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Another stray machine followed me home.

gerritv said:
I avoid wathcing the 'Im a personality looking to make money off YT nonsense' 'machinists' Like Ave, Abom and a load of others. ThatLazyMachinist is an ex-instructor, he has excellent videos, theory and practical. OTOH Suburban Tool makes a living grinding and rebuilding grinders. He isn't the first to remove some material from a wheel to balance it. But it wouldn't be my preference due to lack of practice, and nerve. :)
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I think that is a pretty good way to look at it. I don't trust the self anointed experts, those with vested interests, or the personalities. I'm ok with learning from someone who genuinely has the skills, experience, knowledge, and desire to teach it.

I share your "nerve" reservations. That pretty much sums it up. Ive seen first hand what grinding and cutoff wheels can do when they decide to let go. Even if suburban drills grind stones for a living, and really does know what he is talking about, I think it's irresponsible to suggest that greenhorns should do that. You should watch the video to see first hand what he did to a wheel. Unbelievable.
 
Mcgyver said:
thanks for the kind remarks. Its shades of grey and probabilities imo. Most commercial guys afaik don't balance them, which is a function of their working with larger heavy grinders that damp small vibrations better than light. I would argue with those guys that you can't completely dismiss the idea of balancing, balancing might matter on a small light grinder. That's a bit theoretical in that results depends on wheel, finish desired, work etc...but in my practical experience balancing is not necessary or critical to success. I'll rephrase that...in my experience the state of balance after dressing the OD of a quality wheel is good enough. Dressing removes the OD eccentricity which is most of the imbalance and so long as the wheel is not disturbed (that's why put a VFD on the SG, so there is no jarring to disturb the wheel) it should work well.

I do recall once a Camel wheel that was so badly out of balance it was unusable dressed or not. I balanced it and its work well since.

It won't hurt to balance, I just didn't find it very impactful when I was chasing the best finish possible. A very well balanced motor, 3P, flood, soft start, quality wheel correctly selected, properly mounted chuck, dressed wheel etc are what had biggest impact. If you are going to balance you definitely need to fix the wheel to the adapter and leave it on the adapter for balancing and grinding...if you take it off the adapter you start over.
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Good info @Mcgyver . Thank you.
 
Susquatch said:
. Even if suburban drills grind stones for a living, and really does know what he is talking about, I think it's irresponsible to suggest that greenhorns should do that. You should watch the video to see first hand what he did to a wheel. Unbelievable.
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Is there a link here somewhere...now you've got me curious!
 
I was trained by a grinder hand. He balanced every wheel, regardless of intended use. He felt it was unprofessional to do otherwise.

In his later years, he remounted a wheel and spent an hour getting it 'perfect' it was fascinating to be there and see him do it. and have him explain in detail as to why.

He did many feats of outstanding accuracy in his time, and always chased sub tenths accuracy in his grinding.

I'll never be as good as he was, but I balance all the wheels that I can - diamond wheels are can be particularly difficult - and gind the best I can. My grinder is a Brown and Sharpe Valuemaster 612. A solid, capable machine... I'm sure I'll never get good enough to need a more accurate one.
 
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Here is the Suburban Tool Inc video. At the 8 min mark Don gets into balancing. He does not show the actual “drilling” process to remove the material.


Stan, in this video shows how to use a drill press to balance a grinder wheel.

 
RobinHood said:
Here is the Suburban Tool Inc video. At the 8 min mark Don gets into balancing. He does not show the actual “drilling” process to remove the material.


Stan, in this video shows how to use a drill press to balance a grinder wheel.

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@Mcgyver - You can see the drill marks at 9:26 to 9:50 in the video @RobinHood provided. Suburban Tool goes on to say that this is insignificant.....

Screenshot_20220524-150124_Chrome.jpg


Three holes in a nice stress raiser lineup. Surface flaked off from pounding with what was probably a masonry drill...... Looks like a mine-field. Calls that "insignificant". Lordy Lordy......

Like I said before, I would NEVER tell someone else to do that even if I were as much an expert as he claims to be.
 
I have balanced AO wheels with a masonry bit in a drill press. There *are* rules for safety. You never go more than 1/4 the thickness of the wheel in drill depth. You also never make it a hole (no cylindrical section) but just make the 'vee'... This minimizes the stress rising. I was taught to stagger the holes with at lease 1/3 diameter between holes.

Remember the only force that is significant is an even force in tension - there is little radial force - or there'd better not be... I know Surburban do a pretty deep roughing pass, but the feed speed is very slow with a Very Coarse wheel, which limits those forces (as well as coolant)

I treat grinding operations a delicate operation, and minimize my cut depth and feed rate to minimize heating and reduce stress on the machine. It is the old adage "go slow - but not too slow'

When taking tenth or less, I go very fast to reduce glazing the wheel. Again very low stress.
 
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Dabbler said:
I have balanced AO wheels with a masonry bit in a drill press. There *are* rules for safety. You never go more than 1/4 the thickness of the wheel in drill depth. You also never make it a hole (no cylindrical section) but just make the 'vee'... This minimizes the stress rising. I was taught to stagger the holes with at lease 1/3 diameter between holes.

Remember the only force that is significant is an even force in tension - there is little radial force - or there'd better not be... I know Surburban do a pretty deep roughing pass, but the feed speed is very slow with a Very Coarse wheel, which limits those forces (as well as coolant)

I treat grinding operations a delicate operation, and minimize my cut depth and feed rate to minimize heating and reduce stress on the machine. It is the old adage "go slow - but not too slow'

When taking tenth or less, I go very fast to reduce glazing the wheel. Again very low stress.
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That sounds a lot better than what Suburban did.

What does this vee look like and how is it made? Drill on an angle so it scoops a little gouge out?
 
gerritv said:
it's the same as what Suburban tool did, you go only as far as the tip width, as in a dimple, no side walls.
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I see. Makes sense.

My examination of the suburban drilling is that it was significantly deeper than that. Especially the small hole on the left in my photo. It's hard to tell what they all did. Mostly it looks like a butcher job.

But maybe I'm being too hard on them.
 
I vaguely remember something about air shafts for grinders in high school oh some many years ago. Basically the stone was centered by an air shaft thereby balancing itself. Each start up requires dressing to get it balanced.

Strangely enough all the used stuff I've seen does not have air shafts.
 
Degen said:
I vaguely remember something about air shafts for grinders in high school oh some many years ago. Basically the stone was centered by an air shaft thereby balancing itself. Each start up requires dressing to get it balanced.

Strangely enough all the used stuff I've seen does not have air shafts.
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Do you mean airr shaft or air bearing?
 
Degen said:
Not sure, it was high school oh to many years ago.
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A weird machine tool followed me home the other day along with a cadre of more recognizable tools. I have no idea what it's for but I'm betting it has an air bearing in there someplace....... See the second photo.....
20220525_133820.jpg


20220525_133855~2.jpg
 
While I'm thinking about grinding wheel issues,

I was contemplating grinding some locators for some of my mill equipment when it suddenly dawned on me why some people call a machinist's vise a grinding vise!

Up till now I've been wondering how and why anyone would ever use one with a bench grinder!

But I'm betting I can put a machinists vise on the magnetic chuck of my surface grinder and it suddenly becomes..... A GRINDING VISE!

Funny how owning new and different equipment suddenly changes your perspective of certain things! LOL!


20220525_134913.jpg
 
Nobody have a guess? Seems like the detours got us WAY OFF COURSE and I never got an answer to my question. My sincere apologies if I missed any comments that were provided.

Post in thread 'Another stray machine followed me home.' https://canadianhobbymetalworkers.com/threads/another-stray-machine-followed-me-home.5211/post-77099

Maybe members prefer to critique someone else's thoughts. So I'll take a crack at answering my own question.

I'm thinking that the taper on these grinding wheel adapters is not very precise. In fact, I've seen 3 inches in 12 and other measurements like 2.97 in 12 and a few others floating around.

Making an entire taper fit from back to front prolly isn't very easy to do across the whole length of the adapter taper. In that case, maybe two much shorter sections separated by a recess might improve the fit of the adapter to the spindle taper.

In other words, the recess provides the opportunity to tighten the taper enough to get a good fit.

Best I can do. Anyone disagree?

Second question - for the replacement adapter I am making, do I cut a recess or leave the entire taper intact across its length? Either way, why?
 
Susquatch said:
machine tool
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It is a grinding spinner. Gotteswinter motorized his and Renzetti has made a Harig clone of a similar design. It is used to provide a slow constant rate of spin to accurately grind tapers and cylinders.

If you don't want it I'm sure Dabblers Custom Recycling could find a use for it! (just kidding);)
 
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