Neddy191

My Feedback: (2)

I'm in the early stages of a sig 1/4 scale cub build. I've planned on using a DLE 30 with a Pitts muffler. Since the dle has a rear carb I'll have to move the firewall back quite a bit to keep the prop hub in the correct position, over an inch. Has anyone done this with this kit that happens to have pics or can walk me through what they did? Also, per the Plans there is 1.5 deg of down thrust and no right thrust. If I'm moving the firewall anyway would it benefit me to build in a couple degrees of right thrust?

soarrich

My Feedback: (98)

Cut a hole in the firewall for the carb.

VincentJ

Moving the firewall back isn't as hard as you might think especially during the building process and not as an afterthought. Make sure that you use a piece of ply of adaquate thickness 1/4" at the bare minimumm and not more than 1/2". Be sure to use a good quality Birch ply and to use epoxy for the adhesive. In addition to the epoxyit would be wise to pin the sides of the firewall with wood dowels. I used 4 or 5 on each side on mine. As for theright thrust putting 1 1/2-2 degrees right thrust wouldn't hurt anything. It may helpoffset the thrust of the engine on takeoff to minimize the input of right rudder. I had to move mine back as well, I used a DLE-20 on mine (wished I had used the DLE30). Hope this helps and good luck.

Neddy191

My Feedback: (2)

I was thinking about a Zenoah G26 so I wouldn't have to do as much modification but with the width of that motor I think I'd have to cut holes in the cowl for it to fit which I don't want to do. My local hobby shop has regular lite ply but I didn't birch when I was there last. Since I'll have to move the firewall so far back (somewhere around 1.5") I guess I'll have to leave the lite ply pieces as cheeks and put doublers on them so I'll still have the length in the nose to attach the cowl to. Do you happen to have any more pics of the music wire you used down your "a pillars" to reinforce the forward cabin?

VincentJ

What ever you do don't use that lite plyfor the firewall, it's not strong enough. Will these pictures do?

kork

My Feedback: (65)

From what I recall, I just cut out the existing fire wall and made a new one farther back but measured from the existing. was not that big of a deal. I also used wood dowels through the side of the fuse into the firewall and of course triangle stock to beef it up. The airplane fly's fantastic and comes in at a whopping 14.5 pounds.

Gray Beard

My Feedback: (-1)

I used the rear induction RCS engine and just cut a round hole for the carb to fit through the fire wall. I have used the RCS in a number of planes over the years and even made up a nice box behind the fire wall on one then turned it into a big air cleaner. No reason to re engineer the plane for a rear inducted engine.

Neddy191

My Feedback: (2)

I like how you cut out the original firewall ply to keep for a former. Hadn't thought of that - I'll definately be doing that on my build.

kork

My Feedback: (65)

by leaving the old fire wall inn, you have something to attach the cowl to. the only bad part is the plane will always be set up for a dle 30 or similar. But as we all have learned they end up in the trash at some point.

kork

My Feedback: (65)

Neddy, one more thing, PUTFLAPSONTHEBIRD!! I so wish I would have. Flaps can make for some great fun on windy days!!!!
jason

Neddy191

My Feedback: (2)

I'm building this one as a full wing J3 so I don't think I'll go with flaps on this one. I've got a Super Cub on my short list for future builds so I'll definately do flaps when that one gets built.

bikerbc

My buddy put a DLE 30 on his Cub and he tore the fire wall out on the third flight...So make sure you real have it secure..The 30 is pretty powerfull..I have both the DLE 20 and the DLE 30 and those are very powerfull little moters....I am going to use a Gemini 160 onthe BUSA1/4 cub that I am presently building...I have a OS FS120 on my 1/4 sig Cub that I am flying now...Unless you are way heavy the DLE 20 should be lots of power because my OSFS120 has lots of power for mine...I guess it depends on how you want your Cub to fly..I like mine to fly like a Cub..Sort of scale like..I have enough power to fly off floats too....I don't think you need flaps , Some times I kinda wish I had them to play with but I sure dont need them...One day I might build a set of wings with flaps just to go and play silly bugger but I will probably end up wrecking my plane . My Buddy has flaps on his Wingsmaker 1/4 ARF and he does his best to make me jellous with his shortlandings and takeoffs and I must admit it does work a bit...That thing really drops outa the sky and comes off the ground quick...Its fun to watch...Yup I think I want flaps too.... Not because I need them though but because my buddy has them and he has fun with them and thats what its all about is dickin around and havin fun...

Cub Man

My Feedback: (50)

Neddy191 Check out my site on adding the wire to the top. Look for section on building an open door and window.

kork I would recommend adding some triangle or square stock on both sides of the firewall.

Neddy191

My Feedback: (2)

I'm planning to build in the opening door/window. I've looked at your site and gotten some great ideas. I'm doing a "built on" center section like SunDevelPilot did in his build so I've built up 7/16" laminated birch ply wing roots in the center section that include the stick that does atop the cabin formers. It should be plenty strong not to need the music wire down the length of the cabin so I'm planning on drilling it into the ply and inch or so and then having the wire go down the front window support. I'm trying to figure out what to do at the bottom of the window support.

I know the DLE30 may overpower this plane a bit but its what I have and I don't want to buy another engine right now.

This is my 3rd build - the last 2 were beginner kits (Sig LT-40 and Sig SSE) that I did about 6 years ago. I'm looking at this build as a learning experience - I want it to turn out nice but it doesn't have to be exactly scale. I think doing some of these modifications will be very helpful for the future.

bikerbc

Yes I can understand using what you have and not wanting to buy another motor you can always change motors down the line somwhere if you arent happy with what you have....

kork

My Feedback: (65)

Bikerbc, I just looked at sigs web site and a wing kit is 75.00 so I think I might have to build a wing with flaps this winter. As per this thread, my 30 has had many,many flites and the firewall is rebust just as i built it,rock solid.. I do want to send everyone to the forum, then click on "crash and rebuild" then click on "Tims wow take off"
there you will see why having a little extra motor can save a plane. His citabria looks to have a 100" or larger wing on it. Granted if he would have used his rudder on takeoff, he would of been fine but extra hp's saved his plane.

it's a great video, check it out
jason

Gray Beard

My Feedback: (-1)

Neddy, it's so refreshing to see someone do a search and find several builds to go through and see how people have done things. Most people don't bother or have problems with the search engine. I have seen one of the SIG Cubs with the DLE 30, side draft and there is plenty of OS power with that engine. {{OH****!!}}Sounds like you have all the bases covered already. Have fun with your build!! It's really a fun plane to fly!!

VincentJ

+1

Neddy191

My Feedback: (2)

Unfortunately the search here doesn't work well so it takes a little longer to go to "old search" to find stuff