couple of noob homebrew bandwheel questions

[fallenoak]

been considering making a mill for a while now cash is tight so everythings got to be begged borrowed or liberated for now.

i have an old 3hp briggs and stratton that i plan to power it with for now. which i know is pretty weak, to that end im going to be keeping construction as light as possible. hopefully be running reinforced bicycle wheels as bandwheels, chain driven so as not to waste power. im also hoping to bin the rigid angle/box section track that most use and utilise either ratchet or turnbuckle tensioned steel rope wire. to give me something that i can carry into the woods .  not planning on cutting massively thick timber with it but im gonna make it big enough for the engine upgrade that i will inevitably want to do.

a few questions i have are,

1)do bicycle wheels welded directly to a 20mm drive shaft, tires removed, and outside edge belted with layers of 3mm ply and resin sound feasible as bandwheels? possibly weld some 8mm round bar in as extra spokes for strength.

2) a lot of people use trailer wheels, will normal car wheels/tires work as an alternative?


will get some pics up once i start construction in earnest, almost certainly accompanied by a load more questions.

Thanks,

Sam

[beenthere]

Welcome to the Forestry Forum.

Ask a lot more questions before going too far with the idea of bike wheels, and a 3 hp B&S.
I don't have a mill, but have read a lot on this forum about bandmills on the market as well as builds that others have fabbed. I'd suggest you do a lot of reading in this forum as appears to me... you will be changing your outlook on what will work and what will not. ;)

Tell us more about your experiences milling wood and as well, fabricating things similar in nature to a mill build. Remove all doubt, so to speak, of what you are thinking about doing.

Your location in your profile will help a lot, as now we are not sure even what country you are living. Helps a lot in answering questions.

[EZ]

To give you an idea about weak mills. My first mill was a factory built all aluminum . It didn't hold up very well. The logs were small and still wasn't good. If you build one make it as stout as you can. EZ

[york]

Hi and welcome,

Your Band-wheels are the heart of your build-i would only use Band-wheels that are designed for Band-mills....

Late spring,2015-i am going to list a pair of 19in belted wheels in the for sale section of this forum-take your time and do it right....

[fallenoak]

Ive read a lot of posts on here and i know much of what im saying is not ideal, the main thing is ive got 95% of the materials to do it the way thats in my head. And for now if i dont do something similar to this then it wont happen at all. im not that bothered if its slow in the cut aslong as it can cut.


longer term id like to make a propper portable bandmill, but for now ive got the bits and aslong as it can cut a reasonably straight, plank or post for my small timber framing project then i,ll be happy.

[Joe Hillmann]

The bike wheels and small engine may work if you plan to use small bandsaw blades to make your mill but the wheels for sure won't hold up to an actual sawmill blade.  A 1 1/2 inch blade puts 1000-2000 pounds of weight on each tire axle/bearing when the blade is tensioned.  I can't imagine any bike wheels holding up to that much abuse.

The carriage of the mill will end up weighing 150-500 pounds.  I can't imagine you could stretch a cable tight enough to use as your rail system so that it wont flex when you move the carriage across it.  The cable would brake or your anchors, would move/pull out before you got it that tight.

[blade69001]

  I am a firm believer in the school of hard knocks, doing things the hard way constantly teaches me.  I am not saying go a head with your idea, I would say get it on paper first and look for possible missed details.  You said you already have about 95% of the materials you need to build the thing in your head. If you try and it doesn't work the way you want it to you should be able to figure out why, and what you will need to change.  You tube is full of videos of home made bandmills. This one used motorcycles tires
I will say I would like to know more about your plans to reinforce the bicycle rims. The tires these mills use are rubber and should not affect the set of the blade how are you planning to insure the reinforced rims will crown ricght so the blades are not altered while they are running?
Sean P.
https://www.youtube.com/watch?v=7_Gdp5255kw

[eddif]

I think bicycle wheels have been used for a lightweight bandsaw (cutting small craft projects - bird houses etc., using pre cut lumber).

Motorcycle band mills have been built.  I have no idea if spokes will stay tight with side loading, or if the bearings will last over time.  Look on youtube (there are some using alloy wheels).  The bands are run on the rubber tires.

Small diameter scooter wheels would probably flex and break official band mill blades.  Go to a breaker yard (metal junk yard) and just look.  Take available money and see if you can secure a motorcycle from the cheapest source.

My 20hp mill needs more hp.  The engine is a 15 dollar junk yard engine.

eddif

[fallenoak]

yeah i was planning on running maybe a 3/4 or 1" blade but maybe i should go even smaller? any recomendations or ideas on blade choices for a weak little mill like the one i plan to build.

ive got a 20mm drive hsaft for either side and am fabricating 2x twin 20mm bore bearing assemblys from 47mm id steel tube which the bearings fit in quite snug.
, looking to build the majority of the saw head/carriage from 2" steel tube and 1" box section. i dont think it will comein over 100lbs but cant say for sure.

[36 coupe]

You have high hopes.Time will smarten you up....

[fallenoak]

 

  

 

a very poor drawing of my basic idea. toying with the idea of suspending it from the wire rope rather than having it on top of it

[fallenoak]

36 coupe. hopefully a few failures working with what ive got will help me build a better mill once ive procured some better kit

[fallenoak]

blade 69001 thats one of my main problems, not entirely sure how im gonna make sure they crown right but i think its a bridge im just gonna have to cross when i get there

[beenthere]

Some pics of your parts you are planning to assemble will be more helpful than descriptions alone.
Pics of previous inventions will help as well.

Wish you well, but seems there are a lot of details to work out. 

Thanks for adding your location. Might help to explain a lot about what you are working with.

[Joe Hillmann]

You are going to need a jack shaft between the engine and the drive wheel to slow it down otherwise your wheel will be spinning way too fast.  You want to aim for 40-50 mph for the blade speed.

[Joe Hillmann]

Also with a set up like you have drawn you will have to remove both wheels every time you change the blade which will throw off your alinement.

Something like this would allow you to remove and put on the blade without removing the wheels.
https://www.youtube.com/watch?v=KC-IiYaRCN8

[fallenoak]

Beenthere will whack some pics up over the wekend once ive gathered all my bits togeteher and had a chance to start bodging.

Joe i will be getting my reduction by using bicyclecranks and a chain drive. (i think)

and i really like the look of the mill in that youtube vid, seen a few run on motorbike wheels. anyone know if some sort of special prep is required on the tires as to my eye i just think "how is that blade staying on there".


the "simple sawmill" plans i looked at a while ago used the same system to tension  the blade but using car or trailer tyres i think

[eddif]

  

 

a very poor drawing of my basic idea. toying with the idea of suspending it from the wire rope rather than having it on top of it

If you beat the system, you are the new system (folks will try and take your ideas).

We are not being anything but honest IMHO.

Your axles should sit almost on the main beam.  If you build the supports too long they will tear away from the main beam, or need to be very heavy.  The tension on a band sawmill is rather much.

If you can put up with us, we will keep trying to help.

eddif

[Joe Hillmann]

I just did the rough math and if you have a 2 inch gear on the motor and a 7 inch gear on the a 20 inch wheel the rim speed will be right around 5200 fpm which is pretty close to 60 mph.  So that should work out.  Since you are using such a small motor you may want to go even slower.  A smaller gear on the motor or larger on the wheel would slow it down.

[Joe Hillmann]

  

 

a very poor drawing of my basic idea. toying with the idea of suspending it from the wire rope rather than having it on top of it

If you beat the system, you are the new system (folks will try and take your ideas).

We are not being anything but honest IMHO.

Your axles should sit almost on the main beam.  If you build the supports too long they will tear away from the main beam, or need to be very heavy.  The tension on a band sawmill is rather much.

If you can put up with us, we will keep trying to help.

eddif

I agree with eddif on moving the axles closer to the main beam.  On my mill my main beam is about 2 inches above the center of my wheels and even that I was worried about when I was building it.

[fallenoak]

eddif thatsa very good point that you have made , i would just be creating a big lever by putting the band wheels on such long projections.

one of many pit falls hopefully avoided.

thanks

[beenthere]

anyone know if some sort of special prep is required on the tires as to my eye i just think "how is that blade staying on there"

There is a natural crown to the tires and the band seeks the peak of that crown.

[Swatson]

Regular tires have a natural crown to them so no prep is required for that, however many many tires are not truly round.  It may be hard to see on a vehicle that has 1000 lbs of weight sitting on a tire but when you free wheel a tire many times you can really see how out of round they are.  If they are not round they may cause vibration and flutter.  When I built my mill I was getting quite a bit of flutter for many reasons but one was the tires.  I just mounted them one at a time on the drive side and made a makeshift rest and lathed them round with a lathe scraper.  It dulls the tool real fast but it got them round eventually then I balanced them and that solved the flutter. 

Your are not going to be able to maintain ideal blade speed with a small 3hp motor.  It is going to be a tradeoff. You always have two choices: speed or torque. 

Speed is good for cut quality but you wont be able to maintain ideal blade speed as you enter the cut because the wheels will slow quickly from not having enough power from a small motor....so its better to "gear down" so you can maintain torque to keep the wheels turning. 

I have not used a small gas engine but I have used a small 5hp electric and I cut quite a bit of lumber with it...but it is real hard to compare small gas to small electric for a lot of reasons.

It is good to think outside the box on design...but sometimes unless you have unlimited resources and time to experiment and fail a few times (possibly) it is better to follow the beaten path.

But as they say desperation is the mother of all invention.  Don't think it cant be done because it can but keep your expectations real.  Good luck!  Keep us posted.   

[eddif]

5 electric hp = 10 gas hp (roughly)

eddif

[eddif]

It is hard to swim against the current.  The current?  For years the desire has been longer more aggressive tooth spacing (for years 3/4" tooth spacing) now 7/8" is considered normal. 
High band speeds with high hook angles are standard (both requiring high hp).

Here you come wanting to go backwards in time.  I probably have limited ideas about low hp cutting.   I do have a pretty much unrelated project that may benefit from your desire ( I will not comment on my project now; maybe later).

You might as well think of the highest RPM and greatest reduction ratio you can use ( I guess).  The problem is the little engine will have to spend a lot of time at those RPM's.
Sharpen four times as often.
Use more lubrication than normal (you have no hp to waste on blade friction).
Narrow blade.
Maybe plenty of set.


Others surely know more.

eddif