Speed up your ancient Delta bandsoar
EdHarrow
| Posted in Power Tools and Machinery on
To those with ancient Delta 14″ bandsaws: Take a page from Louis Iturra and crank those babies up! Mine had an 8″ driven pulley which I replaced with a 6″ (gets the blade speed up to around 3K’/minute. The motor was dead, so I replaced that and the belt (with a Fenner – the red linked ones). Amazing.
Louis actually recommends 4K’/minute but I figured I’d start slowly, LOL.
Replies
To think ---
Slowing my Delta down produced better performance.
It's not clear to me whether faster = better. Blade speed, feed, and torque are related. I'd be curious to know what motor you had and what you switched to. I wouldn't be surprised if a faster speed would allow a faster feed for light cuts, and maybe that's important.
What advantages/disadvantages have you found since the swaps?
Pete
Edited 4/20/2005 4:01 pm ET by BRADLEPC
Pete, let me preface this by stating that people fill books with what I don't know...
My saw was given to me five or so years ago, and dates, near as I can figure, to about the big bang. Pre WWII. It was nearly complete as new - 3/4 hp "Induction/Repulsion" motor, etc. The switch on that motor (a toggle switch right on the motor) is broken, and the idea of hot wiring it didn't strike me as the best and brightest idea on the planet, LOL. I poked thru the junk pile at work and found a semi-trashed, open frame 1 HP motor from an old Welch vacuum pump. All comparisons are to this motor.
Previously resawing was a frustration: wandering, barreling, and very rough. No matter what, it seemed that I couldn't move the wood sufficiently slowly, I guess. So, when the motor died, and the price of admission didn't vary by a whole heck of a lot, and being a fan of that old matra, "There ain't no substitue for cubic inches." I got a 2HPBaldor. Now, having changed more than one item, I can't say for certain the source of the difference, but I suspect that the old motor would have looked at the new "final drive" and pass out in a dead faint.
I've not done much with the saw as I'm still in the process of working out some of the bugs (the new motor, mounted solid, as the old, was incredibly noisy. I've now put it on rubber mounts and can actually hear myself think when it's running.). Anyway, I've run a couple of piece of oak thru it, resaw fashion, and it cuts fast (well it does now, after I removed one link from the belt, before that it was slipping a bit), smooth, and no barrelling or other bad stuff.
The only real down side that I can see is that the motor is 208 VAC. That could, at some point, be limiting.
For more on this topic get yourself a copy of Louis Iturra's catalog. If you don't have the catalog, it is a great resource.
That 3/4 HP R/I motor is a great piece of equipment. "They don't make 'em like they used to" applies in the best way, so hold onto it or ebay it. It's not uncommon for those switches to be broken or bypassed and a different switch to be used.
Swapping a 3/4 R/I motor for a modern 1 HP might be a net loss. A 2HP sounds like a boost. Did you swap the blade also?
I have the Iturra catalog. He definitely favors the WWII-era Delta 14s.
Pete
Here's a chart from the Suffolk Machinery web site. Click the link to see all the details.
Examples of optimum Surface Feet Per Minute on vertical band saws running 1/8" to 1" wide blades. It is not considered wise to exceed these values.
WHEEL DIAMETER
S.F.P.M.
WHEEL DIAMETER
S.F.P.M.
12"
=
2,800
24"
=
4,000
14"
=
3,300
26"
=
4,000
16"
=
3,800
28"
=
4,000
18"
=
4,000
30"
=
4,000
20"
=
4,000
36"
=
4,000
As you exceed the S.F.P.M. for a specific wheel diameter, you greatly increase the centrifugal force applied to the body of the blade traveling around the two wheels. This causes you to over-tension your blades in order to make them run stable. This WILL cause premature and excessive blade breakage. There is also a minimum speed you should run a band saw blade. (EXAMPLE: Timber Wolf¯ band SAW blades should not run under 2,400 S.F.P.M. and Timber Wolf¯ band MILL blades should not be run under 4,000 S.F.P.M.)
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Interesting that their char tops out at 4000. Some industrial machines exceed this by quite a bit. I think the general idea of moderation is good though.Pete
Would those machines have a 1" blade, or much wider? Their chart is restricted to blades of that size (maximum).
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Edited 4/22/2005 10:31 pm ET by forestgirl
FG, I find it hard to believe that the curve goes flat at 4000 FPM from 18" on up, and then it is OK to go faster with larger blades.
I think whomever was working up that chart didn't want to have to work late, and just quit doing the math at that point.I think a lot of folks think that Tennawitz is the top of the line for BSs, Here is their link. http://www.max-ind.com/m_catalog2.asp
You might notice that their speed is 5500. and on the larger saws are powered by 10 HP.One thing that I have posted here on more than one occasion, is that if you are cutting thick stock. I think that 1 hp for each 2" of thickness of material is about right for maintaining a proper feed rate.
Edited 4/23/2005 10:57 am ET by rootburl
Might be interesting to contact Suffolk and ask them about that. I hadn't noticed the flattening-out.
To "All": I dug out the Iturra catalog and found the page "Supercharging Your 14" Delta." He suggests the pulley replacement as a compromise to installing a 3450RPM motor with higher HP than the stock motor. He notes that such a drastic upgrading could cause two problems: old tires flying off and metal fatigue in the blades due to running at such high speed on small wheels.
So, the compromise of changing out the motor pulley to a larger size. He got his Delta up to 4000 sf/m. NOtes that the surface finish was better and there was a slight increase in feed rate. Further improvement would require a larger motor.
He suggests the use of "safety-type tires" glued on.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
So tell us what are saftey tires and why glue them on?
Want more info, eh? OK, this all comes from the Iturra Designs catalog, which in addition to merchandise, has some good historic bandsaw info and a comparison between Jet and Delta. Their phone number, should you want to order one, is 1-888-722-7078. A highly recommended read by those of us who have it.
From Page 32:
For the supercharging procedure, he (Louis Iturra) is recommending glueing on even safety tires to prevent them from "flying off" when they age and lose elasticity. Not only would that be a bit dangerous, but if you have an expensive carbide-tipped blade on there, it's severely damages your pocketbook.
Sounds to me that if you supercharge a small (14") saw, it's pretty improtant to check the heath of the tires regularly.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Edited 4/24/2005 11:40 am ET by forestgirl
I had occasion to ask Suffolk about their blade speed chart since I was ordering some blades for my machine (1940s Delta 20", 4500 SFPM factory speed). They said that the 4000 was a conservative "top end" of the chart and that their blades would be fine for this use. The person I talked to said there were reasonable limits of course, so they wouldn't necessarily recommend a blade for some of the old ships saws that run at 8000+, for example.Just to be clear, the Delta 20" was built for this speed, runs a 141" blade, and has tires that are cemented to the wheel. Mileage may vary.As a side note, I'm really pleased with Suffolk. I'm running their 3/8" PC blade, and it's top notch. I bought a 1" resaw blade too, but haven't run it yet.Pete
Thanks for the update, Brad! Keep us posted on how you like the Timber Wolf blades, especially the big resaw blade. I'm a fan, but with my little Grizzly 1019Z, it doesn't carry alot of weight, LOL!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Here's a half-update. I loaded up the big blade, and the saw went from a sizzling sound to bang-bang-bang. Hmmmm...not good. Fiddle with tension, tracking, etc; no dice. Get out some tools and measure a slight step in the weld. Called Suffolk, who listened to the symptoms and immediately shipped a replacement blade and a return label for the original.The big blade is a monster. It's thicker as well as deeper, so it wants a lot of tension relative to a small blade. It runs ok and it does a decent job of slicing up logs. However, I've hit the limitations of the smaller automotive valve spring that someone substituted for the real tension spring somewhere in the past. I can't really deliver enough tension to do it justice until I fix that.The 3/8 blade Suffolk blade remains awesome. Smooth fast cuts in almost everything.Pete
Can't say enough good things about my ancient Delta bandsaur either, and I'm running it almost exactly as it came out of the factory in the 40s.Pete
Edited 8/29/2005 10:32 pm ET by PeteBradley
The 3/8 blade Suffolk blade remains awesome. ..I bet it does..I usually use a 1 inch three tooth LENOX blade.. Just Great! No I hardly ever use it for curves sillies!
Well the old Delta 20" is fixed at 4500 SFPM. The recommended blade size is 3/16" - 1". This is a medium-duty industrial machine. The tires are glued on. Iturra sells stuff to customize your 14" band saw much like the auto parts places sell stuff to customize your car. How much that's worth depends on the person I guess.Pete
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