band saw update (with pix) and a question

[Russ Ambrose]

i posted a week or so ago about an old band saw that i was beginning to restore. some folks asked to see some pix and i was finally able to get around to it last night. my best guess is that this machine is 50-60 years old. it seems to be in pretty good shape - hopefully it just needs a good cleaning/tuning.

my question for today is about the size of the pulley driving the bottom wheel. the saw came with an 8 inch pulley. can i replace it with a smaller (6 inch) pulley. i realize that will increase the blade speed, but is this a big/bad/unsafe problem? i'll be running the saw with a used 1hp motor running at 1725 rpm. any thoughts are appreciated.

finally, someone asked if i could send them copies of the original owner's manual that came with this saw. i'm happy to do that - just let me know where to send it. my profile should be set up so that you can send me an email. thanks again.

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[Julio Navarro]

Great machine. I'll be interested in your progress. Good luck.

[Mike Kelly]

Russ, I would stick to the original pulley. All woodworking bandsaw blades are designed to do their job at about 3,300 SFPM and changing this pulley would get you into a problem with blade loading I suspect. This speed is also OK for some soft metals like aluminum. Most metalworking blades run at 39 to 300 SFPM. The original motor was probably a 1725 RPM so you should be OK there.

[Jeffrey Makiel]

Russ,
What's the size of the pulley on the motor?
-Jeff

[Russ Ambrose]

the pulley on the motor is 2 3/4 inches.

[Jim DeLaney]

the pulley on the motor is 2 3/4 inches.

Russ,
With the original 8" pulley, and a 1725 rpm motor, your blade speed will be 2173 feet per minute (fpm). Switching to a 6" pulley on the saw, and keeping the 2¾" one on the motor, blade speed will be 2897 fpm, which is closer to optimum for sawing wood.

Were it my saw, I'd install the new pulley.

[Mike Cutler]

Russ.

Louis Ittura, of Itturra designs, prints a catalog that is basically considered the "bible" for 14" bandsaws.
His personal preference is the older Deltas, just like the one that you have there. He has a few chapters on the upgrade, and "souping" up of the 14", Delta bandsaw. He finishes by comparing it to a newer Delta, and a Jet 14"'. His Catalog is worth getting.
Here is the info.

Iturra Design
4636 Fulton RD
Jacksonville, FL 32225-1332
1.888.722.7078 voice
1.904.642.2802 fax

[Jeffrey Makiel]

Jim did a nice analysis. I agree with his numbers and conclusion of using the 6" pulley. It should be noted that you will have about 25% less torque. However, your feed rate during resaw will essentially be the same (because the blade is moving faster), but the kerf will be cleaner. When scroll cutting (material less than 1" thick), I would bet that you'd see even more improvement in the kerf quality.

cheers, Jeff

[Craig Stueve]

Russ.

Louis Ittura, of Itturra designs, prints a catalog that is basically considered the "bible" for 14" bandsaws.
Russ,

The saw looks great and Mike is 100% correct about Ittura being the one stop shop for older Delta band saw. I was the guy who asked you about a copy of the manual but I got a copy from Delta. Thanks for the offer though.

If I remember correctly you got the saw from your grandfather. If you are just wanting to give it a good cleaning and see what you have before you paint it you might try the "Magic Erasers" from Mr Clean. That is what I used to clean up my band saw and I am happy with the results. So much so that I am not going to paint the saw now. I really enjoy the look of the saw. All of the little nicks and scratches just add character to it.

I have the same 6" pulley you have and so far have been pleased with the results I have when using the saw. From what I understand you will loose some torque by increasing the pulley diameter. From what I have read you get the most gain from the increased blade speed when you are resawing. With that in mind I might give the bigger pulley a try in the future.

Craig

[Jim DeLaney]

...From what I have read you get the most gain from the increased blade speed when you are resawing. With that in mind I might give the bigger pulley a try in the future.

Craig

Craig,
NO! NO! NO! You get faster blade speed by using a smaller pulley on the saw. If you're gonna install a larger pulley, try a 4" pulley on the motor. That'll give you 3161 fpm.

[Russ Ambrose]

as always, thanks for the great info.

it sounds like the 6 inch pulley is the way to go. if not, i can always change it.

craig (sorry i forgot your name) glad to hear you got the manual and a big thanks for the "magic erasers" tip. yes, this was my grandfather's saw and i really don't want to paint it because then it won't look like my grandfather's saw. hopefully, the magic erasers will allow me to clean it up without losing its "character."

and i called iturra and ordered a catalog. i knew they made replacement springs, but was not aware that they had other similar products. am looking forward to getting the catalog.

thanks again for the help. i'm sure i'll have other questions along the way and as i make progress i'll share photos with everybody.

[Craig Stueve]

Craig,
NO! NO! NO! You get faster blade speed by using a smaller pulley on the saw. If you're gonna install a larger pulley, try a 4" pulley on the motor. That'll give you 3161 fpm.

Correct you are Jim. I had it backwards as usual.:D

Craig

[Tom Clevenger]

Here is a link to Old Woodworking Machines that will give you SFPM. I used this to tune up an old Powermatic 81.

Be careful of the pully size and whether you use an A or B belt. It does matter on speed. For example,

I bought a 3.95" diameter pulley. Using a 1/2" A belt, the working diameter is 3.20". Using a 5/8" B belt, the working diameter is 3.60".

The 3.95" pulley using a 5/8" B Belt give me 3.60" for 4548 SFPM.
The 3.95" pulley using a 1/2" A Belt gives me 3.20" for 4042 SFPM.

That is 506 SFPM just with the different width belts. If you need to determine the working diameter of the pulley, you can search through www.surpluscenter.com (http://www.surpluscenter.com) and find the pulley you want. It will give you the correct working diameter for the belt you are using. Below is an the link to OWWM and the 3.95" pulley used as an example.

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

http://www.surpluscenter.com/item.asp?UID=2006032216581561&catname=&qty=1&item=1-BK40-F