triumphman49

My Feedback: (149)

Hey Kevin, Looks rock solid ! ! ! Is the pushrod spread enuf? Or will you still have bends to contend with?


So sorry to hear about your injury . . . . they're never planned


T-man49 in Al

Melchizedek

Mike,
No, they are not spread at all yet. What I will do next is return to building the stab and elevators. I will need to add a mount block for the 2nd horn. Then I will need to do a layout on top of drawing for pushrod travel. I will need to pick up some ball links and plan my connections. This will determine where the dog legs go and how much spread. I will post this process as it happens. This will be my first use of ball links. Planning on the helicopter type.

Kevin

acerc

Very well done, looks exactly like the picture I could not find. On the epoxy, what about fitting the inside of the CF tube for a dowel then drill and tap for say a 2-56 thru and thru? I am not positive but epoxy may expedite oxidation of the aluminum.

Leroy Gardner

I'm kinda with Robert on the glue, aluminum is a metal that likes nothing but it's self, hard to know for sure what it will react with. Carbon fiber glues well and a short piece of all thread bonded in it after a tap is run in it would be a good way to attach it to the aluminum block, you could also use the carbon fiber tube in the block and eliminate any possible electrolysis reaction. It's a great Idea that I may use on my next build, I never have liked that stab locked in there and your way is more solid than two servos, my way of thinking.

Leroy

Cub Flyer Fresno

Why not use JB Weld? Is it not made for aluminum? I mean, I really, really want to know since I used that on the struts for my Cub!!! I like the idea of the 2-56 screw as well.

As for the two servos, in my way of thinking isn't that kind of like a redundant circuit? If one servo fails, you may still be able to land. What are the thoughts out there on that?

Cub Flyer Fresno

Back off topic once again... Yeah, I believe there are people in our local cycling club with Bacchetta's. Nice looking rides, although I'm not much into bent's, just wedgies. I just can't see pedaling up an insanely steep hill while seated! I like to be able to stand and lean over the front of the bike to keep the front wheel on the ground. But that's just me. As for the "free time bonanza"... there's just got to be a better way!!! And a cheaper way!!!

Sorry, back on topic.

acerc

JB Weld would do well, even though it is a form of epoxy it does not have the same acidity as standard epoxies. I think.......

Leroy Gardner

Flyer I think the way redundancy is accomplished in reguard to Kevins type of set up would be to use two servos on a tray linked together with one push pull rod, still in the case of a brown out your going to loose it. I don't worry about those things in the planes I build. I have lost two this year, they both went in in the exact same way and had different recievers. It was the transmitter that caused the crashes. It tried to tell me something wasn't right on the bench when the bind was lost, I rebound it and it worked fine, that is until I got it in the air. I thought it was the reciever until the second one went down.

Redundancy only works when every thing else does, well in most cases.

Leroy

Melchizedek

Robert, Great idea with filling tube then taping it. It is then removable if needed. Also no way of backing out.
I will go this route

As for epoxy reacting to the aluminum ? I know aluminum oxidizes but doesn't it need air to do that ? Ie air getting between the epoxy bond and aluminum. If good bond, doesn't that preclude that ?

The following is my experience with epoxy and aluminum :

In another life I decided to make my own bicycle frame. I wanted a fully suspended recumbent comfort bike.
All the parts in the following photos are aluminum bonded to CF with epoxy laminating resin. Balsa was used to interconnect the aluminum parts then wraped with Carbon fiber. The silver skin is aluminized fiberglass. The al fiberglass was just for bling, no other reason. All aluminum bike parts on the swing arm were machined with a drill press with 2 axis vise, router and hand tools. The acceptation is the crank arms and drop outs harvested from my wedgy.




This bike is 10 years old and has about 7000 miles on it. No joint failures.
I am not saying that epoxy and aluminum cant fail, but this is my experience.
The laminating resin was West System. Not the hobby epoxy.

This is the bike in its glory days before the epoxy yellowed and buggered the finish.




Kevin

Melchizedek

Finished framing up the elevator and stabilizer.

The leaeding edge of the elevator and the trailing edge of the stabilizer was a laminate. Ply in the middle with gaps for the hinges. So I lined up the hinge slots and cut the trailing edge a little long. Then slipped the faux hing plates in to line it up. If you look close at the 2nd from the right hinge slot. I had previously put a spacer in when the glue was still green. I will have to do surgery to open that slot up again.



I cut in for the 2nd elevator horn block. Also the balsa for the center section wanted to bow. So I cut some 1/6 ply and glued it to the sides of the center section to hold it straight. I also added some balsa gussets to the perimeter joints on stab and elevator. Wanted to secure those joints.



Kevin

Cub Flyer Fresno

Hey, sweet looking ride you had there! Looks like some cushy comfort! If I ever have to repair my bike frame, I'll know who to send it to.

Melchizedek

Thank you, David.

With frame up dry, it was time to try and get that hinge spacer out .

It was loose in the pocket accept for the two back corners. May as well have been a tooth that need extracted with roots that go down to your toes.
Get tooth, kill patient

The first photo is how it should have looked if I had been patient and waited for the glue to dry.



side note, I did take the hinge out for the glue to dry.

Kevin

YellowBlueBird

See post 128 Blue Jay Caos 60 build. fewer parts are always more reliable and one rod goes all the way to the elevator if the joint were to fail. I have learned a lot from these spacewalker builds.
Thanks

Jerry

Melchizedek

Welcome Jerry,
I have learned lots and lots also from the SW builds and so many others. So much to learn so little time.

Say, I did a search on the Caos build. The most relevant that came up was the Sticky one. The others that came up did not have a post 128.
Didn't see anything on the elevator in post 128.

Could you post a link ?

Kevin

FlyerInOKC

My Feedback: (6)

Nice looking hinge pockets!

Melchizedek

Thank you Flyer

That was a trick I picked up on RCSB. If your patient (unlike myself) they end up dead on. no muss no fuss.
For me, cutting hinges in after the fact is not my idea of fun or easy.

Kevin

Melchizedek

Started on the rudder. First up was to prepare the hinge post. The layup of the hinge pockets is a 3 piece sandwich.
2 balsa skins and ply pocket spacer. I used 1/6 ac ply sanded down to the hinge thickness. Then sanded the two balsa skins to come up with a total of 3/8 thickness. The 2 posts are to finish 3/4 wide but I glued them up 1 inch. This way they can be squared up when dry.

The hinge pockets were cut on a band saw taped together to get identical pair. The pockets were cut 3/32 deeper than the hinge. This will allow a max of 1/16 to be cut off the hinge edge at square up. Remainder trimmed off other edge.



While that was drying I sized the elevator push rods. There placement is just a smidge different from the stock singular setup.



The kit pushrods were just the right length.

Kevin

acerc

Out of curiosity Kevin, how far does the CF rod go into the aluminum block?

Melchizedek

Hey Robert,

The block is 3/4 front to back. The tube goes in 5/8. I left an 1/8 of meat for the push.
Did you have an idea of another approach ? Do share, I haven't mounted it yet and there is plenty of rod left.

Kevin

Melchizedek

The Rudder is framed up. The first pic has the vert stab post sitting on it.



Some might think me crazy but I am glassing the tail feathers. I now the tail don't need the extra weight. But when you glass a frame up like this it locks those sticks in like no tomorrow. I glassed my Kadet tail feathers and kick it's hiney around the block and the tail feather didn't flinch. The horizontal stab has glass on now. Side 2 tomorrow. It is a tedious job to cut and clean all that glass in the middle out but none of my sticks are breakin free.


I don't usually build during the week.
The Dr said "don't lift anything heavier than Balsa" I said " OK"

Kevin

FlyerInOKC

My Feedback: (6)

Kevin, the one hard and fast rule of building is "Do what makes you happy!" it doesn't matter what anyone else thinks as long as it works and you are happy with it. I can see how fiberglass would lock the sticks together. What weight of cloth and resin type are you using? I would think a water based PVA resin like Deluxe Materials Eze-Cote would be great for this.

Mike

Melchizedek

Hi Mike

The your way is ok demeanor you have is much appreciated. Thank you.

The resin I am using is West systems 105 with 206 hardener with the metering pumps. Mix ups, easy peasy.
The 206 is slow cure. You can speed the cure with heat. (heat not good for all application's) Some of the bike parts I put in oven
The reason I am using this is because it is what I am familiar with. The bike in the above post was fabricated with this.
This is first class laminating resin. It don't stink and cures hard and is sandable.
The cloth is 1/2 oz finishing cloth.

I have two alkalis heals. I am hard on stuff. Hanger/transportation rash is absolute with me.
Also sanding fill flush with balsa surface. Fill with a hard surface easy peasy.

One other benefit with glassing the frame work is it makes it stiff and keeps it straight.
Cleaning up the frame work is tedious and time consuming.

I brush on one uncut coat.Then let sit for few minutes to soak in some. Then wipe off with rag and let cure. This seals so there is no starved glass.
Then glass with a peel ply top layer over it. The peel ply leaves a puddles clean surface.

Kevin

FlyerInOKC

My Feedback: (6)

Sounds like good stuff Kevin.

Melchizedek

Oh, Mike

I wanted to ask if you have used the Deluxe Materials Easy Coat. How did you like it and what properties it has ( dry time, hardness, etc)

Kevin

FlyerInOKC

My Feedback: (6)

I have purchased some Exe-Cote but haven't got to the fiberglass process yet. It came highly recommended by a friend in the UK that is sensitive to epoxy fumes. Poor sod! I was considering brushing a light base coat on the wood first to seal it before I start the fiberglass process but it really isn't necessary. The airplane in question is a Top Flite Cessna 182 kit with 1/16" thick sheeting, and needs all the help it can get with skin protection. I have a number of things yet to do on the project before I can get ready to fiberglass the airplane. Typical build, I have to male improvements on the design! My building time completely evaporated when my son and his family moved in back in July. He was medically retired from the Army and they are working to get on their feet an into their own place. It should be too much longer they are looking for a rent house now. We will still be doing a lot of baby sitting after they move out but I am thinking I will get some building time then. Grandbabies are small for such a short time and James is a pistol!

Mike