# Shop built band saw project



## Chris Curl (Feb 13, 2012)

So I have decided to bite off more than I can chew, and am going to try to build a band saw.

My current plan is to build a small band saw using an electric motor I got on ebay and some scrap wood I have lying around. The plan is to make the wheels out of 2x8 pine. So the wheels will be about 7" diameter.

Eventually, maybe I'll make 14" wheels and a bigger saw, but I think I better start small.

For the wheels, I will use some skate board bearings. they are 7/8" outer diameter with a 5/16" inner.

















That is all I have right now ... thanks for looking!


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## Chris Curl (Feb 13, 2012)

QUESTION - how fast does the blade in a band saw move?

I'm trying to determine the pulley ratio for the motor and the wheels, so if someone could look at their BS and let me know what RPM the motor runs and the sizes of the pulleys connected to the motor and the drive wheel, that would be great.

I looked at a RYOBI 9" BS at Home Depot, and it looked like the motor ran at 3000 PRM and the pulleys between the motor and drive wheel were pretty close in size, both about 2-3 inches in diameter. If anything, the motor pulley might be a little smaller than the drive wheel pulley.

I wonder if a 14" BS And a 9" BS both move the blade at roughly the same speed ... ?


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## The Warthog (Nov 29, 2010)

You might want to consider a larger saw as being more forgiving. A 1/16" error on a 7" bandsaw is twice as bad as the same error on a 14" bandsaw. Besides, it won't be long before you begin to wish you had made a bigger saw. 

According to my _Band Saw Handbook_, saws generally run at 2600 to 3100 feet per minute. Do your own math.


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## Chris Curl (Feb 13, 2012)

that is exactly the kind of number i needed, thanks!

i am thinking about a bigger saw, but the bigger it is, the stiffer the shell will have to be, which is my concern (being a newbie). that and the fact that the motor i have is only 1/2 hp, so it might not be up to some of the tasks.

but i doubt i'll be re-sawing really big stuff any time soon. famous last words, right?


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## Chris Curl (Feb 13, 2012)

it turns out the bearings are a tad large for a 13/16" hole, and a tad small for a 7/8" hole

i guess i can do the 13/16 and the make it a tiny bit larger with a file or some sandpaper. then the bearings will be nice and tight.

i am going back to thinking i'd like to do a 14" instead ... 

for the wheels, i'm thinking about taking some 1x5 and 1x6 pine and gluing them together at 90 degrees to make the wheels, sort of like they do plywood with the grain perpendicular on different layers.

or would i be better off gluing together 2 pieces of 3/4" plywood?


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## cedarwood (Feb 3, 2012)

Chris just a thought here have you looked at the woodgears.ca website and checked out his building of a band saw


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## Chris Curl (Feb 13, 2012)

yes i have. even though i'm 51 years old, i want to be that guy when i grow up!


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## Chris Curl (Feb 13, 2012)

i picked up a piece of 2'x2' 3/4" BC ply today - $7.63

i should be able to make 4 circles that will, after making sure they are perfectly round, be a little under 12" diameter.

so i am working towards having an 11 3/4" band saw i guess ...

i am going to start extremely simple with the support structure for it and refine it as needed until it is stiff enough for my needs. i won't be re-sawing thick stuff any time soon.


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## jw2170 (Jan 24, 2008)

I will be interested in watching your project as you progress.

To be candid, though, I cannot see the point in building a "T model Ford" (with the risk involved) when there are many "small sedans" available on Craigs List....

If you are building it just to say "I did it" - I can relate to that also.

First, make sure what size you want to end up with. This is not something you can change in mid-stream.


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## Chris Curl (Feb 13, 2012)

it is about 30% "i made it myself", about 70% "i'm a frugal SOB and money is REALLY tight right now", and 100% "i have more time than money"


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## jw2170 (Jan 24, 2008)

> and 100% "i have more time than money"


I can relate to that.....


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## Phil P (Jul 25, 2010)

Chris Curl said:


> QUESTION - how fast does the blade in a band saw move?


Hi Chris

In the USA on 60Hz a 2-pole induction motor should turn at a nominal 3600 rpm. I say nominal because there are slippage losses which means that the motor loses about 10% of that in the real world. That gives a real speeed of about 3250rpm

A comparable small bandsaw might be the deWalt DW739 which has variable blade speeds of 330 to 800 metres/min (or 1100 to 2670 fpm). This corresponds well with the figures in this paper on the MIT website. The bandsaws I've used in the past had a blade speeds of about 1500 to 2500 feet per minute (fpm). So a 14in wheel would need to turn at 410, 545 or 680rpm to achieve blade speeds of 1500, 2000 or 2500rpm respectively which corresponds to pulley ratios for a 3250 rpm motor of approximately 8:1, 6:1 and 5:1 respectively (they actually deliver blade speeds of 1489, 1986 and 2383 fpm respectively). I think it would be more manageable if a 4-pole motor (which nominally run at 1800 rpm) could be found as the pulley ratios are than half of the ones I've calculated, i.e. 4:1, 3:1 and 2.5:1



Chris Curl said:


> I wonder if a 14" BS And a 9" BS both move the blade at roughly the same speed ... ?


They should run at roughly the same speed I'd have said

Good luck with your project

Regards

Phil

PS The calculation I used was:

Band wheel rpm = (Band wheel diameter x ( 22 / 7)) x (speed <fpm> x 12)


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## bobj3 (Jan 17, 2006)

This is the band saw I have

Description

This four speed woodworking band saw allows you to cut curves and compound curves in wood or plastic up to 6” thick! The precision cast iron table tilts 45 degrees for bevel cuts and the table groove makes accurate measurements with a miter gauge easy. Working up to speeds of 2670 feet per minute, this band saw is ideal for handling a variety of woodworking tasks.

Precision cast iron table tilts 45° for bevel cuts
Table groove for accurate measurement with a miter gauge
Speeds: 600, 1140, 1670, and 2670 Feet Per Minute

120 volts AC
60 Hz
8.2/4.2 amps
Frame-to-blade: 14"
Table: 14" x 14" Overall dimensions: 24-1/2" x 19-1/2" x 65-1/2"
Shipping Weight: 179.00 lb.

14" Four Speed Woodworking Band Saw

==


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## Chris Curl (Feb 13, 2012)

great info ... i have always thought the number (9 or 14 inches) was the size of the wheels. that is what it is, right?


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## AxlMyk (Jun 13, 2006)

Chris Curl said:


> that is exactly the kind of number i needed, thanks!
> 
> i am thinking about a bigger saw, but the bigger it is, the stiffer the shell will have to be, which is my concern (being a newbie). that and the fact that the motor i have is only 1/2 hp, so it might not be up to some of the tasks.
> 
> but i doubt i'll be re-sawing really big stuff any time soon. famous last words, right?


I have a 14" 1966 Delta Metal/Wood saw with a riser. Re-saws just fine. I restore vintage machines, and find that restoration costs are minimal, in most cases.

Sorry, but I have to question the common sense in building a saw. 14" saws can be found on Craigslist all day for a couple hundred dollars, or less.
Can you find blades for this saw, or will you be welding them yourself?. 
How are you going to construct the tracking and tension mechanism? 
I can see you putting more money into this project than buying a good used saw.


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## Phil P (Jul 25, 2010)

Chris Curl said:


> great info ... i have always thought the number (9 or 14 inches) was the size of the wheels. that is what it is, right?


Yes it is Chris. The larger the wheel the less the blade (and more particularly the weld in it) has to flex every time it goes over the wheel and the longer the blade should last

Regards

Phil


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## Chris Curl (Feb 13, 2012)

mike, i have my reasons, see my earlier posts. if you follow my other posts, you will learn over time that i am very much a non-conformist, do-it-yourself type, and i spend lot of my time "off the reservation". that is just who i am.

as part of my planning, i have been factoring in the same questions you have surfaced and more.


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## Chris Curl (Feb 13, 2012)

so as a test, i made a little circle jig for my router and cut a 9" circle out of some 1/2" thick plywood. i put a 5/16" hole in the middle with my drill press. then i put a bolt through it and tightened it down with nuts and washers on both sides and put my bearings on, and it wobbles as though the hole is not prependicular to the wheel. 

maybe my drill press is not as perpendicular as i thought it was ... 

so then i turned the wheel on the drill press while it was running to see if that would change the behavior. no difference. it didn't seem to make the hole any bigger either, so it seems to me like the press is pretty perpendicular.

is there something about holding a wheel on a threaded rod with nuts and washers that causes the wheel to not be perpendicular?

if i need to, i can hook it up to the motor and remove material from the sides to true it up, but that would result in removing as much as 3/8" from the sides ... so it will be going through glue layers and stuff, i'm not sure i like that.


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## Chris Curl (Feb 13, 2012)

i can get little 2 little 12" wheels for a kid's bike for about $60 ... but that would blow the budget.

i have been checking craigslist, and a used 9" ryobi one just came up for $50. that would be in the budget.

there is also a 12" central machinery one, also for $50, but that is like an hour away

if it is still available, i might just grab the 9" and be done with it, with the idea to build a bigger one some day.


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## Chris Curl (Feb 13, 2012)

Thinking about options for securing and adjusting ...

The left one is based on the top wheel being fixed, but removable, with the bottom arm also fixed but adjustable vertically for changing and tightening the blade. The arms in this one are 2x4s.

The right one is fixed on the bottom and adjustable vertically on the top. Sandpaper between the arms and the post would make sure it doesn't slip. The arms here are 3/4" plywood.

Opinions?


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## Phil P (Jul 25, 2010)

Hi Chris

In terms of bearings have you considered roller skate wheels? They come with accurate high quality bearings and would be in many ways ideal for use as he centre of a bandsaw wheel IMHO. I'd go for these running on a plain shaft rather than threaded rod as plain shafts make for far truer running



Chris Curl said:


> Thinking about options for securing and adjusting ...
> 
> The left one is based on the top wheel being fixed, but removable, with the bottom arm also fixed but adjustable vertically for changing and tightening the blade. The arms in this one are 2x4s.


You need three forms of adjustment on a bandsaw; it must be possible to move the upper wheel in and out so that it can be aligned with the lower wheel, it must be possible to raise and lower the upper wheel so that the blade tension can be increased and it must be posible to turn the upper wheel slightly from side to side so that the blade can be properly tracked. That is because blades don't always run true

Adjustments on the upper wheel are because access is easier (the table isn't in the way) and because you need to attach the motor to the lower wheel.

Hve you considered what sort of material you are going to use for band wheel tyres? Also are you going for a flat wheel design or a crowned one? Most narrow bandsaws use crowned.

Regards

Phil


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## Frank Lee (Nov 29, 2008)

*D I Y bandsaw*



Chris Curl said:


> So I have decided to bite off more than I can chew, and am going to try to build a band saw.
> 
> My current plan is to build a small band saw using an electric motor I got on ebay and some scrap wood I have lying around. The plan is to make the wheels out of 2x8 pine. So the wheels will be about 7" diameter.
> 
> ...


Go with the www//woodgears.ca It will serve you best in the longrun Frank Lee([email protected]:big_boss:


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## Chris Curl (Feb 13, 2012)

Phil P said:


> In terms of bearings have you considered roller skate wheels? They come with accurate high quality bearings and would be in many ways ideal for use as he centre of a bandsaw wheel IMHO. I'd go for these running on a plain shaft rather than threaded rod as plain shafts make for far truer running


Actually, that is the plan. Skate board and roller blade bearings are the same. They have a 5/16" inner diameter. See my initial post ...


Phil P said:


> You need three forms of adjustment on a bandsaw; it must be possible to move the upper wheel in and out so that it can be aligned with the lower wheel, it must be possible to raise and lower the upper wheel so that the blade tension can be increased and it must be posible to turn the upper wheel slightly from side to side so that the blade can be properly tracked. That is because blades don't always run true


I am thinking that if I ensure that the wheels are the same distance from the spine, then there would be no need for adjustment that way. What is wrong with that logic?

In either case, the 2 sides holding the axel up are independent of each other, so that would ensure the wheels are true to each other. But I think I need a screw or something that I can turn after the gross adjustment is made for finer adjustments.


Phil P said:


> Adjustments on the upper wheel are because access is easier (the table isn't in the way) and because you need to attach the motor to the lower wheel.


Good point.


Phil P said:


> Hve you considered what sort of material you are going to use for band wheel tyres? Also are you going for a flat wheel design or a crowned one? Most narrow bandsaws use crowned.


Not sure about crowned or flat yet ... my research indicates that crowned wheels do a better job of keeping the blade in the same place.

The smaller kids bikes have 12" wheels (including tires). I was at the bike store today looking at them. So an inner tube for one of those wheels would be just the right size for a 14" band saw wheel. 

The next size up bikes have 16" wheels (including tires).

I am seriously considering using 12" or 16" wheels from one of those size bikes. Then I have something already true and with tires. I bet there are a bunch of those bikes at yard sales and thrift stores.


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## Phil P (Jul 25, 2010)

Chris Curl said:


> I am thinking that if I ensure that the wheels are the same distance from the spine, then there would be no need for adjustment that way. What is wrong with that logic?


Nothing, really. My assumptions are based on industrial size saws which always have this feature - you only really use that lateral micro adjustment once when you initially set the saw up (or sometimes after it has been moved) but I can't see how you'd set-up a saw without it. Bandsaws are pretty sensitive to even slight changes in alignment.



Chris Curl said:


> Not sure about crowned or flat yet ... my research indicates that crowned wheels do a better job of keeping the blade in the same place.


I'd agree with that for narrower blades (up to 1-1/2in wide)



Chris Curl said:


> The smaller kids bikes have 12" wheels (including tires). I was at the bike store today looking at them. So an inner tube for one of those wheels would be just the right size for a 14" band saw wheel.


Maybe so, but I reckon it would be far too soft. The "real McCoy" are often either thin vulcanised rubber (as hard as a car tyre) or thin dense cork. They can be applied to a flat wheel and a crown ground on afterwards. Hit soft rubber with the teeth of a blade (as you might in a blade breakage) and it could damage a soft tyre.



Chris Curl said:


> I am seriously considering using 12" or 16" wheels from one of those size bikes. Then I have something already true and with tires. I bet there are a bunch of those bikes at yard sales and thrift stores.


Hmmm. I recall seeing a DIY horizontal bandsaw done with bicycle wheels years back. Worked quite well.

Just to spur you on I thought you'd like to see this. Not good on safety :blink: (needs guards), but shows what can be achieved with a few basic materials

Regards

Phil


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## Chris Curl (Feb 13, 2012)

New plan ... the bolts at the top of the spine would be to better control the alignment and tension. I also added the pulley that would connect to the morot via a V belt.


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## Phil P (Jul 25, 2010)

Chris Curl said:


> New plan ... the bolts at the top of the spine would be to better control the alignment and tension. I also added the pulley that would connect to the morot via a V belt.


Hi Chris

One thing I should point out is that you can only support each bandwheel from one side otherwise you cannot get the blade over the wheels (your drawing shows the lower wheel supported from both sides. The common approach to this is to mount the wheel on a stub axle with two sets of bearings on it for rigidity

Regards

Phil


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## Chris Curl (Feb 13, 2012)

phil, yes ... changing the blade would definately be a pain.

with the lower wheel, i was thinking that i would just take the axel out to get the wheel off and then put it back together after changing the blade. but that would get old very quickly.

it would be a good idea if i didn't have to do that. back to the drawing board


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## Chris Curl (Feb 13, 2012)

So ... I found a RYOBI 9" saw on Craigslist near the office for $50. I am picking it up tomorrow. 

I am still going to do this project though, but it will definately be a 14" saw now.


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## Chris Curl (Feb 13, 2012)

I picked it up today ... it is a RYOBI BS900. I don't have very high expectations for it, but since I am a hobbyist and won't be doing anything major or requiring exactness with it, I believe it will be adequate for me.


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## Chris Curl (Feb 13, 2012)

Phil P said:


> You need three forms of adjustment on a bandsaw; it must be possible to move the upper wheel in and out so that it can be aligned with the lower wheel, it must be possible to raise and lower the upper wheel so that the blade tension can be increased and it must be posible to turn the upper wheel slightly from side to side so that the blade can be properly tracked. That is because blades don't always run true


Looking at other band saws, I have not seen one yet that has the in-and-out adjustment you refer to. Just the up and down of the top wheel for tensioning. They all assume that the wheels are in line and that dimension is not adjustable.

And as far as I can tell, the woodgears.ca guy also did not include it in his design.

As you say, maybe that feature is standard on the high end saws, but for mine, it introduces more complexity than I care to address, at least for this version.


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## Phil P (Jul 25, 2010)

Chris Curl said:


> As you say, maybe that feature is standard on the high end saws, but for mine, it introduces more complexity than I care to address, at least for this version.


Hi Chris

I've had a few really cheap bandsaws in the past which had all three. The adjustment to get the wheels co-planar (in-out) was a matter of undoing three bolts then aligning the wheels with a straight edge in one case - major pain but necessary after a move. I've seen variations on this on everything from small DW bandsaws to modern 700mm (28in) industrial ones. Every bandsaw out there also has to have some form of tracking, too, if only to compensate for blades which won't run true - if you have a belt sander you'll be familiar with the need to retrack when you change belts. This is the same problem.

Anyway I hope that your Ryobi hits the spot.

Best of luck should you take up the challenge again

Regards

Phil


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## routerworks (Feb 20, 2012)

Hi Chris, Seems like an ambitious project ,and one I am also going to do. I just finished the main frame and have started making the 40cm dia wheels. The plans I use are the plans from woodgears.ca. You may find some other great ideas to help in your build also. good luck
Fred


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## Chris Curl (Feb 13, 2012)

I found out that skate board bearings are 22mm in diameter, and found a 27/32" (21.3mm)forstener bit at MLCS for about $5 (free shipping). I also picked up a 22mm bit off ebay for under $4 (free shipping too).

I am thinking the 22mm bearings may result in a fit that is not quite tight enough ... if so, I'm sure I can press the 21.3mm ones in place.


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