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N234CV Yamaha powered overhaul

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Posted (edited)

I want to put my entire project up somewhere so the ideas I come up with may help some others... or just entertain people, either way is fine.

A little over a month ago my father called me up and the conversation went something like this: "Hey, there's an avid B airframe on barnstormers cheap". "Ok, I'll take a look at it". We have been working on a Yamaha apex firewall forward for a little bit without an airframe. Long term plans were and remain to build a Rans S21 from the ground up for Yamaha power but having a cheap airframe to work the bugs out and learn more about our powerplant would be nice. Also, I want a big tire bush plane and the 21 really isn't the perfect animal for that. So calls are made and it turns out that the plane in question is 234CV which suffered a groundloop following catching a landing gear at Goldmine during the high sierra fly in a few years back. The fuse was straightened, a new landing gear was sourced, and that's as far as the project ever went. Negociations went well and finding a shipper to get the plane from California was successful so the deal was made.

To save money I met the shipper in far north Texas and this is what greeted me.

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Cross loaded it and got headed back the other direction.

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Let it sit for a little bit since I wanted to start into the planning phase of the project once my Dad came into town but last week we got into it. Got the gear mounted up so it was easier to move around. New gear legs will be happening eventually but this is a start.

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Changed up my engine stand so I could rough mock up the apex and start to consider firewall options.

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As if mounting a 160hp engine wasn't enough we decided to go completely off the reservation looking for leg room. In all seriousness I've owned some small planes and they're just misery in the long haul. I want to enjoy flying what I own. The sling seat was ditched and we're moving in the direction of a flat floor with some custom cushions. The tubes will be reinforced under our butts so we don't have any problems there. Here's the initial template work for the floor and backrest.

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Edited by ibange
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Posted

One step forward from cardboard templates, here's some temporary cheap ply floors so I can sit in the plane and work out mounting tabs and what not.

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The keen eyed will notice a flaw in my logic already: the aileron pushrod goes where the left hand seat pan is projected to be currently. Well I didn't say I was going off the reservation without meaning it. We're reworking the control system to use cables and pulleys to get the aileron controls back to the pushrods. Somewhat hard to describe with words but it will make more sense once I start fabricating and you can see what I'm up to.

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Posted (edited)

Big project there bud!   You've come to the right place here, and will get some really good advice from the experts on these planes (not me!  LoL).  These guys can help steer you through the rebuild process with some invaluable input!

To the group, Ian is a regular contributor over in the Yamaha Aircraft Conversions Facebook group, and is working on a professional grade wire loom mod for the Yamaha Apex motors.

He is the kinda guy that gets stuff done.

Welcome Ian,  

Anatoli (Brett)

 

Edited by Yamma-Fox
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Posted (edited)

I wonder if a push pull cable might be a simpler way to connect from the joy stick to the mixer controls?  Like what Quicksilver MX used for the elevator, but much shorter of course.  Come to think of it, the Himax used short push pull cables for their aileron controls.  Here is an example of what I'm referring to.  Image result for push pull cable assembliesThe cable could run right along the edge of the seat and side of the fuselage.  Maybe a lot simpler than cables and pullys?? JImChuk

PS Thought I was just linking to the one red cable, but it goes to lots of images of different types of cables.  I'm referring to something like a boat steering cable, but smaller and shorter of course.  

Edited by 1avidflyer

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Posted

I should be out working on other things, but this topic got me thinking.  If I'm right in looking at the manual and such, there are 9 bolts in the control chain from the joy stick to the mixer control.  A push pull cable would have eliminated 6 of those along with the slop that will eventually come as things get looser with use.  Probably a reason Dean didn't design it that way, but I don't know.…  Kind of throwing this out here for discussion, but at the same time, don't want to hijack this thread.  One push pull cable  would have eliminated 2 bell cranks and the push tube that goes between them.  Food for thought I guess.  Maybe would have made for stiffer controls?   JImChuk

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Posted

I think the original reason for the lack of cables was to remove slop but after 4000 hours theres a decent amount of wear in the system. I dont really want the friction of a push pull cable but i have a really good routing for pull pull. I'll put up pictures as i go through the process

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Posted (edited)

After my other post, I remembered that Rans used push pull cables as well.  I parted out a Rans S 12 and still had the cables up in the hangar.  Not sure if this one is strong enough, or long enough, but here is something like I was referring to.  The cable only really needs about 1 1/2" travel.  JImChuk

PS  with a cable like this or similar, you would probably end up using the rear bell crank though.

https://www.ebay.com/itm/Teleflex-TCC69203-3-Control-Cable-4300-Series-1-4-28-Blkhd-x-Clamp-Marine-NOS/113114781174?epid=872143236&hash=item1a562a95f6:g:V9wAAOSw-3FZFiEb
 

Edited by 1avidflyer
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Posted

I have to admit you have me thinking now about the use of a teleflex cable to control the ailerons. I have some concerns about friction in the cable but it would certainly remove some parts and simplify the process. I'll do some more homework and decide if I want to use your idea or my original.

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