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By OPJ
#483596
Here, you can see the hole for the top wheel, which is where the blade (and probably the tyre) made a quick escape:

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Pete, yes, I could build some form of magnetic box-guard to sit over it. However, I'm gradually becoming more aware of when blades are going to break so, after trashing the tyre this time, I don't plan to push my luck quite so far again! :oops:

When it happened, I noticed something jump off the top of the saw, heading over towards my wood pile. When I saw the blade hanging over my head though, I completely forgot about it...

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Bandsaw is on the right and the wood pile is to the left of my mitre saw setup. If you look just above that green sheet of MR MDF, you can see silvery light with flexible shaft - it's magnetic and I did have it stuck on top of the saw - it's travelled quite some way!! :D

So, when I get her back up and running again, I've decided it would be better off clamped to the guide post behind the blade:

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It's a shame Axminster no longer appear to stock this as it's quite a good light. It does have a habit of not working now and again but, I've had the same batteries in there for three-years or so and that giant leap appears to have bought it back to life! (By the way, that glow of light is from the sun, as I have the door open in this shot! :wink:)
By dickm
#483614
OPJ wrote: there is a large hole in the top of the machine's casing - it allows the top wheel to protrude when you're cranking the tension up for a wide blade.


I'm amazed at that. Certainly in your pic, it looks like an original "feature", but surely the machine couldn't be designed to need a hole like that in the top? Seems obvious that in the event of a breakage, there would be a good chance of the blade ejecting like your's did.
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By OPJ
#483790
9fingers wrote:The ends should be scarfed such that the direct of rotation closes the join.


Hi Bob, I just want to check I understand what you are saying...

Obviously, the ends are cut to a 45° angle on the face. Are you also saying that the edge cuts should be bevelled slightly? That looks to be how the bottom wheel on my saw is done.

Well, this morning, I took the plunge and ordered a 2m length of the cork-rubber tyre from Scott & Sergeant (plus the glue and VAT! :x). I only need about 1.2m but, hopefully, it'll be here tomorrow (well, it bloody well should be, £9.99 for delivery!! :x) Startrite have also come back to me and have found a wheel from a scrapped machine (it fell of the lorry! :shock:) and I could have that for around £100. KV Rollers also got back to me but, that was after I'd placed the order (they did seem very willing to help, though :)).

I've said this before but, as I would have to 'scrap' the old wheel anyway, I feel it's worth at least trying to do something with it. I appreciated their advice and that fitting a new wheel with a factory-fitted tyre would be the best possible solution. But, if I can save £50 and put that towards some new blades... :)


Pete Maddex, thank you for the offer. Unfortunately, my wheels are 16in/400mm.

Dick, it looks to be part of the intended design and allows the upper wheel to poke up through the case when you crank the tension up for a wide blade. Otherwise, the saw would have to be several inches taller (increased material costs, etc.) and it was awkward enough to man-handle as it is!! :wink: I may well try to box it in, at some point.
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By 9fingers
#483791
OPJ wrote:
9fingers wrote:The ends should be scarfed such that the direct of rotation closes the join.


Hi Bob, I just want to check I understand what you are saying...

Obviously, the ends are cut to a 45° angle on the face. Are you also saying that the edge cuts should be bevelled slightly? That looks to be how the bottom wheel on my saw is done.


Dick, it looks to be part of the intended design and allows the upper wheel to poke up through the case when you crank the tension up for a wide blade. Otherwise, the saw would have to be several inches taller (increased material costs, etc.) and it was awkward enough to man-handle as it is!! :wink: I may well try to box it in, at some point.


I meant only scarfing in one dimension. doing it on 2 axes sounds like a job for a production jig to me.


I don't follow the need for extra headroom when tensioning a wide blade.
Tension is only applied to a blade when the top wheel STOPS moving.
There will be a minuscule stretch of the blade but that would not justify a hole like this.

?? confused of Romsey.

Bob
By head clansman
#483828
hi olly

not a nice experience is it , good job you not peter crouch, could have taken your head off, or some serious cuts , don't bear thinking off , usually when there about to go you feel the timber trying to pushing back at you whilst your trying to cut with it . now you'll know next time switch off straight away, happy your ok though first time it happened to me it frighten the sh*t out of me, if you can picture an old domino which stood some 8 ft tall when the blade went one almighty bang and the blade flew straight out the side of the machine , lucky then no other joiner was within easy reach , makes the mind boggle what could easily happen . hc
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By OPJ
#483853
Bob, thanks for clarifying. Not to worry too much, though - I've had another look at it is only the 45° mitre. I guess it was a kind of optical illusion when I looked this morning, with the curve of the wheel and everything. :roll: :)

Do you have any other advice on doing this though? Is there an easy way to cut the correct length and any tips for keeping it central as I glue it on?

When I've got it going again, I'll fit a wide blade on the wheels and show you how it looks. I don't think I've seen this on any of the other large bandsaws (Axminster, Record Power, etc.) though, I could be wrong. There are certainly a couple in America that bear some similarities to the modern Startrite designs.

HC, thanks. I've had a few blades break on me in the past (several different bandsaws) but they've always remained mostly inside the saw! I've heard that the worst ones are those large resaws, where the blades are at least 3-4in wide - of course, in a sawmill, you'll be ripping thick stuff (12in plus) all day, meaning the blade has plenty of room to escape if it decides to go! :?
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By 9fingers
#483865
OPJ wrote:Bob, thanks for clarifying.

Do you have any other advice on doing this though? Is there an easy way to cut the correct length and any tips for keeping it central as I glue it on?



Olly, I've not done this before. I wrote earlier of my intentions as and when my bandwheels need attention.

I'm assuming the adhesive is a contact type.

I would cut the material over long, scarf one end only and apply glue from the scarfed end leaving 50mm or so unglued from where you expect the joint to go. Fit the band and once that has stuck, offer up and trim the rest of the band to fit, then glue that part.
I guess band clamps would be ideal to keep everything in place.

Good luck

Bob
By xy mosian
#483868
I've not had ANY experience of this but, to stick my neb in. If the wheel is flat across the rim and the tyre is essentially flat how about scarfing the start of the tyre and running the end over the scarf, trimming afterwards. The scarf line would be better as a tangent to the wheel but this way might take out a tricky length cut.

Please shout if this is a load of b*lls :)

HTH
xy
By Jake
#483903
My 401 doesn't have a hole in the top (but its the version before they scraped some more cutting height out of it).
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By Eric The Viking
#483917
OPJ wrote:I've heard that the worst ones are those large resaws, where the blades are at least 3-4in wide - of course, in a sawmill, you'll be ripping thick stuff (12in plus) all day, meaning the blade has plenty of room to escape if it decides to go! :?


It's like airliners: don't stand (or sit) in line with the spinning bits! If I remember correctly, n the case of the former, electronics conduits and hydraulic pipes are strengthened in that part of the fuselage, in case a turbine blade gets terminally bored.

"It's bein' so cheerful as keeps I goin..."*

Cheers, E.

PS: sorry about the incident - if you need saw-table time in the week, I've got a 5/8" blade on at the moment and it's cutting beautifully. You'd be most welcome.

*courtesy of my late grandpa, who heard it in the trenches of WW1 and ran a 'full-size' bandsaw for most of his working life. It's 35 years ago, but it ate whole trees and I think the blade was about 6".
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By OPJ
#484165
My order from S&S (placed about 24 hours earlier) arrived at 8am this morning - very impressed! :)

What I did in the end was to cut it over length, offer it to the wheel and temporarily held it in place with masking tape, while I marked the the cut (I had to do this at least three times :oops:). The joint isn't 'perfect' but I'm hoping it will be good enough. [-o<

I did secure it with a band clamp, which seemed to work quite well. I haven't dared take it off yet though as I'm not sure how long this contact adhesive 'gel' takes to cure - the instructions are written in German, French and Italian only!! :roll: My GCSE French (going back nine-years...) got me through most of it but I still couldn't see a curing time. :?

I'll probably leave it until the weekend now, as I'm at college for the next two days. Then, it should "simply" be a case of truing the tyre and adding a camber - I'll let you know how it goes!
By Gary M
#484273
OPJ wrote: Over the weekend, I was resawing some oak and I think that just about finished off the 1/2" x 3tpi blade I had been using


Completely wrong choice of blade to resaw with your machine, you would be much better with a more substantial blade more suited to resawing.
Perhaps 1" x 2tpi. Bigger machines like the startrite are made to take bigger blades, cutting tight curves is the only real need for a smaller blade.

OPJ wrote:
You may remember my previous post, where I indicated that the tyre had a few gouges missing from the front edge.

Seems that perhaps there is a fault with your wheel, as its the same sort of damage.


OPJ wrote:I've said this before but, as I would have to 'scrap' the old wheel anyway, I feel it's worth at least trying to do something with it. I appreciated their advice and that fitting a new wheel with a factory-fitted tyre would be the best possible solution. But, if I can save £50 and put that towards some new blades...


I think that you would have been better off following the manufacturers advise and replaced the wheel, as by your own admission the new cork tyre is not fitted very well. I dont think you will have as much confidence using the saw with the repair.

OPJ wrote: Startrite have also come back to me and have found a wheel from a scrapped machine (it fell of the lorry! Shocked) and I could have that for around £100.


You should have bit their hand off :wink:
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By OPJ
#484575
Well, I got home about an hour ago with more energy left than usual so, I decided I couldn't wait until the weekend and have just been out to true up the wheel. It was dead simple with 60g paper, even adding the camber (counting the number of rotations on each edge). The join isn't as bad as I thought (plenty of excess glue to clean up, though! :oops:). It doesn't seem to be loose anywhere from what I can see.

I've already tried fitting a blunt 1in blade (don't worry, I won't use it!! :D) and it looks good so far. I've got a couple of unused ¾in blades I'd like to try shortly and, having seen how my widest blade performs, I am confident that it won't be falling off over the weekend. :)

If I had £100 to spare, yes, I would have considered it the replacement. But then, what would I do with the old wheel??? I got the impression that KV Rollers might also have done it for much less than £100, also (though, don't quote me on that! :wink:).