Bandsaw Spring and other Upgrades

[John Stankus]

I've just decided to try to get my bandsaw working well. It is a Jet 14 inch (with riser block) which I bought new in early 2000s. I followed the Alex Snodgrass (of Carter Products) method for aligning things. It cuts much better using that method.
But...
I noticed the Spring was pretty much completely compressed. The Highland woodworking website has two different springs of different lengths for Delta (2 1/2 inch) vs JET (3 inch). The local Woodcraft has the Carter Cobra Coil (for some reason I keep thinking Karate Kid :)) spring for both the Delta and the JET. One of the Amazon reviews said it was 2 3/4 inches long (split the difference). Will that make a difference in actual usage?

At some point I am thinking of adding the Highland Hardware heavy duty crank. Any opinions on that?

I am going to do something about a fence since the stock one doesn't seem to have the adjustablility to match the blade.

Now I just need to figure out (remember) what all the blades I have bought 15 years ago are. I have two half inch blades, and vaguely recall buying a Timberwolf and maybe Woodslicer. Not sure how to tell them apart (or even if I need to).



John

[John K Jordan]

Years ago, also around the early 2000s, I bought a stronger spring and other upgrade parts from Iturra Design for one of my bandsaws, a Delta 14". This company is well respected for bandsaw part, upgrades, and tools. Very knowledgeable and highly recommended. I haven't contacted them lately but this is what I have:

Iturra Design
KALLL@comcast.net
904-642-2802 • Work
4636 Fulton Road, Jacksonville, Fl 32225-1332

Try to get their catalog if they still send them out. Besides a catalog of parts and tools, it's a thick book and a good education on how to adjust, repair, and get the most out of a 14" Jet or Delta bandsaw.

The springs on these saws are known to be weak and some get weaker over time, not allowing proper tensioning. The replacements from Iturra are stronger than the factory springs. Remember that the tension indicator on the saw is about worthless. I use a tension gauge (I got from Iturra) to be sure about the tension but they are expensive and can be made for nothing - if interested search here or I can provide a link today.

I wouldn't worry about the brand of the 1/2" blades. The biggest thing that matters is the number of teeth per inch. If one is made from better steel it will probably just cut longer before it gets dull, depending on what you cut. I always sharpen mine several times before changing. I primarily cut green wood into turning blanks and use 1/2" 3tpi blades, 4tpi if I want a little smoother cut. I mostly use an 18" saw now but I used the 14" with riser the same way for a long time.

I added a quick tension release lever to my Delta which is great. I think later models have this built in. Set the tension with the knob and release it instantly as needed with the lever. I tuned my saw using info from Duginske's and Bird's books. I was not overly impressed with Snodgrass but many worship him.

JKJ


I've just decided to try to get my bandsaw working well. It is a Jet 14 inch (with riser block) which I bought new in early 2000s. I followed the Alex Snodgrass (of Carter Products) method for aligning things. It cuts much better using that method.
But...
I noticed the Spring was pretty much completely compressed. The Highland woodworking website has two different springs of different lengths for Delta (2 1/2 inch) vs JET (3 inch). The local Woodcraft has the Carter Cobra Coil (for some reason I keep thinking Karate Kid :)) spring for both the Delta and the JET. One of the Amazon reviews said it was 2 3/4 inches long (split the difference). Will that make a difference in actual usage?

At some point I am thinking of adding the Highland Hardware heavy duty crank. Any opinions on that?

I am going to do something about a fence since the stock one doesn't seem to have the adjustablility to match the blade.

Now I just need to figure out (remember) what all the blades I have bought 15 years ago are. I have two half inch blades, and vaguely recall buying a Timberwolf and maybe Woodslicer. Not sure how to tell them apart (or even if I need to).

John

[John TenEyck]

I have an Iturra spring on my 14" Delta with riser and it works well. You still can't more than about 12K psi on those saws on a 1/2" blade w/o risk of damaging other parts though; that's all those saws are capable of. However, they will cut well enough with a sharp and well aligned blade if you are patient.

If you are considering buying a fence so that you can adjust for blade drift I think you should spend some time on table alignment first. Assuming the blade is centered on the top wheel put a straight edge along the side of the blade and check it's distance from the miter slot at the front and back of the table. That distance should be equal. If it's not, loosen the trunnion bolts and pivot the table until it is. With that done the blade should cut straight and parallel with the miter slot at which point there is no need to adjust the fence for drift because there is none. If after doing this and the saw cuts nice and straight but starts to wander in few hours, weeks, months, etc., it means your blade is duller on one side than the other and it's time to change or sharpen the blade, not adjust for drift. I hope this helps.

John

[Frederick Skelly]

I'm another Iturra spring user. Have it on my JET 12", which I use for small work. It works well.

I put on a highly touted aftermarket fence - it was from one of the "bandsaw gurus" (fasttrack maybe?). I used it and hated it for several years. A year ago I finally had enough and switched to the Kreg fence (LINK (https://www.woodcraft.com/products/kreg-precision-band-saw-fence-kreg-kms7200)). I like it far better. YMMV.

[Tom M King]

I put all that stuff on an old Delta 14", with a riser, and a new motor, etc., etc. I've wished several times that I had just bought a new 10-326, or a 1412.

[Edwin Santos]

A word of caution about the aftermarket springs like the one Iturra sells - they are capable of exerting more tension than the factory spring, to the point of damaging your saw permanently by exceeding the tension the frame is capable of withstanding.
Not trying to talk you out of getting one of these springs, just don't fall into the "more tension is better" camp and unintentionally stray into the danger zone.

With saws of your type, I am a fan of Michael Fortune's tuning and tensioning guidelines. He advocates lower tension than others. After attending one of his workshops, I adopted his recommendations with good results. You can find his Fine Woodworking video or article online. I share this because hearing that your spring is fully compressed makes me suspect that you may be attempting more tension than you need.
Edwin

[Mike Kees]

I am in the same camp as Tom and Edwin . Cast iron 14'' bandsaws are great general purpose saws. I too spent good money on a larger motor and riser block to resaw. Like Tom states I would love to have that money back or a different saw. I still have the Delta and it still works great as my small saw for general purpose bandsaw work. the problem with a stouter spring is that it will be to strong for the tension/axle assembly. This will lead to damage and eventually having to replace those parts as well. my conclusion is these saws are best left to do what they are designed for to begin with. If you need to resaw any amount ,look for a bigger more capable saw. YMMV.

[Mike Cutler]

John

A decade or so back I did some testing for Mark Duginkse, which involved testing some springs.
I tested the OEM Jet spring and it was capable of exerting about 9000psi to a 1/2" blade. The Carter Cobra Coil was about 13,400 psi in the same application. So yes, there is a difference. I would recommend the Carter Cobra coil, over the OEM spring. It's a lifetime investment, and the cyclic fatigue life of the spring will never be reached in a home environment.

The principal failure mechanism for the 14" bandsaw is the upper yoke assembly breaks from over tension. This happens when a tension meter is used on the bandsaw blade to tension the blade, or lack of attention when applying tension.
I tested a number of these these tension meters for Mark Duginske, from three different manufacturers, and personally wouldn't waste the $$$$ on one. They're highly inaccurate in the range they're being utilized with respect to blade tension on a small bandsaw. The "best" from a repeatability point of view and use in the application range, was the electronic tension meter Carter had out at the time. I think that they no longer offer it.
When tensioning a bandsaw blade there has to be gaps in between the spring coils at any given tension. I don't give a hoot what the tension meter says, if there is no gap between the spring coils, you're bandsaw is "solid" and well on the way to be broken.
A 14" Jet band saw with a riser is capable of barely tensioning a 1/2" blade correctly. A 3/8' would be a better selection.
The installed OEM tension gauge, while crude in appearance, is actually pretty functional with a Carter Cobra Coil.

I have a 14" Jet with a riser block also, so I know that machine fairly well.

[John Stankus]

Yes, I agree that it is not the best use of resources to upgrade this saw. That being said, having tried several different alignment methods (including proper sacrifices and incantations :o but not having a tension gauge (which according to the internet wisdom are both necessary and superfluous)) I tried the Alex Snodgrass method and the saw cuts reasonable straight. So I am going to run the saw I own. The issue is the spring is almost completely compressed, so the question about a replacement. Not to increase the tension applied, but to get to the appropriate tension with some remaining spring travel for shock absorbance. The Iturra replacement spring from Highland is 3 inches long, the Carter replacement spring is 2 3/4 inches long (the Iturra Delta is 2.5 inches so I guess Carter is splitting the difference). The question is does this 1/4 inch length make any difference? i.e. order from Highland, or go to Woodcraft 4 miles away?

I got good performance with stock guides (and new cool blocks) so the $180 guide upgrade I don't feel is necessary. The replacement tensioning rod was more to just whether it would be more convenient ($49 for easier tensioning/detensioning). $160 for a quick release may be a bit much for the convenience.

So I am leaning towards a functional spring replacement, and maybe a sweeper brush for the lower wheel ($9 but not sure that is even necessary)

The Fence from JET has been crap from day one (I actually have two I think since I had issues when I first got the saw and they sent a replacement). I may fiddle with it a bit more, but went ahead and stopped by Woodcraft today and picked up a Magfence II v2 .

So the bottom line question is --> with a dead stock spring, should I replace it with the 3 inch Iturra from Highland ($16.99 plus $7.99 shipping) or the 2.75 inch Carter from Woodcraft (about $20 plus tax)? Or does it not matter between the two?

John

p.s. I would love to upgrade to one of the MiniMax saws but limitations on money and space will put that off quite a ways.

[John TenEyck]

FWIW, the Iturra spring gives around 12 - 13K psi on my 14" Delta with riser on a 1/2" x 3 tpi blade at the 1/2" indicator on the saw. There is no danger in my mind of breaking the upper yoke at that tension, but there certainly is if you try to fully load the spring. To measure the tension you can make your own tension meter for not much money and it works as well as the commercial ones. I copied this one from a YouTube video:

https://lh3.googleusercontent.com/he83aawP8aV4-gL-3J9EroyqqH7_OMTehlSHxIFMOu1x0aimDrhvonVHTHFEGEnjkR _iBVWWXEKL3taCxH7PT1qPQsXs-XZNUnQ2xEVg19eSyz9o6joV6ecFyX0YthzWX0mlQ6DMTJLu2ro zqhIj3-NK7ZtNK7_icnWdqR5EaeeqV-tXMtzkA3U9q8STRrjRBDCht7-sOhLaF-ZVNdAX63xJJmWzTHaSfj8y7bH048MfWY_xx5zCkxEk-iOXZC7ho60yuDIEHzrPjr0n4YsS8Vxktpydg6FQ5adwoEctdpP Ukyh9ZgeVF0i7lrYNZhf9q2pPT2gDWC223M6ZG5gB6X8w8BFn_ BVfW0ligMeExW7JG8f2DNclYriF2LMSkmOybhRfEVZArwT23b6 pmeWKP1b9RT_cT0RoBMTXqGLuPz1monxPWfOhElrwv0LAm59Ej qCvBK39HytXIHB5_hzBcw1h1UgwYARQ2RVNq3KaPAaXxIkZ3a9 UK7C-wiZNM2Jks1Ro-v_apIyHDHmQQRzHeihTcnNLDIUGDT-LNCSrNDQKPk3wqhS-MeC_69WvSCfO9NaIYliih1gI1ygpzz6gkXWYo1_YH0bBQWD0A1 4BQIwSgFOoXzhky6xDVA4mhjPKyG7wIVcBYYYxdvmvI-Vg9ApaoN6I-jwtyeP71EkWASDloIOa4ZcPYMdzufUJeUqjaF88hD29PIhVn8I sPcY=w835-h626-no

https://lh3.googleusercontent.com/sVGx2qWU6w8SYqW3fbs3X0TGdl5Y2jqafopQp2t8XCSt9KjJ-EBZoXGKomxgIWfu5vK0cWu5mmooh1OjJBW-y4xj6el-hPbxDwQ6YNagNlSlVNnlsA_c1gWoVxxFBirk01jeH4mFD8RGOQ GDKaSJvZMN76cJiFAKqySy0Umi9dzm2BzeUgfW5n6D1QuA4JN3 V9CWUrQSXX-7Ow4PXRs7IlvQR6R9UsFUTwxc-s-ZQNkg3s7Am6mA09wdoa3b8NBXWtGHOhyFXbYIlq5EBU5OOcnWC cip3b0sucyba8yTEIXSlxEMeNXfGXYO0SK1eT4D8MgJUplA5gF QTrVGTzu0TGZTc4ahseICXThQlazvvwHT_MK1wkhB1hTyHBJIX oay1ypTc8P95Ru9ZOJoVR2nqCZ-8A3YBpBRIfZJdUjjwajJA870P6E9mPnxrh3N3SdZkgJsczLRor lZC78VukoL3TF0hgWBDJ8kcc9Ntb-IfXg0BreqxF_qW1Z5bwGQjlRg_m6qPsXZlsT-BTtdHVHCZbfjPvU_ex3St65ZCR6UA_FSc9U-3TVNsWPJewY0iHyAtl0VBy6SKH9MGmWo8BHsxfu_TUdHw73Uzc nDDvBxB4zJA4o-ysJKDUt5ZytPQjduUb04L38fsapL6Kxm6HwswLCA9ruxxFYSOc 8pavYjLb4ImlJ7OYxtdxl6Mmv7SUg4EEOaXqrEe7m6DJgG0JQ= w835-h626-no

Mine has a 12" gage length, but you can make it any length that fits your machine; of course the longer it is the more accurate. The values measured depend upon how you define zero tension. Unless you want to build a load cell based system this is the nature of the beast. But with just a little observation you can define zero in a logical, consistent way and get repeatable results.

Of course a larger saw like shown in the photos make resawing easier and faster, but that's irrelevant to getting the most out of whatever saw you own. I only use this saw for heavy resawing and slicing veneer. Everything else is done on my 14" Delta so I want it set up to perform the best it can.

John

[Rick Potter]

I cannot speak to the wood slicer blade, but I do have several Timberwolfs. There is a dark line down the side of all of them, presumably from hardening the teeth.

[Mike Kees]

John take Mike and John's advice on the spring. I still have the stock spring in my saw since I stopped short on my "enhancements'' before I spent more on another spring. Sounds like you have realistic expectations for your saw. Good luck,Mike.

[David Kumm]

For what it is worth I've had the tension spring discussion years ago with Mark and my results do not mirror his. They can be a little funky to use, but I've had as many as four lined up on my big saws, Starrett, Iturra, and Lenox and all read within 1000 @ 25000. An early Iturra had problems and I sent it back. When it returned it read like the others. I'm not sure I'd spend the money for a small frame saw as there are other methods, but when running a 20' trimaster at 25000-30000, the meter gives me quick repeatable way to set up the machine and protect the blade.

I totally agree that the tension housing is often not strong enough to add much additional tension. My ACM LT 18 with a stiff spring caused frame deflection that made tracking inconsistent. My Yates Y20 handled a much better spring easily so it depends on the saw. Dave

[Mike Cutler]

John
Replace the spring. Whether with the Iturra model, or the Carter, it would appear that there isn't much difference.

I disagree completely that your Jet is not worth investing any $$$$ in. Having that same band saw maybe that's just a personal opinion, but I don't regret the $$$$ I put into mine, and the includes coming to the realization that asking it to resaw with any consistency was just asking too much of the basic machine.( I have a Rikon 18" specifically setup for resawing only.)
Regardless of the size, or tooth configuration of any given blade, you still want that blade to function properly. Whether to resaw, or cut green bowl blanks, it doesn't matter. That starts with a predictable, repeatable, blade tensioning mechanism. Nothing is more irritating that having to re-tune a bandsaw every time you tension the blade to use it.

The biggest "mod benefits" I realized were these;
-I replaced the OEM guides and bearings with Carters. I also machined a small spacer to get the lower guide closer to the underside of the table, like the Delta, and decrease the length of unsupported blade.
- Carter tires. The OEM's are a hard rubber and they suck!!
-The Carter Cobra coil replacement.
- Modifying the tension mechanism with 5/16th's all thread and making my own square nut. This tension mechanism is operated wit a $2.00 ratcheting box end wrench. I also placed a metal pad at the point between the tension rod and the cast iron frame of the saw.
- I modified the door with a 4" dust port, but I I'll be adding the DC modification I saw in Derek Cohen's post to both of my bandsaws.

I never found the brushes to do very much, the bristles are too soft. I used to have a harder plastic "tooth brush" used for parts cleaning that I could attach with rare earth magnets to both the upper and lower wheels. I lost them somewhere, so I'll need to make a new set.

[Mike Tekin]

FWIW, the Iturra spring gives around 12 - 13K psi on my 14" Delta with riser on a 1/2" x 3 tpi blade at the 1/2" indicator on the saw. There is no danger in my mind of breaking the upper yoke at that tension, but there certainly is if you try to fully load the spring. To measure the tension you can make your own tension meter for not much money and it works as well as the commercial ones. I copied this one from a YouTube video:

https://lh3.googleusercontent.com/he83aawP8aV4-gL-3J9EroyqqH7_OMTehlSHxIFMOu1x0aimDrhvonVHTHFEGEnjkR _iBVWWXEKL3taCxH7PT1qPQsXs-XZNUnQ2xEVg19eSyz9o6joV6ecFyX0YthzWX0mlQ6DMTJLu2ro zqhIj3-NK7ZtNK7_icnWdqR5EaeeqV-tXMtzkA3U9q8STRrjRBDCht7-sOhLaF-ZVNdAX63xJJmWzTHaSfj8y7bH048MfWY_xx5zCkxEk-iOXZC7ho60yuDIEHzrPjr0n4YsS8Vxktpydg6FQ5adwoEctdpP Ukyh9ZgeVF0i7lrYNZhf9q2pPT2gDWC223M6ZG5gB6X8w8BFn_ BVfW0ligMeExW7JG8f2DNclYriF2LMSkmOybhRfEVZArwT23b6 pmeWKP1b9RT_cT0RoBMTXqGLuPz1monxPWfOhElrwv0LAm59Ej qCvBK39HytXIHB5_hzBcw1h1UgwYARQ2RVNq3KaPAaXxIkZ3a9 UK7C-wiZNM2Jks1Ro-v_apIyHDHmQQRzHeihTcnNLDIUGDT-LNCSrNDQKPk3wqhS-MeC_69WvSCfO9NaIYliih1gI1ygpzz6gkXWYo1_YH0bBQWD0A1 4BQIwSgFOoXzhky6xDVA4mhjPKyG7wIVcBYYYxdvmvI-Vg9ApaoN6I-jwtyeP71EkWASDloIOa4ZcPYMdzufUJeUqjaF88hD29PIhVn8I sPcY=w835-h626-no

https://lh3.googleusercontent.com/sVGx2qWU6w8SYqW3fbs3X0TGdl5Y2jqafopQp2t8XCSt9KjJ-EBZoXGKomxgIWfu5vK0cWu5mmooh1OjJBW-y4xj6el-hPbxDwQ6YNagNlSlVNnlsA_c1gWoVxxFBirk01jeH4mFD8RGOQ GDKaSJvZMN76cJiFAKqySy0Umi9dzm2BzeUgfW5n6D1QuA4JN3 V9CWUrQSXX-7Ow4PXRs7IlvQR6R9UsFUTwxc-s-ZQNkg3s7Am6mA09wdoa3b8NBXWtGHOhyFXbYIlq5EBU5OOcnWC cip3b0sucyba8yTEIXSlxEMeNXfGXYO0SK1eT4D8MgJUplA5gF QTrVGTzu0TGZTc4ahseICXThQlazvvwHT_MK1wkhB1hTyHBJIX oay1ypTc8P95Ru9ZOJoVR2nqCZ-8A3YBpBRIfZJdUjjwajJA870P6E9mPnxrh3N3SdZkgJsczLRor lZC78VukoL3TF0hgWBDJ8kcc9Ntb-IfXg0BreqxF_qW1Z5bwGQjlRg_m6qPsXZlsT-BTtdHVHCZbfjPvU_ex3St65ZCR6UA_FSc9U-3TVNsWPJewY0iHyAtl0VBy6SKH9MGmWo8BHsxfu_TUdHw73Uzc nDDvBxB4zJA4o-ysJKDUt5ZytPQjduUb04L38fsapL6Kxm6HwswLCA9ruxxFYSOc 8pavYjLb4ImlJ7OYxtdxl6Mmv7SUg4EEOaXqrEe7m6DJgG0JQ= w835-h626-no

Mine has a 12" gage length, but you can make it any length that fits your machine; of course the longer it is the more accurate. The values measured depend upon how you define zero tension. Unless you want to build a load cell based system this is the nature of the beast. But with just a little observation you can define zero in a logical, consistent way and get repeatable results.

Of course a larger saw like shown in the photos make resawing easier and faster, but that's irrelevant to getting the most out of whatever saw you own. I only use this saw for heavy resawing and slicing veneer. Everything else is done on my 14" Delta so I want it set up to perform the best it can.

John


Hi John,

Which model of Grizzly bandsaw is this? Seems to tension a larger blade well and was always curious how much tension/size blade the 17 and 19 inch Grizzly saws can handle.

[John K Jordan]

For what it is worth I've had the tension spring discussion years ago with Mark and my results do not mirror his. They can be a little funky to use, but I've had as many as four lined up on my big saws, Starrett, Iturra, and Lenox and all read within 1000 @ 25000. An early Iturra had problems and I sent it back. When it returned it read like the others. I'm not sure I'd spend the money for a small frame saw as there are other methods, but when running a 20' trimaster at 25000-30000, the meter gives me quick repeatable way to set up the machine and protect the blade....

I have the Starrett tension gauge and it checks out closely to the "long" gauge described by John TenEyck. I only used it when setting up a new size of blade on my 18" saw to see where the built in tension needle points, ignoring the factory numbers. This lets me repeat the tension quickly. With several wood and metal-cutting saws here I consider the cost of the Starrett worth it.

I mentioned this before, but years ago I had to replace parts I ruined on my 14" made-in-the-USA Delta before I knew any better. I tried to run it with a 3/4" blade as advertised in the specs. I now consider that capacity marketing hype or an outright lie. Yes, I did get it tensioned enough to resaw 12" and process green log sections into turning blanks, even with the under-powered motor. However, it destroyed the tensioning bracket by slowly bending it until I could no longer tension anything properly.

I replaced the bracket with a stronger one from Iturra and installed their stronger spring. After that I limited the blade size to 1/2". By using the Starrett gauge, I found the 1/2" blade needed to be set to the 3/4" mark on the worthless tension indicator on the back of the saw. All was well after that.

Here is John T's photo and text from a while ago:
----------------------------------------------------------------------------------------------------
Posted by John TenEyck, SMC 1/1/17
https://sawmillcreek.org/showthread.php?250388-Bandsaw-blade-tension&p=2640833#post2640833

(Measuring tension with digital calipers)
....it's cheap and pretty easy to measure blade tension. Flutter, schmutter - measure the tension and then you'll know. All you need is a set of 6" vernier calipers and two little c-clamps. A calculator and a little math get you an answer in a few minutes. Once you measure blade tension you'll learn where to set the tension scale for any particular blade you use and the max. blade width your saw can run (and likely find it's not as wide as the manufacturer claimed).

In a related issue, if you are using a 14" cast iron Delta or clone, those saws cannot put much tension on any blade wider than about 1/4". They will still cut OK but not anywhere as good as a larger saw would with the same blade. For example, my 14" Delta can comfortably manage only about 12K psi on a 1/2" blade. It cuts OK as long as you keep the feed rate slow enough not to belly the blade. Take that same blade and put it on my larger saw that can easily put 25K psi on it and it will cut straighter, several times faster, and last a lot longer...

401788

...the blade guides are removed or at least backed away from the blade. Clamp the vernier with about a 5" gage length so that each jaw is on the flat of the blade, between two teeth. On really narrow blades it's best to face the vernier towards the back of the saw in order to avoid the teeth altogether.

The basic calculation is Young's Modulus = Stress/Strain, where:

1) The Young's Modulus of steel is about 30 x 10^6 psi.
2) Stress, the value you are after - the tension in the blade in psi.
3) Strain = Deflection / gage length. The vernier measures deflection, and the gage length is the starting distance between the jaws under zero load.

So, you rewrite the equation as Stress = Young's Modulus x Strain = 30 X 10^6 x deflection/gage length

The gage length I started with was 4.768", so when I measured a deflection of 0.003" that was equal to a blade tension of 30 X 10^ x 0.003/4.768 = 18,876 psi.

My little Delta was more than maxed out with the 1/2" blade I was using. The Iturra spring was nearly fully compressed, the frame was distorted by nearly 0.010" and that pulled the upper guide completely out of alignment. The data showed that I can't really run more than about 12K psi on a 1/2" blade. But with a 1/4" blade I can run at nearly 25K psi w/o over stressing the saw. The 1/2" blade will still cut OK at 12K psi, but I have to run more slowly than I would if I could apply higher tension to avoid blade deflection.

----------------------------------------------------------------------------------------------------

[John TenEyck]

Mike, it's a G0636X. I posted a review about it when I first got it a couple of years ago, I think, and another Creeker posted his impressions just a week ago. We both have measured tension values over 40K psi on a 1" x 0.035" blade, with lots of space left between the spring coils. 40K psi on a 1" x 0.035" blade would be 24K psi on a 1-3/8" x 0.042" blade. Grizzly rates this saw for a 1-3/8" blade and the data I've measured suggests it could handle one. I have no plans to use anything wider than 1" running at about 25K psi, which is a very manageable load on both the frame and spring.


John

[John Stankus]

Well, I might have stumbled upon another issue that is contributing to my problems. (will have to verify when I can get back out to the shop and move all the puzzle pieces(tools on wheels) to get to the bandsaw. After mucking with the saw some more today, I got is cutting fairly ok. But noticed that I heard a rubbing sound, which I could not locate other than somewhere in the upper wheel region. After I closed up to come in for dinner, I found a thread from 2009 about someone with a 10 year old Jet where the upper sliding hinge assembly was bent and made a rubbing sound. Apparently the original casting design had issues (for reference mine was purchased in 2001 so contemporaneous with the one with a problem) So I will check next time I can get out to the shop and see if it is bent. Now to find a beefier replacement, once I verify that is a problem.

I have been thinking on the tension gauge thing. So in the range of tensions we should be running these blades the stretch is only going to be about 0.002 over 5 inches (or two ticks on the caliper). Did I do my math right? I tried going the other direction (clamped on at five inches) and then detensioned, but didn't see any movement. Has anybody looked into a side deflection measurement of tension like they use for bicycle spokes, structural cables or sailboat rigging?

John

[John TenEyck]

Yep, 0.002" with a 5" gage length will give you 12K psi. If you use a set of Vernier calipers that can read to 0.0005" or, better still, a dial gage good to 0.0001" you will get accurate results.

John

[John K Jordan]

...Apparently the original casting design had issues (for reference mine was purchased in 2001 so contemporaneous with the one with a problem)

..I tried going the other direction (clamped on at five inches) and then detensioned, but didn't see any movement.

I wonder if that bent part you mentioned is the same as what I called a tension bracket in post #15. I have no idea what the actual name is, but the one on my Delta bent from two much tension. The upper wheel on mine was rubbing on something too.

Iturra said this part was weak on both the Delta and the Jet clones. I installed their much stronger replacement bracket and spring and all was and remains well. Someone might call the problem "casting issues" but to me it just looked like low quality material. In post #2 I gave the contact information I have for Iturra.

The tension check measurement can be made in either direction, according to logic and the instructions that came with the Starrett tension gauge. (Their flyer (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwj_zdX_xYDgAhXvSt8KHUWOBTQQFjAAegQIBhAC&url=http%3A%2F%2Fwww.starrett.com%2Fdocs%2Fother-downloadable-resources%2F682emz-saw-tension-gage.pdf%3Fsfvrsn%3D6&usg=AOvVaw0uaeFH1i8gcw3IiVjngihZ) says the same thing.)

But I always attach the gauge before tensioning (but with the blade taut, not floppy.) That way I can keep cranking to set the tension while watching the gauge.

JKJ

[John Stankus]

Took another look at it today.
The axle for the upper wheel is a few degrees (3 or so) out of 90 with the hinge piece. (granted I don't know if this is supposed to perpendicular or not). The key issue I see here is that the hinge can interfere with the upper wheel guard sheet metal making it more difficult to adjust.

The spring definitely is an issue. That is the location of the spring without a blade on the saw...halfway between the 1/4 and 1/2 marks with absolutely no tension. Spring looks to be only 2.5 inches.


Louis Iturra indicated that my saw should have the improved hinge on it (being a 2001 vintage white saw) and that really just needs a better spring. I'll contact him again with the new observations and at least order a new spring.


John

I'm kind of jealous of my brothers Minimax MM20. I might have to see about picking up teaching some summer classes and looking at a S400P (MM16 new name) or a used one.