Another Tool & Cutter Grinder

rhynardt said:
Hi Mark.
Could you not perhaps make a dummy 5C collet/bush which you hollow out to take ER 25 or 32 collets. the nose part you can cut and thread for the ER clamping Nut.
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I can make the 5C adapter, but I have to buy a collet set and can get it and the set together. Save me making it. just make the adapter for my lathe. I have pretty much decided to make the adapter for my lathe to have the through hole capability. Now to decide ...buy two different collet sets or get the adapter for the grinder. my only concern is every place there is a fitting of sorts, you can lose some run out accuracy. I could be worrying too much and it would not be a problem. I don't know.
 
I would get the 5C adaptor. In the lathe you can then true everything up much easier than in the grinder
 
I personally like the idea of the 5c to er40 conversion. Like you, I don't think the added length would be a problem, but I have no idea if or how much accuracy you would lose?
 
wrmiller said:
I personally like the idea of the 5c to er40 conversion. Like you, I don't think the added length would be a problem, but I have no idea if or how much accuracy you would lose?
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I don't think I will lose any accuracy especially on the air bearing. I think I am going to do that so I only need one set of collets.
 
I made my decisions. but first..... Since the grinder column is mounted permanently and finished, I decided to do some accuracy and squareness checks. Since almost everything adjusts, I can get as close to perfect in all directions as I want to work at. EVERYTHING flexes to some degree. And as heavy as this machine is built, you can grab hold of it and flex it a thou or two with some effort and that is over at least six to eight inches. This is not a problem because there is really no pressures or stress grinding tools. ( it is heavier and more solid than the Bonelle , and it works fine) Next I wanted to check my wheel arbor. :eek 2: And ....holy runout Batman!! this thing has .004" runout. I removed the arbor from the motor and checked the motor shaft ..... .0005" runout. The 12 mm shaft measures .470" and my adapter measures .472" bore. :cautious: That is why there is .004" runout. Now I'm thinking I got to make a new arbor to get it perfect.... or wait!!!! .... I have two set screws , 90 degrees apart.... if I put 4 set screws , 90 degrees apart, I bet I could get this thing almost perfect. by messing with the set screws. By now I have been fussing with this mess for a half hour or so and started looking at the grinding wheels. THE GRINDING WHEELS AREN'T EVEN THAT ACCURATE! ..So What am I fussing about? I spent two hours on the computer trying to find one or figure a way to put an ER 20 collet chuck on this motor. But if I did , I would never get closer than a couple thousandths changing arbors in a chuck. I finally realized that idea is no better than what I already got and what I got is better than any grinding wheel , so I just wasted a whole afternoon fussing over .004" that is almost impossible to make much better.
Now..... what got me started on this whole mess, besides my extreme habit of being a perfectionist, ( which can be a problem when you try to do anything), Is I had a discussion with my good friend ***** ****** about grinding wheels. He mentioned if I put a wheel on and true it up by dressing it, I would have to dress it every time I removed it to use another wheel and put it back on again. And he is correct here. I did not care for this fact. Through discussion , we agreed that mounting the wheels on their own arbor and using a chuck to hold the arbors, this problem would be gone. That is almost true, and I have proven this theory on my Bonelle grinder , which has an ER 20 collet. When you put the wheel and arbor in the chuck, dress it, remove it, and put it back, it is close but not as good as it was. there is always a couple thousandths difference here and there. So to sum this up ... IT AIN'T GONNA GET NO BETTER THAN IT IS .... so I will leave it alone and be happy with what I have made. I may have to re dress the face, but not the periphery of the wheel as I don't grind on it ...much.

Now back to my decisions ..... about the collets for the air spindle. I have decided to get a 33 piece set of 5C collets by 64ths for the grinder and later I am going to also get a set of ER 40 collets for the other machines. When building a machine comparable to a $10,000 commercial machine, it deserves a dedicated set of collets.
 
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Mark
Sounds like you have a plan. I hate trying to solve a problem and everything done seems to be a waste. If I might suggest maybe make a new spindle mount for the shaft, drill and ream it to 12 mm then put set screws but do not use them to start with. Disassemble your motor and take the new spindle end placing it on the shaft with loctite then after set run in set screws. After that put it on a lathe that will cut true and metric threads for the collet nut and the taper inside. A steady rest might be needed to cut the 8° taper. Or just stick with your plan.
Glad to hear you doing better.
Nelson Collar
 
The point I was trying to make in my above rant was......... You cannot make something perfect! you can get close, but you cannot get perfect. This is true with ANYTHING in life. I could spend hours and , to me , a lot of money trying for better, but it won't matter because I cannot achieve perfect. If you buy a new machine, it is not "perfect". I was trying to avoid the need to redress a stone when changed, but realized that is an impossible task. There will always be a tiny bit of error. WE have to be intelligent enough to know when we have achieved the best possible level of quality. Could I reduce .004" error to maybe .002 or even .001? Sure, but it really won't matter because the error is small enough you won't know the difference anyway. This is an important lesson for someone who, like me, expects perfection. I have thrown away a project and started over because of this fault when anyone else looks at my discard and thinks it is "perfect." I know there are others in the world that think like I do in this area and it is hard for us to do things because we find all imperfections and cannot accept them. Can I make a system that would work a little better? sure, but why spend the time, money, and energy if it is not necessary. To achieve the level I "want", EVERYTHING and every part of the collet setup would have to be ground to "perfection" and that is beyond most hobbyist's abilities or availabilities and I don't want that. I want a project to be achievable by anyone and at a quality level as good or better than store bought.

And now back to our regularly scheduled project build.
 
Reality Check --- I want to do everything perfect, even when I don't know how. Great work is possible, perfection is not. The ball is set way to high . We can get close, but the closer we get the farther away it gets. I'm not saying don't reach for it because we always get better. Someone will always see something you don't and the next time you will get by that one. Guess what, it will happen again.

"Billy G"
 
Bill Gruby said:
Reality Check --- I want to do everything perfect, even when I don't know how. Great work is possible, perfection is not. The ball is set way to high . We can get close, but the closer we get the farther away it gets. I'm not saying don't reach for it because we always get better. Someone will always see something you don't and the next time you will get by that one. Guess what, it will happen again.

"Billy G"
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That is correct Bill. That is why I made the point. Some of the hobbyists say " I could never do that good of work". That is self defeating because they can.... They just may not know it. Some folks, even other machinist are in awe of some things I have built , but I see a flawed piece of failure in my view and that is me chasing something unattainable ..... Perfection. Every piece gets better though.
 
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