HF Chain Grinder Thread

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
OK, men, I have now got the $120 Laser, an Oregon 511 clone, working better. If you decide to buy one of these, be prepared to bench mount it. similar to the Speed Sharp or 511a. I made a T-shaped hardwood bracket that allows me to use my bench vise to hold the chain 45" above the floor. The shelf perch should be no deeper than 5-1/2" for this sharpener to provide clearance for the knob that locks the sharpening angle.

There were some engineering corners cut here and there, but you have to expect that for the bargain price. Here are my findings and enhancements:
(1) The motor draws half as much current but runs at the same RPM. I notice no power reduction compared to the 511a, and it has the same low noise level. I'm not sure how the Chinese accomplished this magic.
(2) There were no assembly or operating instructions in the box. There might be some on line somewhere.
(3) You have to remove the L-shaped hinge catch in the back to install or remove the grinding wheel. Otherwise, the clearance is inadequate. I carefully filed the catch down in thickness to increase the height when up by over an inch.
(4) I removed the strong compression spring under the clamp knob that locks the sharpening angle and the vise and replaced it with a common 7/16" steel washer. That works better than the spring which prevented it from locking the vise tight.
(5) I see no way to reduce the gap between the vise jaws. They worked OK for 063 gauge.
(6) There were detents at popular sharpening angles. That I liked.
(7) There were two slant angle gauges, one on the back and the other on the front. I liked that, but there was a 2-degree error in their readings. The one on the back reads 2 degrees lower.
(8) The cam mechanism that locks the chain in the vise initially worked far better on one side than the other, but after sharpening several chains, it somehow broke in and now locks the same on both sides. Sigh of relief.

I have now successfully sharpened six chains with it, all different sizes. So, with these enhancements, it's a keeper. Not the same quality as Speed Sharp or Oregon, but for less than one-third the price, it's hard to be too critical. Needless to say, after getting a few bugs out as documented above, this Laser beats my old HF sharpener (that someone gave me a few years back) seven ways to Sunday.
 
Back to the Mini-Grinders
Oregon 310-120 Grinder
Started a separate thread on the new Oregon 310 grinder here:
http://www.arboristsite.com/community/threads/oregon-310-mini-grinder.283691/#post-5474287

Side-by-side comparison with a similar looking 'HF-type' grinder. Posted most of this in the other thread, but adding it here to keep things straight.

In use, both grinders performed about the same. These are still light duty grinders, best for touch up sharpening, especially on smaller pitch chains. Simple, convenient, require a light touch and patience. Could be OK for an occasional user who does not want to pay for a more expensive grinder. Anyone expecting to open a sharpening service with one of these, to quickly bring back a rocked chain, or to use regularly on .404 chain - good luck.

A 1/4 inch wheel is available for the Oregon grinder for doing depth gauges, but they are expensive relative to the cost of these grinders ($25), and switching wheels is not convenient, so I did not try it. I suppose one could could buy an extra HF grinder and dedicate it to depth gauges?

Can't say anything about longevity, etc., but the Oregon one does come with a 2 year warranty, and they have always been very good to me with customer support. One wheel was defective out of the box, and they mailed me a replacement.

Advantages of the Oregon 310 (right) over my 'Infinity' brand 'HF-style' grinder (left):
- cast aluminum base, instead of plastic;
- larger, more effective chain holding dog on the vise;
- accessible motor brushes;
- came with additional 3/16" grinding wheel, dressing brick, wheel template, extra motor brushes;
- better (but not perfect) owner's manual;
- Oregon support (if needed).
310 and HF Type.jpg

All things equal, I would choose the Oregon over the generic grinder. But the generic HF grinders are often available on eBay, etc. (even Home Depot.com!) for around $40 (although, I have seen them advertised for as much as $160 in some ads!) which is part of their attraction. The Oregon is a new product and only listed by a few on-line vendors, although, I am sure that any Oregon dealer can order them. Current prices are in the $85 - $90 range. Some of this difference can be attributed to the advantages noted. Maybe some of this difference will dampen out in comparable sales channels as more vendors and discounters start carrying the 310?

Anyway, these are the styles that I like the most of those that I have looked at and reviewed in this thread. Within their limits, they can be used to sharpen chains. None of them will replace my full-sized grinder in terms of power and versatility. I will probably hang onto these 2 for a while and continue to 'play' with them, maybe try them for portable use, etc.

Philbert
 
I should add this here too. I have 3 grinders that hold the grinding wheel in place with the identical 'flange mounting knob'. None of the manuals specify which side faces the grinding wheel, and I guess that I was doing it wrong on all three!

If you look closely at the illustrations, they all show the 'dished' side in and the 'flat' side out. So I am passing that on. I also labeled mine with my label maker, so that I don't have to think about this again.

wheel flange 2.jpg wheel flange 3.jpg

Philbert
 
The ID on one of the made-in-China grinding wheels (left) that came with my Oregon 310 grinder was too large. Oregon was very good and sent me a replacement wheel right away; it was their standard made-in-Italy wheels (right), which I had expected to come on an Oregon product. Tonight, I tried it on the same chains.

Oregon Wheels.jpg

Wow! BIG difference!

Earlier in this thread I mentioned looking for other 3/16 wheels for the HF grinders, and even mused about adapting angle grinder wheels (not something I encourage). Having used these once, it will be hard to go back. I assume that the difference would apply to all of the grinders covered in this thread.

At $20 to $30 each (retail pricing), this takes some of the 'fun' out of a $30 - $40 grinder. But it makes sense - these are the part that does the cutting, just like a sharp chain on a modest saw. Molemab wheels from Bailey's might be an option at about $10 each.

Philbert
 
Did not have time to read the whole thread, but was wondering, can those cheap HF grinders be adjusted to sharpen square file chain?
No. (short answer).

The head tilt angle is fixed, and they have less adjustability than a basic 511A type grinder. Even if you decided to design your own square chisel chain grinder, these would not be good motors to use, due to limited power and small diameter wheels (which get dressed to a sharp point for square chain). You would be better off starting with a full sized grinder motor, or even better, one that accepts the standard 8-inch OD 1-inch ID square grind wheels. (long answer).

(Though it did cross my mind once . . . )

Philbert
 
Chicago Electric Revisited

I used the Chicago Electric grinder with the bicycle grip handle for the first time in a while.
Sharpened/touched up a 3/8 low profile (type 91) chain with it, and got adequate results. But I am now better able to compare it to 'competitive' grinders.
photo 5.jpg

I like the idea of the brake handle but it does not hold the chain as secure; is kind of sloppy, even with my tweaks (and the 'Silvey' labels); and is more complex (more things to go wrong) than the similar models with the locking lever. Typically, I had to squeeze the handle twice for each cutter: once to position it (it moves quite a bit), and a second time to grasp it for grinding.

It's also harder to observe the grinding process - I suppose I could remove the clear 'guard', as I doubt it does much. And the star wheels at the ends of the vise make the chain harder to advance - more of a problem than a help.

Again, it sort of 'works', but not as well as the older versions, which are still available with other brand names/labels, for about the same price. If I found a 'dead' grinder of the old style (burned up motor, cracked base, etc.) I would switch out the vise: it would be an improvement, but not worth the effort to fabricate the parts.

Philbert
 
Garage Sale Find

(Future Silvey grinder!)

Chicago Electric 1.jpg
(Curse you 7Sleeper for starting me on these!).

I just got some Molemab wheels on sale from Bailey's, so I will try them on these. Interesting to note that this Chicago Electric grinder has a grounded, 3-wire plug, while all of the others have 2-wire (double insulated?) cords.

Philbert
 
First Use (for me) - Future Silvey Grinder

This is the one that started it all, so to speak! Even though it was 'used', it was never properly 'tweaked'. I cleaned it (our own dirt is different than other peoples' dirt); trimmed off all the sharp flashing with a razor blade; wrapped the center post with aluminum tape (makes cleaning off grinder grit easier); mounted it on a wooden base, so that I can clamp it to work surfaces; and added a Velcro strap to coil up the cord when not in use.

Interesting that the grinding wheel on this, older model, is much better than the ones that come on the newer models - closer to the Molemab and Oregon wheels. Just needed to be dressed.
photo 4.jpg

The vise did not hold the chain well. In fact, the chain positioning stop or dog hit the cutter off center, near the top, and lifted the cutter out of the vise. And the entire cutter shifted to the side, when tightened. The chain did not flow smoothly out of the end of the vise.

- I squeezed the rolled end of the positioning stop with a pair of Vise-Grips (no pun intended) slowly and gradually, until it fit on the mounting post without wobbling, but not so tight that it binds;

- I shimmed the mounting post for the stop with a washer so that it no longer wobbled, and so that it hit the cutter closer to its center;

- I bent the flat metal stop slightly, so that it reached over the tie strap bumper, touching the cutter at its base, instead of near its top;

- I cleaned off some burrs on the inside of the vise clamping plates that interfered with chain flow.

Screen shot 2015-09-16 at 8.45.43 PM.png

Still a cheap grinder, but now it is a happy cheap grinder. Works as intended.

Philbert
 
Interesting that the grinding wheel on this, older model, is much better than the ones that come on the newer models - closer to the Molemab and Oregon wheels. Just needed to be dressed.

Different 'Chicago Electric' brand wheels, similar to the different Oregon' branded wheels shown in Post #188, above. The older on one on the Right works much better than the newer one on the Left.

HF different wheels 2.jpg

Philbert
 
When is '7/8' not '7/8' ?

Sesame Street
taught us "one of these things is not like the other . . . " Frustrating when it comes to grinding wheels.

Most of these 'HF-style' mini-grinders use wheels described as 4-1/8-inch diameter, 7/8-inch arbor. Since a lot of these grinders and wheels are made in Europe or Asia, the metric conversion is important- about 105 mm X 22.3 mm.

If only they were consistent!

I have now tried 4 of these HF-style grinders, and several brands of wheels, and found lots of variation. If the outer diameter (OD) of the wheel is slightly larger or smaller, it is not a problem, unless it is so large that it hits something. If the width of the wheel (1/8", 3/16", 1/4") is slightly wider or narrower, I probably won't notice it in use or in the final results (unless the wheel will not physically fit under the mounting nut or side guard).

But if the mounting hole (ID) of the grinding wheel is too small, it will not fit on the arbor. If it is too large, it will not run true (unless bushed - has its own issues). Unfortunately, I have found lots of variation in the arbor sizes of the grinders, and the wheels themselves.

Sample of 2 grinding wheels that are supposed to have the same ID. One fits one grinder, the other fits the other 3. Note the white ring of the blotter on the smaller ID wheel.

Different ID.jpg

7/8-inch equals 0.875-inches or 22.225mm. Using a dial caliper, I measured arbors and grinding ID's ranging from 0.863 to 0.920 inches. A range of 57 thousands of an inch (not quite 1/16 of an inch) - not bad for carpentry work, but pretty embarrassing for machine work.

Holes are difficult to measure accurately with a caliper, and I have hammy hands, so these numbers might be slightly off. But simply put: Some wheels will not physically fit onto some grinders. Some wheels will fit so sloppily that they will not run true, even if bushed or shimmed. I have had grinding wheels explode, so I do not recommend being careless about this.

Be careful when buying wheels, and check to see if they fit. I have had to return some. It is disappointing that I cannot buy wheels of any brand, like I can buy any brand of saw chain, and know that it will fit, if it is labeled the correct size. Can't even be sure by brand - have to test fit each one.

I have really liked the coarser, pink Oregon and Molemab wheels on these grinders, but they do not fit one model, so I will either have to part with that grinder, or see if I can re-size the larger mounting arbor on that model.

Philbert
 
Do you just need the short, metal piece?

Might be easier to cut a strip out of a piece of steel. Or cut off a piece from a cheap strap hinge, if you want the mounting hole pre-formed.

The chain stops on the Oregon grinders, including the 310 mini-grinder, are stamped into a "U" shape. Would be easy to make this style from a short piece of "U" channel from the hardware store.

The support post could be made out of a small piece of hardwood if needed.

Philbert
 
Back
Top