# Tool bit grinders



## wareagle (Sep 21, 2008)

Well, I am thinking of procuring a grinder like *here* to grind tool bits. Originally I was thinking of building a fixture to go on my bench grinder, but haven't really come up with an easy and workable solution for the grinder I have (and I am not sure the bearings are suited for the task, anyway). My needs are to be able to accurately grind tool bits at various angles for use on the lathe.

My question is, would I be better suited to build a grinding fixture for the purpose, or would I be just as well off buying a purpose built grinder? And, has anyone had experience with these machines either positive or negative? I really don't mind spending the money on one if it will work for my needs, but I also don't want to buy one if it isn't worth the trouble. Thoughts???

The last thing, does anyone have a bit grinding fixture that they like and are willing to share a picture of? At this point, I am really open to any ideas and suggestions.


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## Bernd (Sep 21, 2008)

WE,

Check out this thread http://www.homemodelenginemachinist.com/index.php?topic=2342.0

I bought the HF version. Haven't done any mods on yet. I really like it because it lets you grind a flat side on the tool instead of the curveture of the front of the wheel. Makes it easier to use a stone on it to touch up later.

Bernd


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## steamer (Sep 21, 2008)

I have the grinder in question or at least a far east knock off of it.

They only seem to come with green wheels for TC. Something I didn't use a lot of with the Atlas, though my Logan can handle it so I am using more.

The green wheels are not particularly well made and I spent a far amount of time in the drive way with a fleecing diamond truing them up. They turned out OK.

I bought a good quality ALOX wheel ( same format) for it for a rather steep sum and once dressed works well.

I have it set up with one green and one ALOX.

It seems to run fine and the lamp that comes with it works well

Ground a tool to single point a #2-126 thread for a tap.  Real nice finish which is key on that kind of application

It could benefit from a better mitre fence, but so could the original Baldor item...they look the same.
It needs far less work than building anything I know about. I am thinking about a sled to mount the tool on and push it across the table. I think that will repeat better.

The Wilson T&C grinder I am looking at building has provision for lathe tools but I don't think it will do any better Job than the aforementioned grinder and as such I will probably not build the lathe tool fixture for it. I'll just grind endmills with it.

It doesn't replace the bench grinder as I use that for roughing tools and of coarse, grinding axes and shovels and such.

Hope that helps,

Dave


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## Hilmar (Sep 21, 2008)

wareagle
go to
The Tools and Tips > Tools > Topic: New Grinder.
3rd page close to the end.

Hilmar


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## steamer (Sep 21, 2008)

yep

Pretty much agrees with my experience.

Dave


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## Mcgyver (Sep 21, 2008)

if we all thought the same, the world we be a boring place, right? 

 I'd go with don't bother getting one 

I made a fancy rest system for my 8" grinder when i was a newb and it never gets used, was a waste of time. except for V or acme threads, its easier to grind a tool bit freehand. even grinding threading bits isn't tough either when you have a gauge handy, grind a little, hold it up to light, adjust, and so on....and once you have an nice edge stoned on, and can touch it up with a stone, its a long time before it needs grinding again....i doubt the extra time needed to futz around getting a threading bit ground free hand adds 4 minutes a year time burden. On regular tools, the angles just aren't the critical and you'll quickly get good at it with just a protractor - and the protractor is just for learning, you'll quickly be at the point where it stays in the drawer. and this is from a guy who likes to have every tool out there; just never saw the incremental benefit in what is basically another bench grinder

for someone buying a grinder, do go for an 8". they're not much more money and it really increases your selection of available wheels.... the wheels that come with them generally need immediate replacement - if you haven't done so, do it and you'll fall back in love with your bench grinder


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## Hilmar (Sep 21, 2008)

wareagle
What ever You do , don't buy the Delta GR 450 8" variable Speed grinder.
Also a piece o...s...
Hilmar


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## wareagle (Sep 22, 2008)

Bernd  said:
			
		

> WE,
> 
> Check out this thread http://www.homemodelenginemachinist.com/index.php?topic=2342.0
> 
> ...



Bernd, thanks for the link. I thought that I had seen a topic on that before, but I either over looked it or the search didn't pull it up. I have thought about the HF version, but I personally have had some pretty bad luck with some of their stuff. Makes me very leery!



			
				steamer  said:
			
		

> I have the grinder in question or at least a far east knock off of it.
> 
> They only seem to come with green wheels for TC. Something I didn't use a lot of with the Atlas, though my Logan can handle it so I am using more.
> 
> ...



Dave, that sure does help. I appreciate the response and that tells me that maybe I am on the right track.




			
				Hilmar  said:
			
		

> wareagle
> go to
> The Tools and Tips > Tools > Topic: New Grinder.
> 3rd page close to the end.
> ...



Thanks Hilmar!



			
				Mcgyver  said:
			
		

> if we all thought the same, the world we be a boring place, right?
> 
> I'd go with don't bother getting one
> 
> ...



Interesting thoughts. I have obviously been grinding tool bits by hand, but am lacking the accuracy I need without spending quite a bit of time at the wheel. Maybe I just need more practice!! Repeatability certainly isn't there, and likely for the same lack of practice. Hence the reason I have been considering buying the TBG.

I do agree about angles and such for the everyday normal tool bits. I have no issues there, but when grinding bits for threading or slotting, it gives me much grief. Do you have any secrets on how you are grinding bits that need to be dead on? As I said before, I am open for suggestions!




			
				Hilmar  said:
			
		

> wareagle
> What ever You do , don't buy the Delta GR 450 8" variable Speed grinder.
> Also a piece o...s...
> Hilmar



You know, in my humble opinion, Delta was a great tool back in their day. I forget who bought them up (maybe B&D), but as with so many manufacturers that are bought out, it seems the quality takes a turn for the worst. It's really a shame! And none of them seem to be immune!

Back to the topic, do you have personal experience with the above unit? I haven't seen it nor have I considered it (and won't), but I'd be interested to hear what the problems with it are.


Guys, thanks for the information! It gives something to chew on!!


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## Hilmar (Sep 22, 2008)

Yes,
   I have on. Looks nice on the bench. Comes with a white ,gray and buffing wheel.Speed can be changed from about 3000 - to 2000.
  So far so good. Has Quick release nuts to take the wheels off. One left and right thread.The lever which looks them pushes the wheels off center. Will never balance.
 The shoulder against which the inner flange rest is only < 0.020 " > larger then the shaft. 
So the flange rests on a < 0.010" > material. Will not hold to 90° of the shaft.
The wheels are so badly out of balance You will not believe it. I worked on it for about a week, balancing wheels, making bushings, facing flanshes you name it . It works but I am still not happy.
Hilmar


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## wareagle (Sep 22, 2008)

Hilmar  said:
			
		

> Yes,
> I have on. Looks nice on the bench. Comes with a white ,gray and buffing wheel.Speed can be changed from about 3000 - to 2000.
> So far so good. Has Quick release nuts to take the wheels off. One left and right thread.The lever which looks them pushes the wheels off center. Will never balance.
> The shoulder against which the inner flange rest is only < 0.020 " > larger then the shaft.
> ...



Wow! Sounds like a royal PITA! Thanks for the info!


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## BobWarfield (Sep 23, 2008)

I love my Harbor Freight tool grinder. It has served me well and ran great right out of the box.

I've gathered a few posts and notes over the years about these grinders that may be of help.

Here is an excellent post on selecting wheels for grinding HSS:

http://www.chaski.org/homemachinist/viewtopic.php?t=76065 

He goes through all of the different numbers that specify a wheel, why they matter, and what is likely best for the HSM grinding HSS. Best I've yet seen. Possibly also useful to a new surface grinder owner.

Some more toolgrinder tidbits at the bottom of my project wish list page (some are tooling for the grinder):

http://www.cnccookbook.com/CCWishListFutures.htm

Best,

BW


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## pmerritt (Sep 23, 2008)

I noticed in the latest Enco flier that they are now selling their grinder with one AO and one green wheel. Don't remember the price.

Peter


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## wareagle (Sep 23, 2008)

Bob, I appreciate the links! More food for the noodle!

Peter, would you happen to have a P/N handy on the grinder you are talking about? I have looked at Enco, but haven't seen one with the different wheels yet.

Thanks again!!


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## pmerritt (Sep 23, 2008)

It's in the September Hot Deals flier. Model # SD891-8106 on sale for $169.95.


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## wareagle (Sep 23, 2008)

pmerritt  said:
			
		

> It's in the September Hot Deals flier. Model # SD891-8106 on sale for $169.95.



Thank you!!!!!!  :bow: :bow:


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## wareagle (Sep 26, 2008)

Well, for an update... I have been wrestling with the decision to buy a TB grinder. I have two bench grinders already, and the thought of adding a third caused me much grief. So, I decided to take a stab at building an attachment to grind the tool bits on one of the existing grinders that I have. If it didn't work out, then I was just out some time and scrap material; but if it performed as I needed it to, then it would save me having a third grinder and the cash spent getting it.

I have fabricated this so that I can adjust the table location in relation to the wheel. It will tilt a total of 90 degrees, 40 one direction and 50 in the other. I haven't marked the graduations nor have I done any clean up on it. I will be doing trials on it today and will see how it works out. I think it will be fine, but the proof will be in the pudding!

A fence needs to be made to hold the objects being ground, and if all works out, I will fabricate one for the opposite side and treat it to some good wheels. Then I will have the same basic thing for just a little time. 

My apologies for the poor images. I may to get a new shop camera for taking pictures (the minimum focal distance on the current one is over 24")!!


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## Maryak (Sep 26, 2008)

Neat tool rest W/E and more than adequate for lathe tools 

Bob


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## steamer (Sep 26, 2008)

Hey W/E,

That looks like a winner to me!


Dave


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## wareagle (Sep 26, 2008)

I ground a couple of tool bits with it and it works pretty well. There are a couple of things that I think I will do aside form the obvious... One is to make a longer rest. It won't take very long and it will make the bit grinding a little easier. The second thing is I think that I will see about adding a feed of water to the wheel at some point. That will probably speed up the grinding process considerably.

I think that the effort was worth it. It will do what I need it to!


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## steamer (Sep 26, 2008)

W/E

I think a simple cup and a small copper tube with a simple needle valve will provide all you coolant needs. If you leave the top of the cup open you can dip big tools in. For smaller lighter jobs you can let the coolant flow and the wheel will mist it quite well.  That should be very easy to rig up a prototype and prove out the idea using a soda can, tubing and some silicone caulk.  You can make it as special as you like after that.


Dave


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## baldrocker (Sep 26, 2008)

WE
Forgive the newbie ? but I have given some thought
to water cooling on my bench grinder and am
unsure of the electrical safety of the idea.
I would welcome ypur comments
BR


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## steamer (Sep 26, 2008)

Baldrocker,

Yes water and electricity don't mix well...this is true. That is very observant of you and I commend you for thinking of it

However.

My baldor ( Asian clone) grinder has factory installed one....that is why I mentioned it

Here is why they get away with this apparent engineering gaff.

It is a small drip, not a forceful stream and it is aimed at the perifery of the wheel and not to an exposed bit of wiring. To get internal to the grinder motor would require that the water over come the centrifugal force and get by the shields/seals of the bearings and then find a piece of wire without an insulator on it

Additionally, centrifugal force will sling it out and turn it to mist quite quickly.

I would not suggest a mount for the garden hose mind you. Everything in moderation. ;D

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1676305&PMT4NO=50815847

Here is a link to one ( the genuine article...yikes its expensive!) for sale on the MSC catalog page.

Regards,

Dave


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## baldrocker (Sep 26, 2008)

Ahh. Thanks.
BR


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## wareagle (Sep 27, 2008)

*baldrocker*, if you are worried about a shock hazard, then you can also put your grinder on a GFCI receptacle and that will keep you safe. As steamer said, the ideas isn't to submerge the wheel and the bit being ground, but it is to let the heat turn the water to vapor to carry the heat away from your bit.


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## ronm (Sep 27, 2008)

I have the HF version, runs nice, no problems, but the "green wheels" that came with it appear to be green painted concrete, they don't do what I would call a real good job on either HSS or carbide. One of my priorities when I get more shop time is to upgrade the wheels, one green & one Alox-haven't really had time to do much looking for better wheels. 
Edit: I intended to ask about a diamond wheel...worth the $$$, or not?


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## Tin Falcon (Sep 27, 2008)

a good diamond wheel should last forever in a home shop. it is best if diamond is only used on carbide. steel tends to degrade diamond. 
I have used cheap diamond wheels and burs on a Dremmel for doing profile cuts on HSS I have noticed no ill efects but these are small cheap wheels that i will not cry if they have a short life span. 
Tin


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## Andrewinpopayan (Sep 27, 2008)

Sorry to butt in here, but Baldrocker, if you put an isolation transformer and an RCD into the grinder supply line then even if you do get a short you won't get a shock and the RCD will trip to warn you that have a fault.

The only reason that you get a shock is because YOU form the circuit between "live" and ground. If the supply is "isolated" it means it is isolated from the ground and no current flows to ground (thru you). Of course touching both of the wires you will still get a shock.


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## Bernd (Sep 28, 2008)

ronm  said:
			
		

> Edit: I intended to ask about a diamond wheel...worth the $$$, or not?



Check at the speed that the diamond wheel should be run at. Bog's once told me they should be run slow. Now any of the HF grinder look a likes that have been talked about on this thread run in the neighborhood of 3600 RMP. Is that to fast for carbide or not?

Bernd


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## Lew Hartswick (Sep 28, 2008)

If youre grinding carbide a diamond wheel can be run fast 1800 3600 rpm but if doing steel it should 
be run slow enough to not heat the diamond to the point where it will disolve in the steel. Sort of in the 
100 rpm range and kept wet with water. Like the Glendo Corp. Accu-Finish device. (very nice for 
polishing the edges of a HSS bit) 
  ...lew...


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## gunboatbay (Sep 29, 2008)

I have hade the same HF grinder for about a year now and, after a few tune-up modifications, couldn't be more pleased with it. I purchased the medium grit diamond wheel from CDCO ($59) and use it only for final touchup on carbide tools, so speed hasn't been a problem, so far. I did find that the green wheels that came with the machine require frequent dressing as they tend to glaze over quite rapidly instead of eroding away as they should. I've since replaced one with a better wheel and it works great. The two _major_ modifications I made were an enclosure for one of the wheels with vacuum port for my shop-vac. Wow, what a difference that made on the amount of grit/dust around the machine!! The second major mod was to the mitre-gauge. As purchased, the mitre-gauge slot in the table was typically 'chinese-rough'. I deepened it ever-so slightly and smoothed out the sides, then made a new mitre-gauge carrier out of brass to fit the bigger slot.


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## Bernd (Sep 29, 2008)

Gunboatbay,

Good post. Sounds like you've taken care of a few problems. I still need to do some mods on my grinder. Sounds like you did some nice ones. Any chance of a pic or two of those mods?

Bernd


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## gunboatbay (Sep 29, 2008)

I'll try posting some pictures as soon as my wife gets back from holidays with the camera.


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## gunboatbay (Oct 6, 2008)

I took some pictures of my grinder, but unfortunately can't find any instructions on how to post pictures in a reply. Can anyone help me?


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## CrewCab (Oct 6, 2008)

For information on posting pictures have a look here 

http://www.homemodelenginemachinist.com/index.php?topic=108.0

Basically it's showing you how to host your pictures on an external site such as Photobucket then put a link in your post.

Another way is click on "Additional Options" below the box your typing in, this will open another sub-menu, to the far right of the word "attach" you can "browse" through files on your computer and add them to your post ........... note the limitations though, only 4 pictures per post with a maximum file size of 4096Kb ............... one advantage of photobucket is that it will resize photo's for you.

If that doesn't help I can talk you through it when I get home after work.

Best Regards

Dave


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