H5606

If you're holding the engine in your bare hands, you're going to let go of it if you get it running for any length of time - it gets too hot to hold in a hurry.

Wonder how I know?



Just noticed my previous post is adding to the redundancy regarding battery voltage...

BrightGarden

I hope your glow head is ok, I want to hear how the flying went on Thanksgiving.

H5606

The airplane was dissassembled to remove the engine and I failed to mention from experience, I've found it imperative to take extra care when reassembling Cox airplanes held together with screws like the Stuka.

Before tightening the screws on the fuselage sides, make sure you don't start them cross-threaded otherwise you may split the opposing threaded post - turn the screws CCW until they "seat" with the threads (you'll feel the screw drop into engage the threads) - then and only then, you can start turning the screw in to tighten - don't over-tighten...

Found this video and Including a link for what a successful flight with the Cox Stuka looks like: https://www.youtube.com/watch?v=b1Sc7QgN61g

gcb

A little tourist info...the glow plug element is not Nichrome, it is Platinum. Once the engine is running and the booster is removed a catalytic reaction between the platinum and the alcohol in the fuel keeps it firing. Also might be why plugs cost so much. :-)

George

init4fun

Thank You George , I pulled the wrong word outta the old memory here and yes indeed your correct , it's Platinum not Nichrome .

Nichrome is the stuff that Estees rocket ignitors are made of

init4fun

Sadly , since you did put 3 volts into it , it's a 99.99999% certainty that you did , in fact , burn out the glowhead . No biggie , it's the price of experience and I'll bet you remember glowheads/glowplugs get 1 1/2 Volts only for the rest of your time in the hobby .


PS , when ya finally learn the cut finger lesson , don't worry about glow fuel in the cut , all the Alcohol in the fuel is a great antibacterial !

rgburrill

One of the problems with a glow plug igniter is they tend to vibrate off a running engine. Sometimes they fall into the spinning prop. I went from using a separate igniter to a clip off my starting box power panel.

init4fun

I agree RG , I don't like having a sub c ignitor hanging off of the glowplug either . For my larger planes (anything .40 sized & above) I use a built in glow system from "Electrodynamics" and for my smaller stuff I have a 12V 14AH battery in a small toolbox with an adjustable glow driver/ power panel from Hobbico .

mtrain

Well I remembered I still had the original head on the original motor so I swapped it out, and made sure the head gasket stayed on the engine block.

Tried again to start the engine, but it just wouldn't go. I measured the volts, and with these batteries in parallel I recorded a voltage of 1.5V. I don't know if that is too much or if the old head was burned up like the new head. I thought all D cell batteries were the same, but these were high energy 1.5v.

gene6029

Take the glow head off and connect it to your battery. If it glows its not blown. That still doesn't mean its a good glow head. Make sure you didn't loose the copper shim that goes between the glow head and the cylinder, but even if you did it should be still run off the prime.

mtrain

Ok, thanks I will give it a try.

mtrain

Ok, I just gave it a try, and both heads give a very healthy glow. I'm going to stick with the old original head as the clips connect easier.

So that is good news.

One more question the engine is rotating counter clockwise to start/crank, is this correct?

mtrain

SUCCESS!

Well guys I finally got it to run.

It took about 20 minutes of turning the engine over, then it finally started to fire, which led to more buzzing until it stayed running.

After that I tuned the mixture until the pitch of the engine was a maximum, then let it run till it ran out of fuel.

According to the instructions someone posted [thanks again], I will need to run two more tanks of fuel through the new motor to break it in.

Also, I will have to remember to tape the canopy down, and make sure which way the controls work.

I bought some 25lb test Spider wire fishing line this week so I'm going to use the steel leaders to connect the line to the controls, then off to the school parking lot.

Question, of course the longer the line the less chance of getting dizzy from going in circles too fast, so how far can I run my lines, and still be able to control the plane. [I remember to use the outside holes as someone recommended

Thanks again for all of your support, and help as I couldn't have done it without you.

I also wish everyone a happy, and safe Thanksgiving tomorrow.

gene6029

GREAT! Good luck on your flights with the stuka......Gene

H5606

Hi Mike - I now see I responded to one of your threads six years ago.

Spider Wire is fine and others here will be better able to tell you how to attach... I believe extra care must be taken to ensure knots don't slip.

I use entire spool of Dacron lines on all my Cox airplanes without making any cuts which equates to roughly little more than 25' lines. I unraveled lines on one of my Cox airplanes and measured lines at ~27 feet. I wouldn't go any more than 30 feet lest you get too much line sag. I think less is better here though.

I guess you could measure out a single length of 60 feet of line for 30 foot lines, feed one end thru control handle - hole, then thimble hole, then other hole - ends of lines then go out to airplane so that you have an extremely long "U" in essence... Best to have a helper for next step - after attaching lines to airplane (I used simple square knot - don't glue knot lest you create a stress riser ["up" line goes to rear of bellcrank I believe]) - with helper holding airplane, you can slide control handle out to the exact mid-point of that "U", then wrap a couple loops around the thimble from both the "up" and "down" lines to "lock" the control handle in place. Don't forget to run lines through wing lead-out holes before attaching to bellcrank. With helper holding airplane at chest height, make sure neutral position of handle equates to "neutral" elevator - make adjustments at thimble accordingly.

One last piece of advice: when flying for low time pilots, its best to use straight arm and pivot at the shoulder for control inputs rather than using your wrist so you don't end up over-controlling the airplane.

Best luck and most of all, wishing everyone a Happy Thanksgiving.

mtrain

Thanks I will do it.

mtrain

Well guys I hate to say it, but I couldn't get the dang thing started today.

It would run on prime, but for some reason I just couldn't get the fuel to pull into the intake. I have a clear rubber line for which I can see the fuel, and it just won't free fall into the engine.

If I can solve this puzzle I should be fine.

mtrain

Is there any reason, or trick to get the fuel into the engine?

gene6029

No tricks. Make sure the needle valve is spotlessly clean. The reed valve might be gummed up. I hate to sat it but it may have to be taken apart and cleaned. Sometimes just by trying to start it and running off the prime it will free up a stuck reed valve. Try soaking it in fuel over nite if you don't want to take it apart to clean it. You might get lucky.....Gene

mtrain

Ok, thanks Gene.

Its a brand new motor, never ran, or fuel until last week..

init4fun

If what's in this picture is all you changed , then the valve Gene is talking about is built into the plastic piece on the back that you must have taken from the old engine and transferred to the new one , in other words , your still using the original (possibly gummed up) valve ....

mtrain

OOOH, now I get it, thanks. I will give that a look right now.

Ok, now I have the little, original, fuel block soaking in automotive paint thinner. That HAD to be the problem.

init4fun

You will destroy it soaking it in a solvent that strong . Take it out of the paint thinner and if it's not already began to dissolve put it in a container of the same fuel that it would run on . The Alcohol in the fuel will dissolve the gummy deposits without melting the valve itself (like the paint thinner is gonna do) ............

mtrain

Ok, done.

In the future can I change my current gas tank out for one like this?
http://www.ebay.com/itm/Cox-049-Mode...0AAOSwMNxXWf-h

gene6029

Yes you can, but it will not fit in your Stuka with that tank. When you swapped parts around from engine to engine, did you transfer the gasket that goes between the engine and back plate? Its important that it be there and not torn or leaking.....Gene