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Thread: Twin outboard install, Fine design 32.

  1. #1
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    Default Twin outboard install, Fine design 32.

    I started my twin outboard install on this hull after waiting for my linear actuator to arrive for my power trim setup.



    The hull.



    fd32.jpgfd33.jpgfd34.jpg

    The actuator arrived and I got started, but the actuator is was a bust. In communication with the MFG now to try and resolve the issue and I hope I just got a bad sample as it looks like a really nice unit.


    Anyway,I started on making a unified tilt strut to hold both outboards and simplify the tilt alignment.

    This is as far as I got between jobs at work friday. Not a bad start. Both of the motor pivot shaft holes are in and everything is squared up with some preliminary saw cuts to remove the bulk of the unwanted material.

    When complete it should look similar to the drawing.


    IMG_0508[1].jpg
    Attached Images Attached Images

  2. #2
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    nice, what outboards are you going to use

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    I picked up a pair of Aquacraft EP1's for cheap so Im going with those for now.

    Im not really looking for all out speed, just a decent scale + boat to mess around with. Maybe 30mph top speed.

    Hopefully the fun in this one will be the ability to run it well in all conditions as my favorite spot is on the windward shore of a good sized lake. Some of my other boats dont do so well in heavy chop so with this I wont get skunked when I go out if its windy.

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    I really like your trim idea

    Im building my first scratch build, with twins at the moment as well, but after seeing this Im pissed I didnt do trim ....grrr
    I may just stop and regroup,

    I will start my own thread and post close ups of what I have done , Im open to engineering suggestions, hope you look in
    Attached Images Attached Images
    Last edited by MadProps; 02-11-2018 at 02:51 PM.

  5. #5
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    Yeah, I'm watching your thread and the steerable drive thread also.


    I purchased a linear servo to use as thdrive for the tilt function but I'm having issues with it's resolution. It is an Actuonics pq12r rated fo11lbs of force which is great but so far I can't get it working satisfactory.

    I'm talking to their techs now to come up a way to resolve my issue's.

    Who knows, maybe I got a dud.

  6. #6
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    hope you get it resolved
    I think I have a viable approach to trim my setup using what I have already....just need to think it thru a bit more

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    Do you have an idea as to how you're going to power your tilt/trim?

    I bought a linear actuator from a compant called Actuonix a PQ12R but Im having issues with getting the resolution I want. It seems to be operating in oddly spaced steps of almost 1mm, which isint optimal. I took a video and emailed it to their techs and am waiting for them to decipher it. Hopefully I simply got a bad sample as it is a nice, small, strong package. 11lbs of force @ 6v.


    This is all the farther I got as I actually had to do work for the company at work today.

    So far so good on the mount, but the wiring may be a bit of an issue.


    DSC04399.jpg

  8. #8
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    Quote Originally Posted by RaisedByWolves View Post
    Do you have an idea as to how you're going to power your tilt/trim?
    sorry it took a while to get back to you ....I decided Im really not concerned with tilting the motors full up, and it will be an easier mod to just add adjustable trim for performance......I have so little travel with the stock trim adjustment and so little trim adjustment really required with a surface running prop, I am pretty sure I can get away with just a servo and pushrod that I will connect to a bracket that I will have to fab up that will mount on the 2 inside steering control arms on the motors that Im not using. I also will use a servo speed limiter to slow down the trim travel, when Im in my hydro I can hear the motor and feel the boat respond when I trim it out, since I cant do this with the rc boats and the servo movement is so fast and I have so little travel available I fear I will be constantly searching for the correct trim position because it will move so fast and go right past my optimum trim position.... it wont be as easy for me to judge watching remotely so trim speed reduction closer to scale will be a nicer mod..... just my thoughts how I will approach this, we will see how it works out

    edit: this is the speed controller I use for flaps in my planes that I will use to slow down my trim
    ssdriver.jpg
    Last edited by MadProps; 02-17-2018 at 02:37 PM.

  9. #9
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    Ive often wondered whether a servo alone would be strong enough to maintain its position under load with something like this. I did see where a guy used a continuous rotation servo and a screw arrangement, but i have no idea how he controlled it.

    I dont think Im going to pursue tilt either unless it just happens to work out. I have an idea how it can be worked in easily if everything aligns but its not my main goal.

    I got some more roughed out today. The L shaped bracket will be the pivot for the trim and also the jack plate. The two tabs sticking up off of the motor bracket will be the pivot points and the jack plate will be slotted to accept them and they will be pinned.

    Most likely 50-60% of whats here will be removed. its just easier at this stage to leave everything square and wide enough to give me room between the part and the milling vise to work where I need and still have enough material to grip it. Once I get down to the finer details I can start cutting everything unnecessary away.


    IMG_0514[1].jpgIMG_0513[1].jpgIMG_0511[1].jpg

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    Ive often wondered whether a servo alone would be strong enough to maintain its position under load with something like this.
    I thought about this and decided that Im willing try using a metal gear high torque servo and if it fails I only have a small hole in the transom for a push rod to fill .
    had I thought about trim before I got this far in the project I would have gone another direction Im just not willing to scrap what Ive done and spent so far for this mod...... I have dual thru hull water pickups I would have to work around etc etc etc .....we will see how it goes
    Last edited by MadProps; 02-17-2018 at 08:32 PM.

  11. #11
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    whats the torque of your linear accuator in comparison to my servo
    Torque: 208 oz/in (15 kg/cm) @ 7.2V 4.8V 6V Speed: 0.16 sec 0.14 sec

  12. #12
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    The two different types of ratings do not really cross over.

    Torque on a servo would be measured looking down on the servo shaft in a rotational plane. The linear servos simply transmit force in one direction or the other. You get a linear force from the servo by making it move the rod with the servo arm, but the amount of linear force varys depending on how far out on the servo arm the rod is attached.

    Clear as mud?



    I got the motor mount pretty much finished today including the pivot pins which I turned out of some stainless bolts we had laying around.

    Not really a finalized shape as of yet being as I dont know if my actuator will work or I should say how well it will work, but its enough to let me get the motors mounted and start making up linkages and other stuff. The pivot pins wont be pressed home until the final install.


    IMG_0521[1].jpgIMG_0522[1].jpg

  13. #13
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    its taking shape nicely! how do you intending sealing the actuator thru the transom area

    Clear as mud?
    I get it a fairer way to compare would be measure the foot pound force at the end of the servo/pushrod set up
    Last edited by MadProps; 02-21-2018 at 07:11 PM.

  14. #14
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    That mount/pivot plate looks great. Nice job. I love the ingenuity. Adjustable trim for rough water is an awesome idea. I have always wanted to do a F1 tunnel hull with trim.

    Madprops, I would think a rock crawler servo with 400+ oz/in May be enough. Or maybe a Retract servo? Be a slower speed too.

    I have a bit of experience with the stronger servos and adequate power has to be supplied as they can have over 5amps stall.

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    Quote Originally Posted by srislash View Post
    That mount/pivot plate looks great. Nice job. I love the ingenuity. Adjustable trim for rough water is an awesome idea. I have always wanted to do a F1 tunnel hull with trim.

    Madprops, I would think a rock crawler servo with 400+ oz/in May be enough. Or maybe a Retract servo? Be a slower speed too.

    I have a bit of experience with the stronger servos and adequate power has to be supplied as they can have over 5amps stall.
    excellent idea thankyou , I will give one of those servos a try, Im not cheaping out from buying an actuator, again I was so far into my build with twins before I discovered this great post and trim for RC outboards... I am just limited in transom area space or I would jump and buy 2 liner actuators, and hinge my setback plates

  16. #16
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    Quote Originally Posted by srislash View Post
    That mount/pivot plate looks great. Nice job. I love the ingenuity. Adjustable trim for rough water is an awesome idea. I have always wanted to do a F1 tunnel hull with trim.

    Madprops, I would think a rock crawler servo with 400+ oz/in May be enough. Or maybe a Retract servo? Be a slower speed too.

    I have a bit of experience with the stronger servos and adequate power has to be supplied as they can have over 5amps stall.

    Man, an F1 with tilt and mixing giving you precise down thrust on the bow in turns........

    You could also add a gyro to prevent blow overs.


    Mad, Im probably going to make a mount for inside the transom to hold the actuator. I can bolt it to the transom to transfer the motor thrust to the transom. This will have a pin going through the transom to take the thrust and be sealed with O rings or even a small boot.

    Im pretty sure a mount attached only to the bottom of the hull will get ripped off as the actuator will be taking a large percentage of the forces put on the back of the boat from the motors.

    I plan on using an intermediary link between the actuator and the thrust pin, but until I get it back and test it some more Im not sure if it will be under driven or over driven. That will depend on what amount of resolution I can get with the unit.

    Then again it could always wind up as a direct link to the thrust pin.

    Figuring it all out along the way is half the fun.

  17. #17
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    as I mentioned this is my first scratch build and I have never run twin motors and I have no idea how other are controlling trim I was going to use a speed limiter to slow down a servo but I was mocking up parts today and came up with a tilt & trim system, since we only require a couple millimeters trim adjustment this approach may just work for me???? we will see


  18. #18
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    I would think with active trim you would need stops on each the up an down trim adjustments. The smaller the boat the smaller / narrower the window of adjustment needed? Most of my RC boating experience is with tunnels, I club raced 3.5 cc and 7.5cc nitro tunnels in years gone by, and have been messing with FE tunnels for two years. Too much head ache not enough gain IMHO. The window between too wet an too light is very small, with the wide sweeping turns of a typical race coarse you don't need a lot of boat in the water to make the turn. That being said, I do think as the hull size increases so does the adjustment window needed between full tilt up and down. Only larger hulls would benefit more me thinks. I don't know? Jest thinkin?
    PROBOAT BlackJack 24", ShockWave 26"
    MRP U-31, 3 tunnels VS1, MRP Bud Light, Dumas HS Sprint

  19. #19
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    Agreed

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    maybe I am missing something or dont understand your meaning but I only need less than 1/4" of liner travel to actively trim these motors & I can do it "incrementally & very slowly" there are stop points for the active trim adjustment.... using the 3rd channel mico trim adjustment I can bump it in to any angle I choose just like you can adjust in your rudder trim incrementally in a boat or plane to go straight

    the tilt will go just full up and full down without in between stops , but the trim I can incrementally bump on the fly in to any trim angle I choose "within my range of travel" and at a super slow speed, maybe you didnt see the slow incremental adjustment of the servo arm in the video?
    Last edited by MadProps; 02-23-2018 at 12:29 AM.

  21. #21
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    On our little race boats 1/4" is a huge swing in adjustments. When I set up and dial in a hull I'm only adjusting my tilt/ thrust angle by 1/64" at a time. On my little Dumas HS Sprint the window of thrust angle needed to trim it out is about 3/32". From the sweet spot where my boat is set up and runs and handles the absolute best, if I add 1/32" positive (up) thrust angle, I get a very light loose running boat with handling issues and am more likely to blow it off the pond. If I change the thrust angle down / negative 1/32" from the sweet spot I get a wet, plowing boat that looses 2 mph top speed. I honestly hope that active trim works out for ya. I jest think once the boat is dialed in proper you no longer need to adjust anything. I guess the only advantage is in the speed in witch a hull is dialed in you can do it on the fly, I have to loosen screws on the bench to make adjustments. Once on the pond I see no advantage over a well trimmed / set up boat. IMHO it jest adds complexity an head ache, being that the window of adjustments need is so small. Honestly good luck, keep us posted on your results, maybe I'm just an old fashioned fool set in his ways and totality wrong on this.
    PROBOAT BlackJack 24", ShockWave 26"
    MRP U-31, 3 tunnels VS1, MRP Bud Light, Dumas HS Sprint

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    well that clears things up Im not confused about your meaning you dont understand my approach to the concept & since its jest your opinion..... trim is not needed???? or it may not work! or too much work,a headache? then Im really not interested in your opinion if there will be a benefit ...........I already have benefited from the project

    have you built a tilt trim system doesnt sound like you have .....your just wasting my time.....this 1/4 inch and the speed of movement your confused about tells me..... I personally dont think you have the mechanical aptitude to understand my approach to the concept. did it cross your mind YOU may learn something from our efforts? this is pretty simple stuff here gents and not uncharted waters, others that possess mechanical aptitude skills have installed trim and it worked well!

    what makes you think were are not capable of slowing them down enough to accomplish this ...hear of servo speed controllers....you dont think there is any application benefit for this? changing water conditions that I will be able to adjust on the fly, you say you need to bring your boat back and adjust 2 screws to do this? well I will only press a button on the fly and achieve the same benefit as from a real boat....... try thinking outside the box

    too much headache! too much complexity maybe this conversation is above your skill level, let alone injecting your uninformed opinions, we will successfully engineer trim systems.

    I already know there will be a benefit and frankly it really dosent mean diddly if this turned out as useful as interior lites in a tug boat ....then Im just damned thrilled, Im doing this because I possess the skills to accomplish this engineering mod.............. because Im a modeler


    edit: people are already racing with working on the fly trim on F1 hydros.... and using just a servo....since your so free with your uninformed opinions let me give you mine..... next time you go to post "I think" stop yourself and go google the subject before you waste peoples time, jest a 2 second look I found some already racing F1 with trim, there are boats on youtube with nice slow incremental trim .some boats come from the factory with trim!!!...yeah were all wrong but you

    this excerpt taken from RC groups
    there is a racer in Texas, Ernie LeFleur that runs trim on his 3.5 OB tunnel.Ernie's works rather well, he can hold the engine and it will move the rest of the boat with no problem.

    you have a great day I have a technical project to finish and dont have the time to explain how it works
    but thanks!
    Last edited by MadProps; 02-23-2018 at 01:11 PM.

  23. #23
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    The only downside I can see is weight, but with twin engines......


    The length between the pivot and the locking bolt will make a given measurement of tilt (Which should be spoken of in degrees) will be different for different mounting systems. .015 of adjustment for one setup may be minuscule while for another it is huge. Hence the need to use degrees for any of this to have any meaning.

    My biggest concern is having too fine a resolution where it takes a lot of input to achieve the desired result. On some radios the amount of throw for a given input can be changed to account for proper function which I can utilize on my Graupner MX24.

    Unfortunately that is not the radio I will be using for this boat.


    Mad Props your setup looks nice. Interested in seeing it on the water. You're going to need a pretty stiff rod on the tilt/trim servo. Have you given thought to how your steering links will handle the tilt?

    That is currently one of my biggest challenges along as well as how it will work regarding the jack plate, but the jack plate issue will be a one time setup.

  24. #24
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    Well my build got stalled as I had to send my actuator back to the manufacturer in Canada to get it reprogrammed to work like I want it to.

    Heres the issue I was having.


  25. #25
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    Not so linear, eh?
    Ron - The Villages, FL

    https://castawaysboatworx.org/

  26. #26
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    Quote Originally Posted by zooma View Post
    Not so linear, eh?

    Got an email saying they were able to write new code and flash it to work the way I want it too. I should have it back in a week or so to test.

    Got the mount done and the motors temporarily mounted for fit and everything looks good.

    Also showing my patented wine crate boat stand/storage box. Still needs foam but this lets me put boat/radio/batteries and tools all in one tote.
    Attached Images Attached Images

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    So I have been putting this off to work on my 1:1 boat to eventually do some fishing but Im now getting back to it. I got my actuator back and they reprogrammed it and thats working well. I also milled the forward mount for the actuator and got it light enough that I think it is done. It came out looking like a cross between a Tie fighter and an X wing with all of the angles and extra material removed. Pics coming soon.


    My dilemma now is how to go about creating a steering system that wont interfere with the trim/tilt, or better said, wont deviate the steering inputs when the motors are trimmed. I know I want a push/pull operation with the motors linked via an adjustable linkage Im just not sure how to go about it.

    Can anyone give me some insight into the workings of the twin steerable outdrive setups that look to have some type of piston (Hydraulic?) steering setup?


    Something like what is being used here.

    https://forums.offshoreelectrics.com...5&d=1518063460

  28. #28
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    Cool project You probably know about these guys but if not there may be some product/ideas that could fit with what you're trying to accomplish...

    https://www.servocity.com/
    2008 NAMBA P-Mono & P-Offshore Nat'l 2-Lap Record Holder; '15 P-Cat, P-Ltd Cat 2-Lap
    2009/2010 NAMBA P-Sport Hydro Nat'l 2-Lap Record Holder, '13 SCSTA P-Ltd Cat High Points
    '11 NAMBA [P-Ltd] : Mono, Offshore, OPC, Sport Hydro; '06 LSO, '12,'13,'14 P Ltd Cat /Mono

  29. #29
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    Well this ( https://forums.offshoreelectrics.com...5&d=1518063460 ) would be me. These hydraulic dummies can be bought by themselves and come in a couple lengths. They can/or may have flex cable glued into them. Positioning for smooth operation is key, depending on application (the one pictured being about as tuff as it gets). Now I have also thought of making my own using .098 prop stubs and cable in brass tube. Having steerable drives means you don’t need a lot of rudder throw either. I do have a functioning one here if you need measur.

    Shawn

  30. #30
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    Quote Originally Posted by properchopper View Post
    Cool project You probably know about these guys but if not there may be some product/ideas that could fit with what you're trying to accomplish...

    https://www.servocity.com/

    Thanks, I forgot about them.

    They have some interesting ball links I may have to get.

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