Cox Pee Wee .020 ...Which propeller do you use?

Thank you Mauricio and you too my friend.

I did post the maximum numbers but didn't fuss with a low idle as
these speed props will turn up a high idle. 7k +

I will be testing the Cox 4x2.5 next which has enough weight for a
lower idle.

With a heavy prop or larger diameter prop you should get good
low rpm with the steel strap type throttle. Just don't over size
the exhaust slits or miss align them. The strap type is a great
way of solving the cylinders lower flange issue being in the way
you would have to grind it down smooth to slip on a traditional
throttle sleeve. Or make inner pieces for diameter spacers to
allow a larger diameter sleeve to fit over. My first strap type
throttle was made out of brass for the TD .010  see pic.

And here is where cold water gets poured on the fire  

If we made those backplates for the Pee Wee, I am convinced that we would not even sell 100 per year. The reason I say this is because we had about a dozen or so of those last year, in OEM Cox packaging:

https://coxengines.ca/cox-skycopter-firewall-assembly.html

and it took us like 3 or 4 months to sell them; whereas one buyer bought the last 5 at once.

As the Cox moulds are either scrapped or buried, we would have to get a mould made. The cost is around $6,000. Spraybars are $1, SB seal, reed, retainer and spraybar pressing another $1. If we make 500 backplates (like a 10+ year supply), our cost would be $14; retail price close to $30. That simply will not sell.

If we made 1,000 (a 20+ year supply), retail price would still be around $16-$17. If we can’t sell original Cox ones (that also came with a tank, screws and rotor plate) then I doubt that we would sell more of them than before.

We only sell a few hundred 020 glow heads per year and that is a consumable item, is also used for the Tee Dee and presumably the 020 part that is in most demand.

We still have piles of merchandise where, 6-7 years ago, we heard that there would be “great demand” and where we still have 90% of the stock left unsold. Just can’t tie up capital in items that take decades to sell and many, many years to simply break even. Would love to but can't afford it  

10/4 Bernie we do appreciate your efforts.



Tossing in the water now

I am 1/2 ass follen this and seen Bernie chime in : I would say if you have sit on them (what ever it may bee ) then offer it in BULK at a 3-5$ difference and see what happens ,,, people get stuff off the bay or were ever and may be better than what they have but ; still the NEW will run better Is that a .049 needle your using for a .020??? and the Alum. one will cause Less vibration to the insert when running , that's why they changed it .

Hello Boys! ... I read the comment of Mr. Bernie and I understand perfectly, a few years ago I was flying with the MVVS brand that is from the Czech Republic, I just needed spare parts for that engine and the factory directed me to an Argentine distributor, But there were so few engines in my country that the dealer itself did not economically suit him having a variety of spare parts products .... well not to make the history longer, the MVVS factory sent me directly to my address the spare parts I needed ..... I mean with all this ... I understand the supply and demand and when something is not economically viable ..... For that same reason I believe that the "magic" occurs when we discover a product or We find it from another amateur, it mixes the emotion, the achievement of having found it and the history of something that surely will not be reborn ... hence all these pieces of Cox, at least in my country are for those that we like , a kind of jewelry!

Friend, I did my homework, here are the photos, which works very well to my liking, but unfortunately: it does not work! I tell you; It turns out that the steel tape used, (I speak in my case) is very well adjusted to the cylinder, but when I start, this material takes temperature and dilates more than it should, thus causing gas leakage and therefore the motor almost Not low revs ..... I was very kind, but I'll try again maybe with another type of material! ...!

getback wrote:I am 1/2 ass follen this and seen Bernie chime in : I would say if you have sit on them (what ever it may bee ) then offer it in BULK at a 3-5$ difference and see what happens ,,, people get stuff off the bay or were ever and may be better than what they have but ; still the NEW will run better    Is that a .049 needle your using for a .020??? and the Alum. one will cause Less vibration to the insert when running , that's why they changed it .

Eric, how are you?
What you talk about the aluminum needle and its low weight compared to the bronze needle to avoid vibration and that the needle itself moves, is a very good appreciation and I'm sure that was the factory target.
The Cox Pee Wee .020, in my experience, is one of the most unstable Cox motors, it is very easy to operate the needle, it is very easy to the internal movement of the flap valve, also the air and fuel mixture depending on the day Of weather), the engine will be affected differently than its older brother Cox .049

Did you make sure the exhaust where sealed off as shown:
The seam should never be positioned over the exhaust vents.
Will not seal.





Also I left extra material on one side then twist it to create the control arm.

1/2A Nut wrote:Did you make sure the exhaust where sealed off as shown:
The seam should never be positioned over the exhaust vents.
Will not seal.

Ohhh! You're right! ... the groove of the right ring is almost over one of the exhaust grooves when you close it!
God! Ruin a nice job hahaha .... Thanks friend, you do not miss anything !! , I'll do it again!

Yep yep yep is a exhaust vent, a V gap is there.

Hi guys, I've made an acceleration again, since my friend Brad has certainly oriented me with a construction error on my part.
This time use brass and went to another motor Pee Wee 020 that has skirt or skirt, that is to say is the fine cylinder and this hoop is just the ideal for these cases.
Here the photos ...

Here the test video, what do you think?

Bravo I saw 10.8k to 16.47k peak rpm range 5.67k reduction / with what size prop?

Don't forget to always post what prop you are using so we can determine the power out
also the prop size effects how low the idle can go. Other good information is knowing
the amount of nitro percentage used.  

This works great as a simple solution to get around the cylinder skirt without grinding
away the skirt. Will allow enough rpm reduction to do nice slow passes in front of the
camera and help to land. I gave you a green reputation for your efforts well done!!

1/2A Nut wrote:Bravo I saw 10.8k to 16.47k peak rpm range 5.67k reduction / with what size prop?

Don't forget to always post what prop you are using so we can determine the power out
also the prop size effects how low the idle can go. Other good information is knowing
the amount of nitro percentage used.  

This works great as a simple solution to get around the cylinder skirt without grinding
away the skirt. Will allow enough rpm reduction to do nice slow passes in front of the
camera and help to land. I gave you a green reputation for your efforts well done!!

Brad: Many thanks, sincerely for all your help, and to add to my reputation!!.
True, the data in this case are as follows:
Cox propeller 4 1/2 x 2
Nitro 20%
Beaver 18%
Methyl Remainder

Very Good !! sounds like it is running Hi and Low pretty good numbers for slow and fast fling . I am doing OK Mauricio ,Thanks for asking . Just been cleaning engines as usual Be interesting to see the numbers on a larger prop?

I won an auction and I just received a motor, in the description of the auction did not say if it was a 010 or a 020, but according to details of the photo, I assumed it was a 020 .... I just received it by mail. ... ohhhh if it's a Tee Dee 020 !! I'm going to clean it and share with you the engine running, the spark plug is burnt or out of use, but the rest is fine! I am happy!

getback wrote:Very Good !! sounds like it is running Hi and Low pretty good numbers for slow and fast fling . I am doing OK Mauricio ,Thanks for asking . Just been cleaning engines as usual  Be interesting to see the numbers on a larger prop?  

Eric! Good to leave me your message, if it's true !, I'm going to test different propellers to see the results. The acceleration belt is a beautiful tool to have engine control, I will keep trying to improve !!
I send you a hug and we share a beer in the distance!?