What was I Thinking?
Sometimes I wonder!
Hi Everyone,
For me to explain, I need to go back a while and talk about my Trade. Being a Sheet Metal Worker means I get to play with some weird and wonderful tools and machines with some unusual names. For example one of the first tools we get to use is called a Dolly, I don't know why it is called a Dolly and every tradesman that I have asked over the years has acknowledged that it is called a Dolly but doesn't know why! If you are wondering, a Dolly is used in conjunction with a hammer for shaping metal, a lightweight mobile Anvil if you like that comes in all sorts of shapes and sizes.
Now back to my thinking, I have been working on my project that I am fitting Montesa Cappra wheels to and it has been a bit of a headache. They come standard with Stainless Steel spokes and I would like to retain as much period parts as I can but the aluminum nipples have been out of stock for years and corrode, split and fall apart. To make things worse, use a different thread to all other bikes, at least it seems that way. Along with this the spokes are all too short by varying ammounts!
Luckily I have some Nickel Plated Brass Nipples that fit and I wanted to get away from the exposed threads that never seemed too bothered about. The best idea that I could come up with was to make the spokes longer, at 3.5 mm diameter I figured they could be reduced to make them longer. So out came the John Heine 42 J Jenny, like the Dolly, all the Tradesmen acknowledged that it is called a Jenny but no one knows Why! On a side note I probably have a dozen Dollies (if I counted them) but none of them are called Jenny so I am NOT Forrest Gump!
After machining another groove in one of my bead roll wheels and making a new top wheel, my line of thought was to squeeze the spokes between the wheels to increase the length. After assembling the wheel and working out how much to stretch each spoke to hide the thread, I cut a piece of tube to the desired length for sliding over spokes to use as a measuring stick:
After experimenting, rolling, twisting, rolling, twisting until the desired length was achieved, I thought OK, change the technique until I work it out hoping to sort it out for the rest. Sometimes it takes until the last one to work out the best technique, especially if Mr Murphy is watching. No such luck as I had reworked all 36 without finding an easier way. Maybe using the exact same starting point was Wrong?
Anyone got any ideas why the curves are so Random?
Basket Cases
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- Greg Harding
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Stretching Spokes
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Re: Basket Cases
Greg you should of known that I just couldn`t resist replying to this one. You should know that everything about a Montesa is random including the riders so the spokes doing that is really no surprise at all. The easiest way to solve that is to just put some real wheels on it and use ones. Problem solved!
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Re: Basket Cases
I've seen similar to this 50 years ago. My Dad had acquired quite a few sheets of second-hand corrugated iron roofing panels from a demolition site and wanted to reuse them on one of our farm sheds.
The sheets had not been treated well by the demolishers and some were a bit creased and also were a bit deformed around where the roofing nails had been.
My Dad had heard that a particular plumber workshop had a set of corrugated iron rollers, a lot like Greg's Jenny, but on a bigger scale, the width of a sheet of corrugated iron.
Unfortunately the info about the rolling machine at the plumbers workshop was not quite the whole story. The machine they had was actually a rolling machine that was designed to put curves in corrugated iron sheets, so they could be used for making water tanks.
My Dad never saw the rolling machine so only realised there was a glitch when my Mum brought home all the "straightened" sheets and they looked a lot like Greg's Montesa spokes.
The sheets had not been treated well by the demolishers and some were a bit creased and also were a bit deformed around where the roofing nails had been.
My Dad had heard that a particular plumber workshop had a set of corrugated iron rollers, a lot like Greg's Jenny, but on a bigger scale, the width of a sheet of corrugated iron.
Unfortunately the info about the rolling machine at the plumbers workshop was not quite the whole story. The machine they had was actually a rolling machine that was designed to put curves in corrugated iron sheets, so they could be used for making water tanks.
My Dad never saw the rolling machine so only realised there was a glitch when my Mum brought home all the "straightened" sheets and they looked a lot like Greg's Montesa spokes.
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Re: Basket Cases
As for the name "Jenny", maybe it is similar to "Genny" which I've used as slang name for tools that have both "male" and "female" parts (as in genny calipers)
Confusing though because a female mud-crab is also called a "Jenny" or "Genny"
I'm fairly sure Mark K will be able to sort it all out
Confusing though because a female mud-crab is also called a "Jenny" or "Genny"
I'm fairly sure Mark K will be able to sort it all out
relax, nothing is under control
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Spoke Stretching
Hi Everyone,
David, I think this is what you mean
These are used for rolling curves on BlueOrb corrugated iron which is rolling quality or mild instead of High Tensile like common corrugated iron. This roller is in the Pyramid or triangular format and what your Father needed was Initial Pinch, ie one roller on top of another.
OK, got it now!
You mean keep your Genitalia out of the Moving Parts!
Graham, it just so happens that I have a front wheel but someone in their wisdom has built it inside Out!
What I mean is the bit you see is Rusty and Grippy and the bit you want to be Grippy inside the drum is Shiney and looks like a Bumper Bar off an old Car?
What were they Thinking?
David, I think this is what you mean
These are used for rolling curves on BlueOrb corrugated iron which is rolling quality or mild instead of High Tensile like common corrugated iron. This roller is in the Pyramid or triangular format and what your Father needed was Initial Pinch, ie one roller on top of another.
David Lahey wrote:As for the name "Jenny", maybe it is similar to "Genny" which I've used as slang name for tools that have both "male" and "female" parts (as in genny calipers)
Confusing though because a female mud-crab is also called a "Jenny" or "Genny"
I'm fairly sure Mark K will be able to sort it all out
OK, got it now!
You mean keep your Genitalia out of the Moving Parts!
Bully fanatic wrote:Greg you should of known that I just couldn`t resist replying to this one. You should know that everything about a Montesa is random including the riders so the spokes doing that is really no surprise at all. The easiest way to solve that is to just put some real wheels on it and use ones. Problem solved!
Graham, it just so happens that I have a front wheel but someone in their wisdom has built it inside Out!
What I mean is the bit you see is Rusty and Grippy and the bit you want to be Grippy inside the drum is Shiney and looks like a Bumper Bar off an old Car?
What were they Thinking?
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Greg Harding
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Re: Basket Cases
Yes Greg your pyramid pattern corrugated iron rollers are indeed what they used to destroy my Dad's sheets. The patina on the rolling machine in the photo makes me think they might even be from the same era.
I did get to watch those type of rollers being used properly at South Brisbane TAFE in the 1970s. I think it was apprentice plumbers had to use them to make itty bitty water tanks from corrugated iron sheets, including lead soldered joints. In the same building at that college were some other apprentices whose project was to make complete one-piece steel bodies for a kid's pedal car and the whole body was compound curves. I remember being quite impressed with the work standard. I can't remember if they were panel-beaters or sheet metal apprentices.
That college was also the home of the motorcycle mechanic apprentices and every year an RE5 (rotary engine) Suzuki road bike had to be completely disassembled and reassembled and made to run. The bike had been donated by Mayfairs Suzuki. Someone suggested that they donated it to the college because no-one would buy it.
I did get to watch those type of rollers being used properly at South Brisbane TAFE in the 1970s. I think it was apprentice plumbers had to use them to make itty bitty water tanks from corrugated iron sheets, including lead soldered joints. In the same building at that college were some other apprentices whose project was to make complete one-piece steel bodies for a kid's pedal car and the whole body was compound curves. I remember being quite impressed with the work standard. I can't remember if they were panel-beaters or sheet metal apprentices.
That college was also the home of the motorcycle mechanic apprentices and every year an RE5 (rotary engine) Suzuki road bike had to be completely disassembled and reassembled and made to run. The bike had been donated by Mayfairs Suzuki. Someone suggested that they donated it to the college because no-one would buy it.
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Re: Basket Cases
I'm not so sure about that. I don't know the origins of the name, and a quick google search only leads to all manner of theories and myths, but nothing I'd want to quote.David Lahey wrote: ..... I'm fairly sure Mark K will be able to sort it all out
Greg, it won't make a difference, and its too late anyway, but I'm wondering if you did one single highly compressed push through the machine, and I'm also wondering if it would have had a different outcome if you'd put them all through with the same starting point and a moderate compression, then put them through again with the screw turned a bit tighter, but the starting point rotated 180 degrees, then again a bit tighter with the starting point rotated 90 degrees, then once more a bit tighter still, with the previous starting point rotated 180 degrees. At least in my mind it should tend to even out the pressures and possible distortion.
Of course we could just say that being stainless steel they have a reflective surface, and as such are reflecting the properties of the person doing the job : That is to say - inconsistent, and somewhat bent.
Sorry about that, but I just couldn't resist.
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Straightening Spokes
Hi Everyone,
All good Mark, hard to believe I know but I have been called worse!
I started off similar to what you suggested always the same starting point with the bend pointing to the left. Roll to me and back again twice. Release and rotate 90 degrees and repeat the rolling and after doing a few I realised at 180 degrees was the same starting point but inverted. So I then indexed around 45 degrees and then 90 degrees in an effort to keep them round. The amount varied, 9 spokes were lengthened by 3 mm, 18 by 5 mm and last 9 by 7 mm so the procedure varied in how many times I repeated the process. As for pressure, I would say moderate on all passes as these are old machines.
As you can see there is a guide that attaches to the back so I came up with the idea of adding a 10 x 5 x4 mm bearing as a third roller , so it is similar to initial pinch rollers.
I still find it amazing how random the curving effect was with some 3 mm stretched ones being a tighter radius to 7 mm stretched ones and the curve would go in any direction on the first Pass!
All good Mark, hard to believe I know but I have been called worse!
I started off similar to what you suggested always the same starting point with the bend pointing to the left. Roll to me and back again twice. Release and rotate 90 degrees and repeat the rolling and after doing a few I realised at 180 degrees was the same starting point but inverted. So I then indexed around 45 degrees and then 90 degrees in an effort to keep them round. The amount varied, 9 spokes were lengthened by 3 mm, 18 by 5 mm and last 9 by 7 mm so the procedure varied in how many times I repeated the process. As for pressure, I would say moderate on all passes as these are old machines.
As you can see there is a guide that attaches to the back so I came up with the idea of adding a 10 x 5 x4 mm bearing as a third roller , so it is similar to initial pinch rollers.
I still find it amazing how random the curving effect was with some 3 mm stretched ones being a tighter radius to 7 mm stretched ones and the curve would go in any direction on the first Pass!
2017 Newsflash: RUST IS THE NEW BLING !
Team Hardwood, the only licenced trials riders in Coffs Harbour!
Miles of Smiles
Greg Harding
Team Hardwood, the only licenced trials riders in Coffs Harbour!
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Greg Harding
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Re: Basket Cases
I reckon it is amazing that the spokes are as straight as they are. A suitable challenge indeed you have set yourself Greg
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Re: Basket Cases
Being an old school plumber I can support that the tank rollers can roll tanks and or by hand bull nose veranda iron did hundreds of bullnose sheets and hundreds of tanks a lot soldered and then glued with sealant !
I was taught the old school way and did many colonial copies and restos as a young bloke!
I had a set of similar Jennys but sold them a decade ago because I never used them. I still have the hand tools to rivet a tank together though!
Interesting use and adaptation of the wheels most jennys had half a dozen different wheels that could be swapped over for different uses and you could get a set of wheels that was made to straighten or roll wire for edging sheet metal.
I was taught the old school way and did many colonial copies and restos as a young bloke!
I had a set of similar Jennys but sold them a decade ago because I never used them. I still have the hand tools to rivet a tank together though!
Interesting use and adaptation of the wheels most jennys had half a dozen different wheels that could be swapped over for different uses and you could get a set of wheels that was made to straighten or roll wire for edging sheet metal.
Smiffy60
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