futabaflyer83

This will be my first gasser with electronic ignition. A few of the guys at my club are putting the choke on a servo and using that as the on board engine cut off and a seperate battery for the ignition. I really like the power set up from troybuiltmodels.com (lipo,regulator,optical switch etc.) Just wondering if it is worth the extra few bucks? Thoughts?

Zor

How about a picture with the lonngitudinal axis staight up and down on our monitors ?

I am really trying to figure out such an optical illusion.

I do not understand what the sanding of the top of the bulkheads (formers) have to do with the illusion.

Zor

mikem99

To futabaflyer83
Using a choke and servo to act as a kill switch is kinda OK[&:], but I think that it is better to use an opto kill or a servo/micro switch setup that will cause the ignition to cease. I have a Quadra 42 with magneto ignition in my Super Decathlon and I have a servo actuated micro switch + a fuselage mounted switch wired in parallel so that either can ground the coil and kill the ignition. I have a similar setup but wired in series with battery supply to the electronic ignition box of my Velox. I have an opto kill switch in my Ellipse 50. What is the "BEST" setup?? To me it is the setup that will reliably cause the engine to stop, whether on the ground or in the air. I hope that this helps, and does not create too much confusion.
I was flying this AM with my Velox and Super Decathlon. This was the first time for me this year with the Super D. When you bring them home in “One Piece� you have had a good day
Have fun with yours,

All the best


Mike

futabaflyer83

I have the old style cut off switch left over from my last big gasser. The only hesitation I have about the troy built set up is one battery. Thanks for the input. I will look into the optical shut off switch some more.

futabaflyer83

I will post more pictures as I get back into my shop. I will be living at work for the weekend saddly. I need a flyday.

do335a

Absolutely correct.

What you need is a positive way of cutting the ignition and stopping the engine, right now. Full choke is not the solution.

When we all got started with the giant scale activity with the formation of IMAA, several decades ago, this was not even a question. Any plane at any event without a positive ignition kill did not fly. Now there are lots of people getting involved who do not have a good grasp of fundamental issues and requirements. Some have absolutely no way of stopping their engines, whether gas or glow.

Bottom line: Is the opto kill switch worth the extra cost and effort for installation? You bet your ass it is.

mikem99

do335a

I have always seen the need to be able to stop the engine, in the air (in case of a runawayengine/jammed throttle) or on the bench. Ya never know when someone will flip your prop just for fun or whatever. There are other ways to actuate a switch to kill the ignition, like using a wheel collar or servo arm on the throttle push rod to actuate the switch in the throttle off position. I have seen this used where a spare channel was not available, but I don’t like this arrangement for me.
Another concern of mine is that only plastic (non conducting) push rods should be used for throttle or ignition switches and the receiver and all its servos, batteries and wires should be kept as far away from the engine and ignition as possible. Just IMHO.
BTW, I just finished weighing my Super D with an electronic fish scale, and previously I figured that it was in the 20 - 22 lbs range but it turns out to be 18-3/4 lbs. Still a heavy old bird, by she flies well with the Quadra 42 and a 18-10 prop

mikem99

futabaflyer83
You should use a separate battery for your electronic ignition. There should never be any electrical connections between the receiver and the ignition system. This is just good practice. As far as using Lipos and regulators, I don't see the need, as most electronic ignition systems will operate very well on a 4 cell NiMh or nicad pack, however it should be at least rated for 1800 Mah. I hope this helps you, but please remember, it is only my OPINION, and opinions are like rectums, everyone has one �

futabaflyer83

Iwill be using a seperate battery for the ignition and will order an optical switch for the cut off. That way I can feel comfortable with a little bit of back up.
I would also like to go to Big Bird flyins and be safe. Thanks for tips.

minkiehuoise

i have a ouestion when is the best time to put in the hinges, before you cover or after. when i covered my tcraft i put them inafter and had heck of time finding finding the slots
i am covering with dope and fabric

Nothrottle

Fold the covering around the cut hinge point. make a mark @ the center of each hinge before ironing down the covering. You then can open the slot with an razor knife and then install your hinges.

Zor

Hello minkiehuoise,

As you probably know I am also a dope and fabric guy for good reasons.

I can only tell you how I proceed for the hinges.

It is quite obvious that the hinges would interfere with wrapping the fabic around any location. We do not want them there when covering.

One thing I do is write a note on paper of the diminsions to each side of the slots or of the center from a reference point. After the last coat of butyrate it is usually easy to see the slots through the clear butyrate before using any color. I then make a cut of the covering for the length of the slot (approximate width of the hinges).

Then after using the colored dope it is easy to find those slots in the fabric.

With a sharp #11 Xacto blade it is easy to trim the fabric slots to the width of the slots (thickness of the hinges) as the fabric is now easy to trim being in cured dope.

Voila

I also have my own way of using 30 min epoxy to avoid having epoxy at the hinge line (hinge pin).
Of course I do not use CA hinges; only pinned hinges. The control surfaces have to fall more then their intended deflection by their own weight before being connected to their servos.

I am writing what I do and I am not telling anyone what to do. It is for each to evaluate what is best in their opinions.

Zor

orthobird

My Feedback: (1)

i like your disclaimer

minkiehuoise

hello zor
thanks for the info that good advice.i also use the pinned hinges and when i covered my ultralight i found all the holes and connections and marked them with markin pencil.
i am getting oldand had a brain melt down
thanks mikehuoise

WILDCRASHWILLY

Hi guys,

Have been away from the build for awhile. Had some good weather so I had to get my other planes flight worthy for the year and start flying some. Have been doing a little to the Decath but not much. Now that my other planes have had thier yearly PM and are now flying, I'll get back on the Decath. I have a few pics where I have been doing some misc. cowl fitting, working on the throttle and choke linkages. Also, painted the firewall to give it some protection against fuel, oils etc.
I have to do quite a bit of business travel the next few weeks so my progress may be a little hit and miss. I always watch this thread though, even when I'm at the hotels and have a little down time.

WILDCRASHWILLY

Have a few pics of the combo fuel/ignition module/ig-bat set up. that I installed yesterday eve. The fuse is currently nose heavy but I have not installed the rx or the rx batteries yet The rx batteries will be resonably close to the CG so I'm not sure how they are going to effect it. the rx will be in the rear close to the tail servos, actually about 4 or five inches to the front of them so I don't think this will change the CG much either. I have not installed the control rods to the tail yet other than to do some size checking so this may help.

orthobird

My Feedback: (1)

i know you are pressed for space, but i probably would not put the ignition box right next to gas tank like that.

i am not trying to be negative or anything like that, however, if, for whatever reason your plane did have a nose dive, and tank cracked open and next to spark or whatever, heaven knows what, then it might look like turbine plane crashed IYKWIM.

orthobird

My Feedback: (1)

you can put inginition box under the tank plywood.  i did that for my two beatteries, used this space under the tank, and i made it into a bay area with a lid and screws.

WILDCRASHWILLY

Orthobird,

Great point! I'll revisit that but, I may be limited as the ignition system had a spark plug wire and a sensor wire both about three inches shorter than I would have liked to use in my original planed location in the cockpit area. I'll put some more thought in it though as I should. On another topic, I do keep a fully charged ABC fire extinguisher in my trailer at the back door entrance, mounted on the wall for just such emergencies. That being said, I hope I never need it.[&:]


Thanks for the input,

darrolair

I would place the fuel tank on the c/g. Then there would be plenty of room for the battery and ignition.

WILDCRASHWILLY

darrolair,

Very good idea. That may be what I do since I don't plan to scale the interior anyway. I had thought about mounting a tray and a Go Pro at the CG however, the fuse is so large I can still mount the tank on the CG and the Go Pro tray and servo above it should I decide on the camera.

Thanks,

WILDCRASHWILLY

Moved the tank to the CG and things are much better. Also the fuse seems to be balanced better at this point. The last pic is where I plan to mount the rx. I epoxied a tray in there which is currently weighted with a piece of steel until the epoxy cures.
Thanks Guys for pointing that out to me and thanks to you darrolair for the tank move suggestion. I like this much better than what I had.

WILDCRASHWILLY

Forgot one of the pics prior to installing the fuel tank this time.

Don't know why I initially put the tank up front as I didn't plan to detail the interior. This is going to be something to knock around with. I guess I was in the glow fuel mindset where tank placement is more of an issue. The gas is more forgiving in that department.

orthobird

My Feedback: (1)

this looks great.

however, when i built mine, i put in a saito fg 36 4 cycle engine,
plane weighed at end 19 pounds
and
it was tail heavy


just fyi

also

the fg 36 made plane very underpowered.

WILDCRASHWILLY

orthobird,

I'm a little concerned about what the overall weight will be with the ZDZ40. I made some marks on the fuse where the balance point would be when the plane is complete. After adding the additional trays, the fuse balanced with the ZDZ and servos mounted. When I finish the cowl and install the spinner, propeller along with the control rods and wires from the servos to the elevator and rudder I may not be so lucky. I initially weighed the engine but, that was back in the fall and I forgot what it weighed. I knew I should have written that down[]. I'm guessing the plane will come in at 20 lbs dry but time will tell. I'm running dual A123 2300 mah batteries on the rx but, the extra bat and switch is only 6.6 oz. If it's too bad, I can drop one of the bats but , I like the redundancy of secondary switch and wiring/connectors. Not to mention having 4600 mah avail for long flight times and numerous flights between charges is a nice +.

Thx,