adrian
Flying Squad
Fascinating - how did you make the corrugated rollers? Are they machined or just half/full round strip soldered on a tube?
Wriggly tin in 7mm scale - supplier or how to make?
- Thread starter Dog Star
- Start date
Brian McKenzie
Western Thunderer
They were machined one flute at a time with a shaped tool set in a mill's horizontal arbour - what was described to me once as 'flick milling' - a form of fly-cutting. It was such a laborious task, hand feeding the table that I haven't been racing to make rollers in another scale
-Brian McK.
adrian
Flying Squad
I can't say I blame you for that decision - at my 6th. Form college I had access to a surfacing machine. For some strange reason I thought it'd be good to use to cut out a set of hornguides. Never again!!
jc2001
Western Thunderer
I know Ambis used to supply some but think it is unobtainable now. I came across this supplier a while back: Corrugated Plates - buy now on architekturbedarf.de
John
John
Osgood
Western Thunderer
Brian - thanks for showing your rolls. If the stamped name does not give away a tool room background, if nothing else it reveals a well-justified pride in one's own workmanship 
I have been contemplating the construction of something similar, but have been held back by concern over How I might 'get it right' first time round in terms of what comes out of the rollers! Summed up I guess, by uncertainty of how much the material needs to be over-manipulated to allow for spring-back.
For example, in the simplistic sketch below (showing for clarity a pair of rollers having a flat surface) the variables affecting output geometry (i.e. pitch and depth) would likely be:
1. Depth (which, aside from recommended roll centres adjustment as you have provided, will be limited by position of profile machined on roller face - the sketch shows profile having its centre on the roll surface, limiting profile of output to equal or less than 1/2 the diameter).
2. Diameter of profile
2. Pitch - any spring-back of material will increase the resultant pitch of the sheet corrugations
Given that the target profile has a depth slightly less than 1/2 the pitch (I can't find my sheet profile drawings at present), my instinct is to create the profile at scale dia. and set it with centreline on roll surface so that maximum achievable depth is 1/2 dia, and set the pitch at marginally less than scale pitch required if using soft aluminium foil sheet (reduced a bit more if a hard material like copper sheet is to be used).
Any advice you can offer in this respect would be appreciated.
Tony
I have been contemplating the construction of something similar, but have been held back by concern over How I might 'get it right' first time round in terms of what comes out of the rollers! Summed up I guess, by uncertainty of how much the material needs to be over-manipulated to allow for spring-back.
For example, in the simplistic sketch below (showing for clarity a pair of rollers having a flat surface) the variables affecting output geometry (i.e. pitch and depth) would likely be:
1. Depth (which, aside from recommended roll centres adjustment as you have provided, will be limited by position of profile machined on roller face - the sketch shows profile having its centre on the roll surface, limiting profile of output to equal or less than 1/2 the diameter).
2. Diameter of profile
2. Pitch - any spring-back of material will increase the resultant pitch of the sheet corrugations
Given that the target profile has a depth slightly less than 1/2 the pitch (I can't find my sheet profile drawings at present), my instinct is to create the profile at scale dia. and set it with centreline on roll surface so that maximum achievable depth is 1/2 dia, and set the pitch at marginally less than scale pitch required if using soft aluminium foil sheet (reduced a bit more if a hard material like copper sheet is to be used).
Any advice you can offer in this respect would be appreciated.
Tony
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simond
Western Thunderer
Looking at your "flat roller" sketch, would not a press tool (previously suggested by Adrian & ) comprising a series of round bars fixed to a couple of plates be an easier way to do it? You could set max depth with some form of dead-stop, and you could also pre-cut the sheets so they come out scale size after stamping. A small flypress would be ideal, but worst case, a large drill-press would do.
Food for thought
Simon
Food for thought
Simon
Osgood
Western Thunderer
Yes indeed, Simon. A kind of 'fast food' rolls?
It would certainly make any necessary dimensional revision cheaper in time terms than re-machining rolls.
With care in positioning separate sheets might come out well, but I wonder if overlapping sheets might be better represented by a suitably scored wide roll - overlaps often seem too obvious to me and highlight the overscale sheet thickness.
Perhaps ultra-thin material would help in this respect. About 50 years ago I acquired a reel of 4mm corrugated sheet made from really thin copper which might work well.
Thanks,
Tony
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Osgood
Western Thunderer
The main benefit of rollers over a flat press is that rollers form the shape over just one corrugation.
A flat press, by forming all corrugations at once, has to draw a lot of material from each side towards the centre of the press platters as it transforms a wide flat sheet into a much narrower corrugated one. This results in significant stress and deformation of the sheet material as it is drawn through an ever-decreasing gap between the corrugated dies, which can result in tearing - which is in part the problem experienced with the comb tool described elsewhere.
A practical compromise might be a flat bottom plate with a curved top plate which would replicate better the roll action.
A flat press, by forming all corrugations at once, has to draw a lot of material from each side towards the centre of the press platters as it transforms a wide flat sheet into a much narrower corrugated one. This results in significant stress and deformation of the sheet material as it is drawn through an ever-decreasing gap between the corrugated dies, which can result in tearing - which is in part the problem experienced with the comb tool described elsewhere.
A practical compromise might be a flat bottom plate with a curved top plate which would replicate better the roll action.
Brian McKenzie
Western Thunderer
Tony,
After it being out of sight for a long time I was dismayed to see the tool was made in 1980. I wouldn't have remembered except for the date stamped on it. Where have all those years gone?
Not in a tool room though - much as I would have liked.I remember tracing the end profile of a new sheet of iron to determine the radius of the ridges. A form tool was shaped to cut the dome of one ridge, and used then to mill them individually in a horizontal fly-cutting action. The trickiest part was arriving at a suitable pitch circle diameter (pre CAD days) to yield a scale 3" pitch, using brass bar at hand of 7/8" diameter as a starting point.
Now that I am more suitably equipped, I have just measured the end result after rolling some 0.004" aluminium today. The pitch works out to be marginally less than 3 inches. With aluminium foil, it is fairly safe to say that no allowance for spring-back is necessary.
I didn't try to control the depth of corrugation when grooving the rollers (older iron has a deeper profile apparently to that produced by today's "long-run" machines). The eccentric adjustment of the top roller was primarily to ensure the rollers were firmly engaged with the material - and useful as a fudge for not knowing quite what the roller spacing should be
Although the tool handled the extensive use of 0.006" aluminium foil very well, a larger handle with extended crank throw would be a definite improvement. Some 0.005" brass shim was rolled for a friend who wished to use it as a more durable fencing material. This was fairly tough going with the tiny Meccano-like handle, despite the brass being (and necessarily) fully annealed first.
If ever making new rollers, I would try using steel and perhaps case harden them - to safe guard the ribs from any accidental knocks.
-Brian McK.
Osgood
Western Thunderer
Thank you Brian - that helps no end, in both technical and mentoring aspects!
As an alternative to the ideal solution of a set of rolls, the flat platter with trimming grooves, combined with a profiled roller, might have some merit both for individual sheets and - if indexing the sheet material over the platter - for wider runs.
Both platter and roller could be 3-d printed if using thin aluminium foil to produce a cheap marketable tool.
Tony
As an alternative to the ideal solution of a set of rolls, the flat platter with trimming grooves, combined with a profiled roller, might have some merit both for individual sheets and - if indexing the sheet material over the platter - for wider runs.
Both platter and roller could be 3-d printed if using thin aluminium foil to produce a cheap marketable tool.
Tony
simond
Western Thunderer
Tony,
I did think about this since posting, and came to the same conclusion as you, you'd need to allow the material to be drawn into the centre of the press-tool to prevent the stretching you mention. It's a shame, as it would be relatively easy to make the plates without machine tools.
A curved upper plate would allow the material to be drawn in, it could, equally, be a roller, and the lower side could be a plate, but I don't think this would give any advantage. If you are going to use a milling m/c to "hob" the rollers, you might as well do one twice as long as you need and cut it in two when the corrugations are formed.
Perhaps an alternative would be a soft rubber pad, such as is used in tampo-printing, and a simple wire-and-plate matrix.
But then again, as you say, it would be pretty easy to 3d print the roller(s) which could easily be mounted on a metal axle for stiffness, and would handle foil without much trouble.
Many years back, I bought a plastic tool for making corrugations from beer cans, which was reasonable when I modelled in 16mm scale - far too coarse for the smaller scales - I thought it was a craft-shop item. Whilst looking for a similar item on the w3, I found this, which is rather neat.
Brunel Models Corrugated Iron Maker
apparently, what I had bought was a "tube wringer"
Hair Tools Tube Squeezer Black
mine was very similar, but a fetching red and yellow. I'd never heard of a tube wringer before. The joys of a pain-free learning experience!
Returning to the Brunel Hobbies device, a matrix comprising a plate with wires soldered on at appropriate spacing, and a smooth burnishing tool would do the job very nicely, no need for machining, simple, effective. Probably a bit slow if you're doing square feet of the stuff, but for a shed or two...
best
Simon
I did think about this since posting, and came to the same conclusion as you, you'd need to allow the material to be drawn into the centre of the press-tool to prevent the stretching you mention. It's a shame, as it would be relatively easy to make the plates without machine tools.
A curved upper plate would allow the material to be drawn in, it could, equally, be a roller, and the lower side could be a plate, but I don't think this would give any advantage. If you are going to use a milling m/c to "hob" the rollers, you might as well do one twice as long as you need and cut it in two when the corrugations are formed.
Perhaps an alternative would be a soft rubber pad, such as is used in tampo-printing, and a simple wire-and-plate matrix.
But then again, as you say, it would be pretty easy to 3d print the roller(s) which could easily be mounted on a metal axle for stiffness, and would handle foil without much trouble.
Many years back, I bought a plastic tool for making corrugations from beer cans, which was reasonable when I modelled in 16mm scale - far too coarse for the smaller scales - I thought it was a craft-shop item. Whilst looking for a similar item on the w3, I found this, which is rather neat.
Brunel Models Corrugated Iron Maker
apparently, what I had bought was a "tube wringer"
Hair Tools Tube Squeezer Black
mine was very similar, but a fetching red and yellow. I'd never heard of a tube wringer before. The joys of a pain-free learning experience!
Returning to the Brunel Hobbies device, a matrix comprising a plate with wires soldered on at appropriate spacing, and a smooth burnishing tool would do the job very nicely, no need for machining, simple, effective. Probably a bit slow if you're doing square feet of the stuff, but for a shed or two...
best
Simon
Ressaldar
Western Thunderer
I bought one of these
Amazon.com: Fiskars Paper Crimper (12-93408897)
many moons ago, which gave me the 'wriggly tin' that was needed for an industrial building being built for the Club layout. The 'tin' was a 3" wide strip of o.005" brass shim material. It must have done the job well because the 'crimper' disappeared shortly afterwards, never to return!
cheers
Mike
Amazon.com: Fiskars Paper Crimper (12-93408897)
many moons ago, which gave me the 'wriggly tin' that was needed for an industrial building being built for the Club layout. The 'tin' was a 3" wide strip of o.005" brass shim material. It must have done the job well because the 'crimper' disappeared shortly afterwards, never to return!
cheers
Mike
Dog Star
Western Thunderer
My Good Lady had one of those and it was "borrowed" by one of our children when they were the innocent-side of teenagers... when returned the item no longer functioned as intended, probably a result of trying to crimp 1/4" armour plate
.Thanks for the memory Mike, I had forgotten about that tool - I shall need to keep a look-out when the Good Lady and I are at craft shows.