DIY OD Grinder fixture, For the surface grinder- maybe

[jwmelvin]

Ah, I’ll have to look that up. I don’t know what a double x ring is.

Here's the McMaster page. I just came across them looking for an o-ring to use. I had heard of x-rings, which are an evolution of o-rings, and these are a further evolution. They seem great.

 

[Janderso]

Here's the McMaster page. I just came across them looking for an o-ring to use. I had heard of x-rings, which are an evolution of o-rings, and these are a further evolution. They seem great.

My dimensions need to be,
ID 1.773
OD 1.976

Do I have wiggle room? Do they stretch?
I think .125” thick would be fine.

 

[jwmelvin]

Do I have wiggle room? Do they stretch?
I think .125” thick would be fine.

I don't think I'd want to stretch it that much, but the bigger issue is that you'd have a tough time getting it assembled; you need the seal in the OD groove, and then push the shaft through, expanding the seal. With your dimensions, finding a seal seems difficult. Maybe the positive-pressure setup is a nice way to do it, accepting that an air line will be a little cumbersome.

 

[Janderso]

I don't think I'd want to stretch it that much, but the bigger issue is that you'd have a tough time getting it assembled; you need the seal in the OD groove, and then push the shaft through, expanding the seal. With your dimensions, finding a seal seems difficult. Maybe the positive-pressure setup is a nice way to do it, accepting that an air line will be a little cumbersome.

You have a good grasp of my situation.
I may play around with felt and a delrin retainer??
I don't know. I may just move on and get back to it later. Much to do yet.

 

[jwmelvin]

What about a face seal? You can use an o- or c-ring like that. Edit: I see that the spindle doesn’t have much room for that. Maybe just a thin shield on the shoulder of the spindle (large washer) would cover the joint enough.

Felt seems better than nothing but will trap grit and wear the shaft; at least that would be my concern. Though, if behind a shield, I imagine it would basically last a home shop forever without maintenance.

 

[Janderso]

What about a face seal? You can use an o- or c-ring like that. Edit: I see that the spindle doesn’t have much room for that. Maybe just a thin shield on the shoulder of the spindle (large washer) would cover the joint enough.

Felt seems better than nothing but will trap grit and wear the shaft; at least that would be my concern. Though, if behind a shield, I imagine it would basically last a home shop forever without maintenance.

I agree, simple seems the way to go and you nailed it. This will serve me well for many years.

 

[Ischgl99]

My dimensions need to be,
ID 1.773
OD 1.976

Do I have wiggle room? Do they stretch?
I think .125” thick would be fine.

That’s 45mm ID, so it would be easy to find something in a metric size that will fit the shaft. The OD is small for most seals of that shaft size, so you might need to use an o-ring. McMaster doesn’t have the double x rings in metric, but you could get x ring cord stock and make exactly what you need.

 

[jwmelvin]

That’s 45mm ID, so it would be easy to find something in a metric size that will fit the shaft.

Goodness, seems so obvious now! Thanks for the guidance. This definitely seems like the easy button. I’d use a simple o-ring and not worry about possible benefits from an x-ring.

 

[Ischgl99]

Goodness, seems so obvious now! Thanks for the guidance. This definitely seems like the easy button. I’d use a simple o-ring and not worry about possible benefits from an x-ring.

I worked for German companies and with metric machines most of my career and got accustomed to seeing oddball imperial dimensions when someone converted a metric part to imperial, so any time I see inch dimensions that don’t fit a fractional size, I automatically check and see if it comes out to a whole number of millimeters.

 

[Janderso]

I worked for German companies and with metric machines most of my career and got accustomed to seeing oddball imperial dimensions when someone converted a metric part to imperial, so any time I see inch dimensions that don’t fit a fractional size, I automatically check and see if it comes out to a whole number of millimeters.

I don’t know why I fight the metric system. It’s so simple.
When a dimension says .5 or 6 x 28 mil. I have no idea what dimension that is.
But, if it’s a hex on a bolt, 7/16 or 12mm etc. is easy to understand as this comes from experience.
Old habits and all.