Tool bit grinders

[wareagle]

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.

 

[Bernd]

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

 

[steamer]

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

 

[Hilmar]

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

Hilmar

 

[steamer]

yep

Pretty much agrees with my experience.

Dave

 

[Mcgyver]

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

 

[Hilmar]

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

 

[wareagle]

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

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!

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

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

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

Hilmar

Thanks Hilmar!

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

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!

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!!

 

[Hilmar]

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

 

[wareagle]

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

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

 

[BobWarfield]

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

 

[pmerritt]

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

 

[wareagle]

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!!

 

[pmerritt]

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

 

[wareagle]

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

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

 

[wareagle]

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")!!

 

[Maryak]

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

Bob

 

[steamer]

Hey W/E,

That looks like a winner to me!


Dave

 

[wareagle]

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!

 

[steamer]

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