Choice of engine belting impacts speed

IndianaRog · Choice of engine belting impacts speed

For 3 years now I have been running my Jensen 51 replica using a pair of 24 inch long spring belts tethered from 5 inch flywheel to the cluster of 3 generators. Using my DC Volt meter as sort of an RPM gauge...I consistently could get 22 volts DC from my built in stepper motor generator when no lights or motor load was applied.

After 146 hours of operation one of the spring belts broke today, so instead of just swapping in another, I made up a pair of 24 inch green 2 mm diameter belts (the kind you fuse ends with heat). To my surprise voltage went UP to 24 volts DC under no load conditions from simply changing belting material.

Learning point for me...spring belts work well, but the tension they must be under to avoid slippage creates drag on an engine. Green belting material was only stretched enough to avoid slack and no more...it is "grippy" even when oily and I experienced no slippage.

10% more speed with such a simple change!!! I also like the look of the green belting against the red flywheel and red generators. Not sure if there are other sources of the green belting, but I got mine from US eBay seller " The Steam Chest " at a cost of $1.45 USD per foot in the 2 mm size. So, those 24 inch belts cost me about $3 USD each (cheaper than $2.50/9 inch spring belt) and I expect they will last as long or longer than the spring belt type.

Rog

Rog

metalhead100

Ahhhh

Great news Rog,.....mental note to buy that green 2mm stuff....I saw it before but was worried about the knurling on the Wilesco "model" pulleys chewing up the belt....as they do with rubber bands.

I think i would need to re machine the Wilesco pulleys and remove the knurl.

With them I guess I am stuck with springs or replacing all the pulleys (no thanks).

I already have the "Iggy" belts on my stepper...running in those Tamiya pulleys and they fit perfect! I also have them on Junior.

I will be watching to see how many hours you get on those melt joints.

As constant repair I am sure will cause you to re-spring belt it.

Jim

IndianaRog

I too am hoping I don't have to mess with the melt joints of those green belts. So far I have had a shorter one on the governor with about 35 hours of operation on it...so far, so good. I had trouble getting an "Iggy" belt to stay stuck together on the governor, so tried the green stuff about 6 months ago.

I do use an "Iggy" belt to connect the 3 step pulley mounted between Jensen 15's on my 51R down to the stepper generator beneath it. That belt has 45 hours on it and going strong. Key to success with the "Iggy" belt material seemed to be fresh, medium consistency CA glue...older stuff just wouldn't hold.

On the green belting stuff, I clamp an old xacto blade in a pair of vice grips and heat it with flame til it turns red...then simultaneously touch the green cut ends to each side of xacto instantly liquifying it...trick is to be able to hold them squarely together til they cure, about 45 seconds. They trim up at the lump with a pair of nail trimmers. I'm thinking the green stuff is going to last indefinitely...time will tell. Put 3 hours of operation on it today and all is well.

Rog

xlchainsaw

fantastic rog. i can get 2 mm "o" ring material here. is the "green" stuff similar only green??? the time test is great way to determine a ideas worth.

johnreid

I think the black is very much the same.
I wonder id there isnt rubber coated spring belts out there.

metalhead100

I have seen somewhere a "hot knife" like X-Acto tool that was on a small soldering iron.....

Might have been part of a wood burning kit at hobby lobby....ect

That would free your hands to work with the belt.

Or.... at those "dollar stores" you can find dirt cheap soldering irons that one could attach a sacrificial X-Acto collet too....

Or (yea there is more) Get one of the handy "pen " Bernzomatic mini torch kits from wal-mart ....it comes with lots of tips and can solder...torch....melt....ect...It has a hot "knife" attachment..(like a sharp wedge not a blade).. Under $20 bux...uses butane.

In the plumbing section Rog...back where the plungers and toilet seats and bathroom brass ect is.

I love mine....comes with a nice case ,sponge,several tips and solder!

Jim "the other Pyro" Hail

johnreid

Now that is on my want list, I have bough too many pencil torches at Harbor Freight that just do not work. All too often I would like to have a smaller flame for soldering, and the pencil torches seem so good for the job but do not last long before they will not open or close right

xlchainsaw

ozsteamdemon

Great stuff Rog .

I too noticed the the effects of belt tension versus speed for running hi torque loads such as generators and tried O-rings , but found to get good grip , the O-ring needs to be real tight , and after wrecking a few springbelts , i ordered 10 ft to try it and was so impressed , i ordered another shipment of 20 ft thinking thats enough to last quite a while ............ wrong , used that up in no time ,
so finally i ordered 50 ft . The reason i needed so much was not because of failures , i have never had a failure , its because , once i join a belt , i use use it , then hang it on a nail in the wall for next time , then when i want to run a different set-up , i make new belts to suit . After a while , i have quite a good variety of lengths made up ready to go .

I`m sure that the material chosen to heat the belt is not important , i use a scrap of stainless steel " Band-it " but an old knife blade or a bit of brass would work equally well . The means to heat it is not important , if you have a pair of vicegrips , the kitchen stove would do the job easily .

I must say that i think O-rings are great for running light free spinning loads and the same can be said for springbelts , the springbelts have the advantage of quick and easy installation .

So , its a matter of " Horses for courses " and all types are great for the particular application .

On my Wilesco Wonderland project , i used , 9 Green belts , 12 O-rings and one spring belt . The key to its success was that the Primary drive belt from the engine was the Green stuff .

But i would definatly say , if your playing with generators , get yourself some Green stuff .

Lastly , i would say that the Knurl on the Wilesco pulleys is not an issue with wearing the belts , its more of an advantage in my opinion .

Mark-One

I keep meaning to buy some of that stuff.

I wonder if they make it in larger diameters, and wonder even more if it would be suitable for driving the unimat.

I have a difficult time finding the right size o-rings for that outside of overpriced ones on ebay.

tmuir

I use a green belt on my BTM watch makers lathe.
It is about 4mm (Can't remember what size I ordered and I'm 4500km from home at the moment) and that you melt the ends together and it works perfectly for my lathe so I guess you could get one for a Unimat.

Griffin

A real interesting thread this one. I could have done with using the green belting for my STWWW experimenting.

The problem with the spring bands you always seem to have a degree of slippage when under heavy loading, due to the steel to steel contact of the band and pulley, which is always a recipe for slippage.

IndianaRog

Part of my reason for moving to the green belting was that after 145 hours or so of operation, the metal spring belts I used for my main flywheel to generator connection were wearing the aluminum pulley deeper and deeper. Eventually I expect it would have cut right through it and I wanted to avoid having to disassemble everything and make up a new 3 step pulley.

Comparing the green belting to the black, viton stuff (O ring consistency)...I find the green more "grippy", especially when it gets oil on it. The black seems of smoother consistency and with a bit of oil it will slip unless more tension applied. Also, the black is different stuff because it must be glued vs. heat sealed.

I think there is a place for all three...steel spring belts, green belting and black belting depending on application.

Rog

WeedenSteam

As a pressman we used larger diameter belts on the delivery section, we usually joined them with a Bic lighter and smoothed them out with our fingers dampened with saliva. Had to time it just right, you got burned fingers if you did it too soon or it would set to much to get rid of the lump if you didn't do it soon enough. After a while I got pretty good at joining them without too much of a lump.

Caprice

Thanks, good to hear, as I just ordered some green belt.