Black Magic paint.

[pwdrive]

I might have miss understood the bandsaw tyre question, if you mean those on the pressure roller shown in the video then no we didn't have such a device fitted, the one in the video looks like a homebrew pressure roller, not to be confused with a power feed roller as that is a different animal.
The horizontal arm on the back with the weights hanging off indicates the tension of the band, the top band wheel is jacked up until the arm is horizontal, that will give you the correct tension on a 5" band, the arm that the weights hang off is linked to the top bandwheel fulcrum/knife bearing assembly which the main shaft bearing housings are attatched to, the weights on the end of the arm also act as a shock absorber.

My old Forrestor was tensioned against a heavy duty coil spring which is a different system, I think the Forrestor went up to around 1,000 Kg max. or somewhere around that figure.

Although the bloke in the video looks as he's been doing the job for a long time and looks as though he knows what he is doing he is running that rig dangerous, the top guide block assembly has been removed which is also the carrier for the front blade guard that should be attatched to it, I have done it myself to get an oversized sawlog through but that's it, once the log can fit under the guides and guard assembly then that assembly was re fitted pronto. There is no way I would be sawing small sawlogs with the band open like that.
He should also be using two dogs, using one can easily result in the sawlog shifting by pivoting on one dog if a piece of bark or something gets trapped between one of the table rollers and the underneath of the table which in effect puts a temporary hump in the table as it rides over the bark. that hump can act like a pivot, a pivoted log can shift the blade especially as there are no top guides fitted as mentioned earlier. If the blade hits the table then it's curtains for the blade and maybe the operator, the blade gap between the two infeed tables isn't very wide, maybe .75" or somewhere around that distance, if that.

Good old saw though, brings back many memories.

Lawrence.

[pwdrive]

The biggest mills in the UK are operated by BSW, they have mills at Newbridge and else where, if you ever buy any kiln dried spruce from DIY stores or builders merchants then it probably came from there.

Lawrence.

[Retired]

Hi,

Thanks Lawrence. no you didn't misunderstand my tyre question I did mean the tyre around the band wheel rims. On my Startrite these are rubber and I was curious about the saws you used with red diesel to prevent resin build up on the band; I hadn't realized the wide band saws ran the band metal to metal so to speak; although the band wheels are crowned was there any provision to prevent the teeth coming into contact with the band wheels as this would quickly remove the set of the band on the side with contact on the band wheel?

I too noticed the one dog used and thought it looked quite dangerous and the saw operator appeared to be throwing the sawn timber around randomly rather than stacking it neatly? The large pressure rollers look to be very efficient but as you say they only apply freewheeling pressure unlike power feed rollers.

I imagine if a band suddenly breaks it would be highly dangerous to anyone in close proximity to it; I've had bands break on my own saws and it doesn't half make me jump. Now with lots of practice I can tell when a band is on the way out by the sound of it.

Not a bad job in summer but being so exposed to the elements won't be a joy mid winter?

I've just returned from taking a full car load of conifer branches to the tip. These are the branches damaged by last winter's snow fall so I've removed them as it would have been a big job to try to realign and tie them in position.

Kind regards, Col.

[pwdrive]

Hi,

Thanks Lawrence. no you didn't misunderstand my tyre question I did mean the tyre around the band wheel rims. On my Startrite these are rubber and I was curious about the saws you used with red diesel to prevent resin build up on the band; I hadn't realized the wide band saws ran the band metal to metal so to speak; although the band wheels are crowned was there any provision to prevent the teeth coming into contact with the band wheels as this would quickly remove the set of the band on the side with contact on the band wheel?

I too noticed the one dog used and thought it looked quite dangerous and the saw operator appeared to be throwing the sawn timber around randomly rather than stacking it neatly? The large pressure rollers look to be very efficient but as you say they only apply freewheeling pressure unlike power feed rollers.

I imagine if a band suddenly breaks it would be highly dangerous to anyone in close proximity to it; I've had bands break on my own saws and it doesn't half make me jump. Now with lots of practice I can tell when a band is on the way out by the sound of it.

Not a bad job in summer but being so exposed to the elements won't be a joy mid winter?

I've just returned from taking a full car load of conifer branches to the tip. These are the branches damaged by last winter's snow fall so I've removed them as it would have been a big job to try to realign and tie them in position.

Kind regards, Col.

Yes the bands run metal to metal, the tracking has to be set correct, almost every band will have a different setting, the tracking is altered by tilting the top bandwheel relative to the bottom band wheel, the bottom wheel is fixed once any preset setting up installation adjustments are made to it.
Obviously the teeth must not come into contact with the bandwheels, the tracking is first set by hand, the new band is slipped on and part tensioned, the wheels are then turned by hand and the blade will find a settling point, the tracking is then adjusted to tilt the top bandwheel, this will start to throw out the teeth on the band over the edge of the bandwheel, it is adjusted until the bottom of the gullett overhangs the bandwheel by approx 3 mm, the tension is then set to full and the saw is then blipped up for a couple of secs, re adjusting the tracking as required, then it's a full run to see how the band sits, an odd tweek or two on the tracking is then normally all that's required and off yer go, if it's a new band it will need re adjusting every so often.
Yes, large bands can break, the experienced sawyer will recognize the tell tale signs, these are normally when the band starts to oscillate in a lateral direction, if it's not resin on the band or the bandwheels then almost certainly the band has started the first main crack, normally at this stage the crack will extend from the bottom of the gullett to about 8 mm or so into the width of the band, an experienced sawyer will at that stage change the band and send it off for welding and resharpening.
If the situation is allowed to continue then the depth of the first crack will extend rapidly, once this has happened then smaller cracks will start to appear either side of the main crack and so on, at this point it can if not carefull get dangerous especially if the bandwheels have a lot of resin on them as the band can suddenly break.
If it breaks and all the guards are fitted and the sawdust extractor is working properly then normally not to much of a problem, a bit of a shock maybe.
But trouble can arise if the bottom of the bottom bandwheel (the driven one) is packed with sawdust between the blade and the ground (or the bottom of the sawdust pit)
Because the band is now trapped between the packed sawdust and the driven bandwheel the rotating bandwheel will grip the snapped blade and throw it out like a snake, that's when it can get hairy, that's not good, only ever seen it happen that way once and that was enough.

Lawrence.

[Retired]

Hi,

Many thanks Lawrence for adding such a detailed explanation.

My Startrite Volant is not the usual sized bandsaw to see in a home workshop; with a 24" throat; ten speed; band welder and grinder its certainly not a toy and with the correct band installed will cut just about anything I can throw at it.

http://www.cottandco.com/lots/startrite-...bandsaw--1

Mine is the same model in the link above and I'm pleased I've found this link because I can now clearly see what the original sliding guide looks like; I knew the guide would attach in the slot to the front of the table so now I can make one quite easily. On narrow band saws it's impossibly to set such a guide and leave it set; as the band ages a "lead" is set up allowing the kerf (cut) to wander either to the right or left so this needs to be taken into account. I rebuilt and resprayed my Startrite when I first bought it.

I've tried using the onboard welder and all I've managed to do so far is to heat the band to anneal but not actually weld. This is possibly my fault in not fully understanding the procedure so I need to practice more; the band grinder works OK.

This Startrite is a big piece of kit occupying a rather large footprint but it is so useful I'll not let it go; it is powered from my home made 3 phase installation and a delightful machine to use.

What price range do the wide bands fall into Lawrence; for my Startrite I've seen metal cutting bands up to £38 each; at the moment I'm running half inch bands for general purpose use cutting both metal and timber.

If I correctly set up this Startrite with a suitable wood cutting band and decent guides I'm pretty sure it would cut veneer without much trouble. For ripping timber my preferred and much quicker machine is my Startrite sawbench which is part of my combination machine. For cross cutting timber I have a big mitre saw with a 3" x 12" capacity.

If I don't play with these machines for a while I suffer withdrawal symptoms; even if I don't have any work to put through them I will run them up for a short while just to keep them in good order.

It's a good job we don't get our legs slapped for slightly wandering off topic? This is a great forum and because we are allowed to wander so far off topic lots of useful and interesting information appears which otherwise would be missed.

Kind regards, Col.

[pwdrive]

Yes, Startrite made a lot of saws, mostly workshop types I think.
No idea what a 4" band is now cost wise, I'll ask my mate when I see him next, we used to cut pallet wood together years ago.
He still has the old Stenner VB 42 we used to run, that one has a 60 ft run of rollers to take the 30 ft rack feed tables for cutting 30 ft sawlogs, somewhere on the forum is a picture of it somewhere.
He still has his old Forrestor Tom Sawyer logging bandsaw as well, we cut some stuff on it a while back for our house.
The link below shows a video of an old Tom Sawyer working.

https://www.youtube.com/watch?v=D9rnLKwEKDk

Years ago he had the original Forrestor Horizontal Bandmill that ran on steel rails set into the floor of the concrete yard, that thing could take a log 4 to 5 ft diameter and ran a 5" band, bit of a death trap that old machine was, we processed 4ft dia stone pine log on that, I remember it well, 4ft wide through and through boards, very nice.

When I was running the sawmill I used Chaco blade guides, they lasted well.

Lawrence.