esvajoe

My Feedback: (4)

First time poster here, long time member. This isn't for a kit per say, but for an ARF. I need help with understanding an engine box. Here's the story....I purchased one of the off-brand 97" GeeBee "Y". It showed up in what I thought (and could still possibly be) outstanding condition. I worked on getting the engine in this weekend, and when completed, it looked horrible. The engine box received with it had down and right thrust built in. So much so, that when mounted correctly, the engine had quite an offset to it making the spinner point nearly 1/4" down, and an undetermined amount to the right. For asthetics, absolutely horrible and about one of the most ridiculous things I've ever seen. I'm using a DL55 on the plane. With the spinner installed, it looked stupid to the point where I couldn't stand looking at it anymore. Yesterday, I removed the engine box and cut/rebuilt it for somewhat better positioning. I think in the process, I've probably ended up screwing something up. I know boxes can be built to compensate for the torque, but since I've changed it, how much am I going to lose as far as when I taxi? If its a matter of applying rudder, no problem...just how much is my concern.

Whats bad about this is that trying to get parts for this model is next to impossible. If I need the wierd angles on the engine box for the torque, I'm pretty much out of luck. Any help is appreciated if someone can help with the design and idea behind the angles on the box. Posting this here because it seems to be more of a builder question than an ARF one. This is my first go round with an engine the size of the DLE55 anyway. I've been smaller nitro up to this point.

Anxiously waiting to either correct my screwup or understand what to do next....I'm not going any further on this bird until I get the box correct.

Thanks-
Joe

Rodney

When in doubt, go with the builders plans/suggestions.

esvajoe

My Feedback: (4)

Understand, but for once, I let my desire for a perfect outward appearance outweigh the physics. I've already manipulated the box, so I'm pretty much building a display model it seems if the torque is going to be that much of a factor. But I can honestly say when the engine was assemblied on the box originally, it had so much of an angle in 2 seperate directions that made it appear totally ridiculous.

I guess my next question will be, How can I build a new, correct engine box with appropriate thrust built in? I have no idea on where to even begin to head in that direction. I've run Saito 150-180's in the past that had no thrust built into the mounts and all appeared to track fine. Will I be taking that big of a step up with this DLE55? I truthfully don't know. I'll also apologize for asking all these questions. I was too excited when this thing showed up and its been nothing but hurdles since. Thinking I was overcoming them, I probably screwed things up.

kenh3497

It is my understanding a lot of the IMAC planes have 2 to 2.5 degrees of right thrust built in. I'm currently rebuilding a 60 size CAP 232. Stock right thrust was some where around 1 to 1.5 degrees. It is now 2.5

Build a new box to fit around the outside of the old box. This will give plenty of surface area to glue to and even a mechanical fastener or four would be a bonus. Use the old box as a guide to construct the new box. I'm guessing the box has tabs to lock it together. Triangular stock can be use to reinforce the joints in loo of the tabs and a little fiberglass cloth will add a bit more strength.

I'm sure others will chime in with more ideas.

esvajoe

My Feedback: (4)

Thanks for the replys. I basically took the original box, lopped off the angles and reset the firewall so that there were no angles. Bad move I know. The box did have tabs, but the tabs are no more. I set the firewall in with epoxy and reenforced with some small screws at even points around. I then fiberglassed over for added reenforcement. Overkill I guess but its pretty firm. The ARF itself is beautiful. Having the smaller versions and knowing the beauty of these when complete, I was frustrated when I saw how screwed the engine sits. With the prop and spinner on it and set in at the original angles, it was almost like it was pointing down. I don't know, maybe if someone else on here has ever built one of these I'll get more suggestions. Ultimately, I'll do as you said and prob build another box around this one. I'm assuming with these bigger planes and more torque, rudder comes into play alot more both on taxi and flight.