m gonna play around with this method.

 

[Jake M]

I found this video that I remember watching a while back.
I’m gonna play around with this method.

I saw that one, and it messed me up for some time.

One has to remember that he uses (or used at that time?) new or used inserts made of some kryptonite carbide, that he laps dead sharp for the tiny (borderline miniature) work that he typically does. He's done that for so long that he forgets to mention it sometimes... His tools are sharper than I can grind, it takes fine stoning (and plenty of it) for me to replicate is results. He uses millimeters, but he likes to take (usually) three or four thousandths on a cut, double that off the diameter. I find that if I want to work that way, I can take an HSS tool off the grinder, touch it up on a generic oil stone, and get those results at 0.010 or 0.015 on the diameter. I'm using a fairly light lathe, and I'm sure that matters, but don't be afraid to try numbers that are a little coarser when you're setting up your approach to a dimension.

Those practice pieces you've got are the exact same material, results will transfer nicely to another chunk of the same stick....

 

[mmcmdl]

Your more persnickety than me. I would just run a center punch around the i.d. and smack the bearing in. Mike

For a home job so would I . A little Loctite retaining fluid and I think it would be good to go .

I sneak up on it with a sharp HSS tool bit. Cut the last .003" and blow it by .001" ish.

A couple of spring cuts are needed if you're trying to hold .0005 or close to that . Hard to dial that in on a cross slide . Are you making an internal grinder Jeff ? Pics ?

 

[WobblyHand]

For a home job so would I . A little Loctite retaining fluid and I think it would be good to go .


A couple of spring cuts are needed if you're trying to hold .0005 or close to that . Hard to dial that in on a cross slide . Are you making an internal grinder Jeff ? Pics ?

I'm sure Jeff knows this, but one can take some pretty fine cuts by angling the compound. I've done 0.0001" cuts by setting up the compound to go in 1/10 the dial movement. Just look up in your trig table to find the angle when sine(angle)=0.1. I don't remember the value, I just calculate it on my phone. 5.74 degrees relative to the spindle axis with remove 0.1 x the dial. The tool has to be so sharp you bleed looking at it! But it works. At least it does on 1215, 12L14 and 1144.

 

[markba633csi]

When you get tired the urge to "hurry up and get it done" often wrecks your part
BTDT
road sign: "Caution- croaker sacks operating machinery next 20 Km"

 

[Janderso]

For a home job so would I . A little Loctite retaining fluid and I think it would be good to go .


A couple of spring cuts are needed if you're trying to hold .0005 or close to that . Hard to dial that in on a cross slide . Are you making an internal grinder Jeff ? Pics ?

This is all I got so far.
The bearings are 23,000 RPM rated. .590" ID and 1.259 OD

Internal - External grinder. Hopefully

 

[Janderso]

I'm sure Jeff knows this, but one can take some pretty fine cuts by angling the compound. I've done 0.0001" cuts by setting up the compound to go in 1/10 the dial movement

I know the trick but I forgot to try it.

 

[mmcmdl]

What size wheels are you planning on using ?

 

[Janderso]

What size wheels are you planning on using ?

I was thinking 3" OD and haven't got that far on the ID.
What do you suggest?
Router motor with variable speed. Maybe rechargeable - no cords would be nice.
Harbor freight??