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Forum topic by OmarN posted 03-24-2015 03:36 PM 899 views 0 times favorited 11 replies Add to Favorites Watch
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OmarN

21 posts in 657 days


03-24-2015 03:36 PM

Topic tags/keywords: jig tip jointer tablesaw

HI All,

I’m currently at the design stage for a M. Wandel inspired DIY jointer. For starters I’ll be building a small 3 1/4 wide prototype, based on these power planer cutter knives:

I was originally thinking of using a fractional HP motor, but looking at the prices for used motors, and the price difference between 1/2 hp and 1 hp I think I’d rather use a 1-hp motor (see pix below for siemens motors, in MXN).

My question is whether using a bigger motor will be too much. I’ve seen “Cosma B’s 12 jointer powered by a 5HP motor and I thought that was too much. Is 1 hp too much for a 3 1/4 jointer, if I won’t be working with hardwoods, mainly pine boards and plywood?

Another question is whether I use the same 1 hp for a table saw, like this guy? Won’t it be underpowered for a table saw?

-- jomarnavarro - You better watch your wood.


11 replies so far

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Rob

704 posts in 2530 days


#1 posted 03-24-2015 04:09 PM

If you’re building a 3.5” jointer I would just look at what size motor comes on a 4” jointer. A 4” jointer I found on vintagemachinery mentions 1/3hp and 1/2hp motors, so I would think 1/2hp would be a good starting point. If you’re going to salvage parts from the prototype to make the larger one, then look at whatever size motor you’ll need for the larger one.

If you’re getting rid of any motorized appliances or if you see one on the curb, you may be able to salvage a 1/2hp or 1/3hp motor. I think the motor I pulled from my old dishwasher was 1/2hp. You can probably also find a broken washer or dryer on craigslist for free and chances are, the motor is fine.

-- Ask an expert or be the expert - http://woodworking.stackexchange.com

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SirIrb

1239 posts in 690 days


#2 posted 03-24-2015 04:27 PM

I think my delta 6” has a 1hp. You can not have too big a motor. You can have too expensive a motor.

-- Don't blame me, I voted for no one.

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Rick M

7901 posts in 1839 days


#3 posted 03-24-2015 05:09 PM

Buy whatever motor you plan on using on the 12”. I don’t see the point of building a 3.5” jointer.

-- http://thewoodknack.blogspot.com/

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OmarN

21 posts in 657 days


#4 posted 03-24-2015 05:50 PM

Well, given I can’t currently afford the 12” cutter head, making a very very small 3.25 jointer kind of makes sense. Plus it could serve as a smaller prototype to learn lessons from, so that the 12” jointer works better.

I think I’ll go with the 1 HP motor, because, as you say, I’ll probably reuse that on the 12 incher.


Buy whatever motor you plan on using on the 12”. I don t see the point of building a 3.5” jointer.

- Rick M.


-- jomarnavarro - You better watch your wood.

View TheFridge's profile

TheFridge

5764 posts in 945 days


#5 posted 03-24-2015 08:38 PM

I have an 8” jet jointer with a 2 hp motor that labors when jointing 6”- 8” hard maple and oak I’ve run through it. I don’t take deep cuts either. I think 3hp minimum. 1 hp won’t cut it with an 8” jointer at typical feed rates. You’ll just have to feed really slow. 1 hp for a table saw is a 1/2 hp smaller than I’d want to use.

Just throwin this out there.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View Minorhero's profile

Minorhero

372 posts in 2064 days


#6 posted 03-24-2015 09:11 PM

My 12 planer uses a 3hp motor and runs fine. Since the only reason to have a 12” jointer is for face planing I feel safe in saying a 1hp motor is way under powered. 2hp absolute bare bones minimum and 3hp is better. Look at what other 12 planers and jointers use.

For a 4” you are fine with 1/3 or 1/2. Used motors can be purchased on eBay for sub 100 including shipping. You will want a 3450 rpm motor to get the right cutter speed.

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runswithscissors

2172 posts in 1484 days


#7 posted 03-25-2015 01:23 AM

You could buy a used lunchbox planer and use the cutterhead for your wide jointer, maybe even use the planer’s motor (but an induction motor will be much quieter). But I agree with SirIrb about a motor being too powerful. I can’t see how that is a problem, though I’ve seen the point raised before.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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OmarN

21 posts in 657 days


#8 posted 03-25-2015 06:00 PM

I’m thinking if a low speed motor will do? I hear that I can vary the speed with a bigger pulley, plus, an induction motor will have a greater torque, and not rely on revolutions to get the cuts done, but on the torque. what are your thoughts?


My 12 planer uses a 3hp motor and runs fine. Since the only reason to have a 12” jointer is for face planing I feel safe in saying a 1hp motor is way under powered. 2hp absolute bare bones minimum and 3hp is better. Look at what other 12 planers and jointers use.

For a 4” you are fine with 1/3 or 1/2. Used motors can be purchased on eBay for sub 100 including shipping. You will want a 3450 rpm motor to get the right cutter speed.

- Minorhero


-- jomarnavarro - You better watch your wood.

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Minorhero

372 posts in 2064 days


#9 posted 03-25-2015 07:09 PM

You can’t make up the difference between a 1hp and 2hp let alone 3hp by using an induction instead of capacitor. You can change pulley size its true. But to use a 1750 rpm motor on my 8” jointer I needed a pulley 6.5” in diameter which is really quite ridiculously large for a pulley and was big enough to need me to raise up the motor just to fit. I did it only long enough to realize the hole needed to accommodate the belts was bigger than the hole in the stand due to the increased pulley size. Also those pulleys are all sheath pulleys and are not cheap. Also you will need a double pulley as well. You would be better off just getting a 3450 rpm motor.

View jakep_82's profile

jakep_82

105 posts in 1765 days


#10 posted 03-25-2015 07:37 PM

You need sufficient cutterhead speed to get smooth cuts, and a reasonable feed rate. Horsepower is a function of torque and speed, so no matter what RPM the motor is, you’ll have the same amount of torque available at the cutterhead once you size the pulleys. You’ll probably be aiming for something close to 4500 RPM which makes a slower motor undesirable.

Making a 3.5” jointer seems like a waste of many if you won’t have a use for it after you build the 12” jointer. None of the parts will be interchangeable unless you start off with a 3HP motor. If you really need a jointer, I regularly see 4” machines on Craigslist in my area for $50-$75.

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OmarN

21 posts in 657 days


#11 posted 03-25-2015 08:40 PM

Thanks for your contributions guys. the only thing about building a smaller jointer is not spending too much in parts, plus learning how to make machines (this would be my first machine). I do agree that the motor may be too much, but that one can be reused in other projects.

Unfortunately I don’t live in the states, so parts are not as cheap as in the US. I tried buying the motor alone and it cost the same used as new, so I’ll go with new. Ordering from ebay across the border would be the same case. Shipping would take the savings away. “FreddyS, a lumberjock, built a 4 jointer with a craftsman planer upside down. He spent 400USD on the planer alone :S I have only spent $ 25 in the first parts (cutterhead, knives, bearings). and perhaps some 100 more in between the motor, good plywood, the metal sheet cuts for the surface and the rest of the hardware.

If I make the small jointer accurate enough, I could sell it and recover my expenses… Or keep it and never build the 12” jointer.

If

-- jomarnavarro - You better watch your wood.

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