SEARS SLO-SPEED BAND SAW CONVERTER pt1
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- čas přidán 27. 07. 2024
- Watch part 2 when available -- SEARS SLO-SPEED SAW CONVERTER pt2 #829 tubalcain
also when available- GENUINE DELTA METAL SAW REVIEW #830 tubalcain
What Makes It Work? #33a SPEED REDUCER tubalcain part 1
• What Makes It Work? #3...
What Makes It Work? #33b SEARS SPEED REDUCER pt 2
• What Makes It Work? #3...
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I like the alter ego with the high pitched voice that asks silly questions. He's been in a couple of episodes now.
I think you will hear a lot more from my alter ego
Oh, so, hand reamers are slightly tapered! Had to look it up, but thanks again for yet some more knowledge that will save me from buying the wrong tools!
1725/10.24*2.5/6=70.19 rpm at wheel input. 70.19*3.14*14/12=257 ft per minute (FPM). Modern blades (bimetal) should be good at 300 FPM on steel.
The practical, real-world requirements of carrying out custom work like this is fascinating. Problem-solving skills are just about the most important you can have. Absolutely brilliant video and looking forward to the next!!!
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I have the same saw and have looked into step pulls. Don't think I can find a reducer like you used. Enjoyed your application.
Amen!
You could not use a hand reamer for the blind hole because it has a taper at the end. A chucking reamer is a consistent diameter its whole length.
Thank you for the video Lisle. Good to see you posting more frequently. [(1725rpm/10.24)X(2.5”/6”)X(14”X PI)]/12”Per Foot = 257.13 SFM
A very organized presentation.
Thanks Ted
The taper pin is to prevent (or at least resist) warping of the table casting, which would create a slight step up or down in the table.
To answer why you had to use a machine reamer to ream, a hand reamer have a slight taper on the end where a machine reamer have not.
There is a 3rd method to secure a pulley with only grub screw and that is to drill a dimple in the shaft where it should be located. But most of us don't have angled drilling machines available. Hope you only reamed to a size where the pulley is a press fit when using only a grub screw to locate and transfer power to the shaft. To get the correct speed you will need a 8 and 1/2 inch pulley and not the 12 inch. Your blade speed now should be 254 inch per minute. Why don't you get a 6"/8.5" stepped pully for the top pully, that way you will not have alignment problems when changing speeds? But even the misalignment when the center of the driven pully in between the 2 drive pullies shouldn't be a problem as most home drill presses come with stepped pullies to change the spindle speeds, they have a chard with 6 speeds if there is 2. 3 groove pullies.
The table plug is just there to ensure alignment of the the table where the cut is if there is any stresses in the casting. The hole gets drilled and reamed before the cut is made.
Good morning Mr Pete. Just in time for my coffee, I like it. This series intrigues me. Thank you for a trip into the past.
hand reamer has a slight taper to make it easier to start straight in the hole. machine reamer has no taper.
Cool thing that speed reducer. Made in the USA at a time when things were made to last.
Hi Mr. Pete!!! I hope you remember our conversation from a few weeks ago, regarding a Wilton/LANE TECH vise that I own. You mentioned that you were going to be at a tool convention in Illinois' NW Burbs, and I was trying to get there, but, due to issues beyond my control, I was unable to do so. I'm going through a worker's comp lawsuit, and am unable to do a lot of the things that I want to $$$. Anywho, I have a Jet 14 inch band saw, built in 1982, probably in the same factory as yours was. It HAD one of those cheap, weak angle iron stands that gets bolted together with a hand full and a half of nuts, bolts and washers. That stand was giving out, and no longer able to support my band saw, so I searched the internet, and found a Delta base, exactly like yours, and decided to use it to support my band saw. I had to cut away some metal from the top to allow the belt to line up with the pulleys, but other than that, it's a great fit. I was especially surprised to see that my 110/220 motor fit inside the base perfectly. As I was doing the transplant surgery, I noticed that the lower 14 inch wheel is cracked. I found this Jet wheel www.fix.com/parts/band-saw/jet/fix10376939/lower-wheel-198672/?SourceCode=1&ModelNum=JWBS-14CS&ModelID=6582854 and was hoping you might know if it will fit my saw. The lower wheel shaft on my saw has a 200mm diameter. I don't see why this wouldn't fit, but I wanted to ask you first. If you don't think it would work, maybe you could offer a suggestion as to which wheel should fit. BTW, I live close to O'Hare airport, and I think you said you were in the Chicago-land area as well, a while back. Maybe we can arrange a get together some time so you can see that Wilton/LANE TECH vise that I have. GREAT VIDEO!!!!!!!!! I never knew this speed reducer even existed.
ur lookin back to your old self in this video
The pin keeps the two sides of the slot aligned. A local turning friend was told that the pin did not matter so she did not have it installed. I paid a visit to her shop to tune the bandsaw and observed the rear side of the slot was slightly lower than the front side. I installed the pin then the two sides were aligned. My friend now knows to keep the pin installed between blade changes.
The slow speed convertor is quiet. Shame it does not slow the blade speed down enough. Horrible sound when test cutting the aluminium.
Dave.
Yes
With the 14" wheel I calculate the speed of the blade is about 257 sfpm. I like the idea of adding a double pulley at the top to rep[lace the single 6" pulley. Good class I learned something I didn't know before, Thanks!
You can take the Mr Pete out of the classroom, but you can't take the classroom out of the Mr Pete. Thanks once again.
Thank you Mr Pete, I learned quite a bit in this video. Learned to calculate 257 SFPM for the 14" wheels and out of curiosity I got 183.7 SFPM if that were to have 10" wheels everything else the same. Also looked up the reamer question and learned about the taper present in hand reamers making them no good for blind holes.
I came up with 257 sfpm also
Same here.
I was recently given a Gearbox Delta bandsaw in need of restoration. I decided to rebuild the trunnions, guides, etc and install new tires and leave the cosmetics for another day. Just need to braze up a blade and test it out. I already have a Craftsman with a homemade countershaft rig that gets me by for metal cutting. I think I own 6 or 7 bandsaws in total, but I won't admit to it. 😁
lol
The pin is to align the two sides of the table.
A double pulley on the six inch side wound help in lining things up. I’m sure you could come up with an idler pulley for the belt that would make it a quick change set up. Maybe a future video.
Interesting Mr Pete. I personally modified a 12” Craftsman wood cutting bandsaw that I purchased at an auction for $50. What I’ve done was to build a Jackshaft system on a metal frame underneath the saw. Since the saw had a wooden stand it was something I had to do. It is one of my most used tools in my shop.
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I'm certain somebody's already suggested this, but in my opinion the best answer would be to simply put a double pulley on the top. Even if it does have to hang out slightly there would be more internal bearing surface engaging the shaft, and you wouldn't have to monkey with alignment when you switch from high speed to low speed.
I was going to suggest lining things up to favor the pulley pair used most often and let the infrequent pulley be out of alignment, but I like this ☝even better
Great video! i have that band saw. Wish I had the speed reducer. The tapered pin in the table is to ensure flatness across the cut in the table.
I wouldn't bother to much about the alignment. Belts are very forgiving and the lower the speed the more forgiveness. So I would align the top pulley to the fast bottom pulley with a slight deviation to the slow pulley.
Thanks
The smaller TEFC motors have a fan under the end shroud. If it is getting too warm maybe yours is missing.
Thank you for sharing. Enjoyed.👍👀
I never realized they made these. When my motor on my band saw needed replaced I opted to replace it with a 3 phase 1.5 hp motor and put a proper sized VFD 230VAC single phase/3 phase VFD on it for variable speed control. VFD's are pretty cheap these days and liked it so much I did the same thing to my milling machine, lathe and drill press. I found a cheap electronic magnet based rpm sensor setup on Amazon and put them on the machines to determine the spindles rpm's. For the band saw some simple math and a spreadsheet was used to determine SFPM for the saw. I suspect the three phase motor a lot easier to find than one of these reducers these days!
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Instresting series. Thanks Mr Pete.
Good one Mr. Pete...
On my bandsaw the tapered pin in the table significantly stiffens and prevents twisting between the two table halves.
Thanks Mr. Pete. I bought one of those saws this year with much the same conversion in mind. 👍
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Thank you Mr Pete.
I have the same band saw and a gear speed reducer @ 25:1 so just for kicks, I worked out what that would be and I came up with 105.179 FPM if I include the existing pulley reduction of 2.4:1
I don't think I'll try it because of the added motor load and noise of going through a gear box.
THANKS MR PETE
Very interesting.Thank you.
Mr. Pete, When you move to the larger pulley, you will need a new belt. Make a idler pulley on a cam shaft , so you can change belt positions on the reducer and adjust the belt tension. Just my thoughts.
thanks for sharing . a new topic, Tubalcain makes a double driven pulley for the bandsaw slo speed converter ( to allow changing the drive pulley speed and belt stays lined up )
table pin is to keep the table in line and no flex
I would change the motor out for a 3-phase unit with a VFD, so the speed can be adjusted more, even with the reducer, so chatter can be adjusted out.
That is a great unit, Really a fairly straight forward conversion, I too vote for two pulleys up high for the belt to be inline, a larger pulley like you shower,
I wish you were making a conversion unit for us to copy, but you showed the unit off well enough that we could copy it as well as you could, well close to as well as you would.
GB you have more patients then I have. I have the gear reducer model and added a treadmill motor drive for infinite speed. It is the way to go. Interesting video.
I'm only guessing but the pin in the bandsaw table would be to tie the two sides together so they can't move independently from each other.
This answered a lot of issues I've been having with my band saw. I had no idea about the speed reduction needed to cut metal. I'm going to have to do some thinking on what I want to do or maybe not do anything and relegate the bandsaw to the wood shop forever.
On your motor, you have a sealed motor, its sealed on both ends. The motor has an open shroud, and that open shroud is designed to draw air over the outside of the motor. Thats all you get for cooling. So, on those motors, you need to keep the motor clean so air can contact it well, and the fan and shroud needs to be clean so the proper amount of air flows through the fan and shroud. You might also increase the shroud over the motor and also make sure you have good ventilation access to that fan area.
Good progress so far. Just a bit slower and you will have it.
Great video once again, looking forward to part 2. I have a mental plan to use the transmission from an old Honda ATC 90 which has 4 speeds and a high and low range to reduce the FPM of an old Walker Turner band saw to cut metal.
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Wow, Tubalcain it must be quiz time. The tapered pin is to align the bandaw table. The machine reamer doesn’t have a taper like the hand reamer so it will ream blind holes. According to your data about 260 S-FPM. Excellent video.
Thanks
The hand reamer is tapered. The machine taper is not. The pin locks the table surface in position when inserted. i calculated about 250 fpm on my slide rule.
I have that bandsaw. Made in USA.. I had to true the wheels up they were wobbling back and forth and were slightly egg shaped. I watched your guides , clearly that saw has the same problem. I would true those up first. Then put a coarser blade on there. If necessary, go to a larger final sheave. I like that speed reducer, it's truly nice and simple.
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Will someone please let me cheat off your paper lol
That appears to be an ODP (Open Drip Proof) motor enclosure to me. There can be a cooling fan inside the cover and rather than exit out the other end (it is closed as you noted) the cooling air would exit after coming back up and then out around the endcap. Is the endcap shown at 22:12 larger than the motor housing so that air can escape there? Could be a TEFC but hard to tell from the views shown.
Been watching you for quite a while, have learned many tips. I've been a tinkerer my whole life. (72)years. My solution to the slow speed saw was a zero turn mower transmission. Works like factory, even has adjustable speeds. If you are interested I could email some pictures. Old Jack, C Kutrufis
Yes
lislepete22 At Yahoo. C o m
I get 263 SFM, but that's without any slipage calcs for the vee belt, which could add up to a few percent.
Stopped it at 18.50 the pin is to stop the two parts of the bed from flexing and to stiffen it up. Great vidjeo as AvE would say Lyle, that's a very interesting little unit. If that were me I'd find and put a 4 pole motor on the machine and as we are on 50 hz here in the Uk that would give a motor RPM of just over 900, which would be much more suitable for your purposes.
the blade speed would be 257 fpm. if the 6" pulley was changed to the 12" that would change blade speed to 128 fpm. if the 14" wheels were changed to 12" the speeds would be 220 fpm with the 6" pulley and 110 fpm with the 12" pulley.
I'm sorry but it does not work that way. If you put a 12 inch pulley on there the speed will be a lot less than half speed. Just check the circumference of the 2 pulleys.
Dale in Canada
As belt alignment goes, could you add a second 6" pulley to the driven end of the band saw? Or perhaps a double pulley? Although that would be more expensive.
I've been thinking about the issues with mechanical speed reducers to cut metal on my 14" Delta clone. I've a small shop so saving some space is important, which means it needs to be able to switch from wood to metal and back again relatively easily. As you have found out making a dual use band saw is not trivial.
Recently a project failed, leaving a three phase 1.5 kw spindle motor and vfd available for other uses. I'll have to make a motor mount, should be straight forward as I have mounts from the previous project. I expect the variable speed vfd will give the speed ranges I need, so the change over should just be a blade change.
I wonder what problems will crop up!
To get to 100ftpm you would probably require an extra pair of pulley on a lay shaft. Big job, easier to change motor to 3phase and VFD
Right now you are at 257.22 fpm. If you remove your 6" pulley and use a 12" dia pulley, you will get 128.61 fpm. That will be good for steel. You will have to get a longer drive belt and belt guard , however.
The tapered pin on the side of the table is to maintain table flatness and eliminate vibrations due to the split.
I got: (1725/10.24) * ((3.14 * 2.5)/(3.14 * 6)) * ((3.14 * 14)/ 12) = 257.3 ft/min ... Fun Exercise. (I showed all of my work on my homework paper, but to difficult to fit in all the units here) Thanks. Love your videos.
Thank you for showing your work excellent
can you add another pulley of the same size to the top just like the speed reducer for belt change?
I put a DC motor and controller from a treadmill on my vintage Craftsman 12” band saw. Can change speeds by simply by turning the potentiometer. 300 FPM is ideal for metal and has worked well for me. Use a good quality blade and you’ll get years of use in the home shop. I’ll have to stay tuned to learn about the reamer and table plug. Keep the videos coming MR Pete, you the man…..
I've done this same mod to several old bandsaws. They sell quickly!
Maybe make a collar so the upper pulley can be adjusted in by just loosening and pushing it in to meet the collar? Also, that tapered pin is there to keep the table from twisting/misalignment. Maybe do what I did... buy a General 590 dual-speed saw... (except they are rare, unfortunately).
The 12 inch pulley on the 14 inch bandsaw drive wheel axle will run 35.095 rpms [ 168.457 rpm of the 2.5 inch pulley reduces the 12 inch pulley rpm to 35.095 rpm ] . Pulley B (12 inch ) rpm is found by pulley A's size times pulley A's rpm divided by pulley B's size. That in turn will give you the 110.388 ft/min blade speed. Feet per minute is {.262 x D x RPM } that is .262 x 14 x 35.095 = 110.388 ft/min. Very close to your 100 feet per minute recommended speed.
Since the belt needs to be loosened somehow to change from one pulley to another, how would you do that with the brackets that came with it?
Pin stops table from twisting, assures level table plate.
I’m a newbie at this stuff but i think the hand reamer is slightly tapered and can’t go deep enough into that blind hole🤷🏻♂️
The formulas I see used here to calculate the SFM of the blade are correct. But the figures used for the pulleys are not accurate. To be accurate, we need to use the pitch diameters of the pulleys, not the their ODs. When using 2-1/4 and 5-3/4 for the respective pulley pitch diameters, for example (an approximation on my part to illustrate), the result is 241.6 SFM. Not a big difference, but more accurate than using ODs.
I wouldn't get all so worried about belt alignment. I think I'd set the upper pulley centered on the lower two. Then it's off an equal distance in either speed. Do we worry the belt will wear, yeah sure it might but it's not like this runs eight hours a day under heavy load?
The speed, this is where modern tech and the bain of the home shop meet. If you had a three-phase motor (eww yuck) you could put on a VFD and now vary the motor speed. They are very inexpensive these days and make things a pleasure to use. Yes you would still need the gearbox to get this slow(or a giant motor with the right pulleys) and now you can fine-tune your speed.
$257 feet per minute as is 15 and a half inch pulley would give you 99.5 ft per minute
Wheel rpm = ( 1725rpm / 10.24 ) * ( 2.5in / 6in ) = 70.2 rpm
Wheel circumference = pi * 14in = 44.0in = 3.67ft
Blade fpm = wheel rpm * wheel circumference/rev = 70.2 rpm * 3.67ft/rev = 257 fpm
Expect slightly less because V-belt pulley pitch diameters are less than the outside diameters you have given, resulting in slightly more output rpm reduction.
Motor lag and belt slip will also reduce end result.
I get 257 ft/ min with the reducer being used. Yes, Pretty fast for steel.
My quick calculation came out to 257.2 ft/min. How'd I do?
Awesome T-Shirt, Mr Pete! Where can I get one?
I got the shirt from grizzly many years ago
A little belt misalignment is insignificant. Anyone who works on riding mowers understands this.
I have added a homebuilt 10 to 1 reducer and the blade speed is perfect for steel. I also have a hf bandsaw and the blade speed is 300fpm and I have used it to cut steel.
Chatter likely due to lack of rigidity, which is to say insufficient blade tension and friction guides instead of ball bearing wheels. Metal cutting requires enormous blade tension, which the framework of this wood saw does not provide. The result is chattering because each tooth starts its workpiece engagement with a cutting pressure (i.e., above Young's modulus), but then subsequently rides up into rubbing instead of cutting. A blade with fewer teeth/inch might help since there is more pressure per tooth and more headroom to avoid the mixed mode. Otherwise you get acoustic vibrations of a frequency which falls within the resonance of the low-rigidity system. It's always about feeds, speeds, and rigidity, all three.
Great observations, thank you. I did have the blade tightened for half inch wide even though it is a 3/8 blade
@@mrpete222 Not sure if a wood saw could reach proper blade tension for metal cutting. The rubber tires and large diameter of the wheels limit blade tension to a small value compared to that of a metal-cutting band saw, which would have solid metal wheels, and smaller diameter, for the given horsepower and envelope. The blade has to be rigid inside the work, and only tension makes that happen. It's not a problem for wood because the metal blade is already rigid compared to the workpiece.
257 FPM? Seems about right after a couple runs thru the wet ware...
Good morning Mr. Pete, another great video! I liked your solution to the set screw issue. When I watched the last video on the speed reducer, my thought was to mill a key down to half thickness, or whatever thickness got it to just fill the keyway on the motor shaft and sit tangent to the shaft diameter at the edges. When installed in the keyway, that would give a narrow flat spot for the screw to contact. Maybe too narrow, might allow slip? Was wondering if you know of a reason that would be a bad solution?
Thank you for the suggestion, I think I will show that in the future video. I never even thought of it
Were did buy this from
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Mr Pete, dumb question here. Going back to the motor shaft keyway problem, could a person take and mill a piece of keystock to only half thickness? So when the key was in place, it wouldn't protrude above the depth of the keyway, thus creating a flat on the motor shaft.
You are the third person to suggest that. That is a wonderful idea, and I intend to show it in a future video. Some thing I never thought of, but so simple
@@mrpete222 sounds good!....but above all else, the shop teacher is always right!👍
Bubba says Hey. we limit our friend Bubba to non electronical machines, for the safty of his Young sow Dolly
It’s a screamer!
Be careful with those type right angle drills. We have one in our shop at work. Some years ago one of our guys got his fingers caught in the guard around the chuck. He didn't unplug the drill motor before changing out the twist drills.
Totally agree, I always unplug it because it has the paddle switch which can very easily be activated
Hand reamers are tapered.
Hello Mr. Pete! I calculate 265.7 ft/min with the current setup.
Gah! I made an error! Wheels are 14 inch diameter not 14.5! Correct speed is 257.2 ft/min…
Put a double 6 inch pulley on it
Taper
1725rpm (motor speed) / 10.24 (gearbox ratio) x 2.5 (drive pulley) / 6 (driven pulley) x 14 (wheel diameter) x 3.142(pi) / 12 (inches in a foot) = 257.26ftpm
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The pin in the side of the table is there for miter slot alignment.
You have one more pulley to consider, the ratio of the pulley on the back of the machine and the one on the inside driving the belt. I'm guessing the ratio of them is 2 to 1. This in turn will speed up the blade.
I have a Craftsman 12 wood cutting bandsaw. I would love to have that converter for it. If you are interested in selling it I'm interested in buying. Keep up the great videos.
There is a key way in the sheave
The pin provides accurate alignment of the left and right sides of the table. It doesn't become a loose fit in the hole (so table alignment is maintained) and doesn't fall out (even though it is not threaded) because it has a self-holding taper, like a Morse taper.
The motor fan at the rear may actually be outside the sealed motor casing. The visible slots may be in a detachable metal shroud designed to direct air over the outside of the motor.
An induction motor draws a magnetising current, which is almost independent of motor load and could be up to half of full load current, explaining why the motor gets warm.
Thanks
With the two pulleys on the reducer, could you not install a second grub screw in the other groove?.....and have double the clamping...
No. The two pulleys turn at different speeds.
You ask some silly questions. Why is the pin tapered? If you prefer a straight sided pin, it would hurt faster than the tapered one.
Did you think about filing or grinding the key flat where the set-screw would go? That way you do no harm to the shaft.
The reason you used a machine reamer instead of a hand reamer? Easy... you didn't have a 5/8ths hand reamer! 🤣😂🤣
I make it 163.777669270833333 rpm (give or take a little to account for motor slippage). As you say, a bit fast for steel. An 8 or 10 inch final pulley would bring it in range, plus have the advantage of providing a bit more torque (always a limiting factor with these aftermarket modifications for converting wood-cutters into metal cutters).
Me, I would just purchase a metal band saw and a wood band saw and throw then into the corner.
I do have two metal cutting bandsaw’s. Yes I am going to get rid of that dog gone Delta