What % sawyers on this board sharpen /set own blades ?

[customsawyer]

The pics that I posted here were supposed to be in a different thread. So I have removed them as they had nothing to do with this topic.

[Brucer]

Peter, you might want to play around with some home-made blade wipers.

I recently gave up on my sharpening service, partly because he would not wipe the excessive oil off the blades. I have a grand total of 9 sharp blades to my credit ;D using a borrowed LTAGA grinder. I was already getting annoyed at the water dripping off the blade so this morning I knocked off a couple of make-shift wipers. It took about an hour.

Here's a side view of the installed wipers.



On each side of the blade is an HDPE mounting block with a flexible plastic wiper fastened to it. I used a large spring clamp to hold the mounting blocks in place against the blade clamps on the sharpener.


Here's what it looks like from the end.



A real sandwich. Spring clamp on the outside (black & orange), mounting blocks (sort of white), sharpener blade clamp (steel grey), and in the center, the blade. Toward the camera you can see how I attached the flexible wipers to the mounting blocks. This was very experimental so I tried a socket head machine screw on the right and a slotted machine screw with washer on the left. The left hand one is easier to fine tune.


Here's a side view without the clamp.



It only looks like the mounting block is bolted to the sharpener clamp. It isn't, though. The clamp has three staggered holes at each end to support different blade widths. Since I'm using 1-1/2" blades the blade support bolt (silver bolt below the mounting block) is in the bottom hole.  The black socket head machine screw on the right is threaded through the mounting block but simply slides into highest unused hole. The mounting block can't swivel down because it's resting on the silver support bolt.

Below the clamp you can see the standard aluminum blade wiper that's supplied with the sharpener. It's supposed to be bolted under the clamp adjusting bolt but I just cut it short at the mounting hole and I hold it in place with a larger rare-earth magnet. The magnet is the big black blob below the aluminum wiper (it's completely covered in metal filings and grinder debris).

The side wipers are drawing fluid down the blade so it's important that the bottom wiper contact the blade to the left of the side wipers.


Here's the mounting block and wiper removed from the sharpener.



On the left is my first attempt at shaping a wiper. It actually worked but it wasn't wide enough to cover the whole blade. The first hole was in the wrong place as well. On the right is the wiper-mounting block assembly for the back side of the blade (it's upside down in the picture).


Here's the same assembly seen from the back.



You can see how the machine screw protrudes through the back. I wanted it as deep as possible into the unused blade clamp bolt hole, but not so far that it touched the blade.

And here's the answer to the question on everyone's mind -- what did I make the wipers out of. In this case it was the lid from an 4 oz (or 125 ml) cream cheese container. All sorts of dairy products come in these containers -- cream cheese, yogurt, sour cream, etc. The lids make great wiper material -- it's soft but flexible, cuts easily with scissors, is easy to punch holes in, and is waterproof. I don't know how it will stand up to oil-based fluids but the stuff is so easy to find you can easily make up spare wipers. Just keep your first designs as a template.

The mounting blocks were cut from a single piece of 3/8" x 1" x 3" HDPE (High Density Polyethylene). You only have to make one cut -- the two pieces are perfect mirror images. HDPE is great to work with -- you can drill it, cut is with a hack saw, tap it, trim it with a utility knife or chisel, or use just about any metal or wood-working tool with it. You could also use brass or aluminum, or bend something out of heavy gauge sheet metal.

I tapped the holes for the machine screws (1/4" fine thread) but I didn't bother tapping the holes for the smaller screw that  hold the wipers in place. Just drilled the holes slightly undersized and ran the screws in.



This thing worked really, really well. There's a film of moisture on the blade but it doesn't drip any more. I do have to remove the blocks when I'm changing blades but it's very easy to do.

Even if you don't have a lot of machine tools never underestimate the power of duct tape ;D.

[tommone]

Clever idea , Brucer. Can you bond or otherwise fix a piece of foam or other material to  the wiper to absorb the remaining moisture from the blades . May even come out dry. Just a thought!Tom

[Peter Drouin]

Brucer , look good and thanks for the food for thought, I do have to do some thing :D :D

[Brucer]

Tom: There is a very, very thin film on the surface of the blade. It's already evaporating by the time it gets back around to the sharpener. I would tend to put any absorbent material on separately, positioned after the wipers. Otherwise it would be absorbing all the fluid that the wipers remove. There is more fluid on the sides of the teeth but an absorbent material there would get torn up by the teeth. Perhaps a pair of absorbent rollers outside the fluid tray would work.

Peter: This was very much a seat-of-pants effort. Originally I was going to replace the blade support bolt with a longer one that ran through a pair of 1/16" aluminum mounting strips (which I salvaged from the frames of some old floppy drives). A light spring slid onto this bolt would press the back mounting strip against the rear blade clamp and would pull the head of the bolt against the front blade clamp.

The leading edges of these two strips would be bent back away from the blade at the same compound angles as I used on the HDPE blocks. That would give me a couple of flanges that I could clamp the wipers to. To clamp the wipers I was going to use a couple of those black paper clips that have folding "handles" to open them.

Since I only had one paper clip on hand, and a block of HDPE, I ended up with what you see in the pictures.

I've run 5 blades through these wipers now and I found the wipers tend to take a bit of a "set" so they don't press as tightly against the blade. That turned out to be easy to fix -- just bend them by hand the other way  :D.

[Brucer]

I've read a few comments about problems setting the hook angle on the older LTAGA grinder and also on the earlier CBN grinder. It seems the head will sometimes slip.

When I was rebuilding my borrowed grinder I found the mounting/clamping bolt was incredibly tight. Not only did I need to hammer the wrench to break it free, I had to hammer it all the way off . When I finally got the bolt undone I discovered the threads on the bolt and on the head mounting plate were grossly distorted. I have no clue how the operator ever got it all the way on ???.

I fixed it, but I didn't figure it would stand up to extreme tightening. I also found it difficult to position the head just so and get the bolt nice and tight without shifting the head. So I made a small addition.



This is a simple jack screw that let's me adjust and hold the angle of the saw head while I tighten the clamping bolt. It's just a small piece of keystock -- 3/8" square by 1-1/2" long -- attached to the mounting plate with a couple of #10-32 machine screws. A 1" machine screw presses against the base to hold the head in place.

The threads are coated with "Never-Seez" to keep them from rusting up. I just take some pressure off by lifting the grinder motor slightly and then turn the jack screw by hand. A full turn of the screw will change the hook angle by about 1-1/2°.

It's very easy to hold the angle guage under the motor and make fine adjustments to get it just right.
Best of all, I can tighten the clamping bolt and the grinder head simply won't move.

[Peter Drouin]

nice job