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BLADE TIP SPEED !!!!!!!!!!!!!!

Discussion in 'Lawn Mowing' started by Mowman, Feb 1, 2001.

  1. Mowman

    Mowman LawnSite Senior Member
    Messages: 553

    I'm running a Walker MT-54 gear-drive deck, can anyone tell me what blade tip speed I might be running? Engine size is a 20HP Kolher Twin. Do belt drive decks have more tip speed and WHY? Thanks for your input.
  2. AB Lawn Care

    AB Lawn Care LawnSite Senior Member
    from Ontario
    Messages: 585

    Sorry I can't tell you what the blade tip speed is but I can tell you that the walker 54'' gear driven deck has a better cut than the belt versions.The only draw back is the gearboxes can bust if you really hit somthing large.Blew on apart when I hit a large stump in long grass.It was my fault though becouse I knew better.I should have took in my belt drive scag first.Some people have flamed that deck becose of the gearboxes,but if do take it easy and don't risk it,then you will do alright!

    BUSHMASTER LawnSite Senior Member
    Messages: 519

    Shpuld be 18500.according to spec..
  4. UrbanEarth

    UrbanEarth LawnSite Member
    Messages: 142

    Isn't the maximum allowable tip speed 200mph? I seem to remember reading that as a standard for the industry.

  5. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Messages: 4,830

    I have heard 19,000 feet per minute is the limit, which is 215 MPH.
  6. Greenman2ooo

    Greenman2ooo Banned
    Messages: 176

    To convert feet per minute to miles per hour, multiply by .01136. Eric is correct. That comes out to 19,000 X .01136= 215.84 mph. At 18,500 X .01136 we arrive at 210.16 mph. Obviously, there is very little difference in blade tip speed once you approach the legal limit. I have yet to see a <b>new</b> ZTR with blade tip speed listed below 18,000 fpm. I know for sure the older Toros were slower than that, though.

    Now a mower with 16,500 fpm blade tip speed would only be traveling 187 mph. There would likely be a noticable difference in quality of cut at high speeds with this slow a blade tip speed.
  7. RB

    RB LawnSite Senior Member
    Messages: 316

    I've read all the calculations for blade tip speed, but how do you increase blade tip speed? Is it possible?

    Also, does anyone know the blade tip speed of a Ransomes Bobcat ZT219 19kaw 48" deck?

  8. awm

    awm LawnSite Gold Member
    Messages: 3,354

    Either increase rpm or ratio.Either is taking a chance.
    They dont give these things away
  9. skyphoto

    skyphoto LawnSite Member
    Messages: 221

    If the blade speed makes such a difference in cutting performance then why do companies do any other speed than the max allowed?
  10. Eng Mwr Guy

    Eng Mwr Guy Gravely Manufacturer
    Messages: 249

    The max is 19K feet per minute per ANSI. Which can take a railroad spike and throw it 200 yards through a window...keep those discharge chutes on please!

    This has to be for EVERY mower produced. Therefore, most manufacturers stay well under the specification in order to avoid the variance in manufacturing from engine manufacturers.

    Faster is not necessarily better. It sometimes just is that way in our mind.

    There are many factors affecting quality of cut. Blade speed is only 1.


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