Band Saw Blade Thickness Conundrum

[PGB1]

Hi All!
I have a Sears Craftsman "Continuous Blade Power Hacksaw" Model 108.22920.

The manual calls for 0.020" maximum thickness blade, explaining that the radius is too tight for thicker blades. Unfortunately, I have not been able to find 60" blades with 14 & 24 TPI in 0.020".

I'm writing to ask if any of you who have a similar, small wheel band saw have had luck with 0.025" thick blades. Or, do you have a source for 0.020" blades that I missed in my searching? (I did find one 60" x 0.020", but it was too coarse at 10 TPI.)

In the past, I've had 0.025" blades break at the weld or braze, but that could be my error in tensioning or aligning the blade.

The saw was put aside for years out of frustration, but I decided to use it again. As of today, the saw is aligned. I made & installed new tires, so they're running true. I rebuilt the down-feed cylinder & it's working. Things are lubricated, per the manual. Guide rollers will be adjusted when I get a blade.

Thanks For Your Advice!
Paul

PS: If you don't mind another question:
Is it a good idea to lubricate the bevel gears? The one with the tire is aluminum and the other one is nylon or other plastic. My thought was Synco Super Lube. But, I don't know if the lube will serve as a "chip trap" and cause more wear to the gears than running dry.

PPS: And one more?
The shaft that has the small bevel gear can slide back & forth nearly half of an inch. There is an adjustment to align the gears with set-screws to push the top frame back or forward, but nothing locks the gear shaft in position once aligned.
I did not find on the saw or in the manual a way to lock the shaft & keep it from sliding back & forth.
For those of you with this saw, does your shaft move? (Perhaps this is on purpose so the gears stay aligned?)

Thanks Again!
Paul

 

[RaisedByWolves]

I wouldn't worry about the difference between .020 and .025 blade thickness, blades have come a long way since that manual was written.

I'm currently using and shopping for .025 blades for my 10" 3 wheel saw with smaller if not same size wheels.

What width blades are you looking at?

 

[Nutfarmer]

The small bevel gear is pined to the shaft with a roll pin. The last blades I bought were made from bulk stock for portable band cut off saws. Don’t use cutting oil or lubricant on the blade or the blades won’t say on the wheels. Dry cut only. I wouldn’t try and lubricate the bevel gears. Be careful with the blades coming off the wheels that they don’t go into the small bevel gear and strip off the teeth. If you look around replacements for the plastic gear is available in a printed format. Premade band saw blades are hard to find. The thickness is important. Too thick and the blade will crack.

 

[RaisedByWolves]

Apparently Starrett has started selling pre welded blades to the public.

This was not the case years back. This is the blade they offer in smaller 14/“ 3/8” sizes.

I have no idea of how well these work, but I’m looking to get some to test.

Duratec SFB

www.starrett.com

 

[Ken from ontario]

do you have a source for 0.020" blades that I missed in my searching?

There's a place in Toronto Canada called R & D Bandsaws that sells 0.020" blades (different lengths and widths ) specifically for 3 wheel benchtop bandsaws, the quality of their blades are average but not expensive, R & D ships to USA as far as I know.:

3-Wheel (Bench Top Flexible) - R&D Bandsaws

*For lengths with fractions please enter the length with a decimal. For example 93-1/2", type 93.5 as the blade length, for 98-1/4", type 98.25 as the blade length. There will be a comment box at checkout where you can type your exact blade length, machine make and model.

tufftooth.com

 

[talvare]

I've purchased several blades from this company and they have performed well. They offer .025 thickness blades if you're interested. Here's an example that would fit your saw.

Multicut M-42

A universal M-42 Cobalt bandsaw blade with a high chrome backing for cutting various materials from ferrous to non-ferrous materials up to 45 HRC. Applications include Carbon, Stainless and Low Alloy Steels, Aluminum, Cast Iron and Structural Steel.

www.bandsawbladewarehouse.com

Ted

 

[PGB1]

I wouldn't worry about the difference between .020 and .025 blade thickness, blades have come a long way since that manual was written.

I'm currently using and shopping for .025 blades for my 10" 3 wheel saw with smaller if not same size wheels.

What width blades are you looking at?

Thanks for replying Raised By Wolves. The saw uses 1/2" wide blades.

Thanks, too for the link to Starret Blades. I found a 24 TPI in 1/2 x 60 inch. At work, I found even the plain carbon steel Starret blades to be qite durable in the saws.

 

[PGB1]

The small bevel gear is pined to the shaft with a roll pin. The last blades I bought were made from bulk stock for portable band cut off saws. Don’t use cutting oil or lubricant on the blade or the blades won’t say on the wheels. Dry cut only. I wouldn’t try and lubricate the bevel gears. Be careful with the blades coming off the wheels that they don’t go into the small bevel gear and strip off the teeth. If you look around replacements for the plastic gear is available in a printed format. Premade band saw blades are hard to find. The thickness is important. Too thick and the blade will crack.

Thanks NutFarmer for the information.
I find it odd that the shaft with the small bevel gear can move back & forth. Perhaps because both gears are beveled, some lateral mis-alignment is tolerable. To stop the shaft from going too far toward the user side of the saw, I bored the driven pulley to 5/8" and put a shaft reducing sleeve on the 1/2" shaft. Now when the shaft wants to go too far forward and have the pulley crash into the table, the reducing sleeve stops it. This is by no means a very good solution, but until I find another way to keep that shaft from sliding to and fro, it should help.

I'll keep those gears dry as you suggested. Thanks for the tip on that. To stop the blade from hitting the bevel gears should it come off (when it comes off...) I made a cover that attaches to the upper frame with thumb screws. When the blade comes off, the cover will stop it. (I saw in manuals for newer versions that this cover is standard.)

You mentioned prints for the small gear are available. I did a search found it right here at Hobby-Machinist, complete with STL file. A great group this is!

There's a place in Toronto Canada called R & D Bandsaws that sells 0.020" blades (different lengths and widths ) specifically for 3 wheel benchtop bandsaws, the quality of their blades are average but not expensive, R & D ships to USA as far as I know.:

3-Wheel (Bench Top Flexible) - R&D Bandsaws

*For lengths with fractions please enter the length with a decimal. For example 93-1/2", type 93.5 as the blade length, for 98-1/4", type 98.25 as the blade length. There will be a comment box at checkout where you can type your exact blade length, machine make and model.

tufftooth.com

Thanks Ken for the link to R&D. They sure have a wide selection & low prices. I sent an e-mail asking if they ship to U.S. If they don't, picking up at a drop ship point in Windsor is a relatively quick trip.

I've purchased several blades from this company and they have performed well. They offer .025 thickness blades if you're interested. Here's an example that would fit your saw.

Multicut M-42

A universal M-42 Cobalt bandsaw blade with a high chrome backing for cutting various materials from ferrous to non-ferrous materials up to 45 HRC. Applications include Carbon, Stainless and Low Alloy Steels, Aluminum, Cast Iron and Structural Steel.

www.bandsawbladewarehouse.com

Ted

Thanks Ted for the link to a blade source. They have the lowest price for cobalt blades that I've found.

Being able to use 0.025" opens up a whole lot more possibilities.

Yesterday, I tired the saw with my new homemade tires. (And dry cutting, which is something I learned here.) I don't know if it is the new tires, the dry cutting or the tension I set on the blade, but it didn't fall off after a dozen or so cuts in various steel shapes. Today, I'll torture test it on copper.

Thanks to everyone in this thread and other threads for mentioning cutting dry. I used to oil the blades. Perhaps that is why the blades came off of the wheels often. It was so common that years ago I made a "tracking adjustment cheater" so that I could tilt the idle wheel. (Photo below)

I also learned yesterday, if anyone finds this thread while searching for blade coming off problem, that with the guide rollers 4" apart, if the blade deflects 0.0625" half way between rollers, it stays on better. A deflection of 0.09375" worked, but occasionally the blade would slip on the wheels. Less deflection, the blade walked off the tires.

Thank You Each Again for helping and for educating.

Enjoy This Day!
Paul

 

[Nutfarmer]

The idler wheel has an offset built in the spacer between it and the adjustable slide. If installed backwards the blade won’t stay on the wheel. See the point of the scribe in the picture as to its location. It isn’t obvious that this makes the wheel tilt so the blades will track. If you keep throwing blade try turning it 180 degrees.

 

[PGB1]

Thanks NutFarmer for taking time to reply & make the helpful photo of the spacer. I appreciate it.

Unless I'm reading the exploded view wrong, my model's parts list & exploded view doesn't have the spacer to which your scribe points. Perhaps I have an earlier or later model.

Under the part # 32 Thin Nut in the drawing below, I have the Idler Wheel Washer (#33) that is on the top side of the frame, but no spacer is between the frame and the #44 Idler Wheel Support, as your scribe indicates.

When tightened, the Thin Nut pushes that #33 washer down to the frame, clamping the Idler Wheel Support #44 tightly to the frame.

The wheel actually touches the Idler Wheel Support (and rubs on it while rotating). I see nothing between the wheel & support in the exploded view.
I also don't show the thick spacer that your photo shows under the Thin Nut #32

Perhaps I can add a spacer like the one to which your scribe points on my saw to help tracking. Do you know if it's flat like a washer for a bolt, or has a non-flat shape to it? (I'm guessing it has a shape, as you mentioned turning it 180-degrees.)

Thank You Again for helping,
Paul