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Powertmatic 180 planer adapting a tool post grinder for blade sharpening

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I just bought a powermatic 180 18" planer. It has the grinder bar and carriage attached but no grinder. Then grinder gets hinged and attached to the carriage to allow it to move in and out to adjust depth of the grind.
I am trying to come up with a way to mount a tool post grinder. I do not think the spindle accuracy is as important as in metal work. In wood working 1/1000 is the best possible.
Bill D
 

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Bill - i made one for another planer, dovetail bar and all.
It still gets occasional use on the 12" jointer. The bar is not long enough for my current wood planer, but i have a factory bar tha could be adapted at some point.
For the grinder part, i just bored a block for bearings on each end, made an arbor to take old used up 1/2 x 7 x 1-1/4" wheels from my surface grinder,and bolted it onto a CI DT slide sawed off a small chinese "cross slide vise".

As you note, wood planer grinders are not rocket surgery.
It probably is worth adding a jointing stick/capacity at the same time.
Then you can try it, and choose or not choose to use it going forward.

There is some figuring to do in the planning stage:
I don't know how the PM machines index the head, and if that is adjustable?
The one i made allowed for the indexer to be locked in position over an adjustable range of knife position, so that that setting could occur with the wheel infeed at an optimal knife back angle. If the indexer does not allow adjustment, then the wheel will need some sort of swinging, traveling, or shimmed arrangement from or toward the rail, to put the wheel where it addresses the knife at the correct angle, at the necessary downfeed.

smt
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
That cutter head is about triple what I paid for the entire machine. I pick it up next week. From photos it appears the grinder already has a vertical adjusting system.I need to get it in my shop so I can see how much clearance I have at each end of the travel.
The indexing looks to be a plunger into a crude three tooth gear or disk with drilled holes. I do not see any adjustment. I suppose the pin could be repalced with a offset pin.
I need to read up on how it is used. I see reference to grinding it all even while the cutterhead is spinning then locking it in place to sharpen each knife in turn.
Lots of sparks spraying into saw dust sounds exciting.
Bill D
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
They also make a holder that holds a stationary sharpening stone onto the grinder carriage. After the knives are razor sharp the machine is spun up to speed and the stone moved across to joint the knives just a hair. Other makers recommend jointing first then grinding. Some users say do not bother with jointing.
photo shows a stone holder left of the grinder. the stone is the white bit sticking out at the bottom. I have no idea how the stone or the entire holder is held in place. I assume there is a shim between the setscrews and the stone otherwise the stone might crack.
Bill D
 

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richard newman

Titanium
Joined
Jul 28, 2006
Location
rochester, ny
I have a grinder on my old SCM 20" planer. I don't use the jointing stone, haven't found it necessary. I don't allow my knives to get very dull, then just kiss them with the grinder till there's a tiny burr. I use multiple passes with very tiny feed increments. Knife 1, 2, 3, 4 then tiny down feed, 4, 3, 2, 1 and so on, repeated til the burr appears. Then I hone the burr off with a small slip stone. I guess if I got heavy nicks in the blades I,d joint them out and then grind, but i'm really careful about what goes thru my machine, brush off rough stock to get rid of dirt, etc

I think it depends a lot on what you use your planer for. I built high end, one off furniture - needed as good a cut as possible, but very low volume usage. If I was running a lot of stock, I'd definitely consider a spiral insert head, they last forever, and it's easy to rotate/replace just a few inserts to remedy a chip.

Actually, what I like about the spiral heads is that they can handle really curly or figured wood without any tearout, and can cut exotics like ebony and rosewood without dulling. I have Byrd shelix head for my shaper and in a 6" jointer, and they're amazing! If a shelix for my planer didn't cost $3K, I definitely go for it.
 

stoneaxe

Stainless
Joined
Mar 2, 2010
Location
pacific northwest
I have a grinder on my old SCM 20" planer. I don't use the jointing stone, haven't found it necessary. I don't allow my knives to get very dull, then just kiss them with the grinder till there's a tiny burr. I use multiple passes with very tiny feed increments. Knife 1, 2, 3, 4 then tiny down feed, 4, 3, 2, 1 and so on, repeated til the burr appears. Then I hone the burr off with a small slip stone. I guess if I got heavy nicks in the blades I,d joint them out and then grind, but i'm really careful about what goes thru my machine, brush off rough stock to get rid of dirt, etc

I think it depends a lot on what you use your planer for. I built high end, one off furniture - needed as good a cut as possible, but very low volume usage. If I was running a lot of stock, I'd definitely consider a spiral insert head, they last forever, and it's easy to rotate/replace just a few inserts to remedy a chip.

Actually, what I like about the spiral heads is that they can handle really curly or figured wood without any tearout, and can cut exotics like ebony and rosewood without dulling. I have Byrd shelix head for my shaper and in a 6" jointer, and they're amazing! If a shelix for my planer didn't cost $3K, I definitely go for it.

This.

What is your time worth? What are you going to do with the planer? 500 bucks for a nice old cast iron planer and 1500 for a cutterhead sounds like a good deal to me. I have put shelix heads in a few machines, they work well. I don't like grinding around woodworking equipment.
Iron stain is a PIA.
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I just realized that after each grinding I will have to adjust the planer upper works like the feed rollers ,pressure bar and chipbreaker. It does have a segmented infeed roller and pressure bar so maybe not every sharpening.
Bill D
 

richard newman

Titanium
Joined
Jul 28, 2006
Location
rochester, ny
Bill, if you don't have to grind out nicks, you hardly take anything off, so adjustment is not necessary each time. And it would just need to be the pressure bar at first, everything else is spring loaded

But you haven't told us what intended use is. If you're going to be running a thousand feet per week, you'll be grinding much more frequently, and need to adjust periodically.
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
Home shop use only. So probably one sharpening every year or so. It does have a two positon lock plunger. So main grind and a relief grind angle when needed.
 

wood2steel

Aluminum
Joined
May 17, 2013
Location
georgia
Bill, the grinding fixture is a nice addition to the PM 180 but intended only for an Industrial environment. Properly ground knives will have a Primary grind angle and a secondary grind angle; what we call Micro grind. The grind fixture will only be used for that light cut secondary grind and after a number of touch ups, the knives will be pulled from machine and rough ground to produce a new primary grind. Have run a 180 for 40+ years and have 2 here in the Shop. As far as the upgrade helical heads go; they are a great addition to older machinery, but be forewarned; here in the southeast we run 1,000's of feet of high rosin content reclaimed pine heartwood on a regular basis and the first time you send a bundle of river bed pine through a helical head, it will be a Wake Up call you will not soon forget. :willy_nilly:
I've had rosin build up on cutterheads and feed rollers reach a point that machines would have to be pulled from service to clean.
 

Henry J.

Plastic
Joined
Dec 23, 2016
In response to the OP question about adapting a tool post grinder to use on a Powermatic PM 180:
Won't work. The grinder quill will prevent the full range of motion when it hits the machine frame.

IMG_0456-22.jpg

Note how little room there is between the end of the cutterhead and the machine frame.
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
Henry, good picture, I had not considered that problem. Maybe a bigger diameter wheel would allow the spindle to clear. I know the wheel has to be 1/2" wide or less. I think the factory wheel is 2-3 inches in diameter. I wonder if a 6" wheel may clear.
I need to dig out my father's old Dumore grinder from his 9" South bend lathe. I do not think he used it in my lifetime. I am only 63! I would guess it is about 10 years older then that. I think his tool buying decreased after he got married.
Bill D
 








 
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