With the extra rpms you may want to try a smaller blade. Like a 8” piece of sign post u channel as some others have in their pictures. It will make start up much easier. You may than need to put a few baffles in your tank to get a good mix but in the end the mix will be just as good with much less stress on you and the equipment.
Nick
From:
Sent: Wednesday, June 11, 2008 1:20 AM
To:
Subject: Re: [papercreters] PTO-driven Blade Lesson #2
Eric, our tractor is about twice the size of yours . . . but I take your
information under advisement.
Terry's working to remove the box from the Datsun trailer. LouAnn will get
the tank ordered this week. Things are coming along.
ElfN
----- Original Message -----
From: "Eric Randall" <eric@eric-randall.
>
> Hi Nori,
>
> My gear box is a 1: 1.47 "speed up" rotary cutter gear box, which
> means if I'm running at PTO speed of 540 rpm, I'm looking at a blade
> speed of about 794 rpm. That's fine if you're cutting air, or grass,
> but moving water and cutting paper is considerably more load.
>
> What I discovered is that with about 120 gallons and just 20# of
> paper, I had to have my engine up to PTO speed before engaging the
> PTO, or it would just stall the engine -- and to put that much torque
> into a non-moving mass of water and paper is less than ideal/safe --
> better to bring up to speed gradually. My compact tractor has a 37
> HP diesel engine, so maybe others with an engine twice the size won't
> have this problem. (Nori, how many HP is your tractor?)
>
> With a tow mixer, you have the advantage of just naturally starting
> the blade up slowly, and a variety of transmission gears in your tow
> vehicle. With a PTO, unless you've got a good-sized tractor, you
> have to start up with higher revs -- less than ideal, especially
> considering the mass you have to put into motion and mix--and it is
> just an ON/OFF proposition.
>
> My blade is a 21" lawn mower blade with an airfoil-like curve
> designed to create an updraft -- so this added considerably to the
> drag the blade encountered. So I've decided to reduce the load by
> cutting down my blade to 12-14", eliminating the updraft curve, and
> grinding the blade with a curve so that it will shed chunks it
> can't/won't cut (rather than just carrying them wrapped around the
> blade). The smaller blade, flatter profile, and "S" curve should
> reduce the start-up load and allow me to start up slower and more
> gradually crank up the rpm as needed. Stay tuned!
>
> By the way, my 4" gate valve works really nicely so far. I
> especially like how I can easily control the flow volume and quickly
> shut it off.
>
> Best,
>
> Eric
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
__,_._,___
