I hit a Gopher mound with my MTD mower at speed....

[Chris Hegar]

I hit a Gopher hill on my MTD mower at speed 6th gear with blades down. A slight pause upon impact it blew dirt and grass and rock out the bagger and into the neighbors yard like a miniature mushroom cloud. My 4 cycle question is should I hit the pile with only one blade or take it down the middle with the twins for best results. I'm trying to cut yard mowing lap times back a bit and figured you guys would know the answer. Thanks in advance for any info.
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www.Hegar4.com

[Thom Andresen]

Take out the gopher with a .22-.250 and you won't have anymore 4 stroke mushroom cloud problems
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I spend my money on hunting, racing, women, and whiskey - the rest I waste.

[Chris Hegar]

I can mount it on the hood of my mower, will I need a scope or do they get close enough I can pop off a few rounds to wound the sucker?
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www.Hegar4.com

[Jim White]

Caddy Shack anybody???
Where's Bill Murray when you need him.

[Richard Gray]

The lowering of lap times/correct line is dependent on whether your MTD has counter-rotating blades or syncro/in phase, clockwise or counterclockwise rotation. We need more info on the equipment...
_________________
Richard


"Running into the sun but I'm running behind"

[Benn Herr]

You SOB you!



He's going to track you down and when you least expect it....
_________________
Benn Herr
Come see our Superkart Build Off @
http://www.lostenduros.com/?page_id=1534
beherr3@cox.net
http://www.southwestkarters.com/
http://www.lostenduros.com/
Kart Design
Chandler, Az.

[Jeff DeMello]

Damn Benn I was waiting for his head to explode
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Jeff DeMello
Emmick F125 Pavesi

[Benn Herr]

[Max Wood]

Chris - I think I found a solution to your problem...

http://www.youtube.com/watch?v=5OLpNIBYNQ0

[Tom Jensen]

Take out Digger if you can.
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Sex is like pizza. When it's good it's great and when it's bad, it's still pretty good.

[Chris Hegar]

OK so I can see I'm not getting much real help here, some of you really dissapoint me.

Richard, me and my brother threw the MTD over on it's side with the blades at full tilt and determined one goes one way and the other goes another so I guess that's counter rotating. While we had it up he figured we should do some testing so I chucked a half bag of mom's potting soil at it on one side then one down the middle to see which way spread faster. Man that thing split the sheets like a mother fuker, dirt all the way over the house and into dad's convertible and in the gutter and the second bag went right through the screen door and got on the carpet. We got yelled at. But then who cares right we already got yelled at so we chucked some more stuff at it just fer fun. Lawn chairs and my Lego car I made and a rake and then my brother he dumped gravel in there which was bad news. Man I'm still pullin rock out of my ass. Anyway let me know what's the best aproach for this I figure I got a week before the grass needs a cutting and that little sum wild life beotch is pushin up more piles I can see.
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www.Hegar4.com

[Richard Gray]

Chris – First, I applaud your tenacity and quest for learning .

I don’t know you personally, but as in any complete studies, we must make some assumptions. I assume that with your 3100 posts you are not a newbie in the driving arena, so we’ll dispense with the seat time argument. However, since you are on an MTD with a B&S, we’ll assume relative inexperience in the matter at hand. Please pardon me if we get too pedantic in this discussion.

You don’t know me either, so let me give you some background. I was on a similar quest way back in 1958. I devised a test track in our backyard where I performed many, many trials with my Lawson powered, flat bottom Putt-Nik. The test track was quite small: however, it was demanding. It started out going between the sandbox and the water bib, around the pecan tree, straight towards the alley with a quick left hander around the compost pit, a switchback through the pigeon house and chicken coop veering precariously close to the 20” vertical drop bank, left at the propane tank and another quick left at the porch to start the lap again. By the time I quit the experiments, the track was completely void of all vegetation and no critters were evident in the path..

After graduation from high school several years later, I went on to earn multiple advanced degrees in deck design (MADD) with papers in aerodynamics and propulsion

No down to business. The MTD you are using is not the optimum for getting the job done, but it is what it is and we won’t suggest changes in overall equipment at this time, but as you advance you may consider using a more advanced design. The flat deck, counter rotating blade system will be adequate for you initial purpose. It will need optimization.

There are four interactive variables we must consider. We must look at and optimize the total suckage, or what I call SuxMax SuxMax is a function of the suction velocity (SuxV1), the suction magnitude (SuxMag), the suction volume (SuxV2) and finally we must find the illusive center of suction (CSux)

FSuxMax = (SuxV1+SuxMag+SuxV2) FCSux.

SuxV1 is dependent on the blade design, rotating velocity, deck design, deck height, deck angle and deck discharge. Blade design is not limited and therefore we must reduce our options to those relatively available. Although I would suggest a carbon fiber, tapered airfoil section (if you want the specific name let me know), I suspect that you’d like to stick with the twisted steel, sharpened design currently present on your equipment. This will be OK, but you will need to find the sweet spot. Do this by twisting the blade to gain the maximum pressure differential (someone on this board has trouble with the concept of vacuum, so we’ll stick with pressure differential) and you could try a slight plan view taper. If your existing blade is of concave design, then your taper will need to be a little more. The rotating velocity is of course controlled by the engine RPM (you are going to stick with the B&S aren’t you) and gear ratios. Remember that these gear ratios are tricky and a big one and a little one is not necessarily the same as a big one and a little one with the same overall ratio. I suggest that you overclock the blade tip speed to just shy of supersonic. Supersonic will but detrimental to your long term viability when subjecting the material to solid objects and the neighbors won’t like the successive booms. The MTD uses a flat deck design (FDD) which is known to be inefficient for suckage. If possible, substitute your deck with a contoured super suction deck (available on the internet) or the SS model. You will want the lowest deck height possible without nominal interference in order to optimize suckage. The deck angle is dependent on the deck discharge, in other words, where do you want to throw this stuff. That said you will want a deck angle less than five degrees in any case as going above that will cause loss of suckage.

SuxMag is similar to SuxV1; and SuxV2 is also similar, I said they were interactive. I won’t bore y’all with the details, but here you are still trying to get the most suckage as possible.

Now, the elusive Center of Suckage; quite possibly the most important parameter of the whole study. It is much easier to calculate the CSux of a triple carbon fiber, airfoil, overclocked, contoured deck design than it is for your opposite design. Suffice it to say that the CSux will be somewhat close to the point of potential overlap of the blades, within a one inch band. In the northern hemisphere if will be slightly to the right while in the southern hemisphere it will be slightly to the left. Your approach speed should be minimal, with SuxMax engaged and the positional reference as necessary by latitudinal locale.


Hope this helps.


The above is a complete fabrication from my not so common mind.
_________________
Richard


"Running into the sun but I'm running behind"

[Max Wood]

[Benn Herr]

SuxMax and Chris H, a natural combo!

I wiped out a whole family of rabbits one time with my folks' Gravley, only took a second. That thing would cut down 2 inch saplings all day!


_________________
Benn Herr
Come see our Superkart Build Off @
http://www.lostenduros.com/?page_id=1534
beherr3@cox.net
http://www.southwestkarters.com/
http://www.lostenduros.com/
Kart Design
Chandler, Az.

[Ted Hamilton]

I prefer this model, mostly for it's cornering capabilities:


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Owner, www.hamiltonhelmets.com // UAS Racer #76 // Karting for karting's sake...keep it fun!