IH 1480 vibration

[Jim Basler]

I changed rub bars before harvest.It worked fine in peas and lentils but when I started the wheat and increased the rotor speed there is quite a vibrataion. How do I balance the rotor.

 

[IaGary]

Not sure on the balancing thing but make sure all bolts are tight on the rub bars.

When I bought my 1660 they had just replaced the rub bars. Was fine on corn at slow rotor speed.
Next summer when I did oats at higher rpm it had a vibration. Before I got it shut down one of the bars let loose and flew out the back of the combine. There was still paint in the one hole,so no bolt was ever in that bar.

Gary

 

[1460 man]

Make sure all the dust,dirt,straw and grain has been thououghly cleaned out behind all the rasp bar mounting brackets, also make sure the top of the mounting bracket where the rasp bar bolts on is clean on all brackets. My 1460 always balances itself after running it for awhile.

 

[cadet trooper]

IaGary is probably right on but if that is not the case check to see if you didn't pickup a lot of mud or dirt running the specialty crops building up on the back of maybe one or two or all of the bars, chaff normally doesn't do it but mud has some mass to it due to the fact the 1480 has a bigger diameter rotor than some of the smaller machines the FPM is greatly increased which causes an amplification of the problem, however due to the fact that mud should have dried and not securely fastened it should have disloged within a few seconds and smoothed out. I'm not famaliar with the rub bar design but if it has an angle iron design it may not be able to dislocate and you may have to remove it by hand. This phenom is not uncommon in cylinder machines especially after running corn an beans and going to wheat or going to beans from corn but only occurs for a few seconds.

 

[Anonymous-0]

A little vibration can be caused by dust settling at putting the rotor slightly out of balance , But this wopuld be from time to time and not constant another reason for vibration at high speeds is the jack shaft in the rear of the rotor is worn but a little is ok , My 1480 and 1688 shake a little over 950 and the 1688 has a new balanced rotor , My TR 95 used to shake a cassette out of the radio ?

 

[cadet trooper]

Vibration analysis becomes very complicated and yet very simple it normally takes 1% of the weight of the rotating device to throw it out of balance which due to the weight of the rotor would be quite extreme so the fact of dirt build up is highly unlikely unless you have a giant rock stuck in it. A loose coupling which was mentioned will cause a vibration that should show up as X3 times rotational speed and also will show up at critical speeds. Thus finding your problem can be diagonosed with a vibration analyser finding your X number will tell you what is the problem. If you really want to fix the problem find a local vibration specialist i.e. motor shop, they can pretty much diagnose the problem and maybe make it run as smooth as glass and give it many more hours of running time. Also most of the schools I've gone to about VA is only a fool would run a machine at critical speeds (speed at which the rotating device has all the metal rotating out of sync)every machine has this phenom you just learn to stay out of it or engineers design the speeds to stay out of it. Tip, mechanical looseness is a big factor i.e. bearings going bad but VA can pick that up which can save some serious downtime at a critical time. My two cents CT

 

[cowboy9]

after cleaning all chaff , visual inspection should help you account for the vibration( broken rasp bar, pedestal missing exc.) if thats the cause replace parts as necessary making sure to equalize the sides. If nothing is found on visual inspection place the rotor in neutral and spin it, it should stop in one spot all the time. the bottom is now the heaviest part and by adding weight on the top you can easily correct the problem with a little welding.