anyone had success with homeade bandsaw tyres?

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Hornbeam":29ajckbs said:
We used it in work to make gaskets for access doors/hatches into very large oil/water emulsion tank. It is a fibre reinforced rubber. I cannot remember what adhesive I used other than it was a contact type
See link to an e bay add. No idea of that particular product quality but just an example
http://www.ebay.co.uk/itm/SOLID-PLY-REI ... QA__JbPwtg

Good tip, thanks for that.
 
Can anyone tell me which Vax belts were used here please?
I’ve had a look online but there are so many types.

Thanks in advance,
Jamie
 
I replaced the tyres on an ancient 30" Wadkin some years back. optione were rubber, rubber cork compound and Polyurethane, I went with the latter. It was bonded on with epoxy & a scarf joint. Crowning them was fun, Bottom wheel we ran the motor with the blade off & a jig to hold a sanding block . Top wheel we drove the wheel with a sanding drum on an electric drill while a second person held the sanding block to crown it.
Worked really well!
 
Wow I wished I knew such a material existed!
Great to know it's good for gluing too!
Crowning or dressing flat is easy if you use the side of a plane iron.
Using a large f clamp to hold an offcut from a door stile, lightly clamped on end at the 7 o clock position on the upper wheel cabinet.
Using another small g clamp and a strip to hold the plane iron lenghtways , so it's a 90 degree cutting edge which is great for rubber.
Gradually increase the block with clamped iron to make contact with the tire, the cutting angle is much like a regular scraper, leaning away from the work, the only difference is it you present the block too upright it will dig into the rubber and make a very deep cut, so it needs to be leaning away
from the cut and that means you need a good f clamp for smooth cutter advancement.
The same block can be used at the 11 o'clock position on the lower wheel.
A sheet of ply to stop something dropping and chipping the paint on the base is a good idea.
If you don't have soft grips on the f clamp it might badly stuff the back of the machine.
If you can it's easier to check with the wheel slid out from the cabinet.
I found it was very hard checked with a spirit level type straight edge and nice square for the job.
Maybe that was just my eyes but keep that in mind.
If you're going for a flat tire setup, I have much better luck using axminster bandsaw blades.
I had some serious damage to the tires and have rigged the crowning jig up a few times, so it's handy to do.
That door stile might give better results if not quite square, my piece was square and needed persuasion to counter the force from being clamped on end.
You can relieve a bit of the block to get the plane iron closer.
Nice and tidy job to do making rubber shavings but your fingers do take a blisterin! :)
A blue biro can be used if wanting to know exactly where you're taking material off, as its difficult to see it in the cut as the shavings obscure the view.
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I've made really good tires out of sheet vinyl flooring. Friendly visits to flooring stores revealed that more than one thickness can be found when you explain what you want to do with it and enlist their help. I wound up with about a 30" x 40" free sample about 1/8" thick as opposed to the much more common 1/16" thickness. Cut a strip the width of the wheel and long enough to wrap around it with a slight overlap. If there is heavy embossing such as fake "grout lines", cut the strip so they run across tthe width, not the length of the strip.
Clean off any glue residue from the wheel, wrap the vinyl strip around the wheel and cut through both layers to assure proper length. A square butt joint is fine. Absolutely no need for an angled cut or a scarf joint. Scuff up the shiny side of the vinyle strip and apply a thin even coat of contact cement to that side. Coat the rim of the wheel.
Put several spacer blocks on your work surface and place the wheel on them with an inch or so sticking out past the rim. Bend the vinyl strip into a circle bigger than the wheel. Lower the edge of the strip onto the spacers without touching the rim. Starting at one end of the strip, push it against the wheel and work around the wheel until it is fully adhered to the rim. Roll the wheel to firmly force the glued surfaces together. Lightly hammer the strip to ensure good contact.
Mount the wheel on an improvised shaft so that it turns freely and without wobbling. Place a running belt sander against the wheel rim at aboiut a 45 degree angle so that its rotation causes the wheel to rotate. Rock the ends of the sander in and out to sand a crown (hump) centered at the center of the width of the wheel rim. Try to sand only up to NEARLY the center of the rim. A pen or pencil line along the center is a really good idea! You don't need a severe curve. The "rule of thumb" for crowns is 1/32" height per 1" width. The desired outcome is enough crown to be visible, while leaving enough thickness at the edges of the strip to cushion and protect the blade teeth and tooth "set". Depending on the starting thickness of the vinyl, you don't have to conform to the ''rule of thumb" exactly. Put a square across the rim. If you can see a decent sliver of light at each edge, you're good to go!
 
I had another revisit regarding dressing my tires, as I was to find out that there's no such thing
as a good performing bandsaw which actually has a flat profile on the tires.
Having so is a recipe for compressing set, should one try a mere test run (no cutting involved) with the blade tracked as such that the teeth might be approaching the rubber.
More noticeable, is the distinct lack of beam tension in which one will experience with the blade,
and it will walk back without any force whatsoever into the thrust guides.

If one was to try test cutting using a blade without set, on tires what's truly flat,
and using the same blade after crowning the tires, they would find they would be actually get through the cut, what couldn't be done before.


Seems there's no telling some folk, that the Italian machines actually do have a crown on the tires,
and I didn't cop the convex profile that my spare Centauro tire I bought from S&S had, and ignorantly assumed they were such.
This is best explained on this Cook's sawmill video snippet...


It's the same thing as what's happening here
SAM_7997.JPG

But when stretched out as such...(with gap for the tongue underneath)
SAM_8041.JPG


You can see that there is indeed a profile, a slightly flatter convexity on the rear of the apex,
and slightly more abrupt on the front of the tire.

SAM_8043.JPG


Apex @17.5mm from the front edge, so there's 1mm in the difference between the centre of the tire and the top of the crown.

SAM_8130.JPG


A marker instead of a pen would be better, as it scores the rubber a bit.
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Since there's no room for error regarding any skewing,
I glued another bit onto the block for easier alignment to the wheel
(on two axis, that is) and as you can see some duct tape was necessary,
as some masking tape is for protecting paint job,

SAM_8081.JPG


Block aligned on both axis...
SAM_8082-01.jpeg
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The offcut what's bonded onto the original block, had an old mortise cut into,
so was much handier to adjust the feed of the scraper/cutter (old saw plate)
I agree wholeheartedly about not touching the apex, and you want to always see light of the apex,
as the scraper might likely end up sharper on the apex than the rest of the tool, (whats actually doing some scraping), and it only takes a lick to cause themselves a lot more work.
I used a cheap diamond stick for blunting the apex.

Dressing the lower tire doesn't require a blade installed,
SAM_8100.JPG


But I was to find that on the upper wheel definitely does, require a suitable blade installed if using a scraping tool under the wheel, and made sure the wheel was indeed parallel with the column.
Sorry don't have a pic, but you'll have to imagine the blade installed.
SAM_8108.JPG


One possible caveat here, is my wheels have the faces dressed to about 0.2mm discrepancy.....
 
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My upper wheel had about 0.5mm discrepancy, the thickness of my Shinwa rule,
and the lower wheel about half that.

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If you've got solid wheels, then you could rest a file on them,
Custom made file handle what should be of thicker stock than shown, thus impossible to flip upside down DAMHIK.
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Mark where you can hear, right beside the tramming tool (old saw)
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Draw filing the colour off, as regular filing won't take a bite,
when close best to switch to a finer cut file, as the tramming tool will catch on those ridges
left from the rougher file
SAM_7820-03.jpeg
Keep clean with a paint brush
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Only saying all this as the upper wheel is very touchy, and the fact that that 0.5mm discrepancy translates to a surprising 4mm on the chassis floor, depending on where you place the beam, which is a good recipe for wiping out all the work you done creating a fine apex.

Also worth noting, it might be a good idea to check this before, if using edge of the wheel
as a datum for installing tires, should one not be dressing them on the wheel
and choose to buy stretch on pre-crowned replacements, what's getting bonded to the wheels.
If not wishing to touch up the wheel faces, then they could rig up a tram to check the rubber instead.
Though likely wholly unnecessary on the more modern Centauro's
with alignment groove in the wheels.
SAM_7208.JPG


Some food for thought perhaps.

All the best
Tom
 
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