Grading Finish Blade test - the blades

[Sedgewood]

Re: Finish Blade test

And here's an after picture. The 6 inch stuff is cut to 4 or so and the weedy bits cut well. The uncut stuff I cut with a two pass half overlap which went slowly but gave a fair cut. The goldenrod caused a lot of loading and went really slowly. I had been going back and forth but found later that a clockwise lap cut quite a bit better.

The driveway work is PT done too. And the slope behind the pond is where I'm stalling the wheel motors at 27-30 degrees.

 

[MossRoad]

Re: Finish Blade test

That's a beautiful place you have! Thanks for the pics.

 

[Charlie_Iliff]

Re: Finish Blade test

John: As I advised by private post. I'm sending you a set of my "super custom modified finish blades" for testing. I am hopeful that they will do just a bit smoother job on the shorter grass, but I wouldn't bet on it. I think that what you are getting (and I as well) is actually pretty good for a rough-cut mower. It isn't as smooth as a real finish setup, or as tough as a brush hog, but it does both jobs reasonably well. Nothing certainly is going to make high grass and weeds transform immediately into a golf green. (At least that's what Bubenberg says, but that's no reason not to keep trying./w3tcompact/icons/laugh.gif/w3tcompact/icons/laugh.gif) We seem to be making progress on the uncut stripe problem. Maybe if we try enough configurations we'll actually understand what's happening under there.
Re the hill climbing problem, adjustment of the relief valve, as I recall, is one of the two things that voids the PT warranty. (Skipping the 50 hour service is the other.) So, you need to get their permission before you do it. Or, if you decide just to fix the wheel stall without further communication, please let me know by private e-mail if finding and adjusting the relief valve increases wheel torque or just blows oil all over eastern NY./w3tcompact/icons/crazy.gif

 

[Sedgewood]

Re: Finish Blade test

MossRoad:

<font color=red>That's a beautiful place you have!</font color=red>

Alas, it's not mine. I have a 2000 foot or so private road here that I share with 3 neighbors. That's one of them.

 

[Sedgewood]

Re: Finish Blade test

Charlie:

<font color=red>Maybe if we try enough configurations we'll actually understand what's happening under there.</font color=red>

My observations today tended to confirm my suspicion that its a jambing problem; the large volume of stuff isn't clearing fast enough. I noticed that when I stopped and backed up for some reason that the mower often dropped a clump of grass roughly right behind the front wheels. I think there's just too much stuff under there. It occurred to me while looking under the deck this afternoon that the blade cutting paths overlap maybe two inches. Could it be this is too much causing load swapping from one set to the next. Also, all three spindles turn the same way; what if the center one turned the other way? Then none would oppose any other at the blade tips.

Not to put too fine a point on it but isn't a rough cut mower for cutting rough stuff? Or is it just for cutting fine stuff roughly?

 

[Charlie_Iliff]

Re: Finish Blade test

John:
I haven't had quite the same problems, but I don't think I've cut stuff with as much sheer mass as what you describe. For thick pasture grass, about a foot tall, it seemed to do fine, except for the right-side stripe. Unfortunately, after the ridiculously fast growth last May, our drought stalled the growth in June, and things have been thinner and slower since. Now that I think I've learned a little, I don't have the same stuff to cut.
The best results I've had are with kudzu and light brush, with weed and sapling stems up to about an inch. The results of those, both with the factory blades and mine, have been really good. I've had no apparent clogging, but probably the real density has been lighter than the tall thick grass I see in your pictures. Maybe it's rough stuff as opposed to super heavy stuff that the rough-cut refers to. Or maybe it is designed to leave a stripe so the result after cutting is rough./w3tcompact/icons/smile.gif
I'll think a bit about directions of rotation, and I'm going to try to look under some other decks. Unfortunately, I don't have quick access to a 3 spindle 72" rear discharge finish deck. I do have a side discharge, which has baffles partially around the blades. The blade lift is used to pass everything to the right after cutting. Somehow I doubt that we are dealing with too much blade overlap or a problem with direction of rotation. I think it more likely that air flow is pretty high speed at spots because of the reduced volume between the stump jumpers, with no baffling to prevent it locally flattening the grass below a section of blade, and none evacuating the cuttings to prevent the type of jam you've experienced. (Since I have no experience designing mowers, I can speculate about things like that as if I really have some logical basis: Ignorance with Conviction.)
My bottom line is the rough-cut mower has really done exactly what I needed most - cut my wife's pastures in all sorts of conditions, including once a driving rain, with sufficient cut quality that she has been appreciative.
Incidentally, the wet cut was of pretty thick stuff, at as high speed as I could manage without discomfort, and resulted in as good quality cut as I've done. Does that suggest anything?

 

[Sedgewood]

Re: Finish Blade test

Charlie:

<font color=red>The best results I've had are with kudzu and light brush, with weed and sapling stems up to about an inch. The results of those, both with the factory blades and mine, have been really good.</font color=red>

We're in total agreement here. This thing just pulverizes the brush & that northern kudzu, multifora rose (when you can get close enough that is - some of mine are 20 feet tall with 1-1/2 to 2 inch stems at the butt).

<font color=red>(Since I have no experience designing mowers, I can speculate about things like that as if I really have some logical basis: Ignorance with Conviction.)</font color=red>

If ignorance were bliss I'd be just a grinnin'. I suspect we're just expecting more from a 3 spindle mower than one can deliver. I must say that the results after double cutting are far supperior to what I was getting from brush hogging. So a speed penalty may be worth it (now to convince my customers...).

<font color=red>Incidentally, the wet cut was of pretty thick stuff, at as high speed as I could manage without discomfort, and resulted in as good quality cut as I've done. Does that suggest anything?</font color=red>

hmmm... I'll have to try watering the field first. Maybe I could rig a misting nozzle to squirt just ahead of the mower. Or right down through the deck..?

 

[Sedgewood]

Re: Finish Blade test

Charlie:

<font color=red>As I advised by private post. I'm sending you a set of my "super custom modified finish blades" for testing.</font color=red>

I'm running a bit short on time here so just the facts for now. Got 'em. Made some bushings for 'em. Ran some tests yesterday.

The plot. See attached. Lotsa asters & goldenrod, average 24-30 inches tall. About 1200 lineal feet around per lap. The finished results don't vary much but time to cut does.

Test 1: My roughcut blades - dull. No rubber exit deflector. Three laps in 17 minutes with overlap such that I was cutting about 30-32 inches of new stuff per lap. That works out to about .75 acres per hour. No chaff cloud.

Test 2: Charlie's nice 1/4 inch high lift blades. Sharp. No deflector. Three laps in 16 minutes with 40-42 inches new per lap = about 1.1 acre per hour. This stuff is still green but I absolutely drowned in a chaff cloud. Cooler plugged and alarm went off.

Test 3: Charlie's blades with deflector skirt on. 19 minutes for 40-42 inches per cut = about .9 acres per hour. Chaff much reduced, maybe by 3/4, quite tolerable.

Test 4: My roughcut blades, sharpened to remove secondary bevel - much like finish blades. Deflector on. Test aborted - progress too slow to bother with.

Test 5: Deflector off. 18 minutes at 30-32 inches per lap = about .7 acres per hour. No chaff cloud.

 

[Charlie_Iliff]

Re: Finish Blade test

<font color=red>The finished results don't vary much but time to cut does.</font color=red>
I think the only thing I've found variable about the finish results is the tendency to leave the dreaded right-side stripe. I've not seen it with the high-lifts and the deck canted a bit forward. Otherwise, the cut quality is typical of cutting high growth - not exactly smooth, but acceptable.
<font color=red>I absolutely drowned in a chaff cloud</font color=red>
That was with two blades per spindle and the rear rubber skirt removed. With four blades per spindle and that skirt on, the cloud blowing out the front of the mower was so bad that I sometimes had trouble seeing. The cut was pretty miserable, too.
Great test. Sounds as if we may actually be making some progress.

 

[Sedgewood]

Re: Finish Blade test

Test 6: Deflector off. 9-1/2 minutes at 24 inches per lap = about 1.1 acres per hour. Tolerable chaff cloud. Best cut and speed to date - see attached. For this test I made a set of blades from some cheap double edged reversible blades (with a wavy high lift profile). Unlike Charlie's offset blades these are not offset and seem to pretty well contain the chaff under the deck. Taking 24 inches per cut gives me a triple cut with the 72 inch deck and with the reduced loading the ground speed is roughly double what they would accept at 36 inches per lap. Also a quicky test on a previously mowed field seemed to do a good job of clipping off the stalks left behind earlier and at full tilt ground speed. I haven't had a chance yet to test cutting 6-8 inch grass but hope to soon.