Just a quick post finishing up the carbon rod installation. I glued on small gussets to strengthen the joint where the rods are conected. You could use plywood or lite ply but I used little bits of left over 1/8 Fiberglass end grain balsa, this stuff is super strong about the same weight as lite ply.

chuck norris would be proud

Harv
Are you flying IMAC this year or just those spinning bucket of bolts??

HA that was a good one. Ill probably hit a few events. not really motivated right now. Will go to the local events, and hit a few pattern events. we are still 1 and 1 in masters. hahaha. and as always my spinning bucket of bolts will tag along everywhere i go.

Hey Henry! The build is looking awesome, i got mine just about finished up, just finishing the covering and paint. Seeing as how this is your 2nd one and it will have the same setup as the first, which is pretty close to my setup. Where do you have the CG on your current 126'' 300 with the 200L ?? I had talked to KK and he recomended it be set at 3.75'' - 4.0'' back from the leading edge of the wing tip for precision flying. Is that close to where about you had yours ?

Originally Posted by Henry Piorun

If I understand the question correctly this is the way the motor box comes from the factory. That top plate has the holes already cut out. I'm running this exact set up on my other Carden with a 200 and it works great. If you are talking about the cut outs in the firewall, that's my idea. I did this in the last one too and it works just fine.
The DA 200 is such a smooth running engine I think it puts much less stress on the airframe than any 150 or 170. Rather than "beefing" things up for the 200 I think we can almost go a little the other way, just my opinion.

Henry,
I believe that poprlite was asking about the missing plywood on the back of the motorbox (see picture). I was going to ask the same question. I understand you have removed this to allow the tank to be centered on the CG. Have you experienced any additional flex with the piece removed from your other 126"? When I was designing the Pro we increased the length of the motorbox behind the wingtube so that the tank could be perfectly centered on the CG without removing the rear ply section of the motorbox.
Thanks, Kurt

Ok, I get it. Well I don't think that little bit of ply does a heck of a lot. The way the grain of the plywood runs on that peice is vertical anyway so there is a lot of flex and not very much strength gained from that cross peice. Having said that, the tank mount that I will make sort of replaces that cross peice, it's just a bit further down around the level of the wing tube. I'll have pictures of that up shortly.

Originally Posted by harv

HA that was a good one. Ill probably hit a few events. not really motivated right now. Will go to the local events, and hit a few pattern events. we are still 1 and 1 in masters. hahaha. and as always my spinning bucket of bolts will tag along everywhere i go.

Good to hear, I think your motivation level will come up as the weather gets better. I know mine does!

Originally Posted by JIMZACH

Hey Henry! The build is looking awesome, i got mine just about finished up, just finishing the covering and paint. Seeing as how this is your 2nd one and it will have the same setup as the first, which is pretty close to my setup. Where do you have the CG on your current 126'' 300 with the 200L ?? I had talked to KK and he recomended it be set at 3.75'' - 4.0'' back from the leading edge of the wing tip for precision flying. Is that close to where about you had yours ?

Well thanks! I wish mine was as far along as yours!
I mentioned earlier I like a more forward CG than what Dennis recommends of 3.75 to 4 inches. I tried the 3.75 and the plane flies fine there but to me felt a little tail heavy. It required very little down elevator when inverted if any, (to me that is just a weird feeling) and it just didn't lock in as well as I felt it should. I started to move things forward until I got the feel I like. The more I moved it forward the better it got, very locked in feel, snaps, stall turns, rolls everything seemed to improve. When I checked it again I was at 3 3/8 back. Maybe it's my years of flying pattern that I got used to a more nose heavy feel, I don't know. Every IMAC plane I have flown that belonged to someone else has felt tail heavy to me also, so I guess it's just the way they are set up these days??

Originally Posted by Professor

Henry,
I believe that poprlite was asking about the missing plywood on the back of the motorbox (see picture). I was going to ask the same question. I understand you have removed this to allow the tank to be centered on the CG. Have you experienced any additional flex with the piece removed from your other 126"? When I was designing the Pro we increased the length of the motorbox behind the wingtube so that the tank could be perfectly centered on the CG without removing the rear ply section of the motorbox.
Thanks, Kurt

Thanks for clearing that up for me.

How many flights do you have on your other set up that has the motor box modification? Even with the grain of the ply not being in the direction for maximum support, the overall strength of the airframe is comprised. The reason I have questions about this is on my 118 300 I wanted to do to mine as well but could not bring myself to cut it. I like the idea of the tank being on the cg. Your build is looking very good and I'm looking foward to seeing more of your ideas.

Chad

I took that piece out of my new 126" carden and replaced it with a carbon mount that goes around the tank and supports that area. I agree with Piorun i never saw that piece of plywood doing a whole lot and so I used carbon tow on each side of it on my old 126 and it stiffened it up more than you would think.

Originally Posted by poprlite

Thanks for clearing that up for me.

How many flights do you have on your other set up that has the motor box modification? Even with the grain of the ply not being in the direction for maximum support, the overall strength of the airframe is comprised. The reason I have questions about this is on my 118 300 I wanted to do to mine as well but could not bring myself to cut it. I like the idea of the tank being on the cg. Your build is looking very good and I'm looking foward to seeing more of your ideas.

Chad

I have flown the plane for 2 years now with out that peice of ply in it. The first year with a 170 on pipes and then all last year with the DA 200. No issues whatsoever regarding strength or flex in the motor box. I honestly can't see how that little cross peice does anything, I mean you have the plywood "floor" of the motor box providing tons of strength and tieing everything together. Also the wing tube socket is right there holding everything together too. I just wouldn't worry about it, cut it out and mount the tank where you want it, remember whatever tank mount you install there will provide at least as much strength as the original ply cross peice.

I guess that proof in the pudding! That many flights and then the tank mount adding some strenght back into it. Proceed Sir.

Alrighty, so here I'm installing the cannister mounts, I'm going to be using the Pro-Flows with the KS 2 into 1 headers. Since I haven't got the 200 yet, (there's like two month wait for the Mag case version). I will not glue in the front mount yet. I have fit the front mount into place but will hold off on glueing it in until I have the motor installed. I also decided to isolate the cannister chamber/area from the rest of the plane. I kind of debated leaving it all open to save some weight but I don't know...didn't seem worth it. So I closed it all off. I just glued some 1/16th sheeting along the side of the motor box, along the bottom and a piece of 1/8 to close off the back. Also attatched the 1/4 sheeting on the bottom of the motor box.

Henry,
Are you using the Proflow cans on your current plane? I swear that is the quietest plane I have heard it even gives some of the electrics a run for their money. I keep hearing mixed reviews on the Pro-flows, if these are new for you what made you switch?