049 td runup

Used that rcat unit at our flying club and yes it works fine.
For those who like almost the same performace on a budget should take a look at these;
buck module

Yes you have to supply your own glow lead and battery (i use a old 6 cell nicad pack) and also you need to adjust the pot meters to 1.5v and about 4 amp.
Mine is also fitted with the 4 mm "banana" connector (female) so i can change the glow clip leads depending on what engine i want to start.
It does have lights showing if it is in voltage limit or current limit and that indicates if the plug is working well.
No charge level to see if the battery is half/full but when empty (or disconnected)  none of the status lights work.
ALso covered mine with heat shrink tube to keep it from being damaged and wrote the settings on the botum so it does not get mixed with the others.

These units have become my universal power supply to power my small electronics with watever battery i have lying around/ is charged.  
They can also be used to charge 1 or2 s lipo or even lead batteries (max 5 amp) as long you set the max voltage correct.

I read articles here about the cool buck boards, i ordered one, even ordered a volt/amp meter

Adjustable step down charging board
https://www.ebay.com/itm/115094446079

volt/amp meter
https://www.amazon.com/dp/B072BY4XZ7

my IDEA was to build my OWN charger, by connecting it all to a battery on one end, and a glow connector on the other.
maybe even mount it all in a handsome project box.


Battery -> Board -> Meter -> Glow connector

i KNOW i'm not really old, but for the LIFE of me, I cannot figure out the simple circuit I need to make this work.
I've drawn about 5 napkin sketches, and I just cannot figure out what color wire goes where. - and got really frustrated with myself

so they are sitting on the workbench.

So if you place the meter behind the buck then be aware the voltage and current wil show what goes to the glowplug.
Then confirm if your buck underside looks like this one.



If correct then your battery posetive/ red goes to the "in+" the negative black goes to "in-"
From the meter the THIN black and red also go to the same red +in and black "in-"
This will power the meter

The the thick black goes to "out-"
One of your glow clip wires goes to "out+"  best to choose the wire that goes to the tip of the glowplug
The other side of the glowplug goes to the thick red wire from the meter.
Depending how accurate you want the voltage reading to be you have 2 choices.
For simpler cables just connect the yellow also to the "out+"  but this way any "voltage drop" over the wire to the plug will be ignore. (this will be verry little depending on how thick your wire is)
If you do not mind extending the yellow wire then you can connect it to the glowplug clip "tip" and then you will read the exact voltage at the glo plug clip.

This all is folowing the "independed power supply" connection choice and that is needed because  the voltage a glow plug works at (1.5v for cox) is not enough to make the meter work. (you power it straight from your battery instead)

Do NOT connect a glowplug before adjusting the buck !!!  
Get a small screwdriver that fits in the litte bronse "screw" slots on the blue adjustment "potentiometer"
One is to set the maximum current and the other the voltage.
the one closer to "in" (and thee black chip) controlls the voltage , the other current.
Turn the voltage pot counter clockwise (seen from top) to reduce voltage and clockwise to increase.
Mine came set to 12v so likely you have to turn counter clockwise.
These are "multi turn" pots  so you only see a small change in voltage for every turn ; you might need as manny as 10 tuns or even more to get down to the 1.5v cox glow plugs like.
The current can be adjusted too in the same way but for driving glow plugs you likely want to be able to use the full 5 amp these bucks can give.

Again withour the glow plug connected prepair your battery
This battery must give more then 5 volts  for example a 2 or 3s lipo or like i use a old rc car nicad pack.
The battery also has to give less then 30 volt so do not connect 3 car 12 batteries in series t power your buck  (one or 2 are fine)

The next depends on how confident you are with eletronics; in theory it is possibe the volt meter uses a "common ground" for both power the meter and the  measured input.
There is a small chance it makes a short.
So to be totaly save better limit the current of the battery/ power supplly when you first test it.
If you have a friend with a "regulated lab power supply" then that would be the best way to test if all works well; thosee can be set to limit the current .
If you do not have acces to one then there is a simple way to make a current limiter.

Get a car (12v) light bulb (not led but a old fasioned one) like a indicator light.
Solder 2 wires to it and see if you can light it up on a 12v battery.
Once that is working place one of the bulb wires to the posetive of your battery and the other end to the "in+"  
This way all the power of the battery has to go trough the light bulb; this temporary replaces the wire from "in+" to the battery until its passed the test.
Now when you power the whole setup if all is well the light bulb will NOT light or just a little.
If it is bright then you likely have a short but the current  should have been  small enough to avoid any damage.
Also on your meter the amp (blue) should stay at zero untilll you connect it to a working glowplug

Let up know how it goes and if you have any questions just ask ; poctures might help illustrate any things you are not sure about.

oh I owe you a beer, whiskey, kool-aid

thank you

I will attack this during the weekend.

Once you have it working run a engine on a test stand and see how it behaves when you intentionally flood the engine.
Keep a eye on the light on the board and when the indications light (voltage limit or current limit for example)
There is a good chance once you learn the behavior there is no more need for the aditional current and voltage meter.

Right now my glow driver is powering a speed 400 brushed motor with a "Zagi" / gunter prop.
Just enough to give a nice gentle breeze to help my clothes dry quicker