Rotary cutter..what to expect?

[countrybumpkin]

No the indicator on the tach shows were to run the engine rpms to obtain 540 rpm on the pto. If the engine is running slower rpm then the pto will too, it’s not a direct 1:1 ratio to the engine.

 

[biggziff]

No the indicator on the tach shows were to run the engine rpms to obtain 540 rpm on the pto. If the engine is running slower rpm then the pto will too, it’s not a direct 1:1 ratio to the engine.

My tach has 2 indicators for 540. One is around 1800 RPM (540E) and the other is at 2600 RPM. I'm reading that some tractors have a 2 position PTO engagement lever. One allows the PTO to run at 540 RPMs at 1800 RPM (Economy or 540E) and the other provides 540 RPM at the PTO at 2600 RPM (more torque, less economy) My tractor has a PTO lever that is either on or off. In my case, the PTO cannot spin at 540 RPMs at both 1800 and 2600 RPM. Mine should be run at 2600 to obtain 540 RPM at the PTO.

 

[Sawyer Rob]

My tach has 2 indicators for 540. One is around 1800 RPM (540E) and the other is at 2600 RPM. I'm reading that some tractors have a 2 position PTO engagement lever. One allows the PTO to run at 540 RPMs at 1800 RPM (Economy or 540E) and the other provides 540 RPM at the PTO at 2600 RPM (more torque, less economy) My tractor has a PTO lever that is either on or off. In my case, the PTO cannot spin at 540 RPMs at both 1800 and 2600 RPM. Mine should be run at 2600 to obtain 540 RPM at the PTO.

The above is the right answer...

SR

 

[biggziff]

The above is the right answer...

SR

Thanks, Rob. Learning as I go.

 

[LouNY]

On coarse weeds that your picture shows I wouldn't be overly concerned about blades being sharp even rounded over they will cut good.
Also chopping that heavy course stuff in one pass I'd give the deck more slope getting the rear of the deck 4-6 inches higher then the front.
Also I am guessing that you have a floating hitch for the top link attachment point that will allow the wheels to stay in contact with the ground while you are mowing
and you can adjust the height of cut with your lift arms. Quite often you don't need the full 540 rpm on the pto to do a good job, that said the faster the pto is turning the faster you can mow. Running through those tall weeds keep a good eye on the radiator condition and engine temp the chaff and dander will plug up a radiator quickly some days.

 

[biggziff]

On coarse weeds that your picture shows I wouldn't be overly concerned about blades being sharp even rounded over they will cut good.
Also chopping that heavy course stuff in one pass I'd give the deck more slope getting the rear of the deck 4-6 inches higher then the front.
Also I am guessing that you have a floating hitch for the top link attachment point that will allow the wheels to stay in contact with the ground while you are mowing
and you can adjust the height of cut with your lift arms. Quite often you don't need the full 540 rpm on the pto to do a good job, that said the faster the pto is turning the faster you can mow. Running through those tall weeds keep a good eye on the radiator condition and engine temp the chaff and dander will plug up a radiator quickly some days.

Thanks for all that. Yes, I can adjust the cutter height with the PTO adjust from the driver's seat. I'd agree that more angle might help with cuttings ejection and that would likely lead to a better cut, although like you said...in stuff this high and tangley there isn't much you can do.

I did keep an eye on the temp gauge (never moved once warmed up), but had a front grille covered in grass seed when I was done! I took my big backpack blower and cleared it all away.

thanks

 

[CobyRupert]

No the indicator on the tach shows were to run the engine rpms to obtain 540 rpm on the pto. If the engine is running slower rpm then the pto will too, it痴 not a direct 1:1 ratio to the engine.

It's a direct 2600:540 (or 4.814:1) engine-to-pto rpm ratio.

So in OP's picture where he's running at 2400 rpms, pto is turning 498 rpms instead of 540, basically 7.5% slower. Not a big whoop.

OP could just travel 7.5% (0.2 mph) slower than his usual 3 mph for the mower and pto to experience the equivalent torque (and equivalent blade revolutions per linear foot travel) as it would at 540 rpm .
Adjusting speed .2 mph can be tricky.

 

[biggziff]

It's a direct 2600:540 (or 4.814:1) engine-to-pto rpm ratio.

So in OP's picture where he's running at 2400 rpms, pto is turning 498 rpms instead of 540, basically 7.5% slower. Not a big whoop.

OP could just travel 7.5% (0.2 mph) slower than his 3mph for the mower and pto to experiences equivalent torque as 540 rpm (and equivalent blade revolutions per linear foot travel).
Adjusting speed .2 mph can be tricky.

Maybe I'll install an Arduino controlled GPS auto pilot!

 

[zzvyb6]

Don't forget to clean out the radiator screen(s) after that big/tall of a cut. Seeds, bugs, and other stuff is usually sucked in and that will eventually cause overheating.

I usually cut twice: 1st day is high off the ground, a few days later you chop it to the ground. If the field was ever hayed out, look for old bale twines wrapped around the spindle(s). They reduce the cutting effectiveness.

 

[countrybumpkin]

It's a direct 2600:540 (or 4.814:1) engine-to-pto rpm ratio.

So in OP's picture where he's running at 2400 rpms, pto is turning 498 rpms instead of 540, basically 7.5% slower. Not a big whoop.

OP could just travel 7.5% (0.2 mph) slower than his usual 3 mph for the mower and pto to experience the equivalent torque (and equivalent blade revolutions per linear foot travel) as it would at 540 rpm .
Adjusting speed .2 mph can be tricky.

Well your forgetting the gear box ratio too. Geez

 

[BRMyers]

biggziff, you ever think it might just be easier to go buy some goats?:laughing:

I'm learning a lot off of this topic, didn't know what 540E was and how it worked, now I do. Thanks for starting the topic for us rookies. :thumbsup:

 

[biggziff]

biggziff, you ever think it might just be easier to go buy some goats?:laughing:

I'm learning a lot off of this topic, didn't know what 540E was and how it worked, now I do. Thanks for starting the topic for us rookies. :thumbsup:

These neighbors have had Goats, cattle, horses, pigs, sheep, chickens, you name it. Definitively cheaper, but not as much fun!

I'm a newb right there with ya. Learning every day is my motto.

 

[RSKY]

From looking at the kind of weed you were mowing but without a picture of the cut field it is hard to tell what was going on. That looks like stemmed weeds and not grass. May have grass under the weeds but it shouldn't be anything to pull a tractor down. We always run at the proper rpms to keep the mower at 540 or higher. On the old 4600 Ford I have dropped down a gear and ran it wide open thru the thick stuff. Makes some very interesting noises and throws stuff a long way. I will guess that you were trying to cut too low. Anyway, you will figure it out after using the mower a couple more times.

Whenever you are using a tractor to cut a field that high you MUST keep one eye on the heat gauge at all times. We mowed 24 acres of CRP ground last year that had something growing on it that would plug the radiators solid. We could make one round on the little Kioti and two on the old Ford before having to blow them out. Took two days to do a one day job because of that.

RSKY

 

[NYCheese]

I'm also in Upstate NY, and have done plenty of mowing in what looks like similar conditions to your pics. I've got a ck3510se, with a 2060 cutter. I banged the blades up pretty good last year, so they're far from sharp, but it's still doing a fine job this year cutting.

Like others have already said, your primary culprits are likely: going to fast, and not having the rear of the mower set high enough.

When mowing the really tall and thick stuff, I put it in low range, and keep it to a snails pace. It's faster to do it once slowly, than having to do it twice.

Here's a picture of my cutter from last year (when it was still shiny and new). This is the rear height setting I keep it at. I generally mow in 2 positions depending on which fields I'm mowing. Either the front end riding on the ground, for the lowest possible cut, or raised up about 3-4" for a 6-7" cut.

 

[prof fate]

low hst 'full speed' is about as fast as you want to go in deep grass.

also, the tractor tires will push down grass that won't stand back up and be cut - so it's gonna be ugly. give a couple days and mow again.

This is why I just bought a flail mower. Tired of the grass not being completely cut and having 'mowhawk' look to the field after a couple of days.
The rotary bush hog does well in grass 2' or less...the tall stuff isn't as well cut.

Thanks for the info. This field was bone dry, cutting in late afternoon sun. I had the rear wheel set so the mower deck was pitched 1-1.5" to the front (I read this was best for heavy cutting) I was in medium HST. Sounds like under these conditions, this is about what I can expect for results.

I appreciate all the help.

 

[IndyIan]

I saw someone cutting roadsides with a sickle bar mower last week and it seemed to be working well. I've only cut with a brush rotary mower and a 9' haybine and its amazing how little hp the haybine needs to cut in heavy heavy grass. Mid range all the way and pretty quick until the crimper chokes on too much bind weed in grass.
Anyways I guess my point is that a rotary cutter is probably the least efficient way to mow a field, but does chew everything up so it breaks down nicely. I read sickle bars alone can clog but they sure work well in a haybine, I'm sure someone has modded a haybine to make no windrows and for smooth clear pasture mowing it would be fast.

 

[DieselBound]

Unless you want to mow with the tail wheel off the ground, the rear height cannot be changed from the seat. Actual adjustment here requires shifting a bolt (or two).

I also agree that I prefer to run one pass slowly than two passes more quickly (higher first cut and then lower second cut). Reason being is that going back over means you're going to be churning up all that cut grass from the first pass; and, the grass is likely going to be pushed down by all the cut grass. In my case I've got a lot of obstacles to maneuver around, in which case doubling passes means I double my navigation efforts (subjecting myself to more dangers- tree branches and stuff).

Type of grass that one is mowing makes a BIG difference. One tractor and cutter might be able to run through 4' high grass in medium gear while the same combo might struggle with in low gear with a different type of grass of that same height.

I tend to run at about 2,300 rpm. I'll bump it up to 2,500 if I feel that the cutter is being worked harder (is tending to slow down).

I agree with someone who earlier stated that running half-passes (half width) is something one can do when running through really tough/tall grass. I also do this: one can clean up wheel tracks better this way too.

 

[Threepoint]

Well your forgetting the gear box ratio too. Geez

CB, but wouldn't the gear box ratio of the cutter remain constant in CobyRupert's reasoning? So, regardless of what it might be in the OP's cutter, changes in the cutter's blade RPM, revolutions per linear foot traveled, and tip speed as well, should likewise all be directly proportional to changes in the engine RPM. No? :scratchchin:

 

[JDAOWNER]

They're coming off this morning for inspection and sharpening.

TRACTOR MIKE RECP,EMDS NOT SHARPENING ROTORY CUTTER BLADES. AS SEEN IN ONE OF HIS VIDEOS

 

[DieselBound]

I quit sharpening mine. I cut a lot of brush: better to shatter than leave sharp points all around; plus, it helps break down the brush (greater wounding). With grass and only grass (and NO rocks), it might be OK.