LumberJocks

Old BandSaw upgraded, Pulley questions to fellow Lumberjockers

  • Advertise with us
Blog entry by James Lango posted 01-25-2013 05:24 AM 2574 reads 1 time favorited 12 comments Add to Favorites Watch

This is my 1952 Craftsman 12” Band Saw. She has been soo unrealiable over the years and i was on the verge of tossing her out. BUT- i figured to give it a go and see what she can do when everything is tuned up and running smooth. Did some research and reading, found out that although this saw is old and relatively small (12”) she was able to hold her own back in the day.

New paint.
New guides
New thrust bearings (stainless steel pulleys work in place)
New solid base.
New belt, new shaft pulleys.

The rubber for wheels were Ok but needed glued down. This saw really hasnt seen alot of use thro the yrs.

attached are pics: Im asking the expierenced LJ’s for some help. The saw vibrates not alot, but little too much to know somethings off. And the blade speed is fairly slow. The motor spindle pulley is a 2”, and in the pics my drive wheel pulley is 4”.
Since im using an automotive 1/2” belt, its fairly rigid and doesnt seem to like the sharp curve of making the tiny 2” motor pulley. And since the 2inch pully is small, the belt has less area to grab onto. (slipping)

Question is- Should i buy a 3, maybe 3 1/2, possibly a 4” pulley for main motor spindle? If doing that, i would prolly also have to increase the pulley size of the wheel pulley (but how big etc…) whats your thoughts on this. Any help is always appreciated.
Using a 5amp motor, 1750rpm. 1/3HP.

FYI- the wheels are balanced, all nuts,bolts are tight. I designed the motor to mount on a 2”x6” solid chunk of Maple. Its on hinges and the weight of motor is what gives tension. I also added rubber matting and bushings where needed to eliminate vibration.

any tips…? Thanks JAMES LANGO

-- Longovette@Roadrunner.com



12 comments so far

View Rick M.'s profile

Rick M.

4026 posts in 1047 days


#1 posted 01-25-2013 06:49 AM

If your motor is 1750, the pulleys are slowing it down to 875 but the manual says it runs at 640 rpm. That seems pretty slow to me. I would try a 3” driver (motor) pulley, leave the 4” driven pulley and see how it runs. To find the final RPM you divide the driver pulley by the driven pulley times the motor RPM.
e.g.
2/4 = .51750= 875 RPM
3/4 = .75
1750= 1313 RPM

To figure out the driven pulley size it’s (motor pulley size) times (motor RPM) divided by (target RPM). Or in your case it will always be 2X the driver pulley size to maintain the original RPM. Example if you change the driver pulley to 3.5”

3.5 * 1750/875= 7

I wonder if some of your vibration isn’t just the motor bobbing. Put some tension on it with a bungee cord and see if that helps.

-- |Statistics show that 100% of people bitten by a snake were close to it.|

View James Lango's profile

James Lango

180 posts in 2201 days


#2 posted 01-25-2013 07:00 AM

Great info! Thanks soo much! I thought about adding a spring to pull down on the motor mounting board, but it wouldnt help. (i can push down on the motor and all that happens is the speed lowers but vibration still there. That motors pretty heavy and its own weight should be enough to keep belt tight.

Im running a 2” motor pulley now, and I bet jumping to a 3” would do it. The circumfrance is larger and “should” allow a more smoother transition while going around it.

I narrowed it down to the vibration NOT being in the saw itself, but somewhere from belt on downward.

Hmmm. Heading to buy some pulleys tomorrow. Thanks Rick!

-- Longovette@Roadrunner.com

View Rick M.'s profile

Rick M.

4026 posts in 1047 days


#3 posted 01-25-2013 07:07 AM

The only caveat is that a faster speed could intensify the vibration. Other possibilities…
The belt itself is the problem. In which case a link belt or skinnier belt should fix it.
The motor shaft is bent.
The hinge has too much play.
Less likely but possible, the saw is approaching it’s resonant frequency which speeding up or slowing down should fix.

-- |Statistics show that 100% of people bitten by a snake were close to it.|

View Rick M.'s profile

Rick M.

4026 posts in 1047 days


#4 posted 01-25-2013 07:36 AM

Actually I take back my comment about the saw seeming slow, after plugging in the numbers it’s moving around 2,748 feet per minute which is plenty fast. If it feels slow, it may be the 1/3 HP motor bogging down.

Links:
http://vintagemachinery.org/pubs/detail.aspx?id=4595
http://vintagemachinery.org/math/sfpm.aspx
http://www.temecularodrun.com/ref/rpm_calc.asp

-- |Statistics show that 100% of people bitten by a snake were close to it.|

View JohnInHadley's profile

JohnInHadley

22 posts in 661 days


#5 posted 01-25-2013 01:25 PM

I’ll probably blog about my old craftsman 101.0101 some day, but I got rid of vibration accidently when I used a different motor. I cranked it down pretty tight because I did not have the right belt. That was 10 years ago, this is my main bandsaw, and there is not an ounce of vibration. In other words, I’d agree about the motor and belt being a likely culprit. Also, you might check Mathias Wandels’s rebuild of a 9” Ryobi over at Woodgears.ca as he has really good tips for checking balance and eliminating vibration.

View Tugboater78's profile

Tugboater78

1076 posts in 859 days


#6 posted 01-25-2013 05:16 PM

Ever tried any of those linkbelts? I hear they will lessen vibration too

-- Justin - the tugboat woodworker - " nothing changed me like the first shnick from a well sharpened, decent hand plane"

View Grumpymike's profile

Grumpymike

1089 posts in 982 days


#7 posted 01-26-2013 12:02 AM

Justin stole my thunder … I replaced the “V” belt on my old Craftsman witn a link belt and retentioned the motor and she purrs … better than new.
I have never tested it but I feel that the C’man blade speed is slower than my Rikon … FWIW.

-- Grumpy old guy, and lookin' good Doin' it. ... Surprise Az.

View Grumpymike's profile

Grumpymike

1089 posts in 982 days


#8 posted 01-26-2013 12:04 AM

I just noticed that Woodcraft has that link belts on sale this month … about half of what I paid at Granger.

-- Grumpy old guy, and lookin' good Doin' it. ... Surprise Az.

View Rick M.'s profile

Rick M.

4026 posts in 1047 days


#9 posted 01-26-2013 02:37 AM

According to their website, the Rikon 12” travels at 1181 & 2559 FPM.

Where did you see the link belts onsale? The website is still showing them at $37.00

-- |Statistics show that 100% of people bitten by a snake were close to it.|

View JohnInHadley's profile

JohnInHadley

22 posts in 661 days


#10 posted 01-26-2013 10:08 AM

Oops. I meant 103-0103. Thanks Rick for the link to vintage machinery. I never had paperwork on the bandsaw.

View James Lango's profile

James Lango

180 posts in 2201 days


#11 posted 01-27-2013 08:38 AM

Threw a V Belt from WoodCraft on this saw, and it did help alot. Almost perfect now. Thanks for your help.

-- Longovette@Roadrunner.com

View davidroberts's profile

davidroberts

1003 posts in 2153 days


#12 posted 01-30-2013 08:13 AM

I vote for the link belt. Harbor Freight carries them, if you live near one. Reasonable quality for the price but not the exact same as link that Rocker’s or Woodcraft sells. I put one on my 14” Delta, and the leftover on a bench belt/disc sander. Good to go.

-- God is great, wood is good. Let us thank Him for wood......and old hand tools.

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase