im going to use three phase because they are cheap. I picked up a 10 and a 15 for 150 bucks, both never used. there is a 15hp converter kit on ebay for a little more than $100. I figure the 15 can be an idler. I have to think a 10 hp three phase motor has at least as much muscle as a stihl 090, although I could be wrong on this. available power is my main limiting factor, so ill have to run some bigger wires.
hp for electric saw?
- Thread starter Leroy in Kansas
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I am running a homemade sawmill. I have 28" between the guides, but my 10hp saw dont really like cutting anything over 20". I would like to one day switch to a 20hp, figure then I could push it as fast as I wanted to.
Seems like a static converter ( the cheap kind ) will only give you 2/3rd's of your power so if you ran a 15 motor through a static converter you should get only 10hp worth out of it.
If I had a variable frequency drive would I want to hook it to a 20hp AC or a 20Hp DC ? I was thinking a 20AC but somebody recently said I should use DC?
Seems like a static converter ( the cheap kind ) will only give you 2/3rd's of your power so if you ran a 15 motor through a static converter you should get only 10hp worth out of it.
If I had a variable frequency drive would I want to hook it to a 20hp AC or a 20Hp DC ? I was thinking a 20AC but somebody recently said I should use DC?
im guessing when you say homemade mill, you mean some kind of bandmill.??? I have heard of people using 3 and 5 hp electrics on bandmills that size. it seems you may have some other problems going on here. on the diybandmill site, a guy uses a 220v 5 hp compresser motor from harbor freight on a mill larger than yours with little difficulty..he has a youtube video, check it out http://www.youtube.com/user/67fastback428 . they make vfds for single and 3 phase motors, dc motors use controllers. both allow variable speed. with a static converter say a 15 hp one, you would get about 10 hp if using it to do the work. it would also be really hard on the motor, but if you wire in the 15 as an idler, you have a rotary converter which will clean up the third leg and you get much cleaner 3 phase. if you have the patience you can balance out the voltage with capaciters to generate almost perfect three phase. 2 phase is just another way of saying 220v... the problem with using dc motors is the need to rectify the direct current to alternating current, or you could build a huge battery bank and charge it off solar panels and run the dc motor off of that.( wish I could afford that!) they make some aftermarket golf cart motors that seem well suited for the task. search stealth stalker. if you can pull it off electric is the way to go in my opinion.
My mill is the same size as woodmizers big mills? 28" between the guides. ( for this size saw woodmizer uses a 25hp electric ) And I like to use the chainsawmill to whittle big trees down to where they will fit on the mill and cut wide stuff. IMO a 5hp compressor duty motor is not enough to cut 28" wide white oak. it would take forever. I imagine some people like riding mopeds though.
I agree, its almost ridiculous to think of that little motor on that saw. I think hes burned one up also. my point was only that it does work. I think a 10 hp 3 phase should be plenty, not sure about single phase. I looked at the woodmizer page and the LT 15 which has a 28" cutting max. it comes with 10hp single or 3 phase electric, 10 hp diesel, 15 or 25hp gas. id be interested in seeing a picture of your mill if you get a chance. did you follow a set of plans? Tim
I dont think a compressor duty motor is made to run for long periods of time , make sure you get a continous duty motor that will hold up.
There is a difference between log capicity and distance between guides. Seems like the l-15 only has @ 23" between guides but saw will handle 28" diameter logs. L-40 has 28" between guides and 36" log
I ordered a couple sets of plans from ebay , looked them over then built a saw. Didnt actually follow plans, they just gave ideas.
There is a difference between log capicity and distance between guides. Seems like the l-15 only has @ 23" between guides but saw will handle 28" diameter logs. L-40 has 28" between guides and 36" log
I ordered a couple sets of plans from ebay , looked them over then built a saw. Didnt actually follow plans, they just gave ideas.
dallasm1
ArboristSite Operative
Keep in mind if you are going to use a Variable Frequency drive to convert single phase to three phase, the VFD must be rated for TWICE the HP of the final motor. If you have a 3ph, 10hp motor, you will need a VFD rated at 20hp. You might also consider using reluctors at this size to prolong the life of the motor. Reluctors are large inductors used to soften the output pulse.VERY expensive proposition at this size of motor.
I run a 10 hp three phase on my bandmill, no converter, true 3 phase. It gets the job done - 4800 fpm on the blade. I was up at 5400 fpm, slowed it down & it worked better. I have a 15 hp I'd like to put on it, but it won't fit in the frame, and I'm not going to cut it apart at this point.
found this, so this would only run a 5hp motor? the ratings on these things are confusing! seems they got them with the wrong voltage. http://cgi.ebay.com/Trane-Dan-Foss-...39:1|66:3|65:12|240:1318&_trksid=p3286.c0.m14
dallasm1
ArboristSite Operative
Yes, this would run a 5hp 3phase motor from a single phase 240 volt source.
some of them I looked at specifically state that they will run any motor up to the hp they are listed at. others dont say what size motor they will run. it seems strange they would call it a 10 hp drive if it only ran 5... I have read many conflicting descriptions of what size idler motor you need when running a rotary converter also. some say the idler must be the same size as the motor run, others say it must at least be 2 times as big. seems to be some confusion around this subject.:bang:
Just off the top of my head, the motor's 1730 rpm, about a 6 1/2" pulley on it driving a 14 1/2" one, the bandwheels are 24" dia.
dallasm1
ArboristSite Operative
It is a rule of thumb in the field. The units documentation will indicate the exact load rating for a single phase input. The unit will indeed power a 10hp 3 phase motor from a 3 phase source and provide Variable Frequency (Speed Control). When used as a phase converter it has to be derated as all of the three phase load is now spread over only two input phases. The same energy is flowing through only two wires instead of three. The exact derating would be indicated by the manufacturer.
Try this http://www.##################/members/donp/bandspeedcalc.htm
Well for some reason I dont think this link is working ??? Ok here is what I have. 8" pulley, 1740rpm, 10" pulley, 21" bandwheels, gives 7652 feet per min.
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