Oregon 310 Mini Grinder

[Philbert]

I normally sharpen chains with a standard Oregon 511A type grinder. Several months ago I was challenged to try some of the smaller, less expensive grinders, and started a thread on those.
http://www.arboristsite.com/community/threads/hf-chain-grinder-thread.268303/

Earlier this year, Oregon announced a new line of chain grinders, including one that looked very similar to these 'Harbor Freight type' grinders, and it recently became available. It replaces their model 108181 Bench Mount Mini Grinder, which uses similar 4-1/8 inch diameter wheels.




Manufacturer info for these grinders are available at:
http://www.oregonproducts.com/pro/products/accessories/BenchGrinder_310-120.htm
http://www.oregonproducts.com/pro/products/accessories/benchmountminigrinder.htm

I am going to try it out and compare it to the inexpensive grinders in the 'HF Chain Grinder' thread referenced above. I don't have one of the 108181 grinders to compare it to.

Philbert

 

[Philbert]

General

A sub $100 grinder is attractive for homeowners, and for occasional saw users who cannot justify a $300+ grinder. Some of these are also compact in size, which makes they easy to store, or take along to a site where power is available, or for use off of a generator or inverter. They also offer an alternative to the 'clone' / 'knock-off' grinders (a.k.a. 'Northern Tool grinders'):
http://www.arboristsite.com/community/threads/northern-hyd-grinder-making-it-work-pics.40844/

The Oregon 310-120 grinder (I believe that the '120' refers to 120 volts; other model numbers may be used in Europe, Asia, etc. ?) sells for about $90; that's about twice what some of the 'HF' grinders sell for, but about half of the previous Oregon mini grinder.

Oregon 310-120...120V, 85W, ..0.6A, 0.11HP, 4600 RPM, 4-1/8" x 7/8" wheels
Oregon 108181.....120V, 85W, ...... A, ......HP, 5000 RPM 4-1/8" x 7/8" wheels
Chicago Electric..120V, 75W, ...... A, .......HP, 4200 RPM 4-1/8" x 7/8" wheels
HF-style* ........... 120V, ....W, 0.75A, ......HP, 4800 RPM 4-1/8" x 7/8" wheels
* many versions and brands of these grinders are sold under different names

Philbert

 

[Philbert]

First Impressions

Opening the box, the 310 looks just like one of the HF-type grinders. The earlier photo from Oregon (left) shows a shiny plastic case, and some slightly different details than the current photo (right), and the grinder itself, so I was a little surprised. Wondered if I had just fallen for the brand name.



Upon closer inspection, the base is cast aluminum, instead of plastic. The chain positioning dog is more substantial on the Oregon than the HF grinders, and there are several detail differences, such as accessible motor brushes. Of course, I can't tell visually if there are quality differences between the motors, the plastics used, etc.

Clearly, the general design of all of these grinders go back to the same root, but they likely did not all come out of the same factory. I will post some side-by-side comparisons and photos down the road.




The Oregon 310 does come with 2 wheels (1/8", and 3/16") for sharpening 1/4 to .404 pitch chain; a wheel dressing brick; a wheel profile gauge; and a set of extra motor brushes (!). Some of this was not clear in the catalog description. The manual says that a 1/4" wheel is also available separately for grinding depth gauges.



The manual is actually clear and readable!

The value of these accessories, along with the aluminum base, accounts for some of the additional cost, aside from the Oregon brand name and support. I have been surprised to have only seen this grinder listed at a few sites, although, I am sure that any Oregon dealer can order one. Perhaps it is the perception that it is the same as less expensive 'HF' versions? We will see!

Philbert

 

[Philbert]

Odd Duck Design Feature

The mounting holes in the Oregon grinder are sized for larger (3/8" diameter) bolts than the 'HF-style' grinder' (5/16"). The casting has hex-shaped recesses to hold a bolt head captive. Except that the recess is too large to secure the head of a common 3/8-inch bolt (it spins in there); a bolt with a head that does not spin is too large to fit through the holes!

I bolted it up from the bottom with carriage bolts, and used washers to cover the hex recess. I would like to have used wing nuts, so I could easily remove the base for transport or storage, but the wing nuts would not clear the raised center portion of the base.

Philbert

 

[MarkEagleUSA]

The mounting holes in the Oregon grinder are sized for larger (3/8" diameter) bolts than the 'HF-style' grinder' (5/16"). The casting has hex-shaped recesses to hold a bolt head captive. Except that the recess is too large to secure the head of a common 3/8-inch bolt (it spins in there); a bolt with a head that does not spin is too large to fit through the holes!

Metric perhaps?

 

[Philbert]

Closer Looks

The Oregon spec sheet list the weight for the 310 at 15 pounds. Not sure where that comes from. On a postal scale, the 310, and each of the similar grinders I have, weighs in around 5 to 6 pounds, including the wood bases I made.

Grinder has:
- fixed head tilt angle;
- adjustable base/vise rotation angles;
- no 'down angle' adjustment.
Is double insulated.

Pretty light duty, but very simple to setup and operate. Small footprint. Compact. Quiet - like a sewing machine motor.

I may have spoken too fast about the manual: the line drawings are clear, and it is readable, but it appears to have been written by a non-native English speaker, which makes reading some parts a little awkward. Too bad: proofreading and editing by a junior high school English teacher could have addressed this.

Philbert

 

[Philbert]

Set Up

It's not convenient to switch wheels frequently on these types of grinders. Three sheet metal screws, threaded into plastic, hold the side guard in place. Then a plastic flange nut, tightened and loosened by hand, holds the wheel on the arbor. On my full size grinders the wheel is held in place by a single, Allen head bolt. Might not be an issue for many people who only sharpen one size/pitch chain.

The sheet metal screws could strip out eventually. On this grinder I can drill straight through and replace them with machine screws with nuts if they do strip out. Cannot do this on all of the HF-style grinder models due to different screw locations (some have 3 screws, some have 4 screws).

The grinder came with the 1/8-inch grinding wheel installed - it fit snugly on the motor arbor. The ID of the 3/16-inch wheel was significantly larger, and fit loosely. I tried to shim the arbor with several wraps of narrow masking tape to fit the 3/16 wheel; it sort of worked, but not like it should. I called Oregon and they have already mailed out a replacement wheel.

The flange mounting nut spun off easily, but I had some trouble getting it back on. So I cut a slot in the motor arbor, with a Dremel disc, to hold the arbor with a flat-bladed screwdriver when mounting/un-mounting wheels. Then, I started wondering if I had it on wrong. Doh!

All three of the grinders like this that I have use the same flange mounting nut. None of the manuals say anything about the orientation of the nut, but if you look closely at the pictures, they sort of show it with the dished side towards the wheel, and the flat side out. Worked better that way. I labeled them 'this side to wheel' so I don't space out again

Philbert

 

[Philbert]

Oregon 310 vs Oregon 511A

I had a bunch of STIHL .325 chains to sharpen, so this was a good opportunity to try the 310 side-by-side with my 511A on identical chains, using their respective 3/16-inch wheels.

I was absolutely able to sharpen the chains on both grinders, but there was no comparison regarding power, speed, or ability to do custom angle settings. The fixed head angle on the mini-grinder keeps things simple, but limits options. For example, I was unable to match existing angles on other chains: not a problem if this is the only grinder you use, but requires removal of a bit more metal if you change these angles.

Sharpened 4, 67-drive link chains requiring light touch up on the 310. Did not burn any cutters. Cleaned up one more chain where the cutters had been burned by someone else on another grinder. Could feel the additional load on the motor when taking more off the tooth. Also chased the chain gullets. The motor was warm after all of this use, but did not get hot.

I do not have the wider wheel to do the depth gauges on these chains, and don't want to frequently change wheels, as noted. If a person had a few of these lower priced grinders, one might be set up just for depth gauges, as some people do with full-sized grinders. I will file the depth gauges on these chains, or use my 511A.

General impressions: light duty, or for occasional use. Simple and convenient to use. OK for light touch up, but would be pressed for rocked chain. Better for smaller chains, where less metal is removed from the cutters. Requires a light touch and patience. Motor is smooth, but feels like it is easy to overload.

On a side note, it was interesting going back and forth between the grinders. I tend to fall into a 'rhythm' or 'zone' when grinding; due to muscle memory I wanted to pull out chain locking lever on the 310 horizontally, like 511A grinder, instead of twisting vertically. Afraid that I was going to break it off.

Philbert

P.S. - I should note that Oregon does offer a mid-range grinder in-between these 2 models.
http://www.oregonproducts.com/pro/products/accessories/BenchGrinder_410-120.htm

 

[Philbert]

Oregon 310 vs Other 'HF-style' Grinder

I also tried the Oregon 310 side-by-side with a similar looking, 'Infinity' brand, HF-type grinder (non-bicycle handle type) on the same .325 pitch, 67-drive link STIHL chains. These grinders appear nearly identical, aside from the differences noted in Post #3 'First Impressions'. In general, they operated the same.

I kept the 3/16-inch wheel on the Oregon, and the 1/8-inch wheel on the HF-type grinder. Both of these worked on the .325 chain, although, I went back for a second pass with the narrower wheel to shape the cutting edges and gullet the way I wanted - that was a function of the wheels, not the individual grinders.

Lots of dust was generated by the wheels on both grinders. These are both fine grit wheels, and I dressed them periodically, but found no noticeable wear compared to a new wheel.

The longer vise-locking lever on the Oregon grinder was easier to operate than the stubby one on the HF-type grinder. And the larger, chain-positioning dog on the Oregon grinder held the chain much better; the steep angle held the cutters down, as well as in their horizontal position. This larger dog, however, is not adjustable side-to-side, as it is on most larger grinders, and could be hit with the grinding wheel when sharpening end-of-life chain cutters. I guess this will resolve itself quickly, after grinding a few cutters like that.

All things equal, I would choose the Oregon grinder over the generic HF-style, due to these differences, and the Oregon support. The price difference, however, is significant. Maybe some of this difference will dampen out in comparable sales channels as more vendors and discounters start carrying the 310?

Philbert

 

[OldJack]

It's likely metric.

 

[Philbert]

Replacement Wheel

Received the replacement wheel today from Oregon: made in Italy (right) instead of China (left); coarser grit; correct ID; slightly different OD and thickness as well.



Still have several of those .325 chains to sharpen, so I will see if I can tell a difference.

Philbert

 

[Philbert]

Tried the replacement wheel today.

BIG difference!

Almost like comparing a sharp and dull chain. It was so much fun that I grabbed another chain to sharpen!

These were the wheel that I was expecting to come with an Oregon branded grinder - adds a bit to the price if they have to be purchased separately.

Philbert

 

[Philbert]

Back to the Daily Grind . . .

This little grinder is actually fun to use, with the new wheel, and doing light touch-ups: simple, quiet, small.

I noted, above, how the taller chain holding dog and support post on the Oregon grinder worked better than the one on the generic HF-type grinder. However, I have started to have some concerns about clearance.


This photo shows the almost new Oregon wheel (after about 5, 67 drive link, .325 pitch chains). The 4-1/8 inch diameter wheel can be used until worn down to the paper blotter/label. I have about 3/4 of an inch until I reach that point, but only about 1/8 inch clearance until the grinder motor hits the chain holding dog and support post!!!

Something I will be keeping an eye on! Might need a shorter support post (lower), or a longer dog (so the post can be tilted back farther). Hope I don't. If I do, I hope that it still holds the cutters as well for grinding.

Philbert

 

[Philbert]

Depth Gauges on a Mini-Grinder!?!

Some people file their depth gauges. Some people grind their depth gauges. Even some guys who file their cutters, like to 'do' their depth gauges on a grinder. It took me a little while to get the hang of this, without 'burning' the depth gauges, or especially the thin bumpers on low-kickback chain. Now I like it.

http://www.arboristsite.com/community/threads/depth-gauges-on-a-grinder.200410/

So, when the Oregon 310-120 grinder said that I could do depth gauges with an optional 1/4-inch wheel, I decided to try it. My main concern is that the small, 85watt motor might not have the 'oomph' to spin the heavier wheel. Turns out I could not even mount it. The wheel fit onto the arbor, and I was able to partially spin on the 'flange nut' that secures the wheel, but could not mount the side guard - not enough clearance. Bummer.

I called Oregon - maybe they will fix this on later models, or at least correct the advertising material.

Out of curiosity, I tried mounting this wheel on 3 other 'HF -type' grinders (see related thread). None of these had enough thread on the motor arbor, or clearance under the side guard, to mount this thicker wheel either.

Sending the wheel back for a refund (it cost more than I paid for some of those other mini-grinders!).

Philbert

 

[CR888]

lnteresting review Philbert! l kinda get the impression one would have to factor in the cost of decent ginding wheels when considering this cheaper model. l also wonder if this product was not branded by 'oregon' with all the warranty, parts availibilty ect, would it be worth its price compared to generic chinese models.....possibly, possibly not. l have had so much use out of a 511 copy (4 years), its time for an upgrade so l am in the market for a replacement. l am not sure this model would be best for me, but l am interested in new grinders hitting the market.

 

[Philbert]

l also wonder if this product was not branded by 'oregon' with all the warranty, parts availibilty ect, would it be worth its price compared to generic chinese models.....possibly, possibly not.

These 'mini-grinders' have to be considered as a class by themselves. I started a whole thread on them (see first post, above). They are simple, small, quiet, less expensive, easy to use. OK for touch-up grinding of standard angles. Side-by-side, I think that this one is the best of this group, but it is also the most expensive. I bought Molemab wheels on sale at Bailey's for $9 a piece (close to the same price as the replacement 'made-in China', OEM wheels that come with many of these grinders) - but I would buy them for any of these grinders.

l have had so much use out of a 511 copy (4 years), its time for an upgrade so l am in the market for a replacement.

If you are used to the full-size grinder, you will probably not be happy with the mini-grinders. The 511 type grinders have much more power, are faster, and allow more selection of angles (head tilt, vise tilt, etc.). They are much better for restoring rocked chains, and a better shop grinder for moderate to heavy use. I might still buy replacement wheels if I was using one of the clone grinders, based on some comments in those threads.

That said, this is A.S.: who says you can only have one?!
http://www.arboristsite.com/community/threads/new-oregon-grinders-2015.270287/

Philbert

 

[Philbert]

Bottomed Out

Lack of Clearance Clarence

Things That Go 'Bump' In The Grind

Unfortunately, as predicted a few posts up, I ran out of room today between the motor on my 310 grinder and the top of the chain stop.



Happened on the right hand cutters of a chain only about half used up.



And with a fairly new wheel.



As mentioned, it would be possible to make a shorter chain stop and support, but I will see if Oregon has a solution.

Philbert

 

[MDFisherman]

That seems like a rather large design flaw. I wonder if a 3/8 chain would allow for more of the grinding wheel to be used?

Any word from Oregon? I have had my eye on this thing for a while.


Sent from my iPhone using Tapatalk

 

[Philbert]

Any word from Oregon?

They said that they have addressed the problem and are sending a replacement - I will let you know more when it arrives.

Philbert

 

[Philbert]

Epilog

Oregon says that they addressed 3 concerns with these grinders: replacing the out-of-spec 3/16" wheels; installing a longer arbor to accommodate the 1/4" wheel for depth gauges; replacing the chain stop on the vise so that it does not hit the motor. The replacement unit I received still had all of these issues - apparently a QA/QC issue with keeping the old and new units straight, which was disappointing.

There is still a place for a higher quality version of these 'mini-grinders'. They are small, easy to move/store, simple to use, quiet, relatively inexpensive, and can do a good job with the right wheels. They can be a good choice for the right user: someone who is satisfied with the 30°/60°/0° grind; who is mostly doing 'touch-up sharpening'; sharpens a modest amount of chains; and does not want to spend $300 on full-sized grinder.

I hope that they get these issues resolved. If you decide to try one of these Oregon mini-grinders please inspect it carefully upon receipt to make sure that you get one of the updated versions. And please post your comments in this thread!

Philbert