[4]

Regulating band saw speeds

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#1
Picked up an old Power King band saw of craigslist that I want to try and convert to cut steel. I need to get the RPM's way down. Would one of these work, or would it damage the motor or cause other problems?

staco.jpg staco2.jpg IMG_2301.JPG IMG_2303.JPG

staco.jpg staco2.jpg IMG_2301.JPG IMG_2303.JPG
 

iron man

Active User
Registered
Joined
Feb 7, 2013
Messages
788
Likes
62
#2
We use to call those a variac it will work if you have a AC brushed motor such as a drill , router, sawzall ect. But what you have there is a brushless type inductive motor it will not work I have converted treadmill motors over to work on my bandsaw and they do not disappoint.. Ray
 
Last edited:

fastback

Active User
Registered
Joined
Jan 7, 2013
Messages
485
Likes
14
#3
Chuck, I can't answer you question about the variable control,but I can tell you that you can use a jack shaft with additional pulleys to reduce the speed. That is what I have on my home made machine and has worked very well. I think that a company by the name of Gil-built, Gilliom Manufacturing Company still has some information on this and what size pulley you need.

Hope this helps.
 

Uncle Buck

Registered
Registered
Joined
Nov 10, 2011
Messages
0
Likes
73
#4
We use to call those a variac it will work if you have a brushed motor.. Ray
And if the motor is not brushed? Will it work but burn up the motor, or simply not work?

I have the exact same issue facing me. I have an old Craftsman saw that looks about like this Power King that I want to do the same thing with. Thank you for this thread!
 

iron man

Active User
Registered
Joined
Feb 7, 2013
Messages
788
Likes
62
#5

iron man

Active User
Registered
Joined
Feb 7, 2013
Messages
788
Likes
62
#6
And if the motor is not brushed? Will it work but burn up the motor, or simply not work?

I have the exact same issue facing me. I have an old Craftsman saw that looks about like this Power King that I want to do the same thing with. Thank you for this thread!
Yes it will burn up a non ac brushed motor windings.. Ray
 

CluelessNewB

Active Resistor
H-M Supporter - Gold Member ($25)
Joined
Mar 3, 2013
Messages
1,130
Likes
622
#7
Not sure where my earlier post went either but....

Induction motors like we typically use on machines are designed to run at a certain speed, the speed is controlled mostly by the input frequency not voltage. These motors have two internal windings, a start winding and a run winding. The start winding is controlled by a centrifugal switch that disconnects the winding electrically once the motor reaches about half speed. This winding is not designed to be run continuously. If the motor never reaches speed the start winding will stay engaged and the motor will burn up. For the same reason single phase output variable frequency drives won't work with the type of single phase motors we use on machines.

Gear reduction, belt reduction, chain reduction or a mix of the above are the only choice if you want to cut steel.
 

iron man

Active User
Registered
Joined
Feb 7, 2013
Messages
788
Likes
62
#8
A bunch of post got deleted the other day it must be another glitch in the system..
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#9
Good info here. Thanks. I will investigate the other solutions mentioned.
 

Ruben

New Member
Registered
Joined
Feb 19, 2013
Messages
23
Likes
0
#10
That's a handsome looking machine you have there! However, wood cutting bandsaws sometimes have issues OTHER than just being way too fast for metal cutting.

The blade is typically pretty narrow, making it easy to cut circles and such, which is what they're designed to do. Metal cutting bandsaws typically have a heavier blade, at least half an inch front to back, and more teeth per inch. Verify that a metal cutting blade is available before putting a lot of work and money is that saw.

Another issue "may" be of concern. Check both wheels to see if they will track OK with the heavy big metal cutting blade, AND that the coolant that you'll want to use to prolong blade life won't affect the bottom wheel. Probably not an issue, but wood saws don't expect to be immersed in liquid while operating.

If everything looks good at that point, a jackshaft arrangement should work great. The support stand you have should make it a snap to gear it down.
 

iron man

Active User
Registered
Joined
Feb 7, 2013
Messages
788
Likes
62
#11
That's a handsome looking machine you have there! However, wood cutting bandsaws sometimes have issues OTHER than just being way too fast for metal cutting.

The blade is typically pretty narrow, making it easy to cut circles and such, which is what they're designed to do. Metal cutting bandsaws typically have a heavier blade, at least half an inch front to back, and more teeth per inch. Verify that a metal cutting blade is available before putting a lot of work and money is that saw.

Another issue "may" be of concern. Check both wheels to see if they will track OK with the heavy big metal cutting blade, AND that the coolant that you'll want to use to prolong blade life won't affect the bottom wheel. Probably not an issue, but wood saws don't expect to be immersed in liquid while operating.

If everything looks good at that point, a jackshaft arrangement should work great. The support stand you have should make it a snap to gear it down.
At any welding supply you can get any width metal cutting blade you want I bought 1/4 and 1/2 for mine for $10 a piece. The tires or bandsaw wheels are no different on the wood or metal ones I have seen combo saws that use the same wheels and guides. I have used bandsaws in machine shops that run all day long with no coolant and in a home shop is not needed. If you dont tell the bandsaw it was meant for wood it will never know!!!!
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#12
Here's some more pic's of it if anyone is interested.

These are probably all over the place up north, but in South Florida you don't see too many of these if any. I have mixed emotions for buying this.. sometime I wake up and think.. Why did I buy this?? Other times I inspect it and think.. This is cool!! I must admit though.. I have little or no room in my garage..

I almost left the stand behind, but am now glad I didn't.. It is vintage of the same era. One owner.. Owned by an old man that died. He etched his driver license number on the motor and the cutting deck. He was born in 1919. Probably bought this when he was in his mid 20's. These pic were taken before I cleaned it up.

IMG_2302_zps7d2aa850.jpg




In remarkable condition. Looks like it had little use or it was taken care of. It was given to the guy I got it from just recently, but he never used it. Said the blade kept coming off.. I wonder why?? :) He said if I didn't buy it, he was going to take the motor and throw the rest away. I gave him 75 for it. I probably could have got it for 50. I cringed when he told me he had all the old mans stuff, but threw most of it away because it was rusty. He didn't seem too mechanically inclined from talking with him.. He did make the wood cart underneth though...



IMG_2299_zps8fd041fb.jpg



only thing that might be missing is a pulley guard on this side.
IMG_2303_zps8994f086.jpg

Hard to make out, but you can see the old man's driver license number ending in 19 etched at the top of the motor.
IMG_2300_zps51dbcdf2.jpg






The tires were rotted. I used a heat gun and a sharpened chisel and they came off pretty good. I had to use a piece of fine steel wool with a litte acetone on it to remove rubber film and get the wheel surfaces shiny clean. I ordered a set of tires off ebay. The paint isn't real good, but should clean up better... I might leave it like that and just paint the stand. I want to move the motor underneath.

IMG_2297_zpsb17e28ab.jpg
 

iron man

Active User
Registered
Joined
Feb 7, 2013
Messages
788
Likes
62
#13
If those are 14 inch wheels Grizzly sells the tires for them that is probably why the blade kept coming off great find it should work well for you.. Ray
 

itsme_Bernie

Active User
H-M Platinum Supporter ($50)
Joined
Jan 11, 2013
Messages
1,746
Likes
88
#14
I agree- beautiful find!

I used a cheap lathe countershaft I found on eBay, and hung it underneath the bandsaw to slow it down.

The stand is perfect- easy mounting motor, jack shaft, countershaft underneath to slow it down.
Don't regret it a minute- just utilize the opposite side of the stand for something else-
Maybe even turn the bandsaws to fit sideways, making more room to use on the other side?

What a beauty!

Bernie
 

Kernbigo

Active User
Registered
Joined
Apr 8, 2012
Messages
729
Likes
209
#15
Go on ebay they have the rubber repacement wheels. Use a treadmill motor and the smallest pulley you can find to reduce the speed, they work great , i have done several.As far as the blades go buy doaal blade material and silver solder your own to any lg. you want, using a simple jig. I like 1/4' WIDTH the best in either a 308-601 or a 309-047
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#16
If those are 14 inch wheels Grizzly sells the tires for them that is probably why the blade kept coming off great find it should work well for you.. Ray
Thanks, I know that's why they were coming off.. the 70 year old tires on it were down right ugly. See my post above.


I agree- beautiful find!

I used a cheap lathe countershaft I found on eBay, and hung it underneath the bandsaw to slow it down.

The stand is perfect- easy mounting motor, jack shaft, countershaft underneath to slow it down.
Don't regret it a minute- just utilize the opposite side of the stand for something else-
Maybe even turn the bandsaws to fit sideways, making more room to use on the other side?

What a beauty!

Bernie
Thanks. I will probably center the saw on the stand to make it as narrow as possible. The stand must have been some kind of kit that was available back then.. It is assembled with screws, nuts and these funky clamps:

table.JPG



I am still looking for countershaft/jackshaft info to see what I can do.

I looked at another saw today.. an AMC, American made 14", but it was a piece of junk. The pot metal bracket that held the top wheel was broken. I was thinking about getting it for the lower stand/base and the motor, plus it had a cool on/off switch and a light. Could probably get it for 20.00.

amc.jpg

Go on ebay they have the rubber repacement wheels. Use a treadmill motor and the smallest pulley you can find to reduce the speed, they work great , i have done several.As far as the blades go buy doaal blade material and silver solder your own to any lg. you want, using a simple jig. I like 1/4' WIDTH the best in either a 308-601 or a 309-047
As mentioned in an eariler post, I already have new tires coming. Thanks for the blade info.. I like the idea of cutting them to size myself. I only plan to cut 1/4 mild steel and aluminum.

amc.jpg table.JPG
 

iron man

Active User
Registered
Joined
Feb 7, 2013
Messages
788
Likes
62
#17
The blades I purchased where cut, welded and annealed for $10 hard to beat that and they seem to be lasting just fine I use it all the time.. Ray
 

fastback

Active User
Registered
Joined
Jan 7, 2013
Messages
485
Likes
14
#18
I also weld my own blades. I made a jig and use silver solder. It works great. I use 3/8-inch blade stock. Oh, if you weld your own you can some times find long blades on sale and cut them down to fit your saw.
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#19
Decided to go down and get the above mentioned bandsaw today. Actually the brand is AMT, made in Tiawan. Picked it up for 10.00. The upper wheel bracket was broken. Made of pot metal and also I broke the table brackets, also made of pot metal when I was loading it. Poorly made in my opinion. No big deal though because I got it for the base and motor.
IMG_2309.JPG

I plan on using the bottom base for my Power King. It is mounted on coaster wheels which make it easy to move around. Nice little light too. The Power King is 16" at the bottom and the base is 15 3/4, But I think it will work out okay. I'm thinking of putting a steel plate for strength between the base and the Power King unit. It was missing the side cover for the motor, but I can easily make one.

IMG_2311.JPG


The motor is a USA made unit by Dayton. I'm not sure of the horse power because it is hard to see the label.. motor looks good and runs smooth. Wiring is first class. The motor is mounted sideways and has some slots for belt tension. The box on the side is the cover for the pulley. Probably won't fit on the Power King.

IMG_2307.JPG

Nice quality USA power switch too.
IMG_2310.JPG

Even if the base doesn't work out, althought I would be surprised, I think it was worth the amount I paid just for the lamp, motor and switch.

IMG_2311.JPG IMG_2307.JPG IMG_2309.JPG IMG_2310.JPG
 

Hawkeye

Active User
H-M Supporter - Gold Member ($25)
Joined
Jun 17, 2011
Messages
1,848
Likes
563
#20
For reference, the reason that you can't regulate the speed of an induction motor by just turning down the voltage (that's what a variac does) is how the motor controls the current draw under normal conditions. A motor is also a generator. When a motor starts turning, it starts generating a voltage (counter EMF or CEMF) that opposes the voltage that's making it turn (EMF) . When the CEMF balances the EMF, the speed and current stabilize.

If you put more load on the motor, the speed is reduced and the CEMF is reduced. Without the counter effect, the current increases, adding enough torque to the motor to hold the new, lower speed and set a new balance. If too much load is added, the rotor will stall and maximum current starts to flow. If the control system (or operator) doesn't shut it down, the high current will generate high heat in the windings, burning out the motor. Running at reduced speed and high current, even though still turning, will over-heat the motor and eventually damage it.

VFDs control speed by changing the frequency and adjusting voltage and current for optimum performance. This is quite easy to do on a 3-phase motor, not so easy on single-phase. I'm using a jack-shaft on my bandsaw conversion. Much easier and cheaper.
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#21
For reference, the reason that you can't regulate the speed of an induction motor by just turning down the voltage (that's what a variac does) is how the motor controls the current draw under normal conditions. A motor is also a generator. When a motor starts turning, it starts generating a voltage (counter EMF or CEMF) that opposes the voltage that's making it turn (EMF) . When the CEMF balances the EMF, the speed and current stabilize.

If you put more load on the motor, the speed is reduced and the CEMF is reduced. Without the counter effect, the current increases, adding enough torque to the motor to hold the new, lower speed and set a new balance. If too much load is added, the rotor will stall and maximum current starts to flow. If the control system (or operator) doesn't shut it down, the high current will generate high heat in the windings, burning out the motor. Running at reduced speed and high current, even though still turning, will over-heat the motor and eventually damage it.

VFDs control speed by changing the frequency and adjusting voltage and current for optimum performance. This is quite easy to do on a 3-phase motor, not so easy on single-phase. I'm using a jack-shaft on my bandsaw conversion. Much easier and cheaper.
Thanks for that explaination.

I guess if I use the base from the AMT, I won't have enough room under there to mechnically regulate the rpms. (?)
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#22
Sat the Power King on the AMT base.. fits almost perfect. The Dayton motor turned out to be 1HP, twice the size of the old Craftsman.

IMG_2312.JPG


I like the smaller footprint.. it takes up less than half the space of the original stand. I plan on sand blasting and painting the base dark green. The Power King paint, although not too bad, definitely shows it's age, but I like that it is original. What do yall think, should I paint it too or leave it alone. Perhaps another color than forest green for the base and saw.. maybe gray?
IMG_2313.JPG

The lamp cleaned up nice. USA made by Dayton. This alone was worth the 10.00 to me. :)

IMG_2314.JPG

IMG_2312.JPG IMG_2313.JPG IMG_2314.JPG
 
Last edited:

mrbreezeet1

Active User
Registered
Joined
Mar 14, 2013
Messages
733
Likes
13
#23
Heck yeah, it was worth $10.00. The light is nice.
Bet you moved the Band saw by the table when you broke the trunnions.
Looks like a Delta clone. That motor is about $200.00 new.
Thanks,
Tony
 

itsme_Bernie

Active User
H-M Platinum Supporter ($50)
Joined
Jan 11, 2013
Messages
1,746
Likes
88
#24
Heck yeah! As mr breeze said... Man, I gotta move to your town- no good deals like that by me! Not even on Craigslist! :)

Since you are asking opinions, I would leave as much of the original paint as possible- can't beat that experience these machines have been through in -100 years?! Fantastic.


Bernie
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#25
Heck yeah, it was worth $10.00. The light is nice.
Bet you moved the Band saw by the table when you broke the trunnions.
Looks like a Delta clone. That motor is about $200.00 new.
Thanks,
Tony
I laid it side ways in my truck and then shifted it 90 degrees so I could close the topper and the sudden weight on the table broke the trunnions. Poorly made. The Power King is all solid steel! Loaded it the same way and nothing broke.

Learned something though.. be careful when you load something in the truck. I was lucky I was only buying it for the base :))
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#26
Heck yeah! As mr breeze said... Man, I gotta move to your town- no good deals like that by me! Not even on Craigslist! :)

Since you are asking opinions, I would leave as much of the original paint as possible- can't beat that experience these machines have been through in -100 years?! Fantastic.


Bernie
I don't know about that.. I have seen some nice lathes for sale up north where you're at.. I rarely see any for sale down here. Rarely see any American made machine stuff at all.. I was just lucky and also the dude was a nice guy.
 

Uncle Buck

Registered
Registered
Joined
Nov 10, 2011
Messages
0
Likes
73
#27
I like the original finish on the saw myself. I also like the original stand the saw was setting on though it is a bit clumsier I suppose. I don't suppose you want to sell your old original stand do you?????
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#28
I like the original finish on the saw myself. I also like the original stand the saw was setting on though it is a bit clumsier I suppose. I don't suppose you want to sell your old original stand do you?????
I thought about making a work table out of it, but If you were in South Florida, I would give it to you.

Nice that some one apperciates it, but to be honest with you, I don't want to go through the hassel of disassembling it and shipping it.. I know this sounds cold, but that's the way it is.. I would rather use it for something before going through that.

Now If you knew a forum member here who could pick it up for you..:))


Probably cost 1.98 back in the day.. It really isn't heavy duty, but it is structured and unique.. I like the way the legs curve..

IMG_2315.JPG


IMG_2316.JPG

IMG_2315.JPG IMG_2316.JPG
 

Uncle Buck

Registered
Registered
Joined
Nov 10, 2011
Messages
0
Likes
73
#29
I thought about making a work table out of it, but If you were in South Florida, I would give it to you.

Nice that some one apperciates it, but to be honest with you, I don't want to go through the hassel of disassembling it and shipping it.. I know this sounds cold, but that's the way it is.. I would rather use it for something before going through that.

Now If you knew a forum member here who could pick it up for you..:))


Probably cost 1.98 back in the day.. It really isn't heavy duty, but it is structured and unique.. I like the way the legs curve..

View attachment 50672


View attachment 50673
Actually, it is just real traditional. My vert bandsaw sets on a stand that could be it's twin. I have a 4" wood jointer on another stand that looks just like it as well. Those stands were the norm back when those machines were made.
 

ChuckB

Active User
Registered
Joined
Jan 2, 2011
Messages
327
Likes
41
#30
The Power King is all solid steel!
I take that back.. same parts on the AMT that are cast are also cast on the Power King..:thinking:
 
[6]
[5] [7]
Top