JDSeller

JDSeller, I have had this question for a long time & have decided that you are likely to have a good answer for me if anyone does. This is an old Austin Industries/Austin Products, Inc., Dallas, TX (bough by Servis/Rhino in later years) 8 foot, dual spindle shredder/brush cutter. It has never cut very cleanly compared to three small 5 foot units that we use. I have tried many things: good sharp blades, setup with front an inch lower than rear (measured at blade tips, not housing), verified PTO speeds with PTO tachometer, even went so far as to swap gear boxes around so as to reverse rotation of spindles, all with virtually no significant improvement. Other observances: accounting for PTO speed, gear ratios, length of spindle-to blade-tip, this unit has a blade tip speed of 10,300 feet per minute @ 540 PTO rpm. The 3 other units blade tip speeds are, 10,700 fpm, 12,750 fpm, 16,300 fpm, and new SERVIS catalog cutters show 10,000-heavy brush, 15,000-standard, 16,500-finish. Khun hay mower-15,800 fpm. Of my three 5 foot units, even the 10,700 cuts easily two or three times cleaner than the 8 foot unit and the 16,300 very clean as you would expect, but can't even handle thick heavy grass behind an 8N. I have run the 8 foot behind both 44HP and 67HP tractors and at various ground speeds, all with nasty looking results over several years in different kinds of growth. Question is, do you have any ideas as to why this thing cuts so poorly? Potential remedies? Thanks, in advance for any experience/insight/etc.

I would say lower tip speed and blade shape. Also the 8 foot mower spindles are just about centered on your wheel tracks. That make them both have to pick up the downed material which is harder. Usually one side will cut well and the other poorly.

Question??? Are your gear cases counter rotating??? If so which way is each side turning?

JMOR
Does your cutter have straight or suction blades?

I remember back in the 60's-70's picking up cutters,rear blades & parts on Singleton Blvd in Dallas at the Servis(Austin Bridge) facility. I also assembled the above equipment.

(quoted from post at 14:36:11 10/18/15) I would say lower tip speed and blade shape. Also the 8 foot mower spindles are just about centered on your wheel tracks. That make them both have to pick up the downed material which is harder. Usually one side will cut well and the other poorly.

Question??? Are your gear cases counter rotating??? If so which way is each side turning?

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riginally left-CCW and right-CW, but I didn't know that such was correct when I reversed them. Only difference I ever saw with reversed rotation was that it would windrow the cuttings to the center....didn't cut any better or worse.

(quoted from post at 14:56:35 10/18/15)
JMOR
Does your cutter have straight or suction blades?

I remember back in the 60's-70's picking up cutters,rear blades & parts on Singleton Blvd in Dallas at the Servis(Austin Bridge) facility. I also assembled the above equipment.

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'm not at cutter location now & can't remember so I will look next time I'm there & let you know. My e-mail is open in Modern view, so if you like, you can send me a message & that way I will have your e-mail for when I look at the blades.......this thread will be cold by then.

Does it cut poorly at all heights? I have a JD 1508
that does a horrible job. It can make you wish you
never started the tractor and convince the
neighbors just got reinforcement that you don't
know what you are doing.

Unless you drop the thing into the dirt. If you cut
everything 4 inches tall it will make it look like a
lawn mower did it. It could be foxtail, cockle burrs,
brush, saplings, you name it. It makes it all look like
a million bucks.

I don't bother to hook it up unless I am willing to
scalp everything I mow.

(quoted from post at 22:43:30 10/18/15) Does it cut poorly at all heights? I have a JD 1508
that does a horrible job. It can make you wish you
never started the tractor and convince the
neighbors just got reinforcement that you don't
know what you are doing.

Unless you drop the thing into the dirt. If you cut
everything 4 inches tall it will make it look like a
lawn mower did it. It could be foxtail, cockle burrs,
brush, saplings, you name it. It makes it all look like
a million bucks.

I don't bother to hook it up unless I am willing to
scalp everything I mow.

Click to expand...

don't know, as I set it high enough to get only a little grass, just trying to top the wooley croton (AKA goat weed).

JMOR if your trying to cut real tall them nothing is going to work very ell doing that. The tire tracks will just about always stay flattened down.

lift blades will help it cut better. It throw the grass clear so the blades can cut the next batch of grass.

JDseller & sotxbill, my initial point is the huge difference between the 5 vs 8 foot cutters, both of nearly identical blade tip speeds cutting same material at same height. I have yet to check the lift blades or not.