Chainsaw 2-in-1 Filing Guide Modification

A couple of years ago I purchased a Lynx 40 volt lithium battery chainsaw for some light tree work around our property. Since it uses an uncommon round file size for the teeth, I hand filed the teeth using a single 11/64” round file and flat file for the raker height. Lately I’ve been using the chainsaw more often, so I decided I needed a more efficient & accurate method for sharpening.

I decided to use a 2-in-1 chainsaw filing guide like I’ve been using on my larger chainsaw (Stihl 2-in-1 Filing Guide). It appears there aren’t any filing guides made for this size teeth, so I decided to modify one or the existing filing guides. My chainsaw has teeth sharpened with 11/64” round files (with raker depth of 0.025”), so I chose to use a sharpening file guide that uses 5/32” round files with a raker depth of 0.025”.

Tools needed

- 11/64” drill bit

- drill with “goose neck” drill bit holder

Parts Needed

- (1) 5/32" 2-in-1 Chainsaw Filing Guide

- (2) 11/64” chainsaw files

Here’s a short explanation of how this type of sharpening file guide works. Chainsaws are a series of links composed of teeth, rakers and connecting linkage. In this case, my chainsaw is a 3/8” chain composed of teeth that are sharpened using a 11/64” round file with the raker set for a “depth” of 0.025”. If the teeth are dull or the rakers are not set at the right depth, the chainsaw will perform poorly. If the depth is too deep, the chainsaw will bog down, if the depth is too shallow, you’ll cut too slow or maybe not at all.

Having the chains sharpened professionally usually shortens the life of chains considerably (can usually only be sharpened 3-4 times professionally due to amount of grinding done), can be expensive, and there will be a loss of time. Simply buying a new chain can be expensive. The best solution is to be able to sharpen the chains yourself – if you have the proper tools.

Hand sharpening the teeth and setting the raker depth yourself can take considerable 1) time, 2) effort and 3) can be prone to some inaccuracies. Using a tool like a Stihl 2-in-1 filing guide saves a great deal of time, is very easy to use and is quite accurate. In addition, sharpening with this style of guide usually lengthens the life span of your chains, considerably.

The 2-in1 filing guides are designed so that you can easily replace any of the three files (2 round files and 1 special purpose flat file). Simply open the end of the guide and extract the files. For this modification, the special purpose flat file is being be removed to modify the holes for the 2 round files in the next step.

The special purpose flat file is used in conjunction with the metal rods of the tool (the metal rods are not removable). The metal rods position the flat file in the guide at the proper cutting depth for the rakers, and as you file the teeth the raker is automatically filed to the proper cutting depth. This ensures the proper cutting depth every time you sharpen a tooth. The 5/32” sharpening file guide already has the proper depth set at 0.025”, so the flat file needs no modification.

The round holes in the sharpening file guides are 5/32” and are designed so that you can easily replace either of the round files. In order to replace the 5/32” round files with 11/64” round files we need to enlarge each of the 4 round holes shown in the photos. I used a 11/64” drill bit with a hex shaped base and simply drilled out holes 1-3 using my fingers. For hole number 4, I needed to use a drill with a flexible “goose neck” drill bit holder. The entire modification took about 45 minutes.

After enlarging the hole sizes, I put in two 11/64” round files and the special purpose flat file (be sure to insert in the proper directions). The modification works perfectly and it now takes only minutes to properly sharpen this chainsaw.

I hope you find this Instructable useful.