3"flat belt for generator drive

[1958steveflying]

Hi All,

   Can anyone give (from experience) advise on running a generator on a Lister 6/1 using a 3"flat belt. I have been trying one out and am having tracking issue's and its not doing what the text book say's it should. The flywheel and gen pulley were both flat, i am having a crown put on the gen pulley to try that next.

   Steve

[rcavictim]

You could install a roller guide (with ball bearings) on each side of the belt to keep it centered as it winds onto one of the pulleys, say the driven pulley?  Kinda like half of one of those guides used around a winch cable on an offroad bumper winch.  Called a fairlead?  As for adding a crown, remember British Royaly.  A crown hasn't kept the Monarchy from running perfectly true!   

[Oiler]

Remember that flat belt pulleys, must have diameter that is a bit larger at the middle of the pulley.
The belt will try to allways run on the largest diameter.

Torsten

[RICK]

New to the forum, but have been luuurking from the out side for about two mounths. saw this post the outherday and today saw a inexspencive
and long living solution. located a centry 2hp elect motor, 24in grinding wheel,air comoresser and band saw18-20-in, all driven by a flat belt. all pullies
had a crown created at the center using old time black CLOTH electrical tape.these machines go back long befor my day and the tape is still well inplace
and appears sound and usable. it is K.I.S.S ,,out lived oreginal owner im sure.

[listeroidsusa1]

A few years ago I had a Fellows 6A line shaft driven gear shaper circa 1917. It had a 3 speed flat belt pulley and the pulley was lined with friction tape. It worked very well. The pulleys had both crowns and side flanges. I drove it with a 6/1. It made quite a display for the engines as well as cutting very nice accurate gears. A local military surplus outfit had the gear shaper and when I asked them about it they asked if I knew what it was, and when I said I did and that  it was in very nice condition under the cosmoline they told me if I would move I could have it! I got a rollback over that same day. I called Fellows and asked for a manual. They wanted to know what the serial # was. When I told them they pulled all of the records on the machine and told me it was purchased by the military in 1918 and that they had done all of the maintenance over the years and had done a total overhaul in 1948 and packed it in cosmoline. It was still in the same cosmoline when the military surplus place gave it to me. That ole Fellows and the 6/1 has cut many a nice gear over the past few years.

[SteveU.]

And my vote is we jump both you fellows to Hero status immediately!

SteveU.

[oliver90owner]

must have diameter that is a bit larger at the middle of the pulley.

Oiler, we will take that sweeping statement as a small difference in language.

Our 1952 baler (it was not the earliest model that had a similar drive system), a Massey Harris 701, used an endless flat belt.  Probably 4 inches wide.  For maximum grip, minimum slip, it ran on a flat pulley.  A flat pulley needs a lip either side or some other tracking aid.  A flat pulley can run with more tension than a crowned pulley without mis-shaping the belt.  Modern automotive toothed cam belts run in a guided tooth pulley.  Note I say a, as the other members will allow alignment-float for the belt.

Our baler used an engine of about a 20HP at 2000rpm.  That belt might screech a little if the engine was stalled out quickly and also a bit when the main machine was put into operation ('wadder and ram mechanism').  Otherwise they were never any trouble.  A loose belt would not have coped with that operation.

1958steveflying,

Crowned pulleys go back to the steam era and probably before. 

I believe there are better solutions in the 21st century, than relatively loose belts flapping around.

Loose because the belt length was made to approximate measure (and could be repaired many a time before it was of no further use for the user) but the belt clips were a weak link.  Loose because of the variations along the belt length and the necessary slippage which always occurred.

However, for a flat belt you will probably find you need the more contact area than the micro V belts which use the V wedges as extra friction.  You may need bigger bearings as well, to withstand the extra radial loading (the centre point will invariably be further outboard than a narrower belt).  You will almost certainly need a belt-tensioning device.

BTW most tractor belts using flat belts and crowned pulleys operated at around 2600 feet per minute.  Probably a figure handed down from steam traction engines.

The questions you might ask yourself are why did V belts virtually make flat belts redundant, and why a lot of drives are now micro-V.  Answering these q's will explain why you are spending a lot of time on a less cost efficient drive.

Is your flat belt fastened together with crocodile clips?  If so, give it a rest and send it to retirement.  If an endless belt, get a suitable pulley and tensioner and it will work.

Regards, RAB