homemade bandsaw mill, help

[Kbeitz]

Idler pulleys always goes on the slack side of the belt.
And for best traction they should be on the back side of the belt.

[mazdathumps]

Thanks Kbeitz, wish i had know that about 6 hours ago... haha, I know now tho...

As for blade speed (mentioned several posts back), I physically rotated the engine once and measured actual blade movement... Each revolution moves the blade 13.75"... At 3500 RPM, that would leave me at a blade speed of 4010.42 SFPM...

3500 x 13.75 = 48,125 / 12 = 4010.42

Calculators are about 500 SFPM off from that number... My own calculator and misc internet calculators put me at about 4526 SFPM @ 3500 RPM...

My drive pulley is 3", my driven pulley is 10.25", my exterior diameter of drive wheel is 16.875"...

Anyways, this is my info, not sure how 2+ calculators were wrong on the actual blade speed... Maybe the depth of the v-groove has something to do with it... That's roughly 11% off...

[gww]

Josh

Thanks everyone for the help and info... As always, I can't begin to thank everyone enough... I should be back on in a few days...

Can't wait.

I am so lazy and cheap that on problims like your pillow blocks, lots of times I use a small weld.  Not suggesting others do so cause things become more permanate and then you have to buy whole new shafts and things if it goes bad.  I still do it all the time though.

To me it sounds like you are reconizing the things that need done.  It sounds like sometimes that is happening after the fact but still in the end you will get it correct.  If you look at all kbietz toys, you will see he has lots of practice on building things and sometimes probly doesn't have to do things twice like I would cause I need to see it first to know I screwed up.

12 hour shifts and on the weekend too.  When I did a schedule like that, I had time to wake up and clean up and eat and it was time to go to work.  I didn't build my mill till I was retired and then I worked on my mill full time.  You must have a pretty decent energy level.  Good for you.
Good luck
gww

Ps My view of your blade speed differrence from the caculator probly has to do with the true rpm of the motor.  I am not an expert but think that using that motor, You definatly don't want to go any faster.  I always heard that going slower with a smaller motor gives you more tourqe.  If you run onto a bigger motor that speed will probly be good.  My first motor was off of a garden tiller.  Maby you need to ask all your freinds what is sitting in there garages being unused.  I think sometimes the trannys on the garden tillers go out before the motors.
Good luck

[mazdathumps]

haha, GWW... my energy levels... Yeah, I'm 35 and got 30 years until retirement... 2017 is already a pretty busy year for me.  I put in over 40 hours a week at my local electric company, I have this sawmill I need to get going, I'm adding onto my shed, I make a homemade BBQ Sauce that I'm making legal and having packaged this year for national sales, I have to start on an AA/AS degree for work, my wife is about to start college in July, and I have a 5 year old girl that is all energy... As for my energy levels, I don't have a choice but to keep the wheels rolling... haha

Yeah, I'm looking hard for an engine, but I'm like you, I'm pretty cheap and have been waiting for the right deal on one... I'm not scared to work on it, so even a rough running engine would suit me fine... I tend to think I can do anything I can educate myself on...

[Kbeitz]

The best  pillow block bearings comes with a twist collar.
It keep the bearings from twisting on the shaft.

[Ox]

If you have questionable bearing lock screws and are having problems keeping them from loosening up, use red loc-tite.  Make sure your surfaces are perfectly clean - carb cleaner or acetone for this.  Then put that red on the shafts and screws and everything you want to NOT loosen up.  It's what was called for in the blueprints for my mill.  It works great.  To take apart again, heat loosens up loc-tite.  Of course, you do all this AFTER you've set it up and are absolutely sure everything's where you want it to be.  Having to do this all over again would be maddening and a huge mess to boot.

Of course, what Kbeitz said is absolutely true.  The twist collar, or eccentric locking bearings, are best.  It's what's on lots of farm equipment.

[mazdathumps]

Kbeitz and OX, thanks for the info on the bearings... I will look for them when I go to buy the new ones...

I used the blue Loctite and they backed right out... Maybe i'll try the red this time... I also ground a small flat spot on the axle to seat the set screw on - they still slipped... I was considering drilling a small hole about 1/32" deep into the axle for the set screw to fall into, is that a bad or ok idea??

[Kbeitz]

I'm wondering why your having so much problems with your set screws.
They are there only to keep the bearing from spinning on your shaft.
I'm thinking that your shaft is to small for the bearing or it's bent
I've seen 100's of bearing missing the screws and still no problems.
If things are lined up right it should take very little to keep your
bearings from spinning. You might also have a vibration problem.

[mazdathumps]

Kbeitz, I'd like to know too, why i'm having the problems... Once my blade is tight, there is a force that wants to move my axle backwards out of the bearings... It is so strong that even the external retaining ring that holds the hub in place peals out of the groove sometimes... I'd sure like to know... I've replaced about a half dozen retaining rings between the two sides... and probably replaced a dozen set screws because they back out and fall off the machine (even after just one cut sometimes)... I've also broken my 1" hardened steel axles 3 times... The last time one broke, I ground it down to points and welded it back together (then spun it with a file to the correct diameter) and believe it or not, it's straight and hasn't broke since (also added a third pillow block bearing for more support)... I'm clueless as to why i've had so many problems with this saw... It's been one thing after another on this project... I've successfully cut 5 kind of wavy pine logs since I started about a year ago...

I should have joined this forum before starting, maybe I could have seen and heard some ideas that might have steered me in other directions before starting... I can say that I've learned a lot with this sawmill... I'm still learning as we see right now... haha

[Kbeitz]

I think what I would do is to find a 1-1/2" shaft with bearings and have
someone turn down one side for you to fit your hubs. This way the hub
could not move past the turned part. Or... Could you drill out your hubs
to a larger size?

[mazdathumps]

It would be more likely to mill down the larger diameter shaft... How well do split collars work on things like this?

[gww]

How much tension are you getting on your mill and how do you tell when you have it like you want?  If you ever get it like you like it, It seems to me a ridge of weld behind the collor to keep it from pushing back would work as well as turning the shaft.  It wouldn't help with the fact that the shaft might need to be bigger if you have already broke it once.  However, If you just want it to hold long enough to use it for a while and see how everything works, a band of weld would stop the coller from sliding past.  Just a though from someone who uses weld for everything he can rather then buying stuff.
Good luck
gww
Ps Or drill a hole in the shaft and stick a bolt in it to stop the coller and hope it is strong enough.  Kbiets knows much more about building correctly then I do though.

[Kbeitz]

They will help you a lot. But it wont fix what ever the problem
is that's popping your external retaining ring out.

[Kbeitz]

Just one very little tiny spot of weld will stop anything from sliding
on a shaft.

[Ox]

I'm thinking your shafts are too small.  My mill's blueprints specified 1-7/16" shafts.  Close enough to call it 1-1/2".  I can crank up to over 3000 psi hydraulically and have no problems.  I don't typically run here as it's harder on the bearings but it proves the shaft strength.  Not hardened or anything either.  Your shafts are flexing, I think.  It doesn't take much on a shaft to double your strength in it.  That 1/2" extra will likely triple your strength in the shaft.

If you think about it, a bending shaft will break like yours.  A bending shaft will want to walk the bearings off, like yours.

The red loctite needs to be on the shaft for the bearings to stick to, too.  Clean, clean, clean.  Then don't touch the metal so your fingers don't get oil on it.  Smear the red right on the shaft then slide your bearing over it.  Smear the red around by twisting the bearing's collar on the shaft.  Add locking screw with red on it and tighten.  Wipe off excess with a paper towel or rag.  Don't touch anything or move anything for a day.  This will ensure it holds the best way possible.

[Kbeitz]

My shaft size is 30mm. or 1.1811 . If I could have made it bigger I would
have but the 30mm. bearings was inside my wheels. So far no problems.
But I'm also using 4150 steel containing chromium and molybdenum as strengthening agents.

[gww]

I ran my jack shaft with 3/4 inch soft iron water pipe.  Yes it did eventually break, but I also cut a lot of wood before it broke and didn't have to buy anything to use it.  I (being the me that I am) would use a 1 inch solid shaft if that is what I had till it broke.  I would weld on it and bend on it knowing that everything I do is a throw away item.  Then I would use it as long as I could but while using it I would keep my eyes open for something better that I could get for almost no money.  My jack shaft with the water pipe did take out my tire when it went which was $27 and so it may have cost more then it needed to.  I did get to keep cutting boards for a long time before that happened and so it depends on how you count on wether it was a good thing or bad.  I would drop a peice of weld on the current shaft and use it if I thought all that would happen is the shaft might break but would really hurt nothing else even if it broke. 
I would do this to keep moving and working out other bugs even if my over all plan was to get bigger made for it.
Just my honest opinion.
gww

The above might mean you have to run with a bit less blade tension and look at your drive wheel mounting to make sure it is mounted to put the least amount of pressure on your shaft.

[Ox]

That's true.  If you can keep a sharp blade on you don't need to run as much tension.  I've experimented a little with this.  I've cut straight hardwood boards with 1000 psi and a sharp blade.  How much tension this is on the blade and shafts - no idea.  The pressure gauge is all I have to measure with.

[mazdathumps]

Well, I had a big long reply to everyone's comments typed and it all got deleted when I hit POST... Soo, anyways... Let's try again with less typing...

The axle(s) were purchased from BMI Kart's online as 1" hardened steel axles... I've bought two of them so far... They had the keyways in the right places for my driven pulley and external retaining ring slots and keyways perfect for my hubs, so that's why I used them over and over... Anyways, I have already added a third pillow block bearing inline to the idle wheel side (which is also my tension and alignment wheel) hoping to hold that axle together... Fingers crossed or I might have to upsize the axles...

As for the spot weld on the axles, that's not a bad idea... Maybe that mixed with the split collar will solve the retaining ring issue and hold the axle still in the bearings... With the collars removed, I will have room to grind off the weld when/if I need to remove the axle...

I will be pretty busy this week with helping a buddy on some electrical stuff, but maybe I can find some time to work on this... I'm excited to try some new "fixes"... Thanks everyone for the great info...

[mazdathumps]

I forgot to explain the blade tension on my mill...

I have no idea what the tension is... It is tight enough to make a tone when I tap it and a screw driver bounces around on it when I lay it on the blade and tap the blade... It seems tight enough to me... With full blade tension, the center of my tires are not pulled down into the tire and they are aired up about 50psi... You know that "gut feeling" everyone talks about... Well, my gut feeling is the blade is tight enough it should cut a straight line...

As advised, I have a brand new blade on there right now, so once I make these changes I can see how it cuts with a fresh blade...

[gww]

Josh

As advised, I have a brand new blade on there right now, so once I make these changes I can see how it cuts with a fresh blade...

After playing with the shaft and stuff, take a small amount of time to check and see if the blade is parrelel to the bed.  I can't wait for your first cut after all this. I think you are going to notice an improvement.  I do my tension by the same method as you except I just take a finger and push down on the blade and see how hard it is to push it a half inch or so. 

I have enough flex in my mill that I can only go so far and then can not hold the blade on the tires after a certain point.  Another member on here did beef his up by putting a bar in front of the tires also.  I doubt it is a problim with your mill as it is a four post and mine is only two post.  Either way I don't have a guage or caliper and I just guess and I can't scrunch my tires either.

Help your friend and then cut a log and give us guys that are waiting an update on how your mill cuts.  I bet it does well and for sure hope it does. 
good luck
gww

[mazdathumps]

GWW, I'm anxious to see it working correctly too... Someday I hope to pass on the info learned here with others who need the help... I'm a fan of a network of people... They say it takes a village to raise a kid and I believe it takes a village to be successful... Without resistance, we don't get stronger... I will cut with this mill and learn how to keep it together at the same time...

[gww]

Josh

GWW, I'm anxious to see it working correctly too... Someday I hope to pass on the info learned here with others who need the help... I'm a fan of a network of people... They say it takes a village to raise a kid and I believe it takes a village to be successful... Without resistance, we don't get stronger... I will cut with this mill and learn how to keep it together at the same time...

Cheers
gww

[Kbeitz]

I learned a long time ago that if i'm making a long post to
highlite it and copy before I hit the post button.
If you loose it all you need to do is paste it again.

[mazdathumps]

kbeitz, I'll probably do that next time... lol