Grinder Woes... the final chapter. And one VERY HAPPY ending!

[Joshua Dinerstein]

I posted some time ago asking about whether or not 1 end of a grinder could be bad. Because I just couldn't get it working what felt like right. I got wobble and shake and bouncing tools no matter how hard I tried. And then noticed that my diamond T-dresser was just as bad. When trying to true it up it was bouncing and "ticking" on the wheel.

Enter a very helpful person in Joe Bradshaw, who answered a dozen PMs after having innocently posted in a thread on grinder choices. I followed what he said and just started experimenting. Having never torn a motor apart before it was kind of... interesting.

All I can say is WOW! Seriously WOW! It is not only better it is amazing. Not a baldor but then with all the upgrades it still cost less than $125.

I found an Applied Technologies store in town that had bearings the right size. From them I got some Nachi bearings that were made in Japan. I just felt better about something of a quality that was hopefully higher than the super cheap bearings coming out of china. The Nachi bearings were $6.13 a bearing whereas the Fastenal bearings were $3.16. They also had some SKF that were $13 each and Timkin for $16. So it was a nice price point and not made in China and I went with it. (The bottom line was that I just did not want to have to do this again in 6 months. OK so I had no idea how long they would actually last but it seemed reasonable at the time.

I then got it disassembled. Joe was right and it was honestly a piece of cake to operate on this device. 3 bolts took the inner wheel cover off. 4 smaller blots/screws tool the housing of the grinder off. It was a real pain to get it off. I had to beat on the arbor on the far end to get it out. A wooden mallet a few light smacks and it came sliding out the other end. At that point it took some tools I didn't have, like a bearing puller, but I was able to borrow those from a co-worker and to be honest having a bearing puller is actually pretty darn useful. So I found some at HF for a decent price and I will be adding some to my collection of tools.

At that point it was just reverse the process. I got the bearings on and the arbor back in place and just reassembled thru the point of the main motor housing. I turned it on at that point just to check that it would turn and wasn't hitting or misaligned or anything, AFTER rotating it by hand first. And it worked exactly as expected. I then got the wheels remounted and it checked the balance, I put a ton of time into that in the past, and I had carefully marked things and they were "perfect" on the first try.

I then got out some tools and started sharpening them. WOW! What a difference. It feels like a totally different machine and more importantly process. I had not realized how much I was countering for the "offness" of the grinder apparently from the very beginning. Now that I don't have to it is amazing to me how much easier it is and how much better the edge is. It is so smooth it really is just all different.

Most importantly the ticking and bouncing are completely gone. I get a smooth even grind almost effortlessly now. It really does feel like I am having to "re-learn how to do it" a bit but now things just get better each time instead of being nothing but frustration. I put an awesome edge on all of my tools. You know... for the first time sharpening was almost as fun as turning... Interesting...

Thanks again to Joe and everyone else for all the help! Can't wait to get a Geiger Truing device. I have been drooling after them for months now. But with Twins on the way every penny has been going into getting ready for the new children. (So bear with me Don!) Turns out we need new car seats, new stollers, more bottles, more clothes, more more more. But we have most of it now so soon I get to make this whole process even better!

But the key? Those inexpensive Woodcraft slow-speed grinders are pretty easy to fix if anyone experiences what I did then go to town and for an hour or two and $13 in bearings you will be set. And more importantly for me now?!!? It is time to go back to turning at long last!!!

Joshua

[Steve Schlumpf]

Sounds like you had quite the adventure! Happy to hear that everything is now working - like it should! Hope you get some lathe time in before the twins arrive!

[Bernie Weishapl]

Really glad you got it working Joshua. Hope there is some shop time on the lathe before it all breaks loose.

[Tony De Masi]

Man, after such a long thread it seems silly just to say " glad you got it fixed " BUT, I'm glad you got it fixed.

[bob svoboda]

That's got to be a huge relief. Way to stick with it! I've been hearing some noise from mine that sounds like a bearing problem so glad the fix doesn't sound too bad.

[Thom Sturgill]

Glad you got it fixed. I just got one of Don's truers from him at the Florida Symposium. He had come to our club meeting a week or so before and our president bought one and demoed it at the get together at his shop - what a difference! even though I think that I was getting about as good as it gets with a diamond T dresser, his produces a m-u-c-h smoother wheel and cleaner grind.

Your story goes to validate something I've been saying for a while - one of the key differences in many of the machines we buy is in something as simple as the quality of the bearings, and they are often an easy upgrade.

Now use those sharpened tools and get some turning time!

[Kieran Kammerer]

Joshua,

Having just gotten the Geiger Truing device this week, I can tell you it works extremely well. Don was very helpful through emails. Package arrived as promised, well paked and no problems setting it up and truing the wheels. Once I get some time, there will be some other type truing devices for sale in the classifieds. Kieran

[Scott Crumpton]

Joshua,

What's the bearing series code number for the replacement bearings. It should be something like 6203ZZ or 6804RS. This info would allow one to buy the replacements before disassembling the grinder.

Thanks,
---Scott.

[Joshua Dinerstein]

What's the bearing series code number for the replacement bearings. It should be something like 6203ZZ or 6804RS. This info would allow one to buy the replacements before disassembling the grinder.

Sure. Mine, apparently it is a very common size for 5/8" arbor grinders was a: 6204-2rs.

If I recall the measurements exactly it was a 20mm ID, 47mm OD, and either 12 or 14mm wide. Other brand had slightly different numbers but when I called around to the local bearing vendor shops I gave them that #, 6204-2rs, and they all immediately knew what it was and whether or not that had them.

To anyone looking to do this kind of upgrade/repair I would definitely recommend that you call around looking for prices. Even though I was trying to pass up super cheap stuff from China I found a very large range in the bearings. NAPA had them in stock and just down the street from me for $29.99 a bearing. Ouch! I called about 5 places. Some what basically $20 a bearing and most/many came in at $15. Since I got exactly what I wanted for $6 it was well worth 10 minutes of phone calls.

I would add to anyone looking to do what I just got done with please feel free to contact me and I will happen to tell you what I learned and what my rough steps were. I can post them here if people want more details as well. I am about to do it to another grinder I have to try and help it along. If I do I will try to take some pictures this time and get them posted as well.

Joshua

[Bill Hensley]

Joshua - any additional info about the bearings and the process would be a great help. I have the same grinder and I'm struggling to get it trued up.

Did you replace the wheel bushings?

You can PM me if you'd rather. Thanks much!

[Paul Singer]

Joshua

Please try and post to this thread instead of private PM's because alot of us have this grinder and I am sure there is alot of interest. I bought mine last year after they had stopped selling it for a while. I guess they lost their source and had to find another provider. I am sure the new grinders are no better than the older and maybe worse but if you had problems I am sure there are alot out there like that. My question is when did you purchase yours?

Thanks.

[Joshua Dinerstein]

Sure. Coming right up. I have a pretty long and hopefully thorough write up under way. Should be up today. No pics yet so trying to be clear in what I write.

Joshua

[Don Geiger]

Dear fellow woodturners:

Josh: I'm glad to see that you worked out the problems with the bearings.

When I was just out of high school, I worked in an electric motor repair shop. During my 1.5 years there, we rebuilt and re-wound hundreds of electric motors. It was common practice to cross-reference bearings when odd motors showed up. Please realize- this was before there were PCs on everyone's desk and of course there was no Internet. If any of you have problems with bearings etc. don't hesitate to look up a local motor repair shop and give them a try. Of course if they do the work, they will charge you standard hourly shop rates.

Anyone out there having grinder and tool vibration and wheel wobble problems- these can be fixed by:
1) Replace the plastic bushings with steel headless drill bushings (available from McMaster-Carr and other sources)
2) Shim between the inside of the cup washers and the sides of the wheels using paper sticky dots as shims to eliminate wheel wobble
3) Use a good quality truing device (not just a wheel dresser) to make your wheel absolutely concentric to the axle.

If you do these three things your grinder should perform optimally. The whole process should take about 30 to 45 minutes.


Don Geiger

[Joshua Dinerstein]

For those that requested it here is a write-up and something of a summary of my pathway thru Grinder-doom on the way to what has become a truly great solution. Some of this has been sent in various PM's and I have tried to gather all of that together to get it captured here.

What started this whole thing for me was the realization after being at the local Utah Symposium and watching and listening to Richard Raffan and Jimmy Clewes that they were getting much better sharpening done than I was. Jimmy especially drove home the point that a truly sharp edge was crucial. So I came home and took a good look at things. The wheels were shimmying side to side as the grinder ran. The whole thing as a result vibrated like mad. Not off the table but way worse than what I had seen demonstrated. And as suggested I listened to the tool lightly resting on the wheel while running and there was an audible bouncing/pinging sound that did not diminish. So began my journey.

The grinder I have been having trouble with is "older" model of slow speed grinder from WoodCraft. When I realized I wasn't getting good results I went down to the local store, only about 8 minutes from work, and looked at theirs. The new one was the floor model and the old one was in their teaching room in the back. I haven't used the new one at all so something like the exact model of bearing might be different tho the rest of what I had to do should be exactly the same.

In summary my clue that things weren't working right was when things started bouncing off the wheels. Both the diamond T-Dresser, also from WoodCraft, and the tools I was trying to sharpen. When this bouncing started happening I started to get a truly wretchedly rough/bad edge. At that time I queried here on the creek as I tried to find a higher quality replacement for the Grinder. But the low speed grinders seem to pretty much all be gone, Delta had a great one that is no more, in favor of a shift to variable speed grinders. I do not "know" that these are bad. But when I went and looked at the Porter Cable and Steel City versions at a local store you could visibly see it speed up and slow down trying to stay in a certain range. Personally I thought that that would be detrimental to sharpening so I didn't buy one. YMMV. Which led me to looking at professional grade grinders. I love the thought of a Baldor, I have a birthday coming up if anyone is feeling generous... , for quality and the general OOOhhhhh! factor but couldn't bring myself to spend $800 on an 1800 RPM 8" one. Most of the others were of unknown quality and almost the same price tag. A slow-speed Jet at 10" is still available but I worried about good alignment with a Wolverine jig given the wheel size. Dayton had no slow speed 8" but had a digitally controlled VS 8" that I haven't had a chance to see in operation but it was tempting until I saw that the price tag was over $500. It just seemed that at that point I may as well go all the way to the Baldor and get the best. I had just about settled on either a used low speed old Dayton I found which might have needed repairs, or a new Jet 8" high-speed. It was at this point people here suggested I repair what I had. So I decided to try. After all as the old adage says: "Try to fix it, if it breaks... it needed replacing anyway..."

I had never done that kind of repair work or ever in my life opened a motor. So it was entirely new and more than a little unnerving to try it. But advice here on the creek and a willingness from the LOML to let me go buy a new one if I killed it made me quite brave! Now after having done it once I would recommend doing it to anyone who is having problems. It is easy and direct and improved the performance amazingly.

Further it took only 1 specialized tool, a bearing puller. Which can be had from HF, I know I know but..., for about $15 for a set of 4 of them. Others had told me in PMs they didn't need to use one and that they were able to get them off with a simple hammer out process. I tried to hammer them off and it was not easy so I was glad to have access to a puller.

Fumbling blindly it took me an hour to disassemble the grinder. Knowing what I know now it should take about 10 minutes. Then 5 minutes max to swap bearings. And again a maximum of about 10 minutes to re-assemble. For $13 in bearings added to my $89 grinder I am now just over $100 and is working so well it is truly a night and day difference.

The path I took:

1- I bought better/new Norton white alox wheels from Hartville tool. No improvement.

2- I bought a OneWay balancing system. Minor improvement but only on 1 side. The other side never settled down or got better.

3- I talked here with Don Geiger about his truing solution and got load of advice on how to help things. I purchased the suggested bushings to replace what came on the wheel. This helped a lot but didn't resolve all of the problems or at least not completely.

4- During this time I was using only the right hand side of the grinder as that was where the balancer had worked. It was during this phase that I noticed a ticking sound from the grinder even when on but not grinding anything. I then noticed an even more pronounced bounce when trying to dress or sharpen. So things were degrading quickly.

5- I took the thing apart and found out how simple they are and then put on new bearings and put it back together. I reassembled it in stages to check things out. I first put the wheel with the balancing system back on to make sure it was running true and smooth and it still was. I then put on the right hand wheel using just the same old stampled flanges and it was still running without wobble using a cheap and simple method Don clued me in to.

6- I sharpened all of my tools and I got a finish and an edge like never before. Smooth and easy.

So I am officially done looking to buy new grinders etc... I am extremely happy now.

So the processes as clearly as I can record them. How I disassembled the grinder:

1- I removed the outer covers, the way you do when you want to change a grinding wheel. This was 4 small black screws and the covers came off. I set these aside marked as left and right. I don't know that there is any difference or not I just wanted to be as careful as I could.

2- I then loosened the nuts and took the wheels, balancing system and flanges off leaving just the exposed arbors sticking out. When I turned mine on at this point I could still hear the ticking sound.

3- Since most of my problems were on the left side of the grinder, from the sound, I took that inner wheel cover off of that side. It was 3 larger machine thread phillips head bolts. They were easy to loosen by hand and were washer-less on mine. This left me with the uncovered end of the grinder. At this point I used a Sharpie on the back to mark how it was currently aligned at the rear bottom screw hole.

4- 4 more small phillips head screws held this end cap onto the grinder. Again these I removed. It might be worth noting that I really didn't want to loose any of this stuff so I put them all into small sandwich baggies just to not loose anything in the shaving and dust. The end cap should now have been free and come right off.

5- Not so much. I pulled and pulled and even pried lightly once or twice trying to get it off. No joy. I then got a mallet, that I had turned on the lathe from a piece of Cherry, and with just a couple of light taps on the right-hand end of the arbor it came out easily into my left hand. Due to the type of motor in using nothing from the arbor touches or is even really all that near the outer mounting of the motor housing.

6- Then came the failed hammering with the now separated arbor to get the bearing off. It wouldn't budge. Using the borrowed puller they both came off in just a minute or two.

7- Using a longish piece of metal scrap tubing the new bearings were tapped back in to place. Make absolutely certain that you ONLY put pressure on the inner most race. You don't want to start off with damaged bearing by hitting the out-side. A bit of force was need to drive them onto the arbor but that left no marks and did no damage to the bearings. Make sure to have something underneath the arbor when doing this to prevent damaging that when working on the other end. My buddy used a block of wood with a leather glove on top.

8- That's it for dissamebly and "repair". Time to re-assemble. I took the left-most cover that was taken off the central portion and tapped it back into place. This part worried me. I looked and looked for a way to press it into place. But in my small garage shop I didn't have a way. Personally I found that the force need to re-seat it with my wooden mallet was small and left no marks and I believe no damage to the bearing. 2 or 3 light taps seated it nicely. Now I had the arbor with the new bearings in pace and the left cap. NOTE: The portion of the motor mounted permanently onto the arbor is off center to the left. Make sure you re-assemble it in this same orientation!

9- I slid this assembly back into the motor. It was easy to do. The arbor fits with with a fair amount of space. The bearing on the right hand landed and it became a bunch more difficult. I pressed as I could and then tapped the left end of the arbor with the mallet and in 2 or 3 light taps it was driven home. Before the last tap I made sure that the marks on the rear bottom hole were aligned and then I put in only partially one of the screws. It is tapped in the central housing but not in the cover so it slid down it as I tapped it home.

10- Put the screws back and tighten the screws.

11- Put the wheel cover back and tighten the screws.

12- At this point it is just like putting wheels on in a normal way but there were a few things from my own experience that I wanted to point out. When I put the wheel back on the right side with the OneWay balance it went back on easy and ran 100% true again with no changes needed. So Put the outer cover on and considered that side done.

13- I had used Don't method on the left side of a metal bushing and sticky dots. I took great pains when I took that side apart to not lose that alignment. So it went back together easy for me. If you haven't done that before and have side-to-side wobble on the wheels then PLEASE PLEASE PLEASE follow his process it was a big part of this success.

That's it. So on to Don's process for removing the side-to-side wobble. This is all him with just what I had to do to do it myself:

The method that Don told me about for getting rid of side to side wobble was to use little 1/2" round sticky dots. The kind that you find typically pricing things at a garage sale. I got some from work for free but I found them in a pack of a 100 for about $2 at WalMart. You can also use roughly square pieces of masking tape. I just found the dots easier. In the end I needed to use just 4 dots. That's right just 4 dots got rid of what looked to be a 1/8" side-to-side wobble.

The process:
1- I put the tip of a finger up near the inside edge of the wheel in question and turned it BY HAND. This was done to find the "high spot" on the wheel that came closest to my finger. Then I marked that on the paper disk on the inside of that wheel by the flange. (Again this was the left side on my grinder but it would work on either side.)

2- Then I verified that that was the furthest inward spot and it was.

3- I loosened the nut a bit pulled it and the wheel to the left on the arbor, not off! just over a bit down the arbor. Then used needle-nosed pliers to slip 1 dot in and stick it down. Then tightened things back up and checked it. I could still see it come closer to my finger in that same spot. It wasn't noticeably different so I began to think it was not going to work but pressed on. I tried again with a second dot placed directly on top of the first. Each piece of paper is about 4 mils thick from what I have read so it doesn't add much. It was better I guess so I kept going.

4- When I put the 4th dot, that is right just 4 dots thick, in a single stack in that 1 spot all of the side to side wobble disappeared completely. I was flat out amazed. That about 4 cents worth of sticky dots had solved what a $40 wheel couldn't solve.

5- I thought about it afterwards and it makes sense to me why it helps. I also realized that the sticky on the dots is just to hold it in place as you tighten and loosen so that they don't drop out or shift place.


Again since I had done this "remove the wobble" step before the bearing replacement work I carefully marked everything to try and put the wheel back in exactly the same place after swapping bearings. From a mark on the arbor to the inner flange orientation to the position of the dots. It worked perfectly. I didn't do anything but line things back up on the wheel and tighten the nut down. Fantastic.

Hope this helps others find a way into a good grinding situation!

Joshua

[Joshua Dinerstein]

If any of you have problems with bearings etc. don't hesitate to look up a local motor repair shop and give them a try. Of course if they do the work, they will charge you standard hourly shop rates.

I wanted to add a quick comment to this. Don is absolutely right. My path was to measure my bearing and read the numbers on the side. I called a number of bearing supply houses in the greater SLC area. It worked out great. They were helpful and knowledgeable and were able to tell me just what the proper model was on the bearings that they carried.

Anyone out there having grinder and tool vibration and wheel wobble problems- these can be fixed by:
1) Replace the plastic bushings with steel headless drill bushings (available from McMaster-Carr and other sources)
2) Shim between the inside of the cup washers and the sides of the wheels using paper sticky dots as shims to eliminate wheel wobble
3) Use a good quality truing device (not just a wheel dresser) to make your wheel absolutely concentric to the axle.

If you do these three things your grinder should perform optimally. The whole process should take about 30 to 45 minutes.

And I would second this whole heartedly. At this point I would not personally buy another balancing system. I have found that the bushings and dots made a world of difference. I am just waiting for my next payday for the better truing device.

Go for it. It works.

Joshua