Making Glowplug Igniter Adapter For Cox Engine?

There are commercial ones, but the cable will rob some power and it doesn't work that well with NiMh drivers. With a proper glow driver it is not a problem though.

Ah ha. That was the one I had originally seen somewhere that gave me the idea.

I have learnt my lessons with D-size batteries connected to various glow plug clips and decided to equip my toolbox with a starter panel that conveniently connects to a starter motor, has sockets for fuel pump, glow-plug cables and portable glow-igniter charger, and more importantly, houses a 2Ah lead rechargable battery that holds enough power to cater for the needs of weeks of intense flying.

I have a separate glo-clip for my larger non-COX engines and the COX family both, but they all connect with standard plugs to the adjustable power outlet socket on the left.

This panel is just the right thing and sells for about 24 bucks on ebay (shipped overseas), but you CEF members living in the US will find it in most of your hobbyshops priced around 18 USD.

Thank you. I actually just got a good deal last weekend on a field box complete with power panel, electric starter, and the other goodies. I was now wanting to make a 1/2a sized field box for the little things in life and was going to try to do without the larger battery. It looks like I will just have to bite the bullet and use one anyway.

This 2Ah battery in my box occupies less than 20% of the space inside. In addition to it I have a whole mess of field accessories also jammed inside..Now at least I have to scavenge a much smaller space for my lost tools than before.

Surfer_kris wrote:There are commercial ones, but the cable will rob some power and it doesn't work that well with NiMh drivers. With a proper glow driver it is not a problem though.

I have one of these. It sucks! It won't even light a glow plug from a new D cel in a portable igniter most of the time.

I've been happy with mine. I have a total of four NiMH batteries I keep charged for the igniter and I am careful to connect the glow plug only when actually starting the engine. A 2Ah lead-acid would be a good thing.

The Li-ion battery powered ones are the way to go. They have a regulated output of 1.5V, independent on the charge state of the battery. The NiMh are only sort of okey for a little while directly from the charger....

The extension only works if there are low losses in the cables and contacts. The wires on my adaptor had really poor contacts at the clip (shrink type that allows the Cu to oxidise) but these can easily bee soldered instead and then the problem is solved.

A full field box with lead battery, fuel pump and glowdriver etc. is not for me. I prefer the simplicity of the small planes, especially in combination with diesel fuel. All you need to bring is a jug of fuel and a smile on your face.

Surfer_kris wrote:The Li-ion battery powered ones are the way to go. They have a regulated output of 1.5V, independent on the charge state of the battery. The NiMh are only sort of okey for a little while directly from the charger....

The extension only works if there are low losses in the cables and contacts. The wires on my adaptor had really poor contacts at the clip (shrink type that allows the Cu to oxidise) but these can easily bee soldered instead and then the problem is solved.

A full field box with lead battery, fuel pump and glowdriver etc. is not for me. I prefer the simplicity of the small planes, especially in combination with diesel fuel. All you need to bring is a jug of fuel and a smile on your face.

Yes, I agree. I did just pick up my first fieldbox last week. I did make a small coroplast version for 1/2a this week. That is where I want this for. Small, light, I now have a few of these. I just got my first diesel last year (PWA 1oo, I believe), and while still learning to get it to steadily run, I still have a hard time. I still sometimes look for my glow igniter, or look at it seconds before and wonder what happened to the glow plug, wondering where to hook up.

This is my go to the field box Large but usually the pull out only goes it supply's most everthing I will need   I built it from a kit years ago!  getback

Since the discussion has turned toward flight-boxes.. I figured I'd post some pics of a little Global kit that I built back in the mid 1990's.




Here's the old kit-box.. (note the label which shows a transmitter and tin quart of glow-fuel)



I finished mine in natural wood-stain and sealed it with spar-urethane. A white painted box gets dirty on every trip to the field.. and you don't want a fancy-painted field-box that detracts from your model!

It's a minimalist-box.. but does hold plenty of 1/2A gear. The gallon jug in the 2nd photo gives an idea of it's size. A mini-panel would fit nicely in the side-panel which does have a 5" inside clearance. Partition it off; 3 or 4 inches behind the mini-panel for the right-size 12V battery.. and you've got a nice compact little box that will start your little airplanes all day.. as well as provide 12V for accessories.. even if to just charge your cell-phone.. or video-camera..    I padded the cradle on mine with foam weather-stripping.

Building your own would require a router-table to cut the slots for the partitions. I drew-out plans if anyone's interested. Materials needed are 1/8", 1/4" and 3/8" (3mm, 6mm and 10mm) plywood for the floor, partitions and bin-lids. The 1/4" and 3/8" plywood is fairly inexpensive. An alternative to the 1/8" (used for the two sliding bin-lids) could be luan plywood (like what's used on the back-panels of old bureaus..) or rigid plastic. The home stores generally stock 2' x 2' plywood Handy-Panels in the 1/4" and 3/8" sizes. Hardware parts include two knobs for the sliding-covers.. or omit the knobs and bore finger-holes. Lastly a dowel for the handle. Could be hardwood, aluminum or PVC... I put four screw-on rubber feet (bumpers) on the bottom of mine.

I used this little tote w/drawer extensively when I was actively flying little models.



You could install a mini-panel in that too...

buy it on Amazon

No problems or complaints here, but I just started a topic ' Show Off Your Field Box' here in Models and Modeling for us to all share our stuff.
Link here:
https://www.coxengineforum.com/t9663-show-off-your-field-box#122650

Got it , Sorry New222 I am just not much into coroplast , I like the way it cleans up easy but the plane I built from it was enough for me . They make good targets though! getback

Target backs, good they make. I agree.

getback wrote:Got it , Sorry New222 I am just not much into coroplast , I like the way it cleans up easy but the plane I built from it was enough for me . They make good targets though! getback

I guess a coroplast PT-19 is out of the question then? I do agree that it is a process all unto itself. And a learning experience to boot.

I just "almost" finished my ignitor system. It is based on a Graupner 2 volt 4.5 Ah sealed lead-acid battery and an original Cox clip. The voltage reduction is done by a diode. A "traditional" diode has a treshold voltage of 0.7 volts, so it drops the battery voltage to 1.5...1.4 volts. While I was soldering the system together, I also replaced the cables on the Cox clip with longer, more flexible and a lot thicker ones. I used some old speaker cable I happened to have, the printing on it said it was made in West Germany so it must be from late '80s

I measured the current with a glow head connected, it drew about 2.4 amps, so the battery should be good for an hour and then some. The old glow head was glowing with a nice orange glow. The diode needs to be pretty hefty to be able to tolerate such a current, and a heat sink will most likely be necessary too.

A regulator circuit would be more sophisticated, it would give more constant voltage and it would be the best way to do this should one use a higher voltage battery such as a LiPo (3.7V) or a 12V that most starters require. For a 2V battery a simple diode is adequate and easy.

As I said, it is "almost" finished. I still need to attach the diode to a heat sink and wrap the whole assembly together with zip ties. Later on, if this proves to be functional, I'll install it into a field box. I already have a small wooden crate I am going to use as a base, should work fine for 1/2A engines when no starter is required and a quart of fuel lasts an entire afternoon

Here's a pic of what I have so far:

Nice. I like the design. I may try finding a small battery like that around.

I use this 4ah sub-c cell in my glow igniter. $4 bucks at Interstatebatteries.com
http://www.interstatebatteries.com/1/1/66-1-2v-4ah-nimh-rc-sub-c-hr-asc1033.html


I've been on 3 flying excursions and haven't recharged it yet.
Here it is being tested on a Merlin drop-in for Cox/Norvel, while I was reading this thread.

Rusty

NEW222 wrote:Nice. I like the design. I may try finding a small battery like that around.

Thanks. This is a lot more complicated than Rusty's example where the battery voltage is already suitable for a Cox glow plug.

I ended up with mine when I could not find a pocket size igniter on-line that was "guaranteed" to fit a Cox glow head. I went to the closest hobby shop but nowadays they cater mostly to the "arts and clutter" crowd. You know, styrofoam balls, wood beads, glitter and such. So no help there. The next one sells mostly styro ARFs and RC buggies, their only ignitor model was a LiPo in a plastic bubble pack, cost 30€. They didn't want to open the package, and I didn't have a glow head with me to test the fit with, plus LiPo is useless in the cold anyway.

So, I ordered this lead battery (10€) and a "plug saver" (1.50€) online from one of the local suppliers, a small Finnish one-man-show. The plug saver is supposed to adjust the voltage to a safe level for glow plugs. Well, the battery arrived but it turns out he can't get the plug saver thing anymore. I talked about this to a colleague at work, asked about a regulator circuit, he suggested the diode, asked about the amps and handed me one the next day Then he says, well, you probably need a heat sink too, here you go.

This battery is purpose built for glow plug use, and one thing that made it feasible for me is that I already had a "smart charger" for my LiPos and NiMHs, and this charger also has a setting for 2V lead-acid batteries. Lead acid may not be the best chemistry if you don't already have a suitable charger.

If I were to do this all over again, I'd probably get a couple of D-size NiMH cells at least for Cox stuff. If I ever "graduate" to bigger engines, then it'll be a 12V motorcycle battery and a power panel to accommodate an electric starter and possibly a fuel pump.

Believe it or not the Cox engines are much more picky than anything else I have flown regarding power to the glow head or plug. I suspect this is because the glow head is so massive of a heat sink compared to a glow plug with a 5/16 hex body.

Phil

pkrankow wrote:Believe it or not the Cox engines are much more picky than anything else I have flown regarding power to the glow head or plug.  I suspect this is because the glow head is so massive of a heat sink compared to a glow plug with a 5/16 hex body.

Phil

Good point Phil.. that makes perfect sense. I've been wanting to experiment with a clip for Cox .049 glow-heads, to see if I could make something that would work well.. if not better. Kari mentions beefing-up the wire from the standard Cox clip's (what did Cox use.. 24ga. wire?) to a less-resistant/larger-gage. Better to source some copper wire having a high strand-count. It will be more flexible as well.

Pictured below are some coils of assorted gage wire that I got from a previous job where we made speed-controls for AC powered electric motors. The insulating jacket is super flexible.. and the copper strand-count is higher than standard wire of the same gage. I felt that it was good to have on hand for misc. low-loss connections.. i.e. electric-motor to speed controller connections, building my own battery-packs.. etc.



Standard lamp-cord is 18ga. and easy to source at any hardware store. Wire is only as good as it's connections though. Terminals/ends should be soldered for the least resistance. Your battery(s) will last longer when using a wired-clip with soldered-connectors.. as opposed to "quick" or "crimp" connectors.

As far as the Cox head's larger cooling area.. I wonder if a "hood" could be incorporated into a custom-made clip? Something obviously non-conductive (rubber cap?) that would press-on over the head with a center electrode and side electrode "teeth" that would "click-in" between fins? It would be hard to beat the Cox clip for simplicity though. It would be nice to have a "Winter" clip that might make starting in cold weather easier? You mentioned previously; how you use a few "turns" of knitting-yarn between the fins of the glow-head in cold weather. I want to try that sometime.

Apart from the gage of the copper wire one may want to consider the insulation material of the wire too. Some plastics  (the stock COX wire included) become brittle in cold weather and especially after long exposure to nitro fuel will break here and there. I am not sure which plastic insulation is nitro safe. I have an old electric starter with black plastic insulation on its cable that remains soft in winter and has not been eaten away by nitro for many years by now.