brenthampton79

do you recommend the robart hinges on this model? I was going to use the ca hinges but I'm open to suggestions. I wish they made it easeir to put hinges on rc plances where you could remove the control surfaces easy for mx, than having to cut them off and redo them each time, I have some robart hinge pockets I bought last week and going to see how those would work for easy removal

brenthampton79

also I don't think Im going to use the dummy radial at this time since i'm using an actual radial and want to show off my saito too, but I beleive the engine has plenty of weight, I agree the manual seems pretty well written and gp had only one tech notice on the color of the covering LOL. The model seems really easy to put together without a lot of time consuming things to do just gotta dig in and go pretty much.

PacificNWSkyPilot

My Feedback: (19)

I used Robart pin hinges on mine. The only thing with this model is that the control surfaces have lite ply through the center of them. Keeps them real stiff, but the lite ply is tough to drill into straight because of the lite ply. It was worth the extra effort, though.

I did three videos telling how to install the Robart Pin Hinges, but I didn't do anything on the hinge pockets. I used the Stearman wing as my building example.

~ Jim ~[8D]

brenthampton79

Oh ok I see what you are saying now. I think I'm going to use the ca hinges this time but will probably go to the robarts or something else once I get to the point of needing a recovering job possibly later on. I'm planning on flying this plane quite a bit. I like flying different types of planes a lot but I have a feeling this will be a favorite of mine. Im into learning 3d lately but still like scale type flying since I used to have a full size pitts. ( hoping to get another acro mount when I get my medical back)

PacificNWSkyPilot

My Feedback: (19)

CA Hinges are easy to install, I'll grant you that much.

In those three videos, there's one sentence that stands out more than the rest. "Installing CA hinges in a plane is the same thing as adding an expiration date."

CA hinges are nothing more than a single sheet of plastic that flexes - a LOT. They'll give out. Many factors affect that - the amount of flexation, oils, cleaners, fuels. Maybe just one will fail, giving you time to change them out, or maybe all of them on a surface - and then maybe - down it goes. Whatever kind of hinges you install doesn't matter. How well they hold out matters most, especially on a plane this size.

Maybe I could suggest that you use Robart pins (or some other pinned hinge) on the tail feather surfaces, particularly the elevators, and then if you want to use the CA hinges on the ailerons, there would be less danger should you lose one. The Stearman is a nice bird, not to mention the radial you're talking about; it would be a shame if a surface failed and the whole Bipe was lost.

And yes, you're going to love this bipe. I love mine just sitting still on the table! It's just beautiful.

~ Jim ~[8D]

PacificNWSkyPilot

My Feedback: (19)

I found this when looking for photos of my S-Stearman:

http://www.rcuniverse.com/forum/m_42...anchor/tm.htm#

Post # 1431, and then a few posts below it.

Hope this helps.

~ Jim ~

brenthampton79

I think I'll go that route and use the robarts for the elevator and rudder for sure and then do the ailerons when its time for a restoration! Thanks

brenthampton79

I can't see the pictures on the post, but what size of hinge points do you use? I've only had a couple of ca hinges fail, but I mostly fly smaller planes too like 40 size.

PacificNWSkyPilot

My Feedback: (19)

There ya go, making me climb ladders and stuff.

It looks like I used the larger pin hinges on the tail feathers of my Stearman. You can get the same strength with the smaller pin hinges; just use more of them.

~ Jim ~

brenthampton79

haha thanks Jim I may try these hinge pocket things out so I can remove the tail surfaces for mx and etc. I made a modification to my kit built 60 size extra where I ran a piece of music wire through the hinges that I could remove the aileron by just pulling the wire out. I havent modified the other aileron to mirror that one until i get a few more flights on it to see how I like it. I like the idea of being able to remove the surfaces easily though.

PacificNWSkyPilot

My Feedback: (19)

Sure, everybody has different criteria that matter to them. I've never had a need to pull the surfaces off, once installed. I suppose there are reasons for that.

As long as they fly well for me, and hold together, I'm a happy guy.

~ Jim ~[8D]

brenthampton79

Yeah I like to be able to pull them off to help clean them and when I recover the planes. I usually end up recovering my planes when the monokote gets rough looking. I like to have nice looking models I guess plus I tend to want to recover my arfs pretty quick so mine are different than everybody elses at the field too I have only done one removable surface so far and like it and plan to do it on more of my models when I build them.

PacificNWSkyPilot

My Feedback: (19)

Hmm. That makes sense.

Cool idea. Very "personalized."

~ Jim ~[8D]

cromagnonman2

G'day Folks,
I finished a rather difficult stage of my Stearman tonight. I'd read of a few methods on here on how to reinforce a firewall & racked my brain about how ya can do any of 'em, what with the tight space & lack of visibility. I've got a fairly big hand (see pics) & tentatively tried to put it through the frame that holds the fuel tank. No way I thought. If I could get it in there I probably wouldn't get it out without breaking something. I'd already decided the plan would include two vertical pieces of hardwood on the inside firewall so I started cutting them to shape & hoped some ideas about how to fit them would germinate in the meantime. I think I was sanding some globs of glue off the stock firewall reinforcement using a long thin piece of ply as a sanding block when I realised my whole hand had gone inside! Oh no! But to my relief I found, if I twisted my hand & mouth in exactly the right way I could not only get it out, but put it back in with relative ease. Next problem was not being able to see anything if my hand was in there. I cut the handle of a 1/2" craft paintbrush in half & screwed it back together at 90' so I had a brush with a bend in it. I put a small rectangular cosmetic mirror against the firewall & standing the fuse on it's nose, I practiced painting epoxy in reverse perspective with this brush. My hand was outside the space & I could see what was going on. It wasn't pretty to watch by any means but I convinced myself I could do it for real. I painted epoxy on the difficult bits first, then unscrewed the brush handle to give me a straight short handled brush to do the bits I could see without the mirror. So I got the two peices glued in ok & while they were still curing I made a thinned batch of epoxy & wetted a dozen or so strips of carbon fibre tape on the upper firewall joint. This was the only place I could manouver the brush with enough dexterity to do a half decent job. After all this touch cured I made a couple of batches of thinned 5 minute epoxy & tipped them in stages around the rest of the firewall joint, holding the fuse at a 45' nose down attitude & rolling it axially until the resin cured in a nice fillet. I also put a fillet along the inside landing gear mounting plate & applied a few strips to the outside of the gear mount. Now I think I can get back to the instruction book again & start mounting the tail feathers.I've posted a few pics. I wanted to make sure the firewall was strong because i'm using a DLE 30.
Mick

PacificNWSkyPilot

My Feedback: (19)

I ran into the same problem, and I remember thinking the same things as you.

I ended up drilling a 1/2" hole between the two dowel rod holes, so I could see from the outside while I had my hand inside. I also removed the long shelf with the holes in it, and built a light framework to it for the batteries on top, and the receiver underneath (or vice-versa, can't remember exactly). Once I had all of them secured to it, I put it back in and glued it down again. It helped to keep the weight forward for the balance. I installed the Syssa 30CC on mine, which I think is pretty close in weight to the DLE 30. The problem I had with preparing the firewall for my Syssa was that my mount points were far enough apart that I ended up having fight the tri-stocks out by the sides, where the outside of your added bracing butts up against it. I didn't have to fight with the plywood the tri-stock was glued to. The tri-stock was enough trouble by itself! Finally got it. THAT was a job. I'd definitely do something more like what you've done here if I was building another S-Stearman. Looking at your photos here, I see it's MUCH easier to bring the firewall up higher on the tri-stock than to carve the tri-stock down to the firewall. I used some tri-stock epoxied in on the outside edges, but the carbon fiber looks quick and easy. I'm building an RC Guys Super Decathlon right now, and looking at some rather tight corners that I want to reinforce. Maybe the Carbon Fiber is the way to go. Thanks for the idea!

Looks like you're doing a nice job, Mick.

Keep those photos coming!

~ Jim ~[8D]

cromagnonman2

Thanks Jim,
The carbon fibre is cheap but can be difficult to handle. It's a multi strand tape that has the fibres running in one direction only, so it falls apart very easily. It's very strong in tension though. A woven strand tape or matwould have much better strengthening properties& be heaps easier to use.
Ordered your book a coupla days ago by the way Jim. Hope it gets here in time for my upriver camping holiday in 3 weeks!
Mick

PacificNWSkyPilot

My Feedback: (19)

Well, thanks, Mick!

I sure hope you like it.

I have some leftover pieces of carbon fiber tubing from linkages. I was thinking they might be able to be used for the job, maybe small 1-inch pieces stacked in a triangle pile & tacked with CA before inserting into the outside edges with epoxy. It's fun sometimes to let the juices flow!

Have a great time on your camping holiday!

~ Jim ~

Jim Henley

Just finished the same type of modifications to the Super Stearman, I removed the balsa block ahead of the wing saddle and behind the firewall. These are only lightly glued in from the factory so they are easy to remove. That allows room for a 1/4 ply doubler to be epoxied behind the firewall. I beveled the sides so it would fit tight between the tri stock on the back side of the firewall. By opening up the bottom of the fuse, I could also add some additional tri stock to the formers to strengthen them as well. Finally I found that the formers need to be relieved to ease the access to the Syssa stand off bolts. Likewise I removed the stock fuel tank mount but added a block and blind nut to the back end so the tank can be removed. I learned these tricks after having the front end of the fuselage apart to make repairs, and when I put the Syssa on the fuselage the first time.

PacificNWSkyPilot

My Feedback: (19)

Yes, I just finished rebuilding three ports I cut into the nose of the fuse so I could reinstall and retighten my standoff screws for mine too. After I finished, I found out that Todd has a Triangle metal firewall brace for the back side of the firewall. Ordered one right away, since I'm building a plane that will have a Syssa in it.

I absolutely LOVE the Super Stearman - unless I have my hand inside the nose! Then, not so much. @#$%^&*$%^

I don't look forward to changing out the batteries in a few years. I know, I know, I'm a whiner.

Lol

I'd still like to get some feedback on my carbon-fiber / three-tube-stack idea for bracing the inside firewall corners. It sounds almost too easy to me.

~ Jim ~

cromagnonman2

Jim H - Man that would have made things easy! I wish I had the experience to cut stuff out like that but this is only my second model (yeah dumb I know).
Jim S - Dunno how you'd go getting a 90' angle using round tubes. 3 would give you 60' on each corner. Trouble is the epoxy would not actually penetrate the fibres of already cured tubes so ya really only got an epoxied joint with some stiff filler in it. I dunno whether you'd be improving the tensional strength of the joint much over an ordinary epoxy fillet. Just my two cents (which by the way is 2.0868
of your cents)

PacificNWSkyPilot

My Feedback: (19)

2.0868?[X(]

I'll bet you actually went and looked that up! Goodonya.

The idea with the tubes was to stack them against a 90-degree corner and tack them. It might take 4, or 5. Then again, I can just use tri-stock. But I think the epoxy would penetrate roughed-up carbon fiber tubes as well as it would penetrate the pieces of hardwood tri-stock. And of course, I'd fill the tubes with epoxy as well. {{{Shudder}}} - I was just thinking about the epoxy mess I'd make doing that. Yikes. Okay. Tri-stock it will be. lol

Tune in and watch Jim talk himself out of his own ideas.


[8D] ~ Jim ~ [8D]

raptureboy

Just my opin but your way over powering this with a 30cc engine. My PT-17 weighs 15 lbs and flies very scale on a DLE-20. No problem with the fire wall coming loose yet and if you mount the batteries out front with the engine it balances just fine. There is not enough meat in the wings for robart hinges so I use nylon hinges with a removable pin although the CA ones work fine. I mounted a better tail wheel by drilling 3/8" holes in the tail block and then gluing in dowal pieces and then drilling for #4 screws.Ground handling is better if you don't jam on the throttle and instead power up slowly like the real thing. A couple of pics of my pt -17 and my buddies super.

PacificNWSkyPilot

My Feedback: (19)

Naw. A 30 CC is just fine. I have a Syssa 30CC in mine. And there's plenty to attach the Robart Pin Hinges to in the wings; I have them in mine. It just takes a little care to make sure you clear a proper space in the lite ply that runs through the center of the surfaces. Mind you, the plane WILL fly fine on something like a DLE 20, because it's actually a 1.20-sized bird. But if one installs a 1.20 glow on this plane, they're also going to add 20 ounces of lead to the nose to balance it. No getting around it.

OR - You can install a 30CC, which is very close to what the glow engine AND the lead weights weigh together. Which is what I did. What I like most of all is the nice, big propeller, which looks a bit more scale-ish on an already VERY pretty bipe. Most guys flying 30CC engines in these run either 18's or 19's.

As for the extra power, it's probably similar to the 600+ HP engines they shoehorned into the Super Stearmans. Nice to have it during some of the aerobatic maneuvers, but much of the rest of the time, the stick won't be much past 1/2-way. On my Giant Super Sportster, I spend much of my time with the throttle stick right at about 3/8ths throttle. It's nice to have the extra oomph, and the plane doesn't mind the weight, or the extra power. It still doesn't have unlimited vertical, though it's plenty lively.

You're right about the gradual acceleration. It handles better, and it looks better. Nothing weirder than an antique bipe rocketing off the runway.

Are both of the birds in the photos yours? Nice.

~ Jim ~[8D]

cromagnonman2

There's two nice birds alright.

Mikecam

If your someone who just wants to do circuits then put in the DLE 20. If you want to do some barnstorming with the added weight of smoke then go for the 30.

I did notice I'm getting some wing separation on the top wing. Looks like it is not the glue joint but the sheeting right next to it. I do have a bad habit of carrying the plane with the top wing and looks like this needs to stop as I think this was the problem as the struts should help hold the wings together. No firewall additions for me, so far so good.

Mine flew like a brick till I added small washers to the back row of bolts to put in less incidence on the top wing. The forward wing needs to be the one to stall last and it would appear that it was stalling first. After the change it has been a totally different plane in slow flight.

Great looking plane.