shaper motor

[sk1nner]

I picked up a 10 inch lewis shaper today. Seems to be in good shape. I can see the flaking on the ways. It came with a heavy duty stand. It only has a single speed pully and a 3400 rpm motor. I have a spare 1 / 2 hp motor that was a grinder. Would 1 / 2 hp be enough for the shaper? I plan on caniballizing a cheap china drill press for the step pullys.

 

[Dranreb]

It seems those Shapers where sold in kit form, that motor speed seems rather high http://www.lathes.co.uk/lewis/

Yes 1/2 hp will do at a pinch but a 3/4 hp high torque lower rpm motor would be better suited, this is the original one in my Alba 10" shaper, 960 rpm.



Bernard

 

[sk1nner]

Ok, i just looked at the extra motor better (tags messed up) its a 3/4 hp. I wish the motor that came with the shaper had a tag on it, but it doesnt. Ive also done some looking around online and found a publication from 1937 about the lewis shaper kits, im kinda surprised to see they say 1/3 hp is enough! Heck i may just use the drill press motor along with the step pullys

 

[Hawkeye]

I have a Lewis. Very nice machines. The sizes of the pulleys in your picture show that someone has compensated, at least partially, for the higher speed of the motor.

IIRC, my shaper has a 1/3 HP motor. I can't look at it to check speed until I get my house and tools back in a few months. I have 3-step pulleys on mine. I did workup on cutting speeds a few years ago and the attached file is what mine does at various settings. I hope it's of some use to you.

View attachment Shaper Settings.pdf

 

[Dranreb]

I suppose that having a gearbox in my Alba causes a fair bit of drag which uses up power, hence a bigger motor for the same size machine.

Those Chinese pulleys will work fine but most likely be very lightweight.

Just a thought and I may be talking utter rubbish now but I wonder if using heavy cast iron pulleys would have been the norm back then which would add useful momentum in the system to help out a lower power motor.

Oh and welcome to the wonderful world of shapers, have fun....:thumbzup:

Bernard

 

[sk1nner]

I suppose that having a gearbox in my Alba causes a fair bit of drag which uses up power, hence a bigger motor for the same size machine.

Those Chinese pulleys will work fine but most likely be very lightweight.

Just a thought and I may be talking utter rubbish now but I wonder if using heavy cast iron pulleys would have been the norm back then which would add useful momentum in the system to help out a lower power motor.

Oh and welcome to the wonderful world of shapers, have fun....:thumbzup:

Bernard

The only reason in using the Chinese pullys is that it is what i have. If they wont work right, or im not happy ill either make or buy a new set. Im still up in the air on which motor ill use. The 3/4 hp has more power but it also has shafts on both sidesn (was a grinder). Is there a way to remove the unneeded shaft with out causing perminant "damage"? The 1/3 is single shaft but has alot lesss power (but the info I've found says its enough). Thanks for the info.

 

[Reeltor]

Why not use the motor that came with it? As Hawkeye mentioned, a smaller pulley was already put on the motor to compensate for the high motor rpm. You can work out different pulleys if you need more reduction.

 

[sk1nner]

The motor is already geared down as slow as possible and is still generating too many strokes per minute. I would have to buy custom made step pullys to slow the strokes per minute down to the usable range. As it stands the pully on the shaper is about 8 inches and the motor pully is about 1.5 inches. I would need a much larger top pully to slow it down. The only way i could do it id to have a jack shaft and a second belt, which i would like to avoid, Thanks for the idea though.

 

[cjtoombs]

While the Lewis shaper was advertised as a 10" shaper, you will find it only strokes about 9.5", which makes it an 8" shaper (they always stroke a bit longer than their spec size, in order to allow the run in and out to cut something that size). I believe that Atlas recommended a 1/3 hp motor for their 7 inch shaper, and I would think anything in the 1/3 to 1/2 hp range would be fine. 3/4 hp is probably overkill for this shaper, as you will likely break something in your setup, or the tool before you bog the motor. If you are looking for useable speed ranges, I would recommend something like 50-150 SPM. More than 150 SPM starts to get scary. The actual cutting speed is dependent on the length of stroke as well as the strokes per minute (you need to run higher SPM for shorter strokes to the same surface speed as a longer stroke at a lower SPM). The calculation is in Moltrechts 2nd Machine Shop Practice, and works out to S=7.2V/L, where S is SPM, V is the cutting speed in FPM, and L is the length of the stroke in inches. The constant accounts for the non cutting time and the unit conversion from ft to in. The table in that book shows cutting speeds ranging from 25 for hard alloy steel to 140 for brass. So using a cutting speed of 110 FPM (mild steel) and a stroke of 8" gives SPM of 99. Changing the stroke down to 5.5 inches with the same material gives 144 SPM. One thing about planers and shapers is that they usually can't achieve the high cutting speeds that you would ideally use for aluminum or other soft materials. Enjoy the shaper.

 

[Hawkeye]

Here's a picture of mine the day I got it. You'll notice that the motor is fed to a countershaft, which then uses the step pulleys to carry power to the internal gearing.