| Archive for The Unofficial Mamod and Other Steam Forum The Original Unofficial Toy Steam Forum Established 2006 The biggest, most popular steam forum around! Accept NO imitations! We have a growing community of regular posting members who chat about all aspects of toy and model steam. |
| toxx |
Alternative to spring belt driveH'llo, firends! Spring belts, like Mamod and Wilesco use, are not exactly realistic. I've had the idea of using these instead. There might be a little work to do to make the wheels fit to the 4mm Wilesco flywheel axle (the smallest I could find have a 6mm bore), but the visual effect would be legion compared to spring belts. The drive belt are available in various widths and diameters, and are unkaputtbar (undestroyable). Problem I have is: What do you call these darned things in English?
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| Mister Occlusion |
Certainly wouldn't slip
As to making them fit... I did a quick and dirty job on my PMR generator, which has a shaft smaller than even a Wilesco pulley. I cut a bit of brass tubing to sleeve the shaft with, and ground out a slot near the end for the grub screw to pass through. The screw was plenty long enough to bite. The PMR has a flat ground into the shaft too, which makes it even less likely for the wheel to break loose. I don't know what those toothed belts are called either, but I've seen them on superchargers in the past. |
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| tmuir |
Don't you believe it! My thicknesser (Woodworking machine) uses these belts to drive the blades and it had 3 sets of these belts slide off the last one slid of and actually rubbed so much against the housing it actually melted the plastic cover on my machine. As this all happened under warrenty the company I bought it from then decided to change brands of drive belts and now it is fine. 
My only concern on using them for toy steam is they may be too grippy and would steam some of the engines power. |
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| Les |
Are they not just called toothed belts or toothed drivebelts? | ||
| johnreid |
My Jensen 70 came with one of those Cog Wheels instead of the regular Pulley Wheel, I took the one off of a Stepper Gen and have it on the Jensen 70.
The hole in the center is larger than the Jensen shaft, I did not measure but bet it is 6mm. |
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| Mister Occlusion |
Rubber bands work a treat too, but you cannot get them onto an internal pulley without dismantling something... Of course that's a weakness of these too.
smallparts.com sells o-ring kits where you can splice your own, any size that you need. I wonder how durable those are, considering they aren't meant to do this sort of duty |
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| psantama |
stepper pilleythose pulleys with theeth are used commonly used in stepper motors. Search on ebay as stepper pulley... you will find severa. the are expensive an the diameter is an issue in most cases.Look at these other drives.. http://www.crabfu.com/steamtoys/steam_walker/ that little chain looks pretty durable. |
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| MooseMan |
On my WorMar/Bowman workshop I use meccano chain and sprockets from the engine to the driveshaft:
Turns out to be pretty effective, very little loss of power because there is no elasticity. |
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| Nick |
I love the look of the chain drive, but it looks to large for a toy steam engine. | ||
| Mister Occlusion |
Aye, chain is cool
But with the loads and RPMs I usually pull, I don't know if it'd last 
Nice thing is they don't need to be under tension, so that's less drag on the engine bearings (don't know the proper term). |
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| CCairns |
Yes they are called toothed drive belts, but they are not indestructible!
My old Vauxhall Astra had one of those belts fitted for the cam drive, and this snapped on the M25 at 70mph! Ironically I had one in the boot to replace this belt, but they had changed the design of the cam drive (included an automatic tension adjuster) and I need to get another tool to change this belt. A very expensive repair. I understand that the Volkswagen engines are designed to retract the valves if a belt falls, thus preventing the damage mine suffered. |
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| Les |
I had a cam belt snap on my old Escort. I was only pulling away from a set of traffic lights and ended up bending valves. Cost £900 to repair. In hindsight, would have been better to get another car. |