Had to "ReBlade" my LPGS - Tried a Hole Saw

Gordon Gould · Jul 16, 2014

I originally used light duty 3/8" flat Cutting Edges (read cheap) on my LPGS. Here it is 4 years ago.

After an awful lot of use the front edge has worn down to be almost flush with the skids and it no longer cuts well in packed gravel. The rear edge wore less. I decided to put on a pair of standard 6" double edged box blade cutting edges. The old blades had a 3-2-10 hole spacing with 1/2" holes and the new blades have the more common 6-12 spacing with 5/8" holes. So I had to drill ten 5/8" holes in 3/8" angle with a hand drill to mount the new cutting edges.

Lately I have read on here alot about using a hole saw for this. I have always used drill bits in steel. I wanted to see the difference so I bought a Milwaukie 5/8" hole saw cutter from AceTool for $5.25. Cheaper than a good drill bit. I already had a standard 1/4" mandrel to hold the cutter. I used the hole saw for my ten holes.

On the first couple holes I made I found that the hole saw cut very easily to a depth of about an 1/8" or 3/16" and then it seemed to take forever and ever to finish the hole. I finally figured out that the narrow circular kerf was filling with chips. The narrow kerf is not self cleaning and the cutter teeth just ride around on the trapped chips losing contact with the bottom of the hole. After that, as soon as the cutting action slowed or when I wanted more lube, I pulled out the cutter and cleaned out the kerf with a piece of 12 gauge wire. Doing this the rest of the holes went very quickly and easily.

I can see why a machinist would cringe at the thought of using a hole saw as the hole walls are a little rough in appearance. But the holes are round and easy to place accurely enough for most work when using a mandrel. I would have to say that the hole saw seemed faster and easier than a drill bit when using a hand drill. I would still prefer a drill bit in a drill press.

All this is all just the opinion of a back yard mechanic on a rainy day. Here is the cutter after 10 holes. Still sharp.

gg

k0ua · Jul 16, 2014

What some guys do is drill a couple of 1/4 inch holes on the inside of the circle scribed by the hole saw tangent to the line to allow a place for the chips to go. Wouldn't need to do this for a small hole like a 5/8 but on a larger one it might be worthwhile. Your method of chip cleaning seemed to work. Just be sure to not go too fast and use lube and you holesaw teeth will last a long time.

oosik · Jul 16, 2014

I use hole saws for larger holes - 3/4 to 1 1/2. As James indicates, I've found that going slow, real slow, and lots of lube is the answer to faster cutting and longer lasting hole saws.

jenkinsph · Jul 16, 2014

Gordon,
I drill the pilot holes using a 1/8 to 3/16 inch cnc bit then use the hole saw afterwards. I drill through all the holes then blow out the chips for all of them and then start over again working down the line. That is with a cordless drill turning slow and using cutting oil.

I think you will find that good grader blades will make a big difference in the planes ability to cut/shave.

Gordon Gould · Jul 17, 2014

That sounds pretty efficient Steve when you have a line of holes all marked out and the small pilots predrilled like you do mounting a new edge. I was thinking of the air hose to clean the kerf but didn't want to spread chips around where the grandkids go barefoot. So I used the #12 wire. Keeping the kerf cleaned out was certainly key in making it easy work with the hole saw. I hadn't seen that in any disscussions. Probably a no brainer for most guys but not for me.

I have a driveway lined up for today so I will find out how the new edges work compared to the old ones.

gg

oosik · Jul 17, 2014

I obtained a brand new grader blade from the highway dept and installed on my rear blade. I don't know that it worked any better and I did have to drill new holes in the rear blade. What I do know is that after four year of use this new blade shows hardly any wear. Better steel, I would guess.