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View Full Version : Grinding Newbie Just Got A Surface Grinder



mattthegamer463
02-19-2019, 07:30 PM
I bought a grinder last week after some humming and hawing, and I've got a few ponderings that I've been struggling to find answers. I figure some folks around here have some experience with these smaller benchtop grinders.

It is marked "GSG-612", made in Taiwan. Appears very similar to the Grizzly G5963 with the same oddball right hand table wheel. The grizzly says the stones mount to an arbor and a tapered spindle but my machine doesn't seem to have a way to get the end off. Not sure of theres a taper hiding in there or not.

Also, the Grizzly manual says the table should move with "finger touch" or something to that effect. Mine is pretty heavy, the wheel definitely can't be thrown back and forth like some of the bigger machines on youtube seem to let you do.

There is a one shot oiler but it doesn't appear to service the table balls, which seems to make sense. I'm not sure what kind of oil of grease should go in there, and what kind of resistance to movement is expected for the table? Or how often that needs to be done?

Also, when would someone want magnetic transfer blocks for setup on the chuck vs. just using regular 123 blocks?

Otherwise can't complain. Lots to learn. Can anyone recommend some grinding basics resources? Particularly good videos, webpages, books, etc.

Thanks in advance.
https://uploads.tapatalk-cdn.com/20190220/b4645d213195bf760dfded1d816461e9.jpghttps://uploads.tapatalk-cdn.com/20190220/4dadf3e3fdce3839880ab6a44d5f1564.jpghttps://uploads.tapatalk-cdn.com/20190220/0d0f47464d60b32e3ad0171d4fd55bab.jpg

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JoeLee
02-19-2019, 07:54 PM
Magnetic transfer blocks would be used if you needed to grind a surface on something where it may have a flange or some other protrusion that wouldn't allow it to be mounted directly to the chuck. An example would be say you wanted to grind the back or out side of a small piece of angle. You would need to raise it above the table in order to do so. So you would set it on the transfer block.
They also come in handy for blocking things up etc.
You can use 1-2-3 blocks if you can bolt your part to them, but they don't transfer magnetism.

JL.................

epicfail48
02-19-2019, 08:28 PM
As someone in the same boat, good luck learning! I just picked up an old 6x18 last fall, still in the process of getting to know the machine. Theres a lot to learn, its not just moving the table. Youve also got to figure out speeds you move the table, stepovers between passes, cut depth, matching the wheel to the material, etc. That last one has been the hardest thing for me to overcome, theres not a lot of easily accessible literature to help match wheel material, bond and grade to a specific material that ive found.

Still though, its all sorts of fun to learn, more so than a mill or lathe to me. Could be because i like watching sparks fly more than chips...

ncjeeper
02-19-2019, 09:28 PM
That looks like the one Harbor Freight sold way back in the day.

john hobdeclipe
02-19-2019, 09:40 PM
I have that same grinder, also made in Taiwan but badged MSC 612, and sold by MSC Industrial Supply. The Grizzly grinder referenced by the OP appears to be nearly identical but made in China. The Grizzly manual is good...much better than the one I finally found for mine.

According to the Grizzly manual, the wheel sleeve should slide off of the tapered spindle with no more than a light tap on the end of the spindle...after removing the spindle nut, of course.

The Grizzly manual does have an error in the section of grinding wheel choices, bottom of page 20: "CG Ceramic Grain" is not used for tungsten carbide. It is used on very hard steels such as high speed steel where its advantage is durability and longer time between dressings.

Having a small surface grinder vastly increases the range of things you can do and make in the home shop. Just recently I needed a set of spacer washers of different thicknesses. So I put 20 steel washers on the magnetic chuck, ground one face flat, then flipped them all over and started grinding all of them. At each target thickness I removed a washer and labelled it, then continued grinding to the next target thickness. And on and on. No way I could ever have parted these off at the lathe and achieved this kind of tolerance.

mattthegamer463
02-20-2019, 08:25 AM
I have that same grinder, also made in Taiwan but badged MSC 612, and sold by MSC Industrial Supply. The Grizzly grinder referenced by the OP appears to be nearly identical but made in China. The Grizzly manual is good...much better than the one I finally found for mine.

According to the Grizzly manual, the wheel sleeve should slide off of the tapered spindle with no more than a light tap on the end of the spindle...after removing the spindle nut, of course.

The Grizzly manual does have an error in the section of grinding wheel choices, bottom of page 20: "CG Ceramic Grain" is not used for tungsten carbide. It is used on very hard steels such as high speed steel where its advantage is durability and longer time between dressings.

Having a small surface grinder vastly increases the range of things you can do and make in the home shop. Just recently I needed a set of spacer washers of different thicknesses. So I put 20 steel washers on the magnetic chuck, ground one face flat, then flipped them all over and started grinding all of them. At each target thickness I removed a washer and labelled it, then continued grinding to the next target thickness. And on and on. No way I could ever have parted these off at the lathe and achieved this kind of tolerance.

I need to take a closer look at my spindle then, because I don't see a nut aside from the one that holds the wheel in place. I'll have to post a picture tonight because it seems different than I would expect if it was removable.

mattthegamer463
02-20-2019, 08:46 AM
Tormach's PSG-612 looks very similar, and they show a little more detail with changing wheels and removing the hub. They show sticking an allen key in the motor rear to hold the spindle still, didn't think of looking in there for something like that. I'll have to see what I see on my unit when I get home.

https://www.tormach.com/support/wpdmpro/um10159-psg612-operators-manual-0314a-web/

old mart
02-20-2019, 12:03 PM
The magnetic table should have a small adjustable stop added to the left hand end for safety.

Toolguy
02-20-2019, 12:33 PM
The table should go super easy in X and Y. If the oiler is not oiling ALL the ways, something is clogged up and needs to be opened to allow oil to pass through. Use an indicator to make sure the back gage on the mag chuck is adjusted to be exactly parallel to the X axis table travel. Use a diamond nib in a block on the mag chuck to dress the wheel.

mattthegamer463
02-20-2019, 02:34 PM
The table should go super easy in X and Y. If the oiler is not oiling ALL the ways, something is clogged up and needs to be opened to allow oil to pass through. Use an indicator to make sure the back gage on the mag chuck is adjusted to be exactly parallel to the X axis table travel. Use a diamond nib in a block on the mag chuck to dress the wheel.

I wouldn't describe the table as moving super easy. I think its probably worth the effort to remove the table and inspect the condition. The oiler system doesn't seem to feed the table, as I don't see a oiler tube leading to under there.

Toolguy
02-20-2019, 05:12 PM
Yes, I would remove the table and inspect. Every axis needs lube, whether plain or roller bearing.

mattthegamer463
02-20-2019, 09:49 PM
Well, the balls are pretty dry and one is missing. The oiler system doesn't provide any oil to it.

Also it looks like the spindle has a fixed hub, no taper or removable wheel holder so no external balancing.

Going to clean it up and put some way oil in, see if it feels nicer.https://uploads.tapatalk-cdn.com/20190221/4e8736987784cc80f7559be90360f39e.jpghttps://uploads.tapatalk-cdn.com/20190221/d907f165a6762dcee2620261fcab300f.jpghttps://uploads.tapatalk-cdn.com/20190221/9f93e9bfe7bf2c7174bed93ab6f9525a.jpg

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john hobdeclipe
02-20-2019, 10:15 PM
Your third pic shows the wheel sleeve, held onto the spindle taper by the hex head screw in the center. The screw is reverse thread. At the back of the motor there should be a bit of spindle protruding that can be gripped with a wrench.. Hold that, then unscrew the hex at the business end and the wheel sleeve should come off.

According to the Grizzly manual the sleeve should come off of the spindle with a few taps on the end of the spindle, but you'll actually need to loosen the screw a couple of turns and tap on that. I tried that on mine, though, and no joy. I'll need to devise a puller. Look closely: the sleeve has female threads to accept the puller, although I haven't seen a puller shown or mentioned in any of the manuals that have been mentioned here.

Taper mount interchangeable grinding wheel sleeves or adapters are pretty much a standard feature on surface grinders.

mattthegamer463
02-20-2019, 10:50 PM
Your third pic shows the wheel sleeve, held onto the spindle taper by the hex head screw in the center. The screw is reverse thread. At the back of the motor there should be a bit of spindle protruding that can be gripped with a wrench.. Hold that, then unscrew the hex at the business end and the wheel sleeve should come off.

According to the Grizzly manual the sleeve should come off of the spindle with a few taps on the end of the spindle, but you'll actually need to loosen the screw a couple of turns and tap on that. I tried that on mine, though, and no joy. I'll need to devise a puller. Look closely: the sleeve has female threads to accept the puller, although I haven't seen a puller shown or mentioned in any of the manuals that have been mentioned here.

Taper mount interchangeable grinding wheel sleeves or adapters are pretty much a standard feature on surface grinders.The fan cover blocks two flats I can see on the motor end of the shaft, so I'll have to pull the cover off and give it a try. Silly manufacturer.

I figure a gear puller might work if I use it to grab the wheel nut.

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Dan Dubeau
02-20-2019, 10:58 PM
That thing is cute. Looks like a great size, and capability for a home shop.

Toolguy
02-21-2019, 09:43 AM
On my Sopko spindle, you pull the wheel hubs with a puller that threads into the internal threads on the hub and has a bolt in the middle that pushes on the spindle. It's very difficult to get a hub off without it, but very easy with the puller.

George Bulliss
02-21-2019, 09:54 AM
For that size grinder you really shouldn't have to pull the hub off very often. You have to dress every wheel to use it and for wheels that size that's all it takes (99% of the time) to balance things.

About the only time I ever removed a hub was to use a diamond wheel. You don't want to have to true those every time you toss it on.

enginuity
02-21-2019, 01:23 PM
Are those ball bearings original?

The reason I ask is that thing looks to be made by the same company that makes the Tormach surface grinder (like you already mentioned). The Tormach surface grinder doesn't have those types of ways. It uses standard ways - one flat and and one prismatic if I recall correctly.

The Tormach grinder is alright for what it is. I like to call it the MVG or minimum viable grinder for small stuff. It's a great grinder for a home shop.

The tool to remove the wheel hub should fit into the hole in the back of the motor and there will be flats on the motor shaft. It's not the best setup as most people over tighten and the motor shafts are really soft.

mattthegamer463
02-21-2019, 07:37 PM
I've tried turning it and it isn't coming off. I need to try a little penetrant.

Not sure if the balls are original but I assume so.

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mattthegamer463
02-21-2019, 10:38 PM
I got the hub off but it doesn't seem to match the common tapers. 1.000 large ID .778 small ID across a length of 1.138", calculates to 11 degrees. A more common 2" per foot or 3" per foot taper is 9.5 and 14 degrees respectively.

Not sure how to proceed in finding more info on that taper and what hubs would work.

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mattthegamer463
02-24-2019, 11:19 AM
Seems like its a rare taper. Something like 2.4"/ft. I guess I'll be living with one for now.

Last night I ground a warped vise jaw that I made earlier in 2018. A project of firsts; first time heat treating, first time case hardening, first time quenching a decent sized part. One came out alright but the other got a bad bow, about 15 thou in the middle. I was able to grind it out but the stress relief left a 2 thou bow remaining. I need to grind it further to get closer flatness. A good lesson.

Also, I love this tenths indicator I got. A little sticky but still really nice.https://uploads.tapatalk-cdn.com/20190224/33b2abacd04eb301d77fb89de5e4b424.jpghttps://uploads.tapatalk-cdn.com/20190224/9f5f688b1e401956f47a2bfe3ab80115.jpghttps://uploads.tapatalk-cdn.com/20190224/2a008c2822ada901fc075746e781f68c.jpg

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mattthegamer463
02-24-2019, 09:02 PM
Got my vise jaws parallel to the surface plate within a few tenths today, it was a good learning experience.

I had used a 46 grit white wheel for roughing and tried a 60 grit for the first time, and it seemed as if it was clogging up. It started getting loud and cutting deeper and deeper but overheating and rubbing. Redressed it and it worked again but happened after not too much later.

I assume I am using the wrong wheel for the material. This is glass-hard case hardened mild steel, no fancy alloy. Research is needed.

My next job is grinding a part to a specific dim. Maybe a 1" mild steel cube would be a good idea.
https://uploads.tapatalk-cdn.com/20190225/3d338ea87d5eb877e1f91c1844064719.jpghttps://uploads.tapatalk-cdn.com/20190225/a8013212051d066f43ea8f51372ca2f2.jpg

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J Tiers
02-24-2019, 10:11 PM
maybe the hardness.

Soft material hard wheel. Hard material soft wheel.

You want the wheel to shed the dull grains as fast as they dull, so a soft wheel does that. too hard and it "glazes", gets dull grit all over it, which is why it was good after you dressed it again, you took off the dull grains. Find a softer grade of wheel.

mattthegamer463
02-24-2019, 10:24 PM
maybe the hardness.

Soft material hard wheel. Hard material soft wheel.

You want the wheel to shed the dull grains as fast as they dull, so a soft wheel does that. too hard and it "glazes", gets dull grit all over it, which is why it was good after you dressed it again, you took off the dull grains. Find a softer grade of wheel.Makes sense. I'll have to check the wheel hardness and make sure that adds up.

I wish there was more hobby-type info for surface grinding like there is for milling and turning. Need to go through Stefan Gotteswinter's and Old Tony's videos on grinding.

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pinstripe
02-24-2019, 11:02 PM
I wish there was more hobby-type info for surface grinding like there is for milling and turning.

Check out Solid Rock Machine Shop
https://www.youtube.com/channel/UCKPqKYF73sJbFUSzo5dQxtQ/videos

Doozer
02-25-2019, 08:43 AM
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You do not have to block in something like a big vise jaw.
Yer killin me.

-Doozer

reggie_obe
02-25-2019, 10:33 AM
I wish there was more hobby-type info for surface grinding like there is for milling and turning.

How would (or could) it be any different than the principals and practices used in a machine shop?
Many texts on grinding that discuss use of a surface grinder.
Here's two: https://books.google.com/books?id=5slKAAAAMAAJ&printsec=frontcover&dq=GRINDING&hl=en&sa=X&ved=0ahUKEwjrv9WbmNfgAhUKeawKHfB2AZAQ6AEITDAG#v=on epage&q=GRINDING&f=false
https://books.google.com/books?id=5slKAAAAMAAJ&printsec=frontcover&dq=GRINDING&hl=en&sa=X&ved=0ahUKEwjrv9WbmNfgAhUKeawKHfB2AZAQ6AEITDAG#v=on epage&q=GRINDING&f=false

mattthegamer463
02-25-2019, 02:34 PM
How would (or could) it be any different than the principals and practices used in a machine shop?
Many texts on grinding that discuss use of a surface grinder.
Here's two: https://books.google.com/books?id=5slKAAAAMAAJ&printsec=frontcover&dq=GRINDING&hl=en&sa=X&ved=0ahUKEwjrv9WbmNfgAhUKeawKHfB2AZAQ6AEITDAG#v=on epage&q=GRINDING&f=false
https://books.google.com/books?id=5slKAAAAMAAJ&printsec=frontcover&dq=GRINDING&hl=en&sa=X&ved=0ahUKEwjrv9WbmNfgAhUKeawKHfB2AZAQ6AEITDAG#v=on epage&q=GRINDING&f=false

What do you mean, how would it be any different? Things like wheel choice may not be particularly accessible to a newcomer in the old tome books. Many times I have seen a book tell the reader to do what is "appropriate for the work". A very helpful phrase.


You do not have to block in something like a big vise jaw.
Yer killin me.

-Doozer

All I was thinking about was having that block thrown through my brain. I wasn't interested in testing the magnet. Also, when it was bowed, I was worried the gap between the magnet and the jaw would majorly harm the holding power. I gave it the pull test and it didn't move, but why not block it in anyway.


Check out Solid Rock Machine Shop
https://www.youtube.com/channel/UCKPqKYF73sJbFUSzo5dQxtQ/videos

Thanks, I had forgot about them and I see he has a lot of grinding specific videos including one on wheel selection.

john hobdeclipe
02-26-2019, 09:26 PM
When you took the sleeve off of the spindle, did the sleeve have the means for balancing?

It seems odd and bothersome to me that the companies that sell that grinder (under whatever name) don't seem to supply balancing arbors or spare sleeves.

I agree with George that having extra sleeves may be overkill for the home shop, but it would make life easier if you are in a situation where you often change wheels for whatever reason.

mattthegamer463
02-27-2019, 08:58 AM
When you took the sleeve off of the spindle, did the sleeve have the means for balancing?

It seems odd and bothersome to me that the companies that sell that grinder (under whatever name) don't seem to supply balancing arbors or spare sleeves.

I agree with George that having extra sleeves may be overkill for the home shop, but it would make life easier if you are in a situation where you often change wheels for whatever reason.

It does have three sliding weights held by screws.

Grizzly sells one for their unit for about $60 USD, but they don't have a picture or information about the taper, and so buying one would be a total crap-shoot.

Chipster
03-04-2019, 06:14 PM
I bought the same model at an auction last year. I really like it, it's perfect for a home shop. Mine was missing the handwheel for the x axis, so I added a power feed to the table.
I just posted a thread on this site showing how I did it. Here is a link if anyone is interested.
http://bbs.homeshopmachinist.net/threads/78474-Surface-Grinder-Table-Power-Feed