X's two on having nuts. Over time the vibration will destroy the threads on the push rod at the clevis. (there is a bad joke in there somewhere)

As for the firewall. I like to add some cloth either inside or outside of the firewall. Especially if you are installing a 120SC on the nose.

Wing. I like to use cloth top and bottom of the wing. Glass where the fuse touches the wing on top and on the bottom glass out to the retracts. Additionally, check the retract rails and add glue... they usually fail.

Jimmy Skids

Gerald,

Yes, just a basic nut tightly snugged up against the metal clevis. I would stay with the metal clevis at the speeds you want to go.

Regarding the glue: having seen these race engines seize causing the nose section snap off of other pilot's planes probably 3 or 4 times now, while you likely have enough glue at the joint, I always choose to go above and beyond to reinforce the nose section, and recommend you do as well. Like Skids, I prefer fiberglass; but I like to add tri-stock where possible to not only get more reinforcement on the joint, but it makes the fiberglass easier to lay down properly around that tight corner. (Two 45-degree angles, rather than one 90-degree angle.) All that glue on the back of the firewall and sides, however, means that tri-stock is not going to be a very realistic option for you on this one. One other option might be a U-shaped piece of plywood reinforcing the firewall's connection to the fuse sides. This is what the install looked like when I used one to reinforce the P-39 I detailed building the "Trinity-build" thread. This was in post #216 on page 9 of that thread. The P-51 build with the tri-stock I added to my firewall is pictured in some posts on page 15; and, I guess I am too late with the information now, but somewhere within a page or two of this is my steerable tailwheel installation on that plane.
http://www.rcuniverse.com/forum/atta...mentid=2081084

I have seen some modelers pin the firewall, as you mentioned. Think of this as a dowel joint. The way I have seen it done is to drill holes (perhaps a half inch or so apart) through the fuse sides and into the firewall. Add epoxy and insert a bamboo barbecue skewer or small diameter dowel seated into each hole. Then trim, sand and recover.

I ALWAYS fiberglass the center section of ALL my wings. How much depends on other reinforcements . . . is there a dihedral brace & how substantial? . . . Are the spars spruce, or just balsa? How solid does the glue joint look at the center section? (Beings you are not the original builder, this could be important -- I've seen some horrible looking joints from other builders over the years, with large gaps and little glue, so definitely check this.) The WM Mustang ARF comes stock with a dihedral brace . . . the question is whether or not to assume the original builder installed it. If so, and all else looks good, my Mustangs have held together using two strips of 3" center section FG reinforcement tape, with each strip overlapping 1" on each side of the center section. This would likely be fine for Silver, but if you intend to go faster, and/or do not want to take any chances, definitely follow Skid's recommendation and go out further.

Hope this helps.

Ollie

Everyone has their opinions bsed on 1). common sense 2). their own experiences 3). others advice based on their experiences

My advice- listen to all 3 as you will one day experience all of them yourself if you compete long enough.

All the above are good ideas, some may be over kill, but still totally valid considering the power plant you have on this plane.

Ill see you in PHX in a couple weeks and hope all goes well for you.

Gerald,

Just to be clear, I'm certainly not stating, or even implying, all these are necessary, just trying to answer your specific questions and give you options of methods you might choose towards rectifying any specific concerns. For example, I have never personally chosen to pin a firewall (as I have other preferred methods), but beings you asked what the technique was, I explained it.

Modelers continually argue over "Building to fly vs. building to crash" . . . light enough to optimize flight performance or building heavily enough to survive less than perfect landings and other stresses. Racing is no different; with everyone trying to find that elusive, magically perfect compromise of these opposing attributes. What compromises you ultimately choose depend on your particular piloting and building skills and preferences. Just know that we are always here, and happy to help.

Ollie

Oh so close now. All that needs to happen on all 3 Macchi is hinging the ailerons and installing torque rods. I really enjoy painting so that will seem like a walk in the park. Just a couple more weeks and these babies will be airborn!

Those 3 Macchi looks really nice!


I was able to do my shakedown flight this afternoon that went really well. Plane flys pretty smooth. I didn't get to glassing the wing or over beefing up the firewall yet. I will try and complete before the AZ race. I flew my yellow mustang on a ys120 at the rabbit dry lake bed in CA. I used a http://www.rcuniverse.com/forum/atta...mentid=2081460 4x12 with 20% nitro. The motor takes a while to come up (maybe diaphragm valve open too much) but a after going full throttle for 30 seconds or so the motor comes up. The top speed was 123 mph according to the onboard GPS. So hopefully it will be ok for silver once I increase the nitro and prop it right. I think maybe 14x14, 13x13, or 13.5x13.5, but I will have to practice with that. I am shocked to feel the vibration of the motor tuning on the ground. Rough stuff. Thanks everyone for the advice thus far! :)

gerald

Gerald
Glad it went well out at Rabbit.
Thats a good place to test planes for sure.

All YS engines need the proper time to "pressurize". Never get in a hurry going from idle (when first started up) to full throttle. Ill take as long as a minute.

Once you put 30 -50 percent in that thing with the right prop you will be fine.

There is so much power coming out of these YS engines that I always opt to run the hyde soft mount. Others on here will disagree and will say they lose rpms, which I wont argue, but the gain is worth it. My airframes love the effects of the soft mount.

Central Hobbies has these mounts if you are interested.

Glad we have you on board.

After looking more closely at your pics I would suggest:
1). beef up the fire wall with triangle stock
2). What size fuel tank is that? Id say you need a minimum of a 16 oz.
3). if you do run higher nitro, Id glass the center section of the wing and sheet the stab

now that you know it flies, Id take care of it properly.

After looking more closely at your pics I would suggest:
1). beef up the fire wall with triangle stock
2). What size fuel tank is that? Id say you need a minimum of a 16 oz.
3). if you do run higher nitro, Id glass the center section of the wing and sheet the stab

now that you know it flies, Id take care of it properly.

Those are sweet speed! I wouldn't mind having one just for sport flying!

Thanks Chad, I'm very much looking forward to this season.

Here is my go fast fleet!

do you have a cowl for the Q40?

What do you mean a cowl? Q40's don't have cowls.

i looked it up that plane doesnt have a cowl. the Q40s i have have them. will be slower with out them though.

Q40's aren't allowed a cowl to cover the engine. The formula ones were cowled in but q40 has never been allowed cheek cowls of any sort. FAI has an inverted piped engine that is all cowled as well.

you dont understand what I am calling a cowl lolhttp://www.rcuniverse.com/forum/atta...mentid=2081812 look at this one. what i am calling a cowl is the little cover that goes around the engine to clean up the installation anyway back to warbirds.

the race is coming soon who has new planes?

I understand and there are very few qm40's that even have the partial cheek cowl like yours has. Even yours is not a full cheek cowl like the formula ones had. The Ashley, Loki, vendetta, miss Candace, etc all have totally exposed engines like mine shows. Yours is one of few, I think the polecat, sweet v, and rivets have the partial cowl like yours. Is yours a rivets?

I understand and there are very few qm40's that even have the partial cheek cowl like yours has. Even yours is not a full cheek cowl like the formula ones had. The Ashley, Loki, vendetta, miss Candace, etc all have totally exposed engines like mine shows. Yours is one of few, I think the polecat, sweet v, and rivets have the partial cowl like yours. Is yours a rivets?

thats not mine. I have two sweet V's, a Gp5, 3 pole cats and one Gr7. I have three old F-1 style planes and some quickies too the faster ones i have seen have the cowl/engine cover what ever you want to call it.

It's all good. None of the q40's I've owned had any cheek cowl but there is no racing anywhere close to me so seconds aren't counting for me :). Just going fast for the fun of it. :)

My proud bird and vendetta have cowls. Most of the planes in Phx this year had cheek cowls, Very few do not anymore.

http://www.rcuniverse.com/forum/atta...mentid=2081901http://www.rcuniverse.com/forum/atta...mentid=2081902my miss dara and candice have cheek cowls

I believe they are technically called, "engine covers". Most planes today have them. Are they needed? Not as much as practice on the course.
:)

Hey David!! Missed you in Phx

Like this one... what is it? who made it? :)