Help needed, Craftsman wood planer.

[tonyfoale]

I have a small and very old cast iron Craftsman planer which I bought at a yard sale when I lived in the US. Other than a "don't cut you fingers off" notice there is no other info with it. The table is 4 or 5 inches wide and the drum is a touch over 2" diameter with 3 blades. The spindle looks as it it runs in plain bearings but I have not dismantled it yet.
Does anyone know what RPM the spindle should spin at? Failing that, can anyone give me a guide to surface cutting speeds for wood, Google came up with a lot of useless info, many planer users seem to be confused between cutting speed and cutting feed.

[bruce.desertrat]

You might peruse this page Sears | Craftsman - Photo Index | VintageMachinery.org to see if you can ID it. If you can find the craftsman part number on it you may be able to track it to the OEM and that site has tons of old manuals.

Also, your description sounds much more like a jointer than a planer...4-5" wide would be quite narrow for a planer. The link above also lists numerous jointers,

[hemmjo]

I think that cutter head would run in the 4500-5000 rpm range. Feed rate depends a lot on the specie of wood, grain structure and moisture content of the board, as well as sharpness of your blades and the capacity of your system to clear chips. Typically planers with variable feed rates range from 0 fpm to 70-80 on the high end for big industrial machines. Fixed feed rate models run between 15-30 fpm

With a 3 blade cutting head you have 15,000 cuts per min @ 5000 rpm. If you feed stock at 10 fpm you have 120 in / 15000 cuts or .008" per cut. As you know, it is all a balance between the speed your cutter head bearings can handle and the power your motor can deliver relative to the feed rate you choose.

I just looked at some specs online for new models, they range from;
Grizzley 8750rpm 3 blade with 26 fpm feed rate
WEN 9000rpm 2 blade with 26 fpm feed rate
DeWalt, 10,000rpm 3 blade, no feed rate given but they claim 96 cuts per inch so that would be about 31 fpm feed rate

None of these specify cutter head diameter.

Not sure if it of any assistance, but there some info from state side.

John

[tonyfoale]

You might peruse this page Sears | Craftsman - Photo Index | VintageMachinery.org to see if you can ID it. If you can find the craftsman part number on it you may be able to track it to the OEM and that site has tons of old manuals.

Many thanks. I have identifird it as a Sears Roebuck 149.21871. It is a couple of decades younger than I thought at 1970s/early 80s. Anyway I couldn't find anything on that site to answer my question. Actually my question isn't really machine specific, cutting surface speeds depend on material to be cut and maybe material of the blades. In the absence of additional information I'll aim for around 12,000 rpm which should give conservative cutting speeds. If the bearings/bushes wear out I'll modify it to take ball bearings.

Also, your description sounds much more like a jointer than a planer...4-5" wide would be quite narrow for a planer. The link above also lists numerous jointers,

It is listed on that web site as a jointer, but I can't figure out what sort of joints you would make with it. To me it looks like a small machine to plane with. I could be very wrong but I think that jointer is likely to be the US term only, but although I have done some pattern making in the past I am not an habitual woodworker.

So what exactly is the difference between a jointer and a planer?

[tonyfoale]

i just found this on Wiki
"A jointer or in some configurations, a jointer-planer (also known in the UK and Australia as a planer ......."

I was born in the UK and grew up in Australia, so for me it's a planer.

[Imbeciliac]

I just did a few quick measurements on my 40-yr-old Rockwell/Beaver 6” jointer for comparison: the 3-blade cutting head is 2” in diameter, the blades stand about .150” proud of that so the total diameter is a touch over 2-1/4”. When the 1/2hp 1750 rpm motor blew (in the middle of an actual paying job, as always) I replaced it with the only suitable one I had kicking around the shop because I needed it *right now*, which was a 1hp 1750rpm TEFC motor which is relatively impervious to the dusty environment in which it would be running.

Since I found the head speed too slow with the original motor, I took advantage of the extra power and increased the drive pulley from 4” to 6” and decreased the original 2” driven pulley with a 1-1/2”. This gave me a head speed of 6900 rpm, much better than the paltry 3500 rpm it was running before. I suspect the previous owner probably replaced the actual original motor, which most likely ran at 3450 rpm, with the one that was on it when I purchased the machine.

The massive, high quality bearings on the cutter head are quite capable of handling the upgrades, and the jointer is now far more usable and produces a much finer finish. Prior to these modifications it was something I would use only as a last resort, usually preferring to use my table saw with a jointing jig, because the jointer would leave such a choppy finish, even at painfully slow feed rates, now it is my go-to as it leaves a beautiful, almost polished finish.

I’m not sure if that was helpful or just came iff as pedantic. Hopefully the former.

[Haroun]

i just found this on Wiki
"A jointer or in some configurations, a jointer-planer (also known in the UK and Australia as a planer ......."

I was born in the UK and grew up in Australia, so for me it's a planer.

A jointer is used for flattening boards, a planner is used to get them to the desired thickness. The sequence from rough milled lumber is-
Jointers are used to establish a flat face, then a square edge on a board. then it can be run through the thicknessing planer to flatten the other face parallel to the other. Then the board can be run through tight against the fence to establish an edge square to the faces.

Most jointers also have the ability to create a rabbet on the edge of the board. They also are useful, if sharp & well adjusted, to prepare edges for gluing up large panels.

[Imbeciliac]

So what exactly is the difference between a jointer and a planer?

A jointer is used to provide one straight edge on a board, often in preparation for joining several boards together, which is why it is sometimes called an ‘edge jointer’. The other edge is usually then cut on the table saw to provide a parallel edge to the jointed one. A planer usually employs a much wider cutting head (unless your jointer happens to be a massive industrial version) and is used to plane (obviously) the sides of a board, not only to smooth the surface but also make both sides parallel, and to reduce the thickness, which is why it is often referred to as a ‘thickness planer’.

Hope that helps demystify the names.

Edit: Damn. Haroun beat me to it.

[suther51]

When i get a chance I will look at a book I have that is a collection of articals from the us forest service, there Is a section on jointing planer blades, it may have a some info on surface feet per minute of cutter blades for wood. Barring that I have an old Montgomery wards joiner with what might be a similar size head in it to use as a referance. As long as you do not drive the cutter head so fast that you burn the knives (heat to the point of drawing the temper) the rpm is not overly critical in a non production situation. The wadkin molders where I used to work would jam and stop feeding, the knives would burn real fast. The finish of the molding stock would suffer as a result. In the neighborhood of 1725 rpm may be good if i remember that the pulleys are of equal size on my 6 inch jointer. Hope you find your answer.
Eric

[Daturat100r]

A jointer is used for flattening boards, a planner is used to get them to the desired thickness. The sequence from rough milled lumber is-
Jointers are used to establish a flat face, then a square edge on a board. then it can be run through the thicknessing planer to flatten the other face parallel to the other. Then the board can be run through tight against the fence to establish an edge square to the faces.

Most jointers also have the ability to create a rabbet on the edge of the board. They also are useful, if sharp & well adjusted, to prepare edges for gluing up large panels.

Look at the words used to describe these machines,Plane is a geometric term for a flat surface.
"Planer" is a machine that forms a plane on the work passed over it as with a "Jointer",the term thicknesser makes one surface parrallel to the other and does not itself correct non-planer work.
The term planer/thicknesser most likely came from under and over machines or two siders which both have the ability to make a board face a plane the first in two operations on same machine the second machine does it all in one pass be it a 2 or 4 sider.
Confusion over terminology ,especially as the woodworking trade amongst other love to have their own terminlogy, is most likely due to regional usage that evolves and changes with time.