Trac-Vac 854 PTO Powered Leaf Vacuum

[LC7100]

I have an older Trac Vac Model 856 that I bought at least 25 years ago for my B7100. It was designed to operate at the tractor's 850 rpm PTO speed. A few years ago we purchased a Deere X495 with a 540 rpm PTO speed. The 854 Trac Vacs have two sets of pulleys and belts to keep the blower/impeller speed up. I changed the two pulleys on mine to speed the blower up for the John Deere. It works really well, except that I lost nearly all the adjustment to tighten the belts. I just replaced them, and I had to take the gear box off to get the new belts on. I also checked the gear ratio for the gear box. The output shaft turns approximately 2.15 revolutions for every one turn of the PTO shaft.

This Trac Vac has served me well. I would recommend it to anyone. We have used it to pick up grass clippings and leaves every year since it was new. The B7100 was a little underpowered and we had to monitor the temperature carefully or it would overheat, but the newer Deere has a lot more power and handles it very well.

I did make a few other changes to it. I put a ball hitch on the trailer. The hitch pin kept wearing out the hitch holes on the trailer, and the ball hitch solved that. I also removed the lift arms that connected the rockshaft to the 3 pt. lift arms, and then put chains on to hold the 3 pt. arms. The 3 pt. would otherwise go up and down with the mower. I also had a friend rework the Trac Vac boot that fastens on the mower deck. He split the sides of the boot and lowered the bottom by about 1 1/2 inches, then filled in the void created by a couple pieces of triangle shaped steel. It seemed that some of the leaves and/or clippings would go under the boot the way it was designed.

I have included photos to show the changes. I also included a photo of my 'corn rake' that I use to unload the trailer. Really it is just a pitch fork with the tines bent over 90 degrees. It works really well.

 

[kennyd]

Chuck, your memory is spot on.

http://www.tractorbynet.com/forums/attachments/109171-pulled-trigger-cyclone-rake.html

The slide-out is still in use 2 years later.

Don

Thanks Don...Very cool indeed!

 

[joes_427_vette]

LC 7100 ;

How did you know what size pulleys were needed to get the correct impeller speed ? What diameter and width impeller did your model have ? I assume for manufacturing purposes both models have the same size components, just different arrangements for the shafts / pulleys.
I have a 16" diameter x 4" wide steel impeller I am planning to use. If I turn it at approximately 3500 rpm there should be a formula to determine the true tip speed.

I looked at a used Agri Fab leaf vacuum engine / trailer unit Sunday. It is priced at 500 which I think is a good buy but it has a five hp briggs motor with a very small impeller, probably 12" x 3". I don't believe this unit will create the required vacuum to pick up my embedded pine needles. They seem to stick to the grass and even the 60" mmm doesn't blow all of them out the chute. My impeller is constructed of 1/8 inch material and if need be I can add steel to make it more effective. The Agri Fab model impeller looked really thin and possibly a good size rock passing through would destroy it. I believe it is a 1987 model.

 

[LC7100]

Joes 427 Vette

For my pulley size, I just did some calculation. The original pulleys for the approx. 857 rpm speed of by Kubota were 7.5 in. diameter for the driver and 3.5 in. diameter for the driven. The circumference of these pulleys was 22.77733 and 10.99595, or a ratio of 2.071429. I used a gearbox ratio of 2:1, although I think it might be closer to 2.15. Using this information, 850 rpm PTO speed times 2 for the gearbox times the pulley ration of 2.071429 results in an impeller speed of 3550 rpms. By changing to a 9 inch driver and a 2.75 inch driven pulley with a 540 rpm PTO speed, the ratio is 3.272727. This results in an almost identical impeller speed of 3534 rpm. With those pulleys, the blower seems to work fine, although I did later put on a 2.5 in driven pulley to gain just a little more speed. The only problem, as I stated earlier, is that with the larger driver pulley, I've lost nearly all the room to make adjustments to tighten the belts, and I am bound to almost precisely the correct belt size.

My impeller is approximately 4 in. wide and 16" diameter, the same as yours.

 

[joes_427_vette]

Thanks for the info LC ;
I was trying to weasel around a 1 to 2 gear box but I think it will almost be a must. I have a selection of browning pulleys which should not be a problem. So I'll be on the lookout for the gear box and a series of pillow block bearings. I was hoping my impeller was larger and I could maintain your tip speed with lower rpm.

The fun part, salvage yard hunting for those necessities, and laying out metal for the frame work. Sold my 185 Miller mig so I'm also in the market for a new 250.... Miller or Lincoln.