PM100 Planer - How to sharpen & set the knives?

[Allan Speers]

Too many choices: I'm hoping someone can point me to an already-existing tutorial that both goes into detail, and that I can trust. I haven't been able to find what I need on my own, with any feeling of confidence. Here's the deal:

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This year I bought my first stationary planer. an early 80's Powermatic PM100 12". It did NOT come with the optional knife-jig that rides on top. The knives are a little dull and have a few very slight nicks. It was my intention to retrofit a shelix head, so I wasn't worried about the knives. With a shelix head, you don't even have to worry about setting the height, you just use a torque wrench to get things even.

Sadly, I can no longer afford the Shelix head & bearings (about $1,000) but I need to get this machine working, and I have a LOT of lumber skip-plane.

Obviously I have 2 different needs: Sharpening, and height adjustment. My main concern is the height, as I can get retrofit M2 knives on Ebay for less than $50. - But I have NO IDEA how to do this. I've been searching, and have seen a bunch of videos plus a bunch of products, but there seems to be many different (sometimes conflicting) ideas on the subject.

As I said at the start, can someone point a complete newb to a good website or video that shows a system they believe in? I'd prefer something on the PM100 of course, but ANYTHING would help. - Also something that shows how to make my own jig, if I need one.

Thanks.
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FWIW, it seems to me that the Infinity depth setting jigs would probably work well, assuming I know the depth that I want:
http://www.infinitytools.com/Planer-Jointer-Knife-Setting-Jig-For-Full-Size-Planers-Pair/productinfo/PKJ%2D201/

Any opinion on these?

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-but for sharpening, I have yet to see a "home shop" system that fills me with confidence.

I don't like the idea of grinding the knives while still in the head, as surely that would change the height a little. Yes? So... why not remove them, do it right, and then also have a chance to clean & re-lube the slots & gibs. No?

Another option for me would be to get the Tormek planer knife attachment, as I have their base unit hooked up to a CBN wheel. However, that wheel is only 180 grit. Maybe I could use that for removing knicks and setting the correct bevel, then hone at 400 - 600 with one of those "while installed in the head" contraptions? (And then maybe re-check the depth, to be safe?)
- but I still don't feel good about those contraptions, as the bevel angle could end up slghtly off. No?

[Bruce Wrenn]

Go to Global Tooling and order a new set of knives. Send your old knives out for sharpening. ( I use Dynamic Saw in Buffalo.) As for height setting gauge, Woodcraft amongest others sells a very good gauge. John White's book "Care and Repair of Shop Machines" contains the info needed. OWWM probably has info on their site on setting knives Before you remove existing knives, check their height, so as to have a reference for new knives

[Matthew Hills]

Bob Vaughan's instructions are pretty good. I used them to dial in my Parks.

his writeup:
http://wiki.vintagemachinery.org/Getting%20Peak%20Planer%20Performance.ashx

and a video showing it in practice:
https://www.youtube.com/watch?v=uSM7Jrg34a8


Matt

[Walter Plummer]

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"I don't like the idea of grinding the knives while still in the head, as surely that would change the height a little. Yes?" A very little. I worked in a shop where we had the grinder for the Powermatic planer. It was great. After about the third time you grind them they are just about perfectly set with each other and the finish is remarkable. You don't grind a lot, just a pass across and back usually makes a big difference. Last step I ran a small hone across each knife to take off the wire edge.

[Trevor Remster]

Yes Bob Vaughn's video is good.

[Allan Speers]

Great stuff, guys. THX.

Walter, good to know about the grinder. Of course, that PM grinder rode across the machine, so was likely very precise. I have my doubts about the accuracy of those little hand-held hones, but maybe they're acceptable for light touch-ups.


Mat, Bob Vaughn's info is GOLDEN. - And he does advocate having 2 sets of knives, so there's a lot of agreement going on here. I'd still prefer to be able to do a full grind in-house, but maybe that's foolish without the Powermatic attachment. I suppose if I got 2 sets of carbide knives, then it would be worth sending them out.

[Andrew Hughes]

H Allen,I use a simple jig to sharpen my 12 inch jointer knives.Its worth it for and I like sharpening.But the knives start with a 38 degree grind.After three time Hss steel like the M2 is just too hard to cut away.
Here's a pic of my poor mans sharpening jig.
The angle in this one is 45 I have one at 42 and 47. What I'm doing is pretty obvious but let me know if it's not clear.
Sorry about the pic it rotated not sure why.

[Allan Speers]

Andrew, that's pretty clever. I assume you just cut some 45º slots into a piece of Corian, yes?

Questions:

1: Why 45º and not the standard 38º? Are you adding a back bevel?

2: How do you keep the blades at exactly the correct angle? Surely there must be a tiny bit of wobble, no? I'm thinking this could be avoided by cutting the Corian as separate pieces, laying them on top of a flat base, and then clamping them together, but you don't appear to be doing this.

3: How do you keep the diamond stones dead level?

4: How fine a grit to do finish with? The commercial products I've sen all stop at 600 grit, which seems foolishly course to me.

[Andrew Hughes]

The jig in the photo is my first proto type I use on Dewalt planer blades it worked pretty good.
My current one have the angles screwd down on top like you were thinking.I start with the diamond plate and finish on a granite surface plate I bought for a song.There a lot of them out here on craigs list.Its kinda sad because I know it means a lot of machine shop are closing.
For my machine 42 is the sweet spot,But I have gone as far as 47 too far and the bevel start pounding the wood.So if you can start with a lower angle then you can just work the tops of the knives.High speed steel is not easy to cut so Ya don't even want to work the whole bevel.
And it's just a piece of leftover ikea counter top that was flat.Corian sound nice let me know if you get some to work for Ya.

[Mark Wooden]

I own the same machine, and keep multiple sets of knives for it, including a carbide tipped set for dirty material. Setting knives gets easy the more you do it,
I change mine out in an un-hurried (NEVER hurry!) 30 mins or less.
Go with a good supplier for your knives; I've found the e-bay suppliers are drop shippers and the knives can be of questionable origin. DAMHIKT.
American National- http://www.americannationalknife.com/ and Woodworkers Toolworks -http://www.woodworkerstoolworks.com/ are two of the better places to get started.
I know all about all the reasons to go with helical heads, but I'm staying with the knives in my machine, I get very satisfying results and have for years.

[Allan Speers]

Mark,

I have a few questions for you.

1: I looked at both those websites. American Knife is pretty expensive, but maybe that means better quality. Regardless, the carbide-tipped knives they sell specifically (& only) for the PM100 are 12-1/4 x 7/8 x 1/8". Woodworkers Toolworks lists knives for the PM100 + three other brands, and they are only 12" long. That doesn't fill me with a lot of confidence. I can't get to my shop right now to check, but I read 2 different owners manuals, which spec two different lengths! The 1965 PM100 manual says 12", but the 1982 PM100 manual (mine is 1987) says 12 1/4". Ughh..... Any thoughts?

2: Why do you use your carbide-tipped knives only for dirty wood? Do HSS knives (or M2) give a better finish?

3: Do you grind or hone your own, or do you send them out?