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Discussion Starter · #1 ·
I have a fixed air foil chaffer I am going to try on my TR70. I noticed last fall I was getting more trash than normal in the grain tank in corn. Checked the fan speed with a mechanical tach and can't get over 900 turned all the way up. Should be able to get at least 1100, correct? I replaced the bottom inside sheave on the fan drive shaft because it was getting loose on the splines and didn't gain much. The primary drive belt is not getting completely to the outer edge of the pulley, what do I need to do to get more travel out of the linkage? I don't really want to put that chaffer in without fixing this first because it probably won't work very well.
I also have a TR86. I noticed the last few years on both machines getting small cob pieces in the corn sample, depends more on corn variety. I've tried every setting imaginable for concave clearance to rotor speed and fan speed, but I imagine it's a threshing issue. Also tried closing the sieves a little, but then too many tailings. I usually run 650 to 750 rotor rpm, and setting 10 to 12 on concaves. Anyone else with advice? Just trying to get the bugs out before they get to the field.
 

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fan belt. Once it loses the width from wear and stretches a little bit, it won't ride up to the top of the pulley. Had the same thing happen on a TR98. Changed the belt and up went the fan speed. It was only a width difference of maybe 2 mm, but made a huge difference in fan speed.
 

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Dont have our TR75 anymore to look, the fan is driven off the main rotor belt and drive belts right? With out TR75 once these belts started to wear they would start to slip. Could be something to check. Ours got bad that you would go up a slight hill and it would slip with an emty tank.
 

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As was mentioned the fan drive belt wears a little and then when the drive pulley sheaves are tight together the belt is not clear to the ouside of the pulley. Consequently the fan is not running as fast as it could with a new belt.
 

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Discussion Starter · #5 ·
I'll have to measure it compared to a new one. Thanks. I also had a hydraulic line spring a leak on the right side and soaked the rotor drive belt last fall with hydraulic oil , had to replace the rotor belt and I think I just cleaned up the other belts, but maybe if they slipped long enough they stretched. Seems to me the clean grain elevator and the header drive belt were slipping, too. Anyway, it was an oily mess!
Any advice on the cob issue!
 

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like you said, many times it is a hybrid thing and hard to remedy?

looking at your settings though you mentioned i think you might be able to clean it some? on the rotor speed, try dropping it as low as it will go. open the concaves wide open if running square bar concaves??? put the rollers on every big wire if so doable,,,,if running round bar concaves try different concaves settings until you feel pleased, harder to set for my liking are the rd bars. get the fan as high as it will go.............then if you are running the bottom sieve, open it wide open.........adjust the top sieve to as open a position as possible. too closed and it will blow some out the back. set the chaffer ext. just a tad more open than the top sieve, too much though and you will get those tips as i'm sure are aware.

on the fan problem, we had them with the 70s & 85s also. what we would do and this is just what we did.........we took the bottom sheaves and drilled 2-3 holes completely through the hub........i think there are 2-3 pins in that hub, just center the holes between those pins.........then use 5/16 bolts long enough to go through the hubs, secure with Lock nuts and tighten up on each bolt as even as possible. this would keep that vari from opening up on ya and losing fan speed. we replaced that complete sheave also but eventually it would loosen up just like the old one you replaced,,,,,,it was just made to light to begin with. we found that putting a new belt on the fan with old sheaves only made a short term fix for getting your fan speed back. most times it would twist the new belt and ruin it in short order.

we found the smaller machines like the 70 & 85 to do a better job of threshing, saving and giving higher quality sample than the later, bigger, wider machines.

if could have my dream thresher......it would be a TR-85 with a fixed speed feeder and a urethane slatted feeder chain, the newer S Cubed rotors, a PFP discharge beater, all the OEM beefed up updates of a late model TR 97, the Genesis motor, riding on a set of tracks like the "dream thresher".........that would be the ultimate in my eyes......simple, un cluttered, mechanical drive linkages so you can feel those clutches "popover", low tech electrical system, light on it's feet!

never run a air foil before.....best of luck, joe
 
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