Sopwith triplane rubber power.

Hello Tom.
Welcome to this group of model aviation looneys!  - - I think you are our first Canadian member.
There isn't much free-flight activity on here, but that isn't important. We cater for all kinds of aviation activity, providing it is legal! I think that 'Magpie' is the only other free-flighter at present.
WW1 models are notoriously difficult to fly, because of the short nose, and all the drag of multiple very thin wings and all the rigging - leading to tail-heavy models that glide like housebricks.
Twisted elastic-band power isn't my forte. (Rubber means something very different in those Southern States!) but I do know that the short fuselages mean a very brief power duration, which doesn't help with the other problems!
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You could perhaps try to explain why your models keep crashing, and what happens to cause it. We might be able to provide a solution.
But there is a very relevent saying we all use - Nose heavy flies badly, tail heavy flies once.

I inserted your pictures for you Tom, welcome by the way. Looking at your pictures, I'd say you could teach us a thing or two about model building, but, it looks heavy.
We're also old, most of us also carrying a few age related side issues, however, we always enjoy helping anyone who has questions to ask.
Getting a bunch of sticks to fly nicely is very satisfying.

I've bumped Danny Fentons SE 5A build to the top, he's a master builder, sadly we haven't seen him in a while.

You'll be amazed at what's available for small models in the electrification department.

That looks like an old 2-wire brushed 'can' motor, such as used in slot-cars, probably intended for NiCads (Nickel Cadmium) despite the No Lipo sticker.. Modern brushless motors are much more powerful and efficient.
Changing plugs and sockets is easy enough, once you have learned to solder.
Lipo (lithium polymer) batteries are readily available now, the important things are the cell count, and the amp/hours they can deliver (or be charged at). They will be labelled as - for example, 3S 1000 - or three cells in series (one after the other) 1000mah - or 1000 milliamps (1 Amp) for an hour,
A single lipo cell will have about 3.8 volts in it (3.5 when discharged) so a 3S 1000 can deliver about 11.4 volts at 1 amp for one hour. OR 2 amps for 30 minutes, and so on, right up to it's maximum discharge rate, usually known as the burst power. That doesn't mean the battery will blow up, just that it can deliver X amount in a short burst.
Lipo's can be obtained now from tiny one-cell  things such as used in indoor electrics, right up to multi-cell things like housebricks, for BIG models.
They all need a dedicated Lipo charger, which works very differently to one that you would charge your car battery with. You can research that at your leisure.

IMPORTANT!!! Never but never leave  a battery IN the model, or charge it when the battery is hot, or at the wrong settings. That can cause the battery to overheat, then you can get thermal runaway, where the battery first puffs it's casng up, and then can burst into flame that you cannot put out! (You have probably seen the horror stories of electric cars, or those electric scooters or bikes, bursting into flame).
So never never charge batteries inside the home or shed, and never leave them unattended. Always charge them on and in something that will not burn - just in case.
On the other side, a battery that is not connected to anything, so it is not charging or discharging, will be totally inert unless you damage it in some way - (stick a nail through it, short-circuit the wires, etc). I have never yet managed to burn a lipo, and I have dozens!


Brushless motors are a very different construction. The windings are fixed, and the magnets spin round, turning the outer casing (the bell) and the propeller. These are called 'out-runners'. There are no brushes to wear down or arc. All the work is done by the speed controller. They are both three-phase a/c - not the old dc - and they both have a three-wire connection. The motors are identified by dimension and the KV number - how many rpm's per volt. The speed controller 'reads' the motor, and electronically switches the power between the three wires to give motor rotation, and is rated by how many amps it can pass. If the motor turns the wrong way, you can either change any two of the three wires over, or perhaps programme the speed controller.
The battery, of course, only has two heavy wires, pos and neg, which connect to the speed controller.

Now, I fly using radio gear, so my speed controllers also plug in to the receiver, thus powering the receiver and servos AND getting the throttle commands FROM the receiver, using a light three-wire cable just like a servo would. But that is probably irrelevent for you.
If I am correct, a free-flight speed controller works more like a timer-switch, in that it is only on for a pre-set time, then turns off, so the battery cannot over-discharge, which would ruin it. But that is outside my knowledge range, you would need to read up on that.

As you put, the Post Office will not carry or deliver lipo's. It is the same here in the UK, batteries or liquids are not permitted. BUT courier services WILL deliver them. Of course, if you are going to buy ONE 1-cell battery, that works out expensive!

That is just touching the surface of the matter, though. A bit of internet hunting will give you a lot more reading to absorb, in your own time.
There is more info on this forum, too, if you look for it!
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As an silly aside - I never did figure out how batteries (and all electrics!) are measured the way they are - to my mind, an amp should be a million milliamps, not a thousand!