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Wildcat Cub

Great looking build Stewart, I have enjoyed watching along.
A little of my opinion on locking nuts and washers. A locknut be it all metal or a "Nylon" when on a stud is only as good as the stud is into the base material. If the stud just releases from what it was in it does not matter what kind of nut was on it.
Lockwashers, I have always been frustrated by the common split lockwasher, so many times it cuts into either the base material or into the nut itself. PIA when you have to do unexpected restoration work when on what should be a simple 10 min part swap. No one likes being charged an hour when it is expected to be a 10-15 min job.
Nord-Locks, I have been working with these going on 20 years and I will gladly do so forever. There are times they overgrip and disassembly is challenging but I have not needed to do restoration due to a washer cutting a deep gouge in the material. They sure work better than wave washers that best I can tell just keep the failed nut so it can be reused again.

Back to lock nuts, I tend to only use them on bolts, not on studs simply due to the fact the stud may come out on it's own. A lockwasher does a great job of reducing that possibility, the nut just rides with the stud.
 
One of the things most guys here won't understand is that in a build like this one there are so many unanticipated conditions to deal with it wears the builder out. How do you make an airbox for a fuel injection system you've never seen and fit it into the nose? How do you mount a filter? How do you make an alternate air source when there's no room for it? I asked several past builders about their alternate air solutions. You know what I got? Nada. Not a single answer or picture. That's been the most disappointing part of the build experience for me. The lack of shared information and experience among the builders of similar airplanes. I was determined to change that a little and share mine so others could get an idea of what's involved. Funny how a very crafty solution to the alternate air door on my plane has drawn so much interest over a nylock nut. A nut on a bolt that serves as a shaft to attach a looped end of a push pull cable to and will never see any tension, compression, or shear. Is it the ideal solution from an engineering standpoint? Probably not, but it's an acceptable solution given the conditions. The chance of me needing alternate air is very small. The consequence of the door opening inadvertently? None. If that nut backs off and falls out? The cable will likely stay right where it is. Much ado about nothing.

I am very impressed with the Nordlock demonstrator and am hoping to get my hands on some of their new X series cupped washers for my exhaust studs. For airplane applications I can't think of a better product or a better place to use them. So far I can't find the cupped version and will settle on the standard Nordlocks. I'm surprised I haven't heard of these sooner.
 
There are lots of different personalities on this site, and I suppose every other open forum out there. I truly believe most are sincerely trying to help, and then there are those who just enjoy stirring the pot. Just part of our on line society, for better or worse. My very first post 15 years ago was asking about STC's for putting 18 tail feathers on my J-3. The response was overwhelming- all criticism of my choice to change them, and no answers to my question. I didn't post again for quite some time. I tend to use PM's a lot now.. I'm glad your posting and hope you don't stop.
 
Stewart,

Please keep posting! While I don't chime in much, I am thoroughly enjoying watching your build and all the craftsmanship that you and Mike are putting into your new cub. When I see that this thread has an update, it is one of the first I click on. Thanks for all your efforts to put this info online.

Planning to spend the month of July +/- in Alaska this year with my SuperCub. Hoping to see your creation firsthand.

Jeff
 
Mike has a philosophy that web forums have a high noise to signal ratio. He says when the noise gets deafening, be the signal. Sometimes it's easier said than done. :)

Thanks for the encouragement.
 
stewartb said:
Mike has a philosophy that web forums have a high noise to signal ratio. He says when the noise gets deafening, be the signal. Sometimes it's easier said than done. :)

Thanks for the encouragement.
Click to expand...

I like Mike's advice, I , like you find it harder said than done. On the silly issue of the Nylocks......When I see a build that demonstrates the quality yours has, I just take for granted that The guy Who did it knows the "first oracle" stuff like that and figure he has contemplated the consequences as well as he didn't get to the point of completion you did without addressing the basic stuff!
Again, Great job , Now let the fun begin and bring that thing down south and let's put it to use on some bars.
 
Under seat. Another cool exp aircraft product. A smart controller for electric trim joins my high point brake bleeders and fluid reservoirs. IMG_4356.JPG


Sent from my iPhone using SuperCub.Org mobile app
 

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Are you using trim tabs rather than moving horiz stabilizer? If a moving stabilizer, what are you using for servo? The web page says 1 amp max output. Maybe that's enough to operate a jackscrew motor???
 
The HD model is rated to 10a and has dual inputs/outputs so can be wired for more. No jackscrew in my plane, just a linear actuator, and the current draw and voltage drop were concerns. TCW says it won’t be a problem and provided instructions for my application.
 
stewartb said:
No jackscrew in my plane, just a linear actuator.
Click to expand...
stewart, Does that linear actuator have a fail safe mode? Enough so that it can not move unless power is applied to it? I'm reminded of the trim screwjack failure of the Alaska DC-9 when it turned into an ocean dart in California.
 
I remember the accident. I knew someone on that plane. I think the lesson learned from the investigation is that all of our full trimming horizontals require inspection and proper maintenance. I was taught a long time ago to grab the horizontal's leading edge and give it a stout up and down test during pre-flight. Any play or movement is cause for staying on the ground. I'll continue that habit with my new plane. My bigger failure concern is in the little rocker switch on the stick that controls the trim. It's easy to imagine that switch getting stuck. The 3 second timer in the Safety trim along with the reversing feature manages that concern.

http://www.supercub.org/forum/showthread.php?51419-Electric-Trim-Explained

http://lessonslearned.faa.gov/ll_main.cfm?TabID=2&LLID=23&LLTypeID=2#null
 
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Stewart, looks like a good arrangement.

I have two questions -
I don't see the model # from your photo listed on the Safety-Trim website. Do you have a link?
Would you mind sharing what linear actuator you're using?
 
Yes, I saw the data sheet, but it's for a variety of models.

Yikes, 12" travel, and 1000 lb force? I'd be interested to know why those parameters were selected. Total jackscrew travel on my 12 is about 3 1/8". And at 1000 lb, if all the fail-safe stuff fails, something is liable to break rather than just trip a breaker. Do you happen to know the answers to those questions / concerns?

Another question, what are you using for position indication?

Thanks!
 
I don’t know what the actual stroke is. It has limit switches but I have no idea what they’re set to. I’ll find out soon. Jeff Lefore’s yellow and black Rev 2 seems to work pretty well.

The actuator has a string potentiometer mounted to it and it sends a position signal to the G3X. We used a similar string pot at the flap bell crank so actual flap deployment (including blow back) will also be displayed on the G3X.

IMG_0001.JPG
 

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stewartb said:
Mike has a philosophy that web forums have a high noise to signal ratio. He says when the noise gets deafening, be the signal. Sometimes it's easier said than done. :)

Thanks for the encouragement.
Click to expand...
Lets all chill out and have a new discussion on DOWN WIND TURNS.... great looking plane Stewart, vans airforce is a pretty good source for E-AB ideas....I’m having fun building a RV7
agpilot
 
I thought a full electrical system was two magneto P leads. Looks like I was mistaken. Nice work.
 
A G3X Touch looks elegant and simple from the front but there's an awful lot going on behind it. And a crapload of breakers and switches to support it. Not exactly what I had imagined. Not complaining, just sharing.
 
Thank you for the linear actuator vendor & part # Stewart. I wonder why Backcountry switched from using Firgelli Automation linear actuators to DCAcuators? Big difference in both actuator total weight and force.
 
Can't say. AK Tahoe's old plane had a smaller actuator so the change happened between his and mine, and no Rev 2s were flying during that time.
 
I've noticed this elsewhere, and I'll make a guess - - The higher force actuators have a slower linear speed. That might be more desirable for trimming. My guess is that in this application operating speed is governing, rather than operating force. As long as operating force is adequate, of course. And I have no idea what the required operating force might be.
 
My Safety Trim has a panel switch to select high or low speed for the trim servo. They also offer an airspeed switch but I didn't choose to use that option. 2 speed electric trim is common.
 
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