Bad surface finish 6x12 surface grinder spindle disassembly questions

[dkemppai]

That was my next thing to do. I just got 3 new hubs off ebay. And don't know if they run a "swash plate" wobble.

I may a bit late to the party...

Can you share what hubs fit this machine? I have an almost identical machine, and am having trouble finding what hubs fit this unit. The plan would be to pick up one or two, and dedicate one to a diamond wheel for carbide.

Fortunately the grinder one in the shop here runs pretty well. It really only gets used for little parts, tho. Having this little guy for HSS (and soon carbide) grinding is really handy. It even gets used for the odd off hand grinding when a nice true wheel is needed.

Also, you can use accelerometers like you did with a photo-pickup to balance rotating items. Using the captured acceleration and the photo pickup trace on the scope lets you pick up where heavy spot is. Then grind a little bit of off where needed. Repeat the process until it runs smooth. I've heard you can do two plane balancing like this with two accelerometers, although I haven't tried the process myself.

Thanks,
Dan

 

[metric_taper]

I found these on eBay, and they fit; That auction listing is now dead. They were Sopko. I paid $100 for 3 of them. The machine uses pretty standard hubs. 3" taper per foot. I wish you would have asked this back then, as I would be able to tell you the dimension data.

Just make sure they have LH threads and for 1-1/4" wheel hole, and support the thickness of your grinding wheel.
So while I was awaiting for an order for infrared transceivers, I got some very well balanced grinding wheels, and all the vibration problems went away. So I moved on, as it was a pain to try and balance the wheels. Lesson is, for these light weight machines, don't buy surplus wheels unless you can determine they are balanced, and not rejects. As I said, most of what I got off ebay in the low end were out of balance, from the manufacture.
I went back and looked at my ebay history, and this seller had these that were balanced;

RADIAC ABRASIVES, #381962, 7 X 3/4 X 1 1/ 4, WHITE ALUMINUM OXIDE 36 GRIT | eBay

NEW RADIAC ABRASIVES #381962, 7 X 3/4 X 1 1/4, 36 GRIT, WHITE ALUMINUM OXIDE GRINDING WHEEL 9A36-I2-VOS, K296954. WHITE A/O FOR COOL CUTTING ACTION.

www.ebay.com

This guy has 6 left, as I bought 5 (which at my current usage is a life time supply, a great estate auction for sure). Also I had gotten a hub that would accommodate the 3/4" thickness. I had to leave the wheel guard front face off.

They give real nice surface finish. I was doing cast iron and steel (unknown alloy).
Also some of the hubs had the centerline distance of the wheel change. The guard is movable to give the needed clearance.

I did a lathe repair of several items. the compound top slide was not square to the V ways, I was trying to setup for precision tapers. So that got fixed, then I did the precision taper. The original adapter that came with the lathe, that converted the head stock 90mm metric taper 20:1 angle to the #4 Morse taper center did not fit. The major diameter was 4.5 thousands bigger, so it would rock in the hole. So I got my tool post grinder set up to regrind it as it was hardened, and really no way to hold it outside of between centers.

If you go to the Grizzly site, they have the hub and nut (Wheel Sleeve and wheel sleeve washer, parts 70 and 75) for sale.

 

[dkemppai]

Hi,

Thanks for the fast reply. That picture and description was enough for me to identify holders similar to the ones you found. I think the HHIP F320's (sopko style) are the same thing. All matching the 3" taper per foot (but in metric numbers). 3" per foot is about what I measured the balancing shaft at, so that makes sense. (Also, time to make a frame for balancing!). My original hub doesn't have the threads or nut to pull it from the machine, so it looks nothing like the sopko style.

These little machines might be in the hobby or 'toy' category, but I really like them. Honestly it gets used more than the 7x24 sitting next to it. It's just so handy. I was dreading dressing the chuck I that came with it (old L.W Chuck CO, Toledo electric chuck), and just threw the chuck on the big grinder for roughing. When mounted on this little machine, at the last minute I decided to indicate to see how far off it was. I was very surprised to find that it wasn't! I didn't see a tenth over the surface. I never did dress the chuck on this machine. (Maybe I will, when those nice 36gr stones you pointed out arrive from ebay! )

Thanks again for the info.

Dan

 

[metric_taper]

<snip>(Maybe I will, when those nice 36gr stones you pointed out arrive from ebay! )

Thanks again for the info.

Dan

I hope you get a good one. I really like the finish from the wheel. My whole problem started out with seeing ripples in the surface of the work. Yes it was flat, and you could not measure them (or at least I could not with a tenths test indicator on a surface plate). But optically it just did not look right. I have not been back to using this machine since I got the tasks done earlier this year.
Putting new bearings in it was worth the cost, as they built mine with ultra cheap deep groove, not a matched angular contact set. I think wheel balance was probably the biggest issue, as if they are trued with a diamond, they should be concentric. So vibration would be the problem. I've not solved that yet, as I need to get phase information to know where the excess weight is.
Oh, one thing this machine's totally enclosed motor, blows real cold air on you if your standing in front of it. Mine is out in a unheated shop that stays above 40 most of the winter. I made a cardboard shield to block that cold air. This also reduces the grinding dust being blown on the operator.

 

[dkemppai]

I hope you get a good one. I really like the finish from the wheel. My whole problem started out with seeing ripples in the surface of the work. Yes it was flat, and you could not measure them (or at least I could not with a tenths test indicator on a surface plate).

I think these are going to be good wheels. I've got a similar one that came with one of the grinders, and that open pore structure does a nice job. The norton SG 5SG series are also pretty nice wheels. Not open, but the friable ceramic works well on hardened tool and hardened stainless steels.

Absolutely know what you mean about being flat, but still seeing the ripples. Nothing compared to 'optical flat' levels, but the custom knives made in this shop get ground and polished pretty smooth. Ripples like what you describe would never fly on a mirror finish!

 

[dkemppai]

I found these on eBay, and they fit; That auction listing is now dead. They were Sopko. I paid $100 for 3 of them. The machine uses pretty standard hubs. 3" taper per foot. I wish you would have asked this back then, as I would be able to tell you the dimension data.
View attachment 389352

Hi,

Merry Christmas, and Happy New year, and all that jazz!

Do you happen to have a photo of the nut you use with these adapters?

Received the new hub the other day however the existing nut won't fit, too large in diameter. The picture of the grizzly nut look the same as the OEM I have here. Any idea who sells a M16x1.5LH Nut that's small enough to fit these adapters? Sopko doesn't seem to have one I can find on line. My lathe won't turn metric. McMaster seems have one, but it would need to be extended and turned down. (Maybe TIG a bolt to the McMaster nut???)

Short of buying one, I'll thread mill something on the CNC. Not the end of the world, but it really shouldn't be this hard!

Thanks!
Dan

 

[metric_taper]

Hi,

Merry Christmas, and Happy New year, and all that jazz!

Do you happen to have a photo of the nut you use with these adapters?

Received the new hub the other day however the existing nut won't fit, too large in diameter. The picture of the grizzly nut look the same as the OEM I have here. Any idea who sells a M16x1.5LH Nut that's small enough to fit these adapters? Sopko doesn't seem to have one I can find on line. My lathe won't turn metric. McMaster seems have one, but it would need to be extended and turned down. (Maybe TIG a bolt to the McMaster nut???)

Short of buying one, I'll thread mill something on the CNC. Not the end of the world, but it really shouldn't be this hard!

Thanks!
Dan

I had to make a new one for my machine, as the factory hand tapped the nut, and it was a swash plate. So I ordered from Ebay a HSS tap.

HSS Metric Left Hand Tap M16 M16X2 LH Straight Fine thread tap M16X1.5X1.25X1mm | eBay

USE: Left Hand. We will declare it as with a lower value. This lower price does not reflect the total price you paid or the market value of the product and may not apply to countries with different tariff rules.

www.ebay.com

 

[dkemppai]

I had to make a new one for my machine, as the factory hand tapped the nut, and it was a swash plate. So I ordered from Ebay a HSS tap.

HSS Metric Left Hand Tap M16 M16X2 LH Straight Fine thread tap M16X1.5X1.25X1mm | eBay

USE: Left Hand. We will declare it as with a lower value. This lower price does not reflect the total price you paid or the market value of the product and may not apply to countries with different tariff rules.

www.ebay.com

OK, I was afraid you were going to say you had to make one. Being that I only really need one, I may just thread mill the thread.

FYI, These HHIP adapters look pretty nice. The spindle of the grinder has about .0002" run out on the taper, and it measures the same on the hub wheel ID interface. On the flat there's about .001" runout, which is probably fine for this grinder (didn't spend a lot of time looking at it tho...)

Thanks,
Dan

 

[metric_taper]

OK, I was afraid you were going to say you had to make one. Being that I only really need one, I may just thread mill the thread.

FYI, These HHIP adapters look pretty nice. The spindle of the grinder has about .0002" run out on the taper, and it measures the same on the hub wheel ID interface. On the flat there's about .001" runout, which is probably fine for this grinder (didn't spend a lot of time looking at it tho...)

Thanks,
Dan

You never know when you'll use a left hand bastard metric thread tap. I have a lathe that can cut threads, but I didn't want to mess with an internal thread as my internal small hole thread tooling is non existent. I did cut an external thread. My lathe for threading is Imperial, it has all the change gears for metric, BUT you can't disengage the half nuts, so threading is a real pain.
I did make some custom spanner wrenches for the surface grinder, one for this nut washer we are talking about, but also the same for the grinding wheels. They are made with 3-4 inch round stock drops I got somewhere. But I used the mill to put in the pin holes in the right places. I use drill rod, that is not heat treated for the pins.