Yamma-Fox

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Everything posted by Yamma-Fox



  1. Yamma-Fox added a topic in 4-strokes   

    Yamaha Apex Skytrax Adapters
    Helping Teal out here with some info on his new adapter (prototype as of March 2018) for the 150 / 162 HP Yamaha Apex EFI.
    The Apex motor shares much with the RX-1.  It is a inline 4 cyl 1000cc 4 stroke with internal gear reduction and internal rubber dampening.  It is EFI and in it's it stock (N/A) form it produces 150 hp on model years 2006-2010 and 162 hp for 2011-2017.  Turbo kits are available from several vendors and range from 180-280 HP.  In the sled world this motor has an excellent track record in the 7-10 psi boost range (200-230 hp).  The Apex has the same engine block and mount as the RX-1 but uses a slightly different crankcase end housing so the Skytrax RX-1 adapter cannot be used on the Apex.
    For the Apex, Teal decided to go with a gearbox and adapter as an "all in one" unit.  This replaces the end housing (as did the RX-1 adapter) which has the advantage of more rigidity (more consistent gearbox alignment with pto) and wider spaced, more robust (with more fasteners) mounting of the gearbox to the engine.  The total engine and adapter length is reduced greatly from the RX-1 with C box (which was about 27.75") by approx 4 or 5 inches. This new setup also eliminates the need to source a Rotax C / E gearbox as was necessary for the RX-1 adapter.
    This new gearbox is a three gear design (pto drive gear not pictured below) so it'll turn a CW (Right) prop.
    Here are a few pics of the CAD rendering and of the first prototype off the mill:
     





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  2. Yamma-Fox added a post in a topic Hanging from the rafters   

    Thaks guys.  Sounds like the plan I had in mind isn't to far off for once!  
    And yeah Ed, I was thinking the same thing.  It's because of the straight lotus (squishy) floats that I thought the hanging scale way might be better.  Put the crane scale on each of the 3 lines and use comealongs from above to level her out. Seems like a PITA otherwise on my dirt floor with floor scales I dont have access to.
    And I can work the W&B calcs from any arm locations, so the center of the spar and any location on the tail will work.  It's really just a summation of moments problem like I learned to do to find operating CG as a PP student.
    Finding accuacte crane scales and getting the tare right are my main obstacles, but I think I have a good idea now on that as well.  
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  3. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Sorry for the info overload here!    But since I have a minute, and am a big Yamaha fan, I'll add a few more advantages of these Apex / RX-1 motors:
    Fully liquid cooled (no shock heat / cool issues) and also no need to preheat or cowl blanket a snowmo engine!
    Electronic rev limiter that makes over rev virtually impossible (rev limit is well over 12,000 rpm and is based on sport bike protection which can protect the motor at full throttle in neutral)
    Integrated oil cooler on engine block, gear driven oil and water pump, spin on filter.  Large capacity remote oil reservoir which acts as an addnl radiator and aids greatly in overall cooling
    No carb heat required  (RX-1 uses liquid heated and also electric heated carbs).
    35 amp, 490 watt alternator (stator) integrated within the mag side of the motor.
    4 individual coils (over each spark plug) gives a level of redundancy in the ignition system.  Tests (snowmobile and aircraft) have shown approx 80-85 hp output running on 3 (out of 4) cylinders.
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  4. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Chart is from this website:
    http://www.amsnow.com/news/dyno-tests/2010/09/2011-yamaha-apex-dyno-test
    Take the pto rpms off the hp chart and multiply by 1.23 to get crank rpm.  And 3.83 is from crankshaft so use crank rpm / 3.83 for prop rpm.  It's typical static crank rpm range is 7800-9000 with a fixed pitch prop, and 9200 - 10,200 in the air after ram rise.  (The 10,200 is just a max hp figure and the rev limiter is much higher)
     
     
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  5. Yamma-Fox added a topic in Technical tasks   

    Hanging from the rafters
    Jims recent post of ski install (with a pic of his plane seemingly hovering in the air) reminded me that I need to hang my KF5 from my pole barn rafters to install my floats.
    How should I go about doing that??  My idea was to replace the front wing spar (wing swing pins) with eyebolts... big hd washers on bottom and then sling the tail with a padded cradle.
    I'm sure there is a better way.
    And could a guy do W&B this way as well?  Get a good hanging scale and do calculations from the weight on each of the 3 lines.
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  6. Yamma-Fox added a post in a topic Skis installed   

    It's not black magic...
    Jim uses his Jedi training he learned from Yoda (X-wing lift out of swamp)
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  7. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Yep most yamaha coversions come in around $7 or 8K counting all the little costs.
    Tempting if you want big power since modded 912s or the135hp 915 runs a wee bit more! 
    Also nice to have abundant cheap parts (used and new), but for now going Yamaha does put the "experimenting" into "experimental" to more of a degree than going  Rotax.
    Hopefully that will change when more options for standard proven configurations and FWF fabricated components become available for other planes like they are for Just Aircraft through Steve at Wild West.
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  8. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Limp modes like that are definitely a big concern.  Right now the solution for that one is to simply unplug the lead from the ECU to the temp sensor. The ECU then assumes normal operating temperature.   For better cold starts one could easily incorporate a connect/disconnect (start/fly) switch for the temp sender.
     
    There may be a better solution down the road in a custom ECU that has no limp modes. Then a person could feed all sensors and info to the ECU at all times with no worries.
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  9. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Over in the "Yamaha Aircraft Conversions" Facebook group we have Jim Hensel of Spa City Sled parts who parts out sleds and has quoted prices for used mid-mileage version 1 Apex motors from approx $2000 shipped to cont US.  This includes all accessories to run the engine.
    Teals preliminary estimate for the gearbox is in the neighborhood of $3000.
    Also, Ian Bange is working to adapt the wire loom (which is somewhat complex) and provide that modification for people who are converting the Apex.  Price TBD
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  10. Yamma-Fox added a post in a topic Slam   

    I'll message him to come and say hi.
    Are you looking to do an rx1 conversion?
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  11. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    And John, maybe you already saw my bulid thread here.  It is a slow WIP, and I have been on hiatus here in the depth of winter, but I should get moving again here soon on it.

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  12. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    Yep they are very similar, and use the same mount, but that pto crankcase end housing (which is replaced with teals adapters) is slightly different between the rx1 and apex.
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  13. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    Exactly the reasons I chose rx1!  ... all stuff I can handle.
    In 3 years I'm sure I'd go apex, but I want some other pioneers to get it all figured / proven out!  LOL!
    And sky4play, you on the FB group?  Make sure you contact Jim Hensel there.  He can get you an rx1 motor with all needed to run it starting at $1750 + shipping!  
    There's just no way you can beat that price (if you count any value to your time in finding a sled.. tearing it apart.. selling off extras...)
    Jim Hensel of Spa City Sled Parts in upstate NY.  607 329 8676
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  14. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    Thats right, that new gearbox is for the EFI Apex motor and the RX-1 uses the C / E box.
     IMO I think the Apex will be clearly the way to go, but until it gets proven out a bit, the rx1 is the still the easiest choice as far as simplicity to convert and track record.
     
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  15. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

     
    Very generally speaking,  the 3.0 ratio is preferred for the 72" sized props, 3.47 for the 79", and 2.62 for the smaller props.
    Teal has a possible new lead for rebuilt c boxes, otherwise a saved ebay search will still bring a few up now and then or the E box could be adapted (see previous posts here).
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  16. Yamma-Fox added a post in a topic FACEBOOK - BS - NOT HAPPENING!   

    All good buddy!
    That is the reason I signed up for FB under an alias name.  
    I don't want to have anything to do with it in general either!
    Being incognito there is definitely the way to go IMO, super easy to ignore requests and have no social worries!  LOL 
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  17. Yamma-Fox added a post in a topic Yamaha RX1 Engines   


    I really think you did the right thing!  
    It looks great on the front of my plane.

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  18. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    I haven't seen the "shake" myself, but am told it can be pretty rough.. 
    I decided to skip that excitement / frustration and go with the TMR400 clutch from Twisted Metal Racing (Canada).  Tony there was a co-designer of the original RK400 and holds production rights.  After discussion here with Leni, and after talking with Tony, Teal, and Steve Henry I became convinced that the clutch was the way I wanted to go for a couple reasons:
    1. Cold starts and uncoupled warm up with the big prop
    2. Easier on everything during start and shutdown.  No shakes during startup, and the yamaha 4 strokes shut down fast and hard compared to 2 strokes that "coast down" smoother.  Both of those situations (especially the shakes) can be a little tough IMO on the rubber hardy disk, gearbox, engine mount, airframe, and any components mounted FWF.
    3. The engine already has a rubber damper built into it (see pic and post above), so there is less need to have additional dampening.
    4. Seaplane use of "Neutral" at idle
    5. I can go up front and tell people I'm running a turboprop while freewheeling the prop by hand.  (The only reason really.... I made that other stuff up!)  
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  19. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    Good info Willis!   Thanks.   And keep an eye on that rubber hardy disk.   It holds up great for most everyone, but I hear it can possibly get stretched with use on bigger/heavier props.
    Guess I've only heard of one instance,  so probably not a big worry, especially like teal says that the disc's fail mode is running but without dampening.
    Just maybe something to keep an eye on during inspection, or maybe you could detect that with a prop free play check during preflights.
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  20. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    I think teal said that the e-box will not fit on the RX 1 with the starter attached. The starter sticks too far back where the motor is.
     
    The issue with starting without the clutch is more of a  low idle engine problem, and not a starter problem.   As I am told, with a big prop the starter spins it up fine, but the motor itself will not be able to fire off and accelerate to idle.  It can get into a "shake" unable to achieve full Idle.
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  21. Yamma-Fox added a post in a topic Yamaha RX1 Engines   


    Although it still remains to be done, in theory an E box would be a direct fit on teals  RX1 adapter.
    The clutch would still work fine.  The reason the clutch is not listed for use in the ebox is that you couldn't start through the ebox starter (with a disengaged clutch).  But in the case of the RX-1 you wouldn't need to.
    Obstacles include:  slightly more weight and bulk, would have to remove the starter, block off the hole for the starter, and fabricate a spacer where the starter shaft was.
    Upside is that new e boxes are readily available from rotax.
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  22. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    The 3 cyl is in the Vector, Nytro (120-130hp), and sidewinder (180-280hp factory turbo) sleds.
    Rx1 is 4cyl 140hp carb and apex is 4 cyl 150/165 hp efi.   The 4 cyl motors have a built in rubber damper within the internal gear reduction (see pic) and are arguably beat suited for conversion because of that.  The 4cyl motors are sometimes turboed in the 210-280 hp range in sleds.
    A great read on yamaha engine development:
    https://global.yamaha-motor.com/business/4st-snowmobiles-10th-anniv/edition3/feature_001/

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  23. Yamma-Fox added a post in a topic Oshkosh 2018...Who’s going!   

    Bring a finite amount of cash.. 
    Have your wife put a credit hold on your SSN and leave credit cards at home.

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  24. Yamma-Fox added a post in a topic Oshkosh 2018...Who’s going!   

    My plane was built in OSH.  I gotta get it back there someday.  But probably not this year.... 
     
    Too bad you aren't flying your plane over Vance.  My place would be right along the way!
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  25. Yamma-Fox added a post in a topic Luga / Kool / "NR" Propellers   

    No flying yet on my new prop, but it sure is a work of art!   79" SL-118 3 balde:
     

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