lt 40 hd band speed?

[arkansas]

Guys. I have my 98 lt 40 hd that some of you here helped me get id'd.
it is up and running now but making some of the finest dust you ever seen.
I don't mean good kind of fine either.  The last owner had converted it to 20 hp
electric.  I checked my band speed today and I am getting 1170 rpm at the wheels
which is around 5700 fpm.   A call to Wm today could only tell me that they shoot for
4500 to 5000 fpm.  Do you all think that the increased band speed could cause
My fine dust and lack of power?

[scully]

I have not seen many electric 40's run but I would ask WM what size pully they use on the motor and compare it to the one you have . Also is the elec conversion a WM conversion ?  How is your feed rate and cut quality ?  What Bands are you useing ?  I know tech service can put you in touch with someone who has dialed one of these in . It would be worth a call . How is the sawdust removal ? Is it packing up in the cut ?  Does it bog down easiely ? Just some thoughts here .......

[Magicman]

It may be unrelated but what degree blade are you using and is it sharp?

A 4° blade in White Oak, for example will make much more powder than a 10° blade in Pine.  Dull blades make powder.

[scully]

great point Magic !

[arkansas]

I have not seen many electric 40's run but I would ask WM what size pully they use on the motor and compare it to the one you have . Also is the elec conversion a WM conversion ?  How is your feed rate and cut quality ?  What Bands are you useing ?  I know tech service can put you in touch with someone who has dialed one of these in . It would be worth a call . How is the sawdust removal ? Is it packing up in the cut ?  Does it bog down easiely ? Just some thoughts here .......

It was a shade tree conversing at best.
feed rate in hickory and ash are slow but very good cut quality.
saw dust removal is poor at best.
tried Wm 4 and 7 at. 045 and 7 turbo. 055
Saw dust is very packed in the cut.
it does bog more than I think it should

[pineywoods]

Do you have true 3 phase power or single phase plus a phase converter? I agree with magicman, a dull blade will make very fine sawdust and leave a bunch of it in the kerf. One of the hardest things for new sawyers to learn is how to tell when a blade needs sharpening. If it ain't razor sharp, it will do un-intended things.

[Coon]

Are you sure you are not getting belt slippage while under load?  A minimal amount of slippage can create a world of difference.  How about the set? Not enough set and the gullet could be packing full causing binding in the cut thus slowing the band speed and bogging the motor.... to me it sounds like this is the case along with dull bands.

[arkansas]

Do you have true 3 phase power or single phase plus a phase converter? I agree with magicman, a dull blade will make very fine sawdust and leave a bunch of it in the kerf. One of the hardest things for new sawyers to learn is how to tell when a blade needs sharpening. If it ain't razor sharp, it will do un-intended things.

I have single phase with converter.  It is balanced and works like it should. 
Blades come straight out of box from Wm.  They cut slow and true until they get dull
then they take a dive.

[bandmiller2]

Too much speed is as bad as too little and will suck the power right off the top. Motors have good torque and band FPM is best at the lower end or the recommended speed, your bands should stay sharp a little longer too. Change pulleys but don't go too small on the motor shaft. Frank C.

[ladylake]

 Slow it down for sure, I'd shoot for the 4500 FPM.   Steve

[Magicman]

feed rate in hickory and ash

That is a reason for concern.   

[Tom L]

I've only done 2 jobs cutting ash, and both time it didn't matter what blade degree or blade size from 1-1/4 to 1-1/2" the sawdust was like baby powder on both jobs, and the feed rate was way down.

could just be the wood, try out a piece of oak or pine and see if it cuts better.

[millstead]

How did you calculated the rpm did you use a foot per minute gauge or revolution per minute gauge also what is your motor actually spinning if you are using a handheld speed indicator they generally reed in feet per minute so to convert that into rpm you take your reading multiply by 12 then divide that number by  the circumference in inche. I would check the motor aswell I would think if there was an issue with the speed it would be that the motor is not running properly. What kind of motor are you running does it run hot have you checked the voltage at the motor

[arkansas]

How did you calculated the rpm did you use a foot per minute gauge or revolution per minute gauge also what is your motor actually spinning if you are using a handheld speed indicator they generally reed in feet per minute so to convert that into rpm you take your reading multiply by 12 then divide that number by  the circumference in inche. I would check the motor aswell I would think if there was an issue with the speed it would be that the motor is not running properly. What kind of motor are you running does it run hot have you checked the voltage at the motor

I have an optical rpm meter.  Motor is at 1753 and name plate says 1755.  1170
rpm at band wheel.  Band wheel at 18.75" x 3.1415/12 x 1170 rpm should be around
5800 fpm?
motor runs nice and cool well with in amp draw and very good voltage.

[red oaks lumber]

i say your under feeding, every tooth need to cut or you'll dull real fast(they over heat) the way i judge my speed, first how do the chips look, good curl. second after i'm in a cut can i hear the motor  pull down. if i have good curl and some motor pull i increase my speed. for me its kinda like nascar, to get stuff done you need to be on the ragged edge.
the guy i learned to saw from on an 2005 lt 40 sh this is no b.s. cutting pine he cranked the feed dial wide open and let er buck. hardwoods almost half throttle. granted he was using .055 thick bands by 1 1/2 wide he only uses # 4 blade. but when sawing is your living, rubbing a band on the wood makes no money. the only way to find the sweet spot for each mill is push it to the point bands break or you cut is real wavy, then dial down a little.
i'm not telling you specificaly to saw this way rather telling you our method of sawimg.

[Cypress Sam]

The only electric that I get to run is a WM1000. But my Advice is to push it till it make waves with a sharp blade then slow down a bit. If is still making powder or the blade dulls quickly call Woodmizer for pulley recommendations.

  Sam

[Brucer]

The physics ...

Power = Speed x Torque

You can rearrange that formula to get

  Torque = Power / Speed.

Your Power is fixed, the Speed is too high, so you are getting less Torque.

  Torque is the rotating equivalent of Force.

So you aren't getting as much Force as you need to pull the blade through the wood while maintaining an efficient cutting speed.

The effect of all this is to cause your teeth to take a smaller "bite" than they should (hence the fine sawdust), while at the same time your teeth are making many more passes through the log to cut a given length of log (causing rapid dulling of the teeth).

The 4° and 7° tooth angles take more Force to pull through a cut than say a 10° blade. The 0.055" blade take more Force than the 0.045" blade. And Force is what you're lacking.

Everything is conspiring against you. Figure out how to slow the blade down and things will improve.

[ladylake]

Yes, slow it down first then worry about feed rate etc if you still have trouble. I'd think it will go away by slowing it down.    Steve

[arkansas]

Ok.  Have pulley and hub along with another motor.  Will chang the pulley
out today and let you all know how it works out.  Thanks for help so far.
Mike

[arkansas]

7.25 pulley on today.  Man what a difference.  Much taster feed rate. More
Power and better cuts.  Still getting dust packed on boards but will try
7degree blade tomorrow. 
Thai you all for the help so far.

[ladylake]

Good to hear, maybe too much set with a lot of dust on the boards.   Steve