Aeroworks 40% Carbon Cub Users Thread

[BobM]

I know some have used a push button latch for the rear cover behind the wing.....can anyone give a source or manufacturer for these ?

Thanks,

Bob

[lenb]

http://hyperprod.bizhosting.com/canopy_locks.html

[BobM]

Perfect.......Thanks Len !

[BobM]

Just about have all the hard work done on my Carbon Cub now.

I completed the tow release, battery compartment, and carbon fiber hatch cover that is just behind the trailing edge of the wing the other day. I ended up using a Quick Latch for the latch mechanism. Seems to work really well on the bench and keeps the cover tight over the compartment......it's a single push button latch that captures a small thread rod and a ball end underneath the hatch cover. Push to unlatch and the latch lets go to remove the cover.......push the cover down over the latch to re-ingage the latch and lock the cover in place. I like that it is just a single push either way, keeps it simple for opening and closing the hatch. ( www.quick-latch.com )

I've been working on the installation of the canisters and the internal formers that hold them in place. One last check of the fit there and I'll put the formers in with some West Systems resin and a bit of fiber filler mixed in to help with making fillets on the glue joints.

I'll complete the wiring harnesses next for all the servo connections and complete the throttle and choke servo install, then it's really down to the final work on the airframe.......completing the control linkages on the flight surfaces and installing the main gear and tailwheel.

I'm hoping to have the majority of the work completed by the end of the weekend and finish up any details during next week.

I'll post some pictures of the airframe and details in the next couple days.

[BobM]

Thought I should give a quick update. Progress on this project seems to be taking longer than I plan......but it is progressing well.

I have been working on it on and off since last post. All the electronics are now fully installed and ffunctional. I have the radio and batteries in a compartment right behind the trailing edge of the wing. I think Len found this to be a good placement with a removable hatch cover for easy access to the batteries for changing them out.





The programming on the 28x made the setup pretty easy and straight forward. Wiring is set throughout the fuselage and wings. I used heavy duty twisted servo wire throughout for all servo extension with Hansen Hobbies connectors. The wiring to the ignition at the engine is 2 wire 20 ga to carry the current well (probably not necessary, but what the heck).

The engine is set now as well, servos are installed on the choke and throttle and all seems well with the setup on those. I used 4-40 heavy duty ball links on both ends of the pushrods and titanium fixed length turnbuckle rods from Hangar 9....those are really great for connecting servos as long as the length isn't more than 5".



Gas for the engine is supplied by 2 tanks, a 100 oz main tank and a 10 oz header tank. I still have to finish up the plumbing, but the cabin floor is in place and the tanks are mounted with velcro.



I made the cabin floor out of a layer of 3/32" aircraft ply and then 3/16" balsa underneath for insulation. There are 3/8" square balsa strips install on the top of the floor to help keep the tanks in place. The tanks themselves have velcro on the bottom that attaches to velcro on the floor under the tanks, then some 1" velcro straps to hold everything down so it doesn't come loose.

Underneath the floor in the exhaust area I used some foil insulation material to help keep the heat from the canisters away from the cabin floor. This is similar to what Peter did with his.

I made a ply plate that fits in where the exhaust exits. I'll cover it with white ultracoat and set up up with screws to hold it in place. I have beth of the bottom hatches set with cutouts to keep airflow moving through the whole area effectively for cooling purposes. This should work well to draw fresh cool air in through the front of the cowl and move it back through the canisters and out. The rear most hatch is not installed yet..I'm still mounting a couple of the final remote antennas for the radio.



Not ready to go yet, but next I tackle the main and tail landing gear and then the wings and struts, and finally mount the horizontal stabs. Some final programming of the radio and it should be about ready for some initial test flights.

[Xroadie]

I like the cover you made for the exhaust nozzles! I may have to copy you on that Bob

[BobM]

Easy enough to make. I just used a couple of 3/32 ply strips attached with resin n the inside and then cutout the hatch with the right thickness of ply to match the fuselage. A couple quick measurements with some trial holes on a large piece of cardstock and I was able to get them right on the plywood for the cover.

I did worry a bit about the effect of the cover on the cooling of the exhaust system, but I think with the large cutouts on the rear covers it will draw air through very effectively by making somewhat of a vacuum......the front openings are somewhat smaller than the exit openings, which should cause good airflow through the whole area...I hope !

I have to think about opening up the front of the cowl as you did to make sure the carburator remains cool during the hotter seasons.

Working on the plane tonight and hoping to have the landing gear set before I quit for the evening.

[BobM]

Ok.......so I am really getting close.......finally.......seems like I've said that one before !

Enngine installation and all radio equipment is full installed now. Headers fit in nicely and the lower cover is in place where the header exhaust stacks come out.

Just need to connect the flying surfaces to the servos (pushrods and servo arms to be installed) and finish the struts.......it will be flying next week.

Here is a quick shot of it while working on some of the final assembly before I set up the horizontal stab, wing panels, and struts. The windshield and cowl will be put on last after all the other work is completed so they don't get damaged. Last step will be the registration numbers and graphics.

A quick question to other Carbon Cub owners: For the windshield installation they have a large number of screws that hold it in place along both sides. Do you also use some RC 560 or similar canopy glue on the front bottom that rounds over the top surface of the cockpit ? Seems like if glue isn't applied then wind and air during flight may cause this to pull up slightly and pull at the canopy causing stress. Thanks in advance.

[lenb]

Good job Bob,

But who would have thought that by the time you finished the plane and had it ready to fly the company would go out of business? It could be your fault?

[Stew2]

Bob,

I wouldn't worry about aerodynamic forces as much as I would about vibration. I bet you will develop cracks at the screw holes from vibration if you don't use glue. I used household Goop on the Bidule canopy after removing a 1/4" strip of covering under the perimeter of the canopy. I did install a few screws, but only as clamps while the Goop dried. I left them in and no cracks on that canopy, yet anyway. I think it is a good technique for installing canopies. What is the span of the horizontal stabilizer anyway?

[JimD]

Agree with Scot...every canopy that I placed screws in eventually cracked at the screw holes ...100% of them!

That said, Shoe Goo or Goop has been great, zero failures with it...not so with RC-56 or Formula 560.

[lenb]

I did not use any glue on my Carbon Cubs, as I wanted the ability to remove the canopy and top ( one piece) any time I needed to for maintenance. I was fortunate and never had any cracks in the windshield until it hit the tree's.
I did use a rubber edging on the bottom side and pulled it tight. Eventually there would be wear marks on the covering where the rubber channel was from wind and vibration making the windshield move around.
I would probably go with the goop approach if I did it again. Check in with Pete George ( Xroadie) I know he recently had an issue with the windshield and had to do something with glue.

Len

[JimD]

...and as of this moment, there are no replacement parts. Would be nice if someone would pick up some of these planes, seems a shame for all of this design work to simply be lost. .

[BobM]

Many thanks for the suggestions.....very helpful !

I like the idea of the rubber channel. It would be very easy to run a thin bead of something similar to goop for a seal on all the edges. I do like the ability to remove the canopy for work though.

Len....I waited to finish the plane after Aeroworks closed as it is now a collectors item......soon to be a vintage or classic !

Servo arms and pushrods tonight and then I should be close to the final steps of the struts and finally the cowl and canopy.

[Xroadie]

Looks great Bob!

I am on my second windscreen...I lucked out and got a new one just before Aeroworks shut down. My first one I attached the windscreen as designed....a million screws all round the canopy except for the front lip. Note: I order a "shitload" of the smallest rubber backed washers from RTL and used them on the canopy. After my first flights I noticed that the front of the windscreen was being pushed back against the V-struts above the dash. I had a V shaped abrasion on the inside of the windscreen. Because the real Carbon Cub has screw/rivets that go across the front lip, I thought I'd kill two birds with one stone and add a row of screws across the front. Because the turtledeck in that location was just sheet balsa I glued in some plywood hard points for the screws to bight in to. That worked without any issues for about year of flying. I did however get a crack that started on the right "shoulder" of the windscreen, where the windscreen wraps around the outside of the false wing rib on the top edge of the cabin. I stopped the crack temporarily with a "stop" hole and some hot glue. Then earlier this summer, I noticed that the windscreen had torn around one of the screws I placed on the front lip. It did not start at the screw hole but started in between two screw holes and made a semi circular tear around one of the screws leaving the screw holding about a half square inch of windscreen. I removed all the screws glued the torn off piece back on and secured the front lip to the turtleneck with a strip of red Ultracoat. This held for a little while but kept coming loose.... at events I would use tape to temporarily hold it, till I could get home and ironed on an even wider strip of Ultracoat to the lip...it still came lose on me. By this time my canopy started looking a little ugly with the two cracks so I spent the $45 or so for a new windscreen.

The replacement windscreen from Aeroworks was predrilled and almost none of the holes lined up with the screw holes on the existing canopy frame, which required drilling new holes. I covered the old holes, which would be visible through the windscreen around the top with dots of red Ultracoat. This time.... after thoroughly cleaning the front turtledeck of oils and adhesive residue, I attached the front lip with a bead of RC56 canopy glue. I attached about 75-80% of the lip, leaving a gap on the lower sides so that if I have to get the windscreen off again, I could run a length of dental floss through to work the RC56 lose. So far.... after a few hours of flying this is holding.

Before you attach the windscreen make doubly sure that the screws that hold the top of the V-sruts in place are secure....mine keep coming lose. I have even gone with bigger screws to secure them. You have to remove the windscreen to re-secure them. If I had to do it all over again, I would drill a hole straight through and use a bolt with a locknut in place of the wood screws.

Speaking of the V-struts, Len noticed that the bottom of the V-struts don't actually tie in to the structure.....making them mostly cosmetic. I can't remember what Len said he did, but I flipped the model upside down and with the windscreen and dash removed poured some epoxy thickened with chopped up FG and made a "Puddle" around the area where the lower end of the V-struts pass under the turtledeck, to better "tie" them into the structure.

Hope this helps!
Pete

[Xroadie]

Bob, What is the span of the horizontal stabilizer anyway?

51 1/2 inches!!!

[BobM]

Many thanks for the information on the windshield from everyone.....thanks for your report with all the details Pete.....very helpful !

Scot, sorry I didn't have the measurement of the stab off hand.....Pete saved me on that one.

I do know that it was only after I got my Carbon Cub I thought to ask Len about the stab width......won't fit in my trailer assembled, but I think it does fit into the back of my car. I had very brief thoughts of using Saws All on the back of the trailer to fit it in assembled

[Stew2]

You'll have to design a rig so the Cub can be put in on its side maybe? Really, I wonder if something could be done with that?