LumberJocks

Bandsaw Tension Spring

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by ja6ke posted 08-06-2020 09:50 PM 379 views 0 times favorited 13 replies Add to Favorites Watch
View ja6ke's profile

ja6ke

52 posts in 2419 days


08-06-2020 09:50 PM

Hi all,

I am attempting to resuscitate an older Bridgewood 18” bandsaw and am stuck. I need (or think I need) to replace the compression spring used to tension the blade. I can measure all the spring dimensions but have no idea what the pounds per inch compression value of the spring should be.
Anyone have any ideas how I might determine this?

I should mention what little documentation I have for the saw doesn’t mention anything about this.

Thanks

John


13 replies so far

View MrUnix's profile (online now)

MrUnix

8211 posts in 3046 days


#1 posted 08-06-2020 10:17 PM

I need (or think I need) to replace the compression spring used to tension the blade. I can measure all the spring dimensions but have no idea what the pounds per inch compression value of the spring should be.
Anyone have any ideas how I might determine this?
- ja6ke

What makes you think you need to replace it? Unless you can bottom out the spring (full compression) during normal operations, then it is fine. If you do want to replace it. Otherwise, head on over to your local ACE hardware store and find one the same size… It doesn’t have to be an exact match, and as long as you can’t fully compresses it under operation, then it will work just fine.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View ja6ke's profile

ja6ke

52 posts in 2419 days


#2 posted 08-06-2020 10:27 PM

When it was all together and working I could easily bottom out the spring. I am the second or third owner and I know I have occasionally accidentally left the blade tensioned overnight.

Ace is a good idea. I was just hoping to figure out the right compression amount before assembly. I really don’t want to go through assembly/disassembly again if I can help it.

Thanks
John

View Craftsman on the lake's profile

Craftsman on the lake

3467 posts in 4285 days


#3 posted 08-07-2020 12:10 AM

I know these are rugged springs. Sort of like miniature car springs. That being said, a thought came to me. Why not put a couple of spaces in the coil, sort of like we used to do on auto springs when they got older and weak? Or maybe a spacer at the top or bottom between the spring and adjustment nut?
Just thinking out loud here.

-- The smell of wood, coffee in the cup, the wife let's me do my thing, the lake is peaceful.

View ja6ke's profile

ja6ke

52 posts in 2419 days


#4 posted 08-07-2020 01:01 AM

Spacers is an awesome idea. If I can’t get a replacement for whatever reason I will give that a try.

Thanks
John

View GrantA's profile

GrantA

2850 posts in 2255 days


#5 posted 08-07-2020 02:09 AM

Is that a miter gage slot to the left of the spring? If so it’s much bigger than the 14” delta style, first I’d have a look at grizzly, odds are they have an eerily similar saw. Then take that grizzly saw part number to the separate grizzly parts website and you’ll probably find a replacement spring.

If that is a dead end I’d look towards automotive valve springs, look to a manufacturer’s catalog like comp cams and I bet they have them listed by dimensions

View Lazyman's profile

Lazyman

5794 posts in 2235 days


#6 posted 08-07-2020 03:10 AM

Carter Products sells the Cobra Coil replacement spring. I remember seeing that in a magazine article a few years ago as a recommendation when you refurbish or upgrade an old bandsaw.

You can also buy it at Woodcraft or Amazon.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View GrantA's profile

GrantA

2850 posts in 2255 days


#7 posted 08-07-2020 03:21 AM

Nathan the cobra coil is only for 14” saws this is an 18” and looks to have a much bigger spring

View Lazyman's profile

Lazyman

5794 posts in 2235 days


#8 posted 08-07-2020 03:56 AM

Sure enough. I didn’t notice it was for an 18”.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View therealSteveN's profile

therealSteveN

6241 posts in 1422 days


#9 posted 08-07-2020 05:17 AM

Dontcha love it when you want to show someone a part, and they stored their pics at PhotoBucket.

Your pic made me think of my 18” Rikon, but I have the older green one, not sure if it’s changed, but kinda looked like your pic, but sizes could be way different?

Anyhow with my thought in mind you might look at 18” bandsaws to see if their parts list has a spring looking anything like yours. Sometimes machines are totally different, sometimes they are mostly all alike.

Louis Iturra has long been a bandsaw guy with a collection of info, parts, and even if he doesn’t have it, sometimes he can say where to look. I long ago quit trying him by phone, his email is [email protected] I’m pretty sure he even checks it, about every other month. But hey, you might get lucky.

-- Think safe, be safe

View CaptainKlutz's profile

CaptainKlutz

3586 posts in 2342 days


#10 posted 08-07-2020 07:41 AM

Sorry, there is nothing magical about compression spring in mechanical equipment?
Just need a little knowledge and know where to look.

Unless dealing with expensive alloys or special temper; generally the type & diameter of wire and distance between coils set spring rate. The overall length determines the total pressure rating. So if you can find a spring with similar wire and number of springs, it will be close enough to tension your band saw blade.

Can find replacements on McMaster Carr, and many other places (Century Spring, Lee Spring, Tricor, or Raymond Springs, etc, etc). Have used Raymond for stamping die springs for many years. Pick size/force from catalog and order it from local distributor. Done.

Probably the easiest way to find a replacement is visit the local spring shop. They exist in most major cities. Have at least 4 mfg here in Phoenix, and dozen distributors of springs for machinery and stamping dies.

If you want do this online; measure the dimensions your existing spring: wire size, spring OD/ID, and height. Would assume that pressure over time has reduced the height by 10-15%, and shop for that larger length in the above catalogs. If tension mechanism allows for longer spring, that gives you even more flexibility finding a new one.

Best Luck.

-- If it wasn't for bad luck, I wouldn't have no luck at all, - Albert King - Born Under a Bad Sign released 1967

View AlaskaGuy's profile

AlaskaGuy

5984 posts in 3157 days


#11 posted 08-07-2020 08:10 AM

Call this company and see what they can tell you. They were the distributor for Bridgewood tools. I have a Bridgewood wide belts sander. I understand they may still have some parts for the Bridgewood line.

https://chwilke.com/

-- Alaskan's for Global warming!

View Craftsman on the lake's profile

Craftsman on the lake

3467 posts in 4285 days


#12 posted 08-07-2020 11:05 AM

Hi, I’m the guy earlier that recommended the spacers.

I’ve got an old Craftsman bandsaw with a spring that looks very much like that. The saw is 45 years old. I bought it when I was 21. I’ve noticed the spring in mine is getting weaker but it still works. I have to tension it more so the setting for a 1/8th in blade show that I’m tensioning it for a 1/4” blade but I tighten it up to what seems right and the saw runs. Are you sure you need a new spring?

-- The smell of wood, coffee in the cup, the wife let's me do my thing, the lake is peaceful.

View splintergroup's profile

splintergroup

3978 posts in 2070 days


#13 posted 08-07-2020 03:00 PM

Spacers are a good trick, assuming your spring is not bottoming out with fully collapsed coils.

Most bandsaws have a common arrangement with the spring directly inline with the top wheel axis and some small offset between the wheel centerline and trunnion. Chances are good that any spring designed for a bandsaw with the same wheel diameter class and frame design (cast iron or stamped steel, max blade tension limit) will use the same spring geometry.

ereplacementparts.com has good photos with the ability to determine the dimensions and might be able to help you find an equivalent. Their prices are very high, but I found an original spring for my old Powermatic 14” that was mislabeled and cost about half of everybody else.

If your saw has a old style cast iron frame, check for old Delta or other brand 18” cast saws.

Have your say...

You must be signed in to reply.

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