Jointer help....Update!

[opfoto]

Hello everyone,

I have a Woodmaster 6 inch jointer that is a Shopsmith copy. I want to mount a motor on it and put it on a stand. I am not very motor savy at all and I am looking for help in the RPM/HP/pully size depts. I am in no hurry to complete this now but with an eye toward the near future. I only have 110v available. I have a HF close by so I can look there. I appreciate all the help. Thanks

 

[beamer]

The pulley sizes and RPM of the motor will need to be such that the spinning cutterhead rotates at the right speed. Surf around for jointer specs to get an idea of what the cutter head RPM should be - most instruction manuals will tell you this. Then size your motor in about the 1hp to 2hp range - most are 3650rpm but you will also find 1725 is very common as well. The pulley sizes you use will be determined by the final RPM you're after - for example:

Cutterhead Speed: 5500rpm
Motor speed: 3650rpm

That would be roughly a 2:3 ratio, so any pulley combinations that yield one pulley that is .66363... times larger than the other should give you the right ratio. Your horsepower rating will become important here if the ratios are such that you loose most of your power just making it go fast.

If you had a 1725rpm motor instead, that puts you at more like 1:3 (.313636...) and you'd need more horsepower to overcome the resistance of the wood meeting blades in this case because going up in speed will reduce your power at the cutter head. It moves faster, but can't power through the thick stuff.

How's that for clear as mud?!

 

[tas2181]

Most jointer / planer blades rotate at about 10,000 rpm so you have to size your pulleys accordingly as Beamer stated previously.
I would use a 1 1/2 to 2 horse motor, which is about as large as you can get in a 110 motor.

Tom

 

[Rudy Vey]

Most jointers run at or around 5000 rpm cutterhead speed (motor rpm is mainly 3400 rpm), but normally the cuts per minute (cpm) are mentioned in the tech data and when compared in the diverse wood magazines. Most jointers with 3 blades run somewhere in the 15000 cpm range. At least Delta's do....

 

[JimGo]

Whew, I was afraid maybe Dave (DaveTurns) has responded.

 

[opfoto]

Thanks for the responses...

I'll price the motors between 1-1/2 and 2hp. The size of pulleys I understand will increase the rpms to the 5k or 10k rpms I need. Higher = finer finish I hope. Does the length of the belt come into the equation at all or can I use whatever suits the stand & motor mounting combination I decide on?

 

[beamer]

Length isn't really a huge issue, usually. Vibration might be a slight problem, though. My 8" grizzly has 2 belts and the original ones were so lumpy, the whole machine shook frighteningly more than I was comfy with. I tossed on a pair of those fancy schmancy link belts and all vibration was removed - amazing, those things are.

Faster may not always be better. I caution against going too fast for you may end up getting some burning. It really depends on how many knives you have as the cuts/min are important. My jointer has 4 knives, which probably explains why it only goes at 5500rpm - for about 22000 cuts/min. That's probably right around the sweet spot of 18000-25000cpm. If you have 3 knives, that'd be about 6000-8000rpm at the cutter head. With 2 knives, you're getting closer to 10-12k.

 

[opfoto]

Well,

I just returned from HF and they had the following...

2hp 3450rpm compressor duty motor 115/230v $84
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=30189
or
3hp 3450rpm compressor duty motor 115/230v $94
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=7570


Thinking for the additional $10, it may be cheap insurance that I won't bog down with hardwoods. Does this sound reasonable?? I have no problem waiting to see if these go on sale. But I am not too sure what compressor duty means!!!(forgive me)
Also noted their CM Jointer only had a 1hp motor. The one I have is 3 blades by the way. Thanks a bunch.

 

[beamer]

The extra 10 bucks sounds worth it to me. Since their 1.5 is actually MORE than their 2hp, that's probably out. 2hp is probably more than enough. My 8" grizz has a 2hp.

Compressor duty is mostly just marketing hype, but it does indicate a slightly higher duty cycle. This means it can run for a longer period of time than whatever the marketeers consider an inferior rating. I think you'd be perfectly fine with the 2hp (a 1hp is probably fine, too). Since the 2hp seems to be the best deal they offer, I might be inclined to go that route.

Check the amperage and make sure it doesn't overload your circuits, though. Also keep in mind that upon startup, they will pull a little more than their rated amperage. My 2hp grizzly motor tripped my 220v15a breakers upon startup 2/3 the time. Just something to keep in mind

It may turn out that the 1hp for the same price works better for your wiring application:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=40132

Silly they cost the same, but if it goes on sale soon, who knows!

 

[tas2181]

Like beamer said 'check the amperage'.
I looked at the specs for the two motors you referenced- the three horse motor is 230 volts only. The two horse is rated at 25.4 amps @ 115v. If I were you, I would look closely at the 1.5 hp rated at 15 amps @115v.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=30188
Also as beamer stated I checked both my planer and jointer the cuts per minute are ~20,000 - as they are both 2 blade models they run at 10,000 rpm.

Tom

 

[reed43]

Just be sure they are the same rotation as your jointer requires.

 

[beamer]

Very good point, Reed. If Marc has limited space behind that jointer, flipping it around may not be an option if it rotates funky. But if there's enough room under it, you can mount the motor in whichever orientation it takes to get the spin to work.

 

[opfoto]

Hey All,

Just wanted to update this...I just purchased the 2hp motor at HF tonight. Was on sale for $79.99 plus I got a 15% off email coupon!!! The motor is #30189.

Here's a link:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=30189

Normally sells for $94.99. Now to build a stand and find some pulleys....and a belt, some wire, switch...oh it never ends. So much for not being in a hurry.

 

[beamer]

hahah, glad you took advantage of the sale. I got the flyer the other day and saw them and thought of you!

A fan belt would probably work fine. The pulleys should be pretty common at the hardware store. Just gotta match the bore to the shaft (motor shaft and spindle shaft). Many times i've forgotten and ended up with pulleys i couldn't use (at the time!)

 

[Firefyter-emt]

FYI, OWWM had some great calculators for pulley size based on what RPM you want (4000 to 5000) and what pulleys you have. They also have a nice calculator to measure the belt size based on pulley size and spacing. Just fill in the blanks.

http://www.owwm.com/Math/Default.asp