Homemade Band Guide Idea - Whatcha think?

[rwthom279]

I want to update the guides on my mill to "Cooks", but I had an idea...Use a stub axle and hub (1250#) and machine the hub similar to what is already manufactured,  It would have larger roller bearings, speed rated, and greasable...at less cost.  Please excuse the rough illustration:NTS   Justa thought...What Yall Think?> Heat buildup?, Flange Wear?, etc.

  

  

 

[5quarter]

If you're a machinist, roller guides are and easy fab. If you're not, time spent is money spent and it might be cheaper to just buy the guides. If you adjust the flange 1/4" from the back of the blade and keep the blade sharp, wear should be minimal.

[rph816]

My concerns would be two-fold.  First, while the bearings are speed and load rated, that is for when a 12-14" wheel + tire is mounted to the outside.  Say for the sake of argument the tire has a circumference of 40", even at 70 MPH the hub is only turning at 1850 rpm +/-.  Machine that hub down to say a 2.5" diameter roller, let's say 3" for the math, that means about 9.5" circumference.  Now rub that 3" wheel up against a slow band at 4000 fpm and you're turning at 5050 rpm +/-.  Those roller bearings are not rated for 5000+ rpms.

Second issue is that the hub is likely cast iron, maybe cast steel.  While that is all well and good for ductile/tensile strength, it's not very hard.  Most commercial band guides use very high wearing hardened steel. 

Don't want to be a negative nancy, but those are just the first things that came to my mind.  If you have the machining capability, what do you have to lose?  Those hubs are super cheap. 

Ryan

[eastberkshirecustoms]

I agree with rph816 for the same reasons he stated.

[losttheplot]

When these stub axles are used on trailers the bearings are set with a little play in them.
This allows for the expansion of the metals due to heat, and prevents the bearings from binding as they warm up.
Not sure how that would affect the band.

[Magicman]

Since your blade guides are a critical element to insuring uniform lumber, personally I would opt to obtain a set of guides from one of the manufacturers on the left.  I sent a set of used guides to a fellow FF member last month. 

[beenthere]

Would you lose some width, thus reduce the max size of log you can saw? 
I would think the quality of the bearing might be the limiting factor too.
But hey, give it a try if you have a real burn. Won't know until you do then we will all know.

[rwthom279]

All very good points.  I talked to a fellow metal worker and he suggested a "Hardox" face press fitted against the flange to prevent wear.  It sounds like a good idea. 

About the bearings...I figured if the teenie weenie things they put in factory guides hold up....surely two tapered rollers would be better.  Heck, might be over engineering this too...tryin to save a buck or two.  Anything is better than what I got.

[5quarter]

rwthom...nothing wrong with reinventing the wheel. That's how better wheels are made.  . As long as your living does not depend on your saw, you won't lose anything by giving it a go. Do your homework though...rph816 makes good points and its always nice when you can get things right the first time out.

[rph816]

The tiny bearings that are installed on machines from the factory are specifically designed for high speed use.  The radial sealed ball bearings are likely tested and rated to 10,000+ rpm.  The heavier timken style tapered roller bearings are designed for higher load, lower speed application.  I'm not saying that it definitely won't work, just know that bigger isn't always better.  The initial investment is pretty small, again, if you do the machining yourself. 

Not that I've tried this particular one, but it seems like when I try to save a few by "reinventing" the wheel I end up feeling penny wise but pound foolish.

Ryan

[mad murdock]

Taper roller bearings will work as long as you have proper setup. Bearings need to be well lubed with good quality grease, and preload needs to be on bearings, otherwise they will not last and self destruct. We use taper roller bearings in several places on helicopter transmissions, albeit they are oil lubed, grease will work if it is a good semi or full synthetic bearing grease with good timken load rating(at least 65). On the helo's, highest shaft speed for the tapered bearings is 6,016 rpm. Periodically check bearings for over temp, until you have a good working knowledge of how they run.

[bandmiller2]

RW.even when your done machining them down those hubs will be quite large and as stated you will loose some cut width.If you do it, use a light synthetic grease to cut down on drag especially when cold.What I did on my bandmill for guides is use two 203 sealed ball bearings back to back and anouther horizontal behind the band.Its worked well for me every so often give the bearings a spin with your finger you can tell when their wearing out. Frank C.

[rwthom279]

Well...might have found another issue with this idea...the structure of the cast.  While everything points to a "maybe" on working, the cast itself may not take the excess heat generated and crack between the "ridges" where the blade would ride.  With the bulk of the hub being squared off, the thinner areas between the bearing races(internally) may lack the structure to efficiently heat/cool as the rest of the hub would.  "losttheplot" brought up the expansion, which led to this.  Glad we got more minds thinkin then mine!!!

[york]

Work smarter,not harder?

then,just order the Cooks guides.....

[rwthom279]

Wouldn't it be "smarter" to try to save a "hard" earned dollar or two if its possible?    and avoid this.... ...at the end of the month paying bills?

[Hilltop366]

What I did on my bandmill for guides is use two 203 sealed ball bearings back to back and anouther horizontal behind the band.Its worked well for me every so often give the bearings a spin with your finger you can tell when their wearing out. Frank C.

I wondered if a person could put the two bearings like you mentioned with a third slightly larger behind it on the same stud for the backup bearing. Perhaps the side ways thrust on the backup bearing would make it wear out fast it may be a thrust bearing would work better. I also see that you can get shouldered bearings but I not sure how much height and thickness it would need to work well.

[york]

Wouldn't it be "smarter" to try to save a "hard" earned dollar or two if its possible?    and avoid this.... ...at the end of the month paying bills?

Yes,i was young once myself and understand,but i don`t like your plan,do not think it will work-look at other home made guides-there are a few out there.

i have cooks guides,they are decent.....bert

[rwthom279]

Hilltop, a fella I know has a small manual mill that is/was setup like that.  It DID work, but he noticed that the lateral pressure caused premature failure.  I have the "sandwich" setup currently and the backup bearing runs behind as "bandmiller" suggested.  The small bearings just don't hold up....and the backup ALWAYS gets a grove cut in it....have even cut the race in half before.

I maybe ahead try to find a used set-up or just call Cooks and drop $250 for theirs.  I'm not trying to re-invent the wheel, but if us humans had not asked questions, we'd all still be livin in caves, eating roadkill, gruntin' at each other   some of us still do

[eastberkshirecustoms]

Just a thought... buy the roller and maybe the key from Cook's, then fabricate the rest. That is what I did to save money. I even made my own BC jaws with carbide inserts.

[rwthom279]

That has crossed my mind...I think Banjo said he didn't have nor needed the lower jaw.  Be my luck if I didn't have it....I'd need it...wouldn't take but a dive or two to make a person spit nails .  $460 a set is alot to swallow...but I think everyone agrees...makes no sense to throw good money after bad.  I do appreciate everyones opinion so far...we may all benefit/learn from this!  Not gonna give up yet