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Thread: checking neuform 3 blade prop

  1. #1
    Senior Member
    Join Date
    Dec 2006
    Near Caernarfon North Wales

    checking neuform 3 blade prop

    does or has anyone ever checked there own neuform prop on their C42??

    I was wondering just how i check the blades are 23 deg on the neuform 3 blade prop on my C42.

    I have checked the neuform website but its not clear exactly what tool you need and how to do it as the spec is 175 cm x 23 deg @ 310mm from hub.

    for example what is the 175cm bit? and is the 310mm from the edge of the hub or centre?

    any pictures of the tool would help.



  2. #2

    checking neuform 3 blade prop

    [1]Hi, I have fitted a new 3-blade Neuform propeller to my C42 some time ago now. The 175cm is the diameter of the prop, which is 68inches. The 310mm as far as I can remember is from the edge of the hub to the reference point on the blade. [/1]

    [1] [/1]

    [1]The easiest way to set the pitch is by using the pitch-setting tool, which I obtained from Aerosport UK. Basically itís a matter of removing the prop from the aeroplane (remembering to loosen the three small screws partly before removing the six main bolts). The prop is placed face down on a level surface, then placing the pitch setting tool on the back of the prop. One end of the tool sits on the back face of the main hub and the other adjustable end sits on the inside of the blade to be adjusted. The adjustable arm of the tool should meet the blade at two points when the angle of the blade is correct with the pitch setting tool, ie it should touch at the leading and trailing edges of the blade. The three small screws are kept in place to hold the prop together and just loose enough to allow the blade to be turned by hand. The pitch-setting tool takes care of correct dimension from the hub to the point of reference on the blade. [/1]

    [1] [/1]

    [1]I have attached a couple of pictures of the pitch setting tool, using a paint can to illustrate how it should sit on the hub! To be honest the angular divisions on the tool are so close its hard to set it to exactly 23 deg, but as you will already know the main thing is to get the three blades to exactly the same pitch, and this gauge is a great asset in achieving this. I tried it a few times at slightly different settings and found the best overall performance was when I was getting a full power static of 5000rpm, which is where it should be in theory at 23 deg. I hope you can understand my explanation, if I can be of further help or if you need to get hold of the tool, just let me know! [/1]

    [1] [/1]



    Attached files

  3. #3
    not real name 500 Club
    Join Date
    Oct 2011

    checking neuform 3 blade prop

    I see from this month's LAA Mag there is a possible issue regarding cracked propeller hubs on the C42 fitted with a Neuform propellor

  4. #4
    Diamond geezer 500 Club
    Join Date
    Dec 2005
    North Cheshire UK.

    checking neuform 3 blade prop

    Is the engine archiving the RPM it should.

  5. #5
    Member Settling in
    Join Date
    Jan 2009

    checking neuform 3 blade prop

    Hi C42 owners

    We are in the process of issuing a service letter to all owners who have a Neuform propeller to remove the spinner and check for cracks. There is no need to remove the propeller to do the check and we ask for email feedback on your aircraft with the total hours on the propeller and whether it is fitted to an 80 or 100hp engine. See attached picture of the cracks

    As mentioned in the LAA article 2 have been found with cracks in the hub but all the others in the LAA home built fleet are OK

    I have checked several C42's in the last few weeks and all were OK, one of which has done over 6,000 hours, so the hope is that the problem may be related to a specific batch of material and is not a design issue as such, although we need more data to be sure. If you know any C42 owner who may not read this forum please let them know.

    In reply to the pitch setting question started by Nick Farrow the best method I have found is to use a Warpdrive 360 degree spirit level type of tool as this can be done in-situ on the aircraft.

    We do have a tool we can lend out (a refundable deposit is now asked for as we have lost several on loan). The setting should be as the C42 TADS - BM68 Iss9 which can be downloaded from the BMAA website. The setting of all 3 blades to exactly the same pitch is more important than the pitch setting itself which should be verified by a ground run at full throttle (good chocks are needed!) which should be 4800 to 4900 rpm

    Red Aviation

    Attached files

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