BELT TENSION

[overbore]

I am using the 8 groove auto belt driving the custom matching pulley.  What belt deflection should be used to have the correct tension?     Many thanks.
overbore

[dieselgman]

Auto-tensioners are a great way to go... Cummins - Caterpillar - John Deere - Detroit Diesel and so on, all use them on commercial engines. Simply a spring loaded idler will do the trick.

dieselgman

[BruceM]

I have slippage on surge loads on my 6/1 and ST-3 setup unless I keep my belt quite tight. I'm using the automotive type ribbed flat belt. 

My 2 stage air compressor setup is dual B belts, and I find that due to the large pulleys on both ends, I can run just one "B"  belt, and it doesn't have to be very tight.

I think the auto flat ribbed belts are overrated, as they have to be run so tight, but I admit it sure was handy to just run it on the flat flywheel, and the special pulley I got from Utterpower made it a snap to do.

[overbore]

Auto-tensioners are a great way to go... Cummins - Caterpillar - John Deere - Detroit Diesel and so on, all use them on commercial engines. Simply a spring loaded idler will do the trick.

dieselgman

OK; good idea but mounted to what? I see no quick pad / bracket on the "Roid so it goes on the gen base frame?

May thanks,
overbore

[millman56]

I`ve recently used one on a generator for the first time and am pleased with the result and have not had noticeable slippage so far, its a 6 groove poly-vee belt  running on the face of a 6-1s  25" flywheel driving a 4.75" pulley on a 4KVA 3000 rpm alternator,  at a guess the contact angle on the driven pulley is 130 degrees.    Never had any problems running 2 X  "Z" or "A" section vee belts on a similar set-ups, in fact the "Z" section belts would lay over on their sides around the face of the flywheel and twist back into the vee pulley without issues. 

One thing that stands out is the (nowadays)  massively overspecified 2 X "B" section belts on SOM sets,  the reason I guess  is that 1930s belts were nothing like as good as modern ones.

Mark.

[overbore]

Per the good suggestion from Dieselman, E-buy has Cummins tensioners for about $60 in 8 groove flavor which need some midnight engineering to securely mount to my 6"  I beam and have a variable height feature for initial belt tension. Anyone done this?
overbore

[buickanddeere]

Spring tensioners can sometimes start oscillating  if they have the same natural frequency as the engine's or load's power pulses.

[overbore]

AGREED--- however, I have in mind another heavy angle section attached to the far I beam, near the belt, which would have a tube welded to the angle section. The vertical tube would contain a threaded rod  with securing and  adjusting nuts above and below the tube-rod assembly  attached to the tension device thereby eliminating most to the load harmonics you referenced.
Any ideas? Many thanks, friends,
overbore