View Full Version : Critique of the HF lathe tool grinder

01-18-2007, 05:07 PM
They didn't have work and I got today and friday off (I am a part time worker in a machine shop).

This critique is for those that may intend to buy a Model 46727 lathe tool grinder and considering it only lists for about $165 you get what you pay for. This is to make you aware of the faults I found and should be corrected.

My tool grinder came this morning and after lunch I took it out of the box and began the assembly. The box as shipped weighed 100lb. The Fed Ex delivered it.

Before I put the grinder together I turned it on. It had a slight squeal in the bearings so I taped the housing with a soft hammer to center the bearings in the bores and the squeal stopped.

Next I tried the cast metal quadrant parts on the side of the grinder and found them to be a poor fit. The castings were also somewhat warped. It was necessary to open the slot where the locking handle fits with a die grinder and a bur. It was also necessary to dress the slots where the plastic pins slide in the quadrants to adjust the table angle with the die grinder and a square ended bur. I also found the sides of the quadrants were not flat or at a 90 deg angle so it was off to the belt/disc sander to dress them up. I also scraped the paint off the area where the table sets on the quadrants. I ran a lathe file over the top of the table and found one table to have high spots on one edge that I filed off to get the table flat.

I then assembled all the parts and tried it out. Before grinding I dressed both wheels. They are very hard and will need constant dressing as they glaze over quick. I pulled one of the wheels to see what grade it is but could not read the printing on the wheel. They appear to be some form of white wheel of hard composition. I then ground some carbide lathe tools and some HHS lathe tools. Both ground ok but I don't like the grade of wheel and will be getting replacement wheels later on.

I am not a perfectionist but I am a fanatic about doing something right and having my tools and machines in very good working form. I usually completely check over and disassemble, repair or revise any machines or tools I buy to get them to the best working condition posible. It pays in the long run for me as I then have confidence in what I am doing and what I produce and that the tool/machine will perform as expected. This seems to be a good grinder and having used some of the more expensive brands of these grinders for years in job shops I feel good about the HF grinder for me.

edit: I got mine on sale for the $130 price also.

01-18-2007, 05:33 PM
Mine should be on the doorstep when I get home today.

I'd sort of figured it was a "toolgrinder kit"

I'll report as well...

Optics Curmudgeon
01-18-2007, 06:09 PM
It's on sale for $130 now.


01-18-2007, 06:12 PM
You're right about the wheels. I think they're made out of cast concrete or some such compound. ;) I also found the water/coolant valve to be less than functional but I didn't have any problems with castings. As with any of the HF machines, they're pretty much a "kit" that needs refining. All in all, I believe it to be a bargain and worth the price. The alternative is about $800 so I'm willing to put forth a little work to make it a useful tool.

I just finished building a stand, adding reinforcement and adding power drive to a HF 40" Combo Shear (shear, brake & roll). I'm pretty happy with it NOW. I've got about $40 in the stand and about $60 in the drive. The shear itself cost me about 8hrs. in traded labor. I still need to make some chain guards and panels for the stand. The alternative? About $8,000+.


01-18-2007, 09:48 PM
Cast concrete:eek: you may be right:D . Ken, that's a fine job you did on the shear. It looks real nice and the chain guards is a good idea.

01-18-2007, 11:12 PM
My wife bought me that model HF tool grinder about 3 years ago that was on sale then as well. I got a good one right out of the box (lucky THAT time). The wheels then sound like they were a little better composition silicon carbide (green) but they were too course for touching up the final edge. I sprung for a diamond wheel at about $90 for one side. I have not had any problems with mine. A great solution compared to the $800 USA versions. I mounted it to a pedastal stand with wheels so I can move it near the lathe when I am using it.
CC Ken ...VERY nice job on the shear/brake!!

01-19-2007, 01:46 PM

That combo slip roll is a nice machine. I like your stand and power drive. My workplace had one we bought from Enco, about 20 yrs ago. We built a stand for it and used it for all kinds of fab work. The shear was not heavy enough to do much real work but we had a 4' squaring shear so that was not a problem. The brake and slip roll, however, were worth their weight in gold. If I get a chance to get one for myself I will get the 40" one for sure. Our Enco was only about 30" and sometimes was just too small to do the job. The 40" seems to be made of heavier castings.

01-19-2007, 11:21 PM
47 kilos of Chinese metal were shivering on the doorstep when I arrived home from work today. I dragged it down to the shop and assembled it. It actually looks a bit better than most HF stuff in the store. How they can sell these at about $1.30 a pound is beyond me.

The thing I noticed first is that the RH table isn't level in the fore n' aft direction, it slopes toward the user. Is this deliberate? do I remove the wheel guard that the table hangs from, slot the bolt holes for adjustability and set them up flat?

Mine came with pale green stones which dressed right up. It runs very smoothly, although it's a bit noisy as it accelerates. Once at speed it's quite quiet. At Cabin Fever tomorrow I'll be looking for some proper wheels for it.

I got it for $129 plus $10.99 freight, and if you google search "Harbor Frieght Coupons" you can probably find a link to a code which will get you a $10 HF gift card. For $130.99, you can't go wrong with this thing.

loose nut
01-20-2007, 11:00 AM
My wife got me the same grinder for Xmas, it actually looks like a decent piece of equipment, it's quiet and siting unsecured on my bench it's vibration free when running. The only thing I had to do was file down the guide bar on the angle guage (or what ever it's called) so it would slide a little smoother. This is the first time that I have used a tool grinder like this and I must be missing something, the guage only goes over to 45 degrees so you can't set it to grind a 60 deg. threading tool or to grind a shallow relief angle on the front of a bit. To get around this I have made a 90 deg reciprical angle attachment that clamps onto the angle guage so that i can grind shallow angles. Have I missed something obvious that you guys know. Is there a better way to grind these angles.

01-20-2007, 01:59 PM
That's how my tool grinding station is set up.

moto, I checked my tables and they are very close to level to each other but leaning to the front as yours are. I don't think it will affect much as you are still free hand grinding and to an approx. angle. It would only move the tool up or down on the stone face.

loose nut, I would just make a fixture to hold the tool to the desired angle with the table set at 0. It still won't be as perfect as a fixture on a surface grinder but close enough.

EDIT: the two trays under the table will walk off my grinder so to keep them from falling in the floor I put a bungy cord from one side to the other side as seen in the photo's.

01-20-2007, 03:19 PM
My wife got me the same grinder for Xmas, it actually looks like a decent piece of equipment, it's quiet and siting unsecured on my bench it's vibration free when running. The only thing I had to do was file down the guide bar on the angle guage (or what ever it's called) so it would slide a little smoother. This is the first time that I have used a tool grinder like this and I must be missing something, the guage only goes over to 45 degrees so you can't set it to grind a 60 deg. threading tool or to grind a shallow relief angle on the front of a bit. To get around this I have made a 90 deg reciprical angle attachment that clamps onto the angle guage so that i can grind shallow angles. Have I missed something obvious that you guys know. Is there a better way to grind these angles.
loose nut the 60 tool consisted of two 30 grinds with the appropriate side relief set with the table tilted. The protractor set over to 30 would get a finished tool with a 60 profile.

01-20-2007, 09:56 PM
That's true Tinker, but he still has to reset the table to grind the clearance. I don't think I would trust the true angle of the markings on the quadrants anyway. It would be best to set the table with a square and use a fixture to hold the tool with the proper angles designed in.

01-20-2007, 11:24 PM
Carl that's just added complications in making a fixture for every type of tool he'd need to use. He does not need any fixtures just a nice square block holder for the toolbit... a center gauge and a bevel protractors nice to double check gradients. Set table to 0 for front relief use the guide protractor set at your front angle and dress with toolbit laying on side. Reset table for your side relief and the guide set at 30 and do each side. Free hand the end radius allowing for the thicker heel to support the tip on the end and stone. Check with center gauge. I do some free hand grinding of bits allot with chip breakers. Knowing how to grind a tool that works and cuts well is a handy skill. Not all my tools fallow recommended guidelines but will peal steel like a paring knife.

01-21-2007, 12:48 AM
I took the green monster partially apart this evening and trued up the aluminum drive plates the wheels bolt to. Mine were nothing like straight, and the backsides were not machined at all. I used an expanding arbor, faced the fronts and backs and the nut seating areas. It runs smoother now for sure.

01-21-2007, 01:17 AM
I didn't suggest a fixture for every tool nor did he inquire about that. He was interested in grinding a threading tool. He can do it as you suggested and I agree it would work. My thought on using the fixture is to keep from moving the table settings so much. He would have to set the table at 30 deg and grind each side to the right length. Then reset the table to 5-10 deg for side clearance and carefully grind each side of the V untill it comes to sharp edge on top. With a fixture made to use the slot in the table he could grind both sides of the V with the 30 deg angle and the relief at the same time and only have to turn the block 180 deg to grind each side. There would be several ways to make a fixture for a two step sharpening of a threading tool. Less time sharpening and more time to machine. I got tired of wasting time years ago. But as I have said before, if you are doing it as a hobby it makes little difference but if you are trying to earn some spending money then time is important. Some stuff I do for money and some stuff for fun but I still do it the fastest way I can think of. I guess it's just the job shop attitude in me and it's been hammered in to hard to quit that way of thinking. I guess it was driven into me as a child. One of my mothers expressions was, S--t or get off the pot, and she meant, get the job done, whatever you were doing or she would do it herself. Believe me, you did not want to have her do what she told you to do.

BTW, I free hand grind all my lathe tools and drill bits except the threading tool which I have a fixture that I use on my surface grinder that does a perfect job with two movements of the tool bit.

The reason I bought the lathe tool grinder is to speed up the grinding/sharpening process and get more satisfactory and repeatable grinds. I set my tables at 10 deg and never move them except for special tool angles which is very seldom.

moto, mine ran pretty true but I may do that when I change the wheels out for they did run out some but not enough to bother with now. It's those blasted concrete wheels that I don't like.

01-21-2007, 01:44 AM
Carl I think we're on the same page... just different interpretation of the same infomation. Only real difference is using the protractor guide set at 30 and the tables set for side relief using a block to hold the tool flipping 180 from side to side.

As was mine good out of the box.

loose nut
01-21-2007, 11:21 AM
Tinker, I get what your saying about grinding opposite 30 deg. angles and not using the protractor that came with it as a guage. The protractor is perendicular to the face of the grinding wheel so to set it to grind a 30 deg. angle you have to set the protractor to 60 deg and it only goes to 45 deg. The only way you can grind a 30 deg angle by setting the protractor to 30 deg . is grind on the side of the wheel and thats a bad idea. I tried setting the protractor with a thread guage to get the right angle but the protractor won't swing around enough to set the proper angle on the wheel face, that's why I made the jig so I could grind angles reciprical to the protractor settings. I thought a tool grinder should be able to grind all the necessary angles out of the box, so I must be doing something wrong but I don't know what. My way work's too, if there is a better way I would like to learn it.
Carl the grinding block is a good idea if only to keep my much abused pinkies away from the wheel

01-21-2007, 11:45 AM
Yep, to me some of the most dangerous things to fingers are wire wheels, grinder wheels, sanding belts and disc's, bandsaw's, and hand held grinders. I was using a hand held grinder with a wire brush a couple of weeks ago and it jumped off the work and hit my arm in an instant. The brush gouged a spot about an inch in dia. and about 1/8" deep. It was a stupid mistake as I usually wear a long welding glove when holding a part. I was in a hurry and it bit me.

Bill Pace
01-21-2007, 12:27 PM
I was in a hurry and it bit me.

Lordy, Lordy!! How many of us have said that!!

A band saw seems to have a grudge against me in my shop, I get more blood off them than any other tool, though a wire wheel or grinder is prolly second.

01-21-2007, 02:39 PM
loose nut... I do use the protractor guide fence that came with it and block to hold the toolbit it give a bigger surface to grip and better control of the tool. The wheel is back mounted with a plate and the side face is meant to used. Unlike the composite wheels on a common bench grinder from the hardware store that could cause the wheel to fail it the side it used. The bond between the plate and the stone seems like it would resist compressive loading better then the potential shearing loads that would come from using the circumference of the stone... the reverses of the common bench grinder. Not only that but if you only use the edge when you dress it it will get smaller in diameter and the relief face will have more of a concave to it. Whereas dressing the side face just makes it thinner and make no changes to the finish angles of the tool. With that being said I do use the edge lightly to add needed contours to bits but is not my primary grinding surface. So using it in this manner does allow any angled bit to be shaped with the table and fence right out of the box.

loose nut
01-22-2007, 11:31 AM
Ok Tinker that makes more sense, I was taught to only grind on one face but this type of wheel is new territory to me. I usually rough grind on a bench grinder then finish on the tool grinder. So today wasn't a total waste I did learn something.
P.S.the wheels that came with my grinder are a green coloured concrete instead of the white concrete that other people have on there's, are they a carbide only wheel, a high speed wheel (they will grind HS) that is just green coloured, something else like some sort of universal wheel or maybe they realy are concrete 'cause there pretty rough. I'm getting better one's next time i'm at Wholesale Tools. Any ideas.
P.S. again Carl, OUCHHHH! Been there done that too!!! don't worry it usually grows back if the damage isn't to bad.

01-24-2007, 12:20 PM
Sneaky! Sneaky! Sneaky!

I looked up 46727 on the HF website yesterday and saw it for $129.99. Today I looked it up and it was $164.99. I looked around a bit more and found it again for $129.99. Whattup!!!

They must store a cookie on my machine.

46727-5VGA is $164.99.
46727-1VGA is $129.99.

Same product, I think, but different item suffix means different price.

Those bastards!

I called the local store to see what their price is and I didn't even have to ask for the lower price. The guy said that if it's on sale online bring in the printed add and I can have it for the sale price. They have them in stock.

Works for me! :D

01-24-2007, 02:02 PM
Nope! They must have been in the middle of updating their website. A few minutes later the URL that had the sale price on the -1VGA had the -5VGA listed at the regular price. Fortunately I printed the sale price page before it was updated. I'll see if the local store still honors it.

BTW, there is a boat load of information on this grinder on this website. I remember several discussions about it over the past couple of years. Someone listed high quality replacement stones for it available on the web. It seems to be a very well thought of tool for upgrading.

loose nut
01-24-2007, 08:48 PM
When I bought mine their website listed it at $129.99, but the store price was $165. The cashier said that there are web site sales that the store dosen't have, you have to print out the page and take it to the store to get the sale price. Didn't know that, after driving 100 miles to get there the manager said she would sell it to me for the sale price, took my word on the price and didn't even look it up, I could have said it was on for $99.99. Damned honesty cost me another $30.00.

Jim Hubbell
01-24-2007, 09:32 PM
I got my grinder for $140 on my doorstep. All the way from someplace in VA!
As received nothing fit. It was a kit. The four table quadrants were as cast. I used the mill to finish them. The mounting bosses on the tables were off so they also were trued up. A little work on the groove in the quad brackets had them operating smoothly. The Al face plates and the spacers was removed from the spindles. The spacers were discarded and new ones made. The Al face plates ( wheel drive ) trued up to run OK. A lead washer under one wheel mount screw cut the vibration to a minimum.
I am thinking of making a guide to run in the table groove and be adjustable in and out toward the wheel. The end of which will have an angle of 120deg. The bit would ride on the left , then on the right of the guide thereby leaving a 60deg. end on the bit.
I am quite pleased with this tool so far.

01-24-2007, 10:14 PM
Anyone got the Enco version? I know it's basically the same grinder, but is it any beter finished?

01-25-2007, 09:17 AM
The one I saw a few months back was just a different color best I could tell. My HF is a nice grinder just needed a bit of deburing on most every part. I don't see how one can go wrong with the HF if you buy it on sale for about $130. Even after buying a couple good AO wheels the price is less than most anything else I have found.

01-25-2007, 10:51 AM
It looks like Grizzly has one for $199.50 at the bottom of page 180 of their 2007 catalog.

In my experience the Grizzly products I've purchased are significantly better made than the HF products but at $70 more than the HF version I'm guessing it may not be that much better.

Anyone have any experience with the Grizzly version of this grinder? It's model H7762.

01-25-2007, 11:28 AM
I bought my HF tool grinder a couple of years ago and immediately replaced the left wheel with a white AO wheel from KBC. The AO wheel made so much difference on HSS that a few months later, I bit the bullet and ordered a diamond wheel from one of Enco's sale fliers. I had to bore about 020" out of the center hole of the diamond wheel to get it to fit over the grinder's arbor, and then had to re-drill & CS the wheel's mounting holes, as they were too small for the HF screws. After I got it all bolted together, I found the diamond wheel had quite a bit of axial wobble. Since the original 'green concrete' SC wheel didn't have this wobble, I figured it was the Enco diamond wheel that's defective. Shoulda sent it back to Enco and asked for another one, but since I'd bored & drilled on the thing, I just kept it. Any advice on how to deal with the wobble?

01-25-2007, 12:41 PM
I just bought a very lightly used Baldor cup grinder that I am sure the HF model is "based" on. Truing the cups face/OD/ID really reducing the vibration induced tray movement. To eliminate the tray movement and rattling I very carefully spread the centres on the mounting pins out enough to create a bit better friction fit. It really did't take much force to achieve the results I was after.
Wholesale Tool in Warren, Michigan sells the plate mounted cup wheels in 46 grit aluminum oxide and 60 or 100 grit silicon carbide. I went with the 100 grit in the carbide. They were very reasonably priced but the sic carb was pretty eccentric. They both cut beautifully.