coriolan

Not a bad idea for a reed valve Cox but then it require some bearing on the coupler. Since I will use my Astroflight starter with it I'll just put a small V-block under the front of the engine and clamp it down with an aluminium strip and screws.

joseywales

would like to make a small JAE rigger and run a cox in that..

jetpack

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Josey!

No, you can't do that...riggers aren't boats Where's your style [sm=redface.gif] yawn. zzZzz.

I am thinking if I ever do build a rigger it would be a JAE with a Cox engine, but staying with the .15 size converted to marine. Nice engines because you can pretty much tune them for what you need without machining because the cylinder case is seperate from the crankcase which allows easy changes in port timing. The motor I have is saved for an airplane though, but could make a nice marine engine.

Nice how the thread came back alive with videos and new people, really liked the links and pictures. Only effort in my Cox boats lately is I picked up a SilverBee engine with the large capacity tank. Not the stunt tank with the fill and vent tubes built into the tank, but a one piece fuel bowl that is larger than a standard BabeBee.

I had to clean the tank quite a bit but its back to being fresh again and seats nice into the tank back. Need to order new tank venturi seals, crankcase and cylinder assembly...then put aside for the Miss Thriftway. Extra capacity tank is nice for the boat because you run a pretty rich needle. Boats dont do well on MPG's.

I still have been dreaming about the Drag N Fly Jr. project, thinking of how to lay up the sheet wood layers.

I have bought some wood veneer which I think I mentioned earlier back, but trying to decide how to laminate it and what with. Cross graining a ply of balsa between the veneer sounds tempting, but then again using 1/64 ply as its inner core. The veneer is about .025" thick to start.

jetpack

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"... The new Profi 1cc (.061) has been a big hit. Performance is a huge surprise with significantly better numbers than the competition and 3000 up on the .049 (34,300 rpm) when using the same prop. Appearance and weight is the same as the .049..."

Pricey, but nice! That pic is off of a french free flight website

misshydro

you just dont like rigger,,buzz saw....bet it would go alot faster then the german rigger in that video..

coriolan

The outrigger in post #312 was the most impressive 1/2A boat I have seen so far and even more impressive when you see the crude build in post #317 with that very long cable without any support and the sharp break on the sponson curve. The rudder bracket is very long and thin so must flex a lot which explain the crash at the end of the run[:-]
These Fora and Profi are indeed nice (have seen some used in c/l combat & 1/2A proto)and there is just no comparaison with a more than 50 year old Cox design. But they are tricky to use, run only on bladder pressure and very picky about prop choice and no trottle which would be necessary. The real eye opener for me was to realize that even a Reedy Cox could swing something bigger than a 1" Dumas prop, virtually all the 1/2A (.049)before were using similar small low pitch prop with narrow blade and all had tepid performances at best. The outrigger I am refitting now is just a recycled FE to get it in the water quick, but I can't wait to build a "proper" boat[8D]

jetpack

My Feedback: (1)

I have an Octura 0930 and a 1427 prop comming. Both are about a 1/16" over 1" to try out and are aluminum which I don't think will pose any problems. Maybe easier to rework also.

Earlier I mentioned my first boat being built when I was a teen. An Atlas Van Lines 18" and I powered it with a TeeDee .049 and 1" plastic prop. It was on pace with that rigger which we seen run, maybe even faster. This is what is keeping me interested in getting a Cox boat together, they aren't really slouches for their size. Keeping up with it in the fishing boat with a fresh 10hp Merc was a challenge and it cooked. With the right boat around it, these motors can do pretty good.

The round prop has a pitch just over 1" and the 1427 has about 1.5" pitch. Try them stock first, then start cutting...lol. The stock plastic Dumas prop pitch to me, is still unknown..

It would be nice to keep with one size propshaft and I already bought 1/8" gear and working on getting something together to bore props with so I can also hang Graupners on it.

robot797

hey guy long time no see
i still havent been able to sail my cox boat
(weather)
and the second problem is starting
what is the best way to start a cox medalion in a boat?
i always have problemas with that
is it posible to put a recoil on it?

jetpack

My Feedback: (1)

Robot do you think you would be able to make one of these? The springs are easy to get, the disk you have to make unless you want to bid on eBay right now.

A sharp chisel and hammer can make the cuts in soft aluminum (which I believe these were made from), or even maybe a jeweler's saw.

You would have another problem however, Cox spring starters are designed to be fit onto BabeBee type engines but there are TeeDee springs. They are very rare to find.

Cox car engines have a pull starter assembly, but use a special taper on the end of the crankshaft which means only one crankshaft is available for it, the Bee engine.

robot797

oke so i have to build somthing that fits on a tee dee

jetpack

My Feedback: (1)

If you have a groove in your flywheel, an electric starter with a pulley and a small belt or O-ring can work.

Start at this post and read the whole page about starters.

http://www.rcuniverse.com/forum/fb.asp?m=10363034

jetpack

My Feedback: (1)

I was re-reading and come to think of it, I am not sure I've ever heard of a Firecracker engine??

jetpack

My Feedback: (1)

Robot, Air Mover had a post that showed a TeeDee .020 that can be looked at and it shows what a TeeDee starter spring looks like. You might be able to adapt a standard Cox starter spring like the one in the pic.

jetpack

My Feedback: (1)

Some Cox advertisements I've dug up on spring starters if you want to look for the right product number.

robot797

i am gonna try to mak a spring starter for my medalion

Eddy de Vries

Look what I found: Brand new in the box .049 glow plug !
Anyone interrested ?

coriolan

On this side of the pond we now have a good source: http://coxengines.ca/product.php?pro...&cat=27&page=1
But would be of interest for european users with reasonable shipping charge.

forsakenrider

I've actually got a 1/2a sized JAE rigger started! plan to be powered by a norvel .061. what the water froze up here in the Great White North i lost a little motivation and shelved it. You will see it this spring I promise though!

coriolan

What size is it and what will you use for hardware? No ice here but still too cold for west coast sissy [8D]

coriolan

Since the original venturi in the Reedvalve engine is so restrictive I moded the back plate to accept a TD venturi. Not sure if I'll have enough suction to work without a bladder but I'll test on bench first,the engine was running strong with a TD .051 piston/sleeve but it might be even better with an unrestricted intake and the tank can be even closer to the needle.

robot797

guy i have great news
i have almost compleated my recherche of diesel
i almost have converted a normal cox to diesel witout a diesel head
there is one problem
the engine needs to be hot +50C and if you dont run nitro after it itgets gummed up

coriolan

So its still easy to find diesel fuel in Europe, on this side of the pond it is very difficult to find ether to mix fuel[&o]

robot797

that is true
but you have cheap dryice XD

forsakenrider

hey coriolan,
I found my notes sheet with my decided dimensions. So far I have finished some sheeted foam sponsons.

Sponsons:
Width: 3/4" with 7/8" on the bottom for overlap,
Spaced 8 1/2" apart on the inside

Tub:
1 3/4" wide
15 5/8" long
1" deep

I basically scaled the plans on the net to about that size and printed them off. I'm really excited to finish this! also the hardware I plan to use is stuff for those small hydros on ebay. its nice looking stuff but I dont have much to compare to. I think HK even has simular stuff now. I got one of the 31mm "racing props" for it as well and some 427's. the racing prop has pretty small blades (chord) so im thinking it will be a ripper!

coriolan

The hardware for small FE hydros fit the bill well for 1/2A stuff, the Octura stuff is my favorite for stub shaft&cables and I get what I need from OSE:
http://www.offshoreelectrics.com/pro...oct-oc098L-24c

Started cutting wood for my semi-scale hydro yesterday since the outrigger is completed now. Will be a round nose 50's style and TD .049 for power, this time I'll use a trottle having much more radio room than the outrigger! The hull will be 17" long with a 4" tunnel and straight 1/16" music wire drive shaft to run similar to full size. I think X427 will be best for it but I like the plastic X431 too because its easy to trim and cheap. Next build will be the "Wild thing", I have the hardware and engine for it already so just need to build a hull.