Hey folks, gotta question…. I just picked up an old Delta 8″ jointer,cast iron base,heavy dude.this machine was in a public school it’s entire life,so it’s in fine shape…the motor was replaced with a Century half horse in 220V(with AllisChalmers pulley). the jointer originally had a one horse motor,but most all the 1 horses are 3 phase..with the single phase 220s being outrageously priced in comparison. is there anyway to convert the 3 phase to single phase? and how do I determine which pulley to put on to maintain the 1725 RPMs the machine was designed for?
Thanks in advance….
ButchE
Replies
Butch,
I was quite shocked to read your message. First of all, a 1/2HP motor is grossly underpowered for a 8" jointer. That's the kind of motor you'd find on a 6" benchtop model for $200. Even 1HP seems a little small. I know that there are 1 or 1.5HP 110V motors available, as they are often found on table saws. I've never seen a 1HP 3-phase motor, though I confess I've never looked. If all you can find for whatever reason are 3-phase motors, phase converters are available. My 8" jointer (DJ20) runs on a 2HP 220V 1-phase motor. There is a neat calculator for RPMs and pulley sizes on this site http://www.csgnetwork.com/pulleybeltcalc.html.
Chris @ www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Thanks for the link..it'll come in handy. and thanks for the reply, I appreciate your thoughts.
Butch
I bought an old 8" Delta from a school shop about 5 years ago. I replaced the three phase motor with a similar HP single phase with the same RPM. Pulley was easy--used the one off the 3 phase motor as the shaft was standard size.
This is a pretty easy conversion--you can use the magnetic starter, just use one of the legs. For this you may want to have a qualified electrician do the hook-ups and also check the motor heaters in the starter to make sure they are sized correctly.
Motor wasn't very costly--maybe $100 to $125. Remember getting it at a Tractor Supply store. Get a farm duty motor and you'll be golden.
I don't have any of the manuals, etc. here with me, but if you need more info, shoot me a private message and I'll try to dig out what you need. I got the contact info you'll need to get replacement parts, etc., and if you don't have a manual for the machine, I'll photcopy and mail you one.
Tony Z.
the formula for determing the rpm you need is: rpm(driven) x the diameter of the driven pulley= rpm(driver) x the diameter of the driver pulley. For example if the diameter of the motor pulley is 4" and the rpm is 1724 and the diameter of the pulley on the cutterhead is 3" the rpm of the cutterhead will be 2300rpm.
We get to soon oldt und to late schmart
Surely the cutter head wasn't designed to be turning at only 1725 rpm. They are typically spun at about 5,500 rpm, and the motor is typically a 3,450 rpm TEFC motor. 1 1/2 hp. is what you want for that jointer. The current equivalent has that, and some 8" jointers even have 2 hp. & 3 hp. jointers. You don't want to underpower what should be an excellent tool.
That's what I was thinking... 1/2 HP is too underpowered... as for the RPMs, it's all Greek to this Dummy....
I haven't had the time the past few days to pull the cover off my jointer, but I do have the instructions for the jointer in front of me. First, my jointer is the Delta 8" Long Bed jointer, and depending upon the motor combo, it has several model numbers. Mine is Model 37-315.
The instructions include a section titled "Electrical Recommendations" and in that section, specifies a choice of 3/4, 1 or 1-1/2 HP. No reference to motor speed is made.
When I picked up my jointer (also three phase), I simply pulled that motor out and picked up a single phase of the same HP, RPM and shaft size. This permited me to use the original pulley.
This evening, I'll try to find time to open the cabinet, and determine HP, RPM and pulley size. I'll then post the info.
As I mentioned last week, if anyone wants copies of the original instructions, send me a private message and I'll copy and mail.
T.Z.
ButchE,
I sent you a private message, but I'll also post the jointer info here: the motor is a 1-1/2HP 1725 RPM motor, with a 7" pulley. The cutterhead has a 2" pulley.
The knives on the cutterhead adjust by springs under the knives and are no longer available from Delta, although I have not tried to track down another source.
If you or anyone else needs a copy of the original Delta manual, send me an email. I have two manuals one dated 1958 and the other 1972 (If I remember the dates correctly, but the jointers described are the same machine).
Tony Z.
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