Forester 04844 Chain Grinder

[Philbert]

General

Several years back I was challenged to evaluate some of the less expensive 'mini-grinders' for sharpening saw chain. These grinders typically have 4-1/8 or 4-1/4-inch diameter wheels; fixed head tilt angles; and fairly small (70 to 85 Watt) motors. While limited in angle adjustment and power, they are also compact, quiet, and relatively inexpensive, ranging from about $30 to $80, depending on the model, vendor, etc. They can be a good choice for touching up chains dulled from normal use, or for guys who just don't like to file, providing sharp, consistent cutters at standard angles.




At the lower end, these mini-grinders come with all plastic / composite construction, thin metal components, and a single grinding wheel. The Forester model 04844 comes with a sturdier feeling, cast aluminum base; a heavier gauge chain vise and chain stop; 1/8" and 3/16" grinding wheels; a wheel dressing brick; a plastic wheel / sharpening gauge; and even a spare set of brushes for the motor. It also comes with a fairly clear User's Manual.



This grinder is said to be identical to the Oregon 310-120, except for minor detailing and branding. It feels well finished, and requires only very minor assembly. I also liked the Oregon model, but that one had a few glitches when first released. I assume that those have been addressed, so pricing could be a factor in choosing between the two.

Philbert

 

[Philbert]

Use

Overall, I like this grinder, especially when compared to others in this size and class. I like the heavier grade components used. I like the threaded; machine screws used in the chain vise, over the sheet metal type screws threaded into plastic, used on some other grinders.



Operation and adjustments are smooth, and easy. The chain clamping lever is repositionable, so you can adjust pressure and keep it out of the way. The vise angle scale, cast into the aluminum base, is easy to read. The grinding head lowers easily and returns easy. The wheels run true. The motor is very quiet in use.



Changing grinding wheels requires removal of 3, sheet metal type screws on the side cover: I would prefer threaded machine screws here too, to eliminate wear from changing wheels frequently for different chains. I keep a Phillips head screwdriver with the grinder for this purpose, although, I recognize that many users will only change wheels when worn out.



As on most of these small grinders, the power switch is located on the back, and is hard to see while grinding. The small, recessed, buttons are also hard to feel if wearing gloves. It's something you have to get used to. I was surprised to discover that it is equipped with a magnetic safety switch, which prevents unintended restarting if the power goes out. Turns out that a few of the other mini-grinders also have this, but not all of them.


Philbert

 

[Philbert]

Grinding Wheels

The grinder is supplied with 2, fine (100) grit, red/brown, wheels, similar to several other mini-grinders. I prefer the coarser (60 - 80) grit, pink wheels that Forester, Oregon, and Molemab also sell. To give this grinder a fair evaluation, I tried the supplied, fine grit wheel on a couple of 72DL, full 3/8 pitch, STIHL loops that just needed 'touch-up' sharpening. After the first loop I switched to a pink Forester wheel, purchased separately. Again, a BIG difference. The pink wheel ground faster, with less heating of the cutter, and left a comparably smooth finish on the teeth.

I definitely recommend upgrading to the coarser wheels.

https://opeforum.com/threads/better-quality-forester-grinding-wheels-for-hf-type-grinders.22330/

Philbert

 

[Philbert]

Depth Gauges?

The manual states that this grinder can be used with 1/4-inch wheels for adjusting depth gauges and includes instructions for shaping the wheel. But Forester does not offer this wheel: the only one I could find was the Oregon OR4125-14A, which sells for around $25. When I tried to mount this wheel there was not enough clearance under the side cover to run it. Forester admits that this was an error in the manual. I will try doing depth gauges by profiling a second 3/16" wheel for this purpose.

Philbert

 

[Philbert]

Some Fussy Stuff . . .

The User's Manual specifies 5-3/4-inch OD wheels instead of the 4-1/4" wheels supplied (a typo). In some cases 4-1/8" wheels are used with these grinders.

The grinder head angle is fixed at approximately 65°, which is a few degrees steeper than some of the other mini-grinders (60° to 62°). This is likely not an issue with most users.

The cast aluminum base has molded, hex-shaped recesses for securing mounting bolts, as illustrated in the manual, but they are sized for the heads of metric bolts: SAE bolt heads will either turn in these recesses, or be too large in diameter for the holes. So, I placed large washers over the holes for mounting.

None of these grinders have a washer between the plastic knob for chain vise rotation and the metal grinder base, which I think is important, so I added one.

I have never been able to remember the 'universal' 'ON' / 'OFF' symbols on the switches, and the position is not consistent among all of the grinders I have evaluated. This manual does not help, by using these same symbols to identify the symbols on the switch. So, I marked these clearly with a label maker to be sure.



The grinding wheels supplied have a paper label or blotter on one side only. There is a question about whether these are required. This is important to me, so, I will make my own out of cereal box cardboard and mount them with the wheels.

Philbert

 

[Big_6]

The portable chain sharpeners are pretty good. I find that the supplied motors are lacking in power.

Sent from my SM-N975U using Tapatalk

 

[Philbert]

The portable chain sharpeners are pretty good. I find that the supplied motors are lacking in power.

They do not have the power of the 5-3/4" grinders, which also have higher wheel rim/circumference speed, even with lower RPMs. These are better when cutters need to be reshaped, or have been heavily damaged, etc.

As noted in the first post, these mini-grinders are better suited to edge touch up sharpening, periodic 'evening up' of hand filed cutters, and fixing the occasional rocked cutter.

e.g.: 120V, 4.3A, 300W, 3400 RPM, 0.4 HP motor on Oregon 520, compared to the 50W motor on the one in your photo, and the 85W on this Forester (0.1 HP).

But no laws I am aware of that say you can't have both!

Philbert

 

[jakethesnake]

What is the approximate price on this unit?

 

[Philbert]

What is the approximate price on this unit?

I am always hesitant to quote prices, because they change, and vary with vendors, sales, shipping, etc. I have seen it on eBay; at local saw shops; and recently at Menard's, in the $50 to $80 range.

Philbert

 

[Philbert]

Depth Gauges - Revisited

As noted, neither this grinder, nor the similar Oregon 310-120 one, accept 1/4" wheels for depth gauges ('rakers'). This was a disappointment, since grinders are a great way to set these at equal heights.

So, I tried profiling a 3/16" wheel for this use, by placing the dressing brick on the chain vise, as described in the Owner's Manual. This only increases the contact width by about 1/32", but creates a flat surface for setting depth gauge height.



It worked! I tried it on 3/8 low profile, .325 NK, and 3/8 chains, setting all of the left side depth gauges first, then re-checking height and setting all of the right side ones. There might be some chains, with wider depth gauges or low-kickback bumpers that require two passes, but it is 'do-able'.

Philbert

 

[Wood Doctor]

Heck, Philbert, I might get one for one thing only: setting the depth gauge height. However, I have an ancient HF grinder that will also do it (after a fashion).