# .098 V twin using 2 Cox .049 Cylinder assemblies.



## argat1

I am absolutely new to this community! I came here in search for info regarding the construction of an engine using a V twin configuration. I have several Cox .049 engines. Recently, I saw a home made simple of what I want to build.

Is there somewhere a set of plans and info regarding this subject?

I, of course, will appreciate all the posible help anyone can provide me with.


Ar.


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## Tin Falcon

interesting question. 

a v twin recently sold on e-bay and there is currently a radial 3 for sale out of italy so $22 ww shipping.

3 cylinder cox engine
Tin


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## cidrontmg

There's also http://www.jamesengine.com ,especially the HEX-2, HEX-4 and Cox V-4. Drawings are included (free!), and there's also HEX-2 plans, published in Model Engine Builder Issue #9, HEX-4 plans were published in Model Engine Builder Issue #14. 
There are also Italian designs, 3- and 5-cyl. radials, but I don't think there are drawings, or plans, just the fully and ready assembled engines. Nice interesting engines.


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## stevehuckss396

I have 2 of the Hex-4 engines. One was bar stock and 1 was built using the casting.







I also built a 9 cylinder but have not started it.







I also designed a 5 cylinder radial but have never built it.


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## DICKEYBIRD

I can't tell from the pic Steve; do your radials have individual engines geared together or 1 crankcase with a vane type blower like Ralph Barnette's 5 cyl radials?  (R.I.P. Ralph, we miss you.)

Those look awesome!  I've got boxes & boxes of Cox stuff squirreled away but never got around to making a multi.  One of these days....

ps: That 9 cyl. will take some heavy duty wattage to light up 9 glow heads!


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## stevehuckss396

DICKEYBIRD said:


> I can't tell from the pic Steve; do your radials have individual engines geared together or 1 crankcase with a vane type blower like Ralph Barnette's 5 cyl radials?  (R.I.P. Ralph, we miss you.)
> 
> Those look awesome!  I've got boxes & boxes of Cox stuff squirreled away but never got around to making a multi.  One of these days....
> 
> ps: That 9 cyl. will take some heavy duty wattage to light up 9 glow heads!




It is a single crankcase with a blower. I traded emails with him many times during the design phase of the project. I had no idea he had passed.

The wattage is the biggest reason I have not run the engine.


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## DICKEYBIRD

stevehuckss396 said:


> It is a single crankcase with a blower.


Wow, that's fantastic!  Do you have any pics of the crankshaft & master rod setup?  I'd love to see how you did that!

As far as the plug driver, I'll bet there many on the forum that could draw up a simple circuit to supply 20-25 amps @ 1.5V.  You'd need a couple good ebay buys to keep it reasonably priced though.  I guess the easiest way would be to strap together 9, 5ah NiCds with individual leads.  Years ago, a friend gave me a box of old Anton Bauer 12V videocam packs and I was able to cut them open and pick out the cells that were still good.  Those things were great for starting Cox engines.

Yes, I miss Ralph; he was a unique & talented fellow.   He passed in early 2011 if memory serves.  I used to run into him every year at the S.M.A.L.L. event in Little Rock and we talked at length about our projects.  He showed up one year with a tri-motor with 3 of his 5-cyl. radials on it.  What a sound that thing made!

He lived only 40 miles from my me but I never got around to visiting his shop.  I was heavy into Cox powered r/c model aircraft design/building/flying at the time and and didn't do much machining.  By the time I got heavy into machining & learned enough to be able to ask intelligent questions, he was already having health problems.


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## argat1

Tin Falcon said:


> interesting question.
> 
> a v twin recently sold on e-bay and there is currently a radial 3 for sale out of italy so $22 ww shipping.
> 
> 3 cylinder cox engine
> Tin


 

Hi Tin,

Yes, in fact that engine on which I was bidding got off my reach because my cell pone died on me and I just couldn't enter a higher bid. I was away of my computer too. :wall:So, I decided to make miself one like that to start my way in this amazing world of building an engine that Works.

Ar.


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## argat1

cidrontmg said:


> There's also http://www.jamesengine.com ,especially the HEX-2, HEX-4 and Cox V-4. Drawings are included (free!), and there's also HEX-2 plans, published in Model Engine Builder Issue #9, HEX-4 plans were published in Model Engine Builder Issue #14.
> There are also Italian designs, 3- and 5-cyl. radials, but I don't think there are drawings, or plans, just the fully and ready assembled engines. Nice interesting engines.


 

In deed they are nice! The Hex 2 looks very apealling. The thing that always makes me wonder is the heat treatment for the crank cases. I have no way or means to do that. 

The other design that uses the engine's own case look nice and more... "flashy" but I wonder if the wight-power ratio is worth the pain.



Ar.


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## argat1

stevehuckss396 said:


> I have 2 of the Hex-4 engines. One was bar stock and 1 was built using the casting.
> 
> 
> 
> 
> 
> 
> 
> I also built a 9 cylinder but have not started it.
> 
> 
> 
> 
> 
> 
> 
> I also designed a 5 cylinder radial but have never built it.


 

Steve,

I love the 9 radial! 

Have you ever mounted the Hex 4 on a plane?


Ar.


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## John Rus

stevehuckss396 said:


> I have 2 of the Hex-4 engines. One was bar stock and 1 was built using the casting.
> 
> 
> 
> 
> 
> 
> 
> I also built a 9 cylinder but have not started it.
> 
> 
> 
> 
> 
> 
> 
> I also designed a 5 cylinder radial but have never built it.



PM sent. 

Cheers,
John.


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## stevehuckss396

DICKEYBIRD said:


> Wow, that's fantastic!  Do you have any pics of the crankshaft & master rod setup?  I'd love to see how you did that!




The master rod is a Cox rod silver soldered to a machined part.







The crankshaft












Drive shaft for the blower


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## DICKEYBIRD

That's incredible Steve, thanks very much for the amazing pictures.  Too bad my best ol' flyin' buddy Brian Pate's gone on to a better place.  He'd be havin' a fit after seeing those.  He loved Cox engines more than anybody I've ever met.


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## deverett

There appear to be 2 types of Cox 049 cylinder: one type with single wide exhaust ports and the other with twin narrow slot exhaust ports.  Does it make any difference which type of cylinder is used on these types of engine?

Dave
The Emerald Isle


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## DICKEYBIRD

No difference in performance from the different exhaust ports*.  The single opening style cyls. were the earlier version before reports from customers of fires occurring when priming/starting them caused Cox to first add screens across the exhaust ports then change to the twin slot port system. (In the 80's if memory serves)

*Unless you want to talk about the effect that sub-piston induction/free porting has.


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## deverett

Thanks for that explanation dickeybird.

Dave
The Emerald Isle


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## petertha

DICKEYBIRD said:


> As far as the plug driver, I'll bet there many on the forum that could draw up a simple circuit to supply 20-25 amps @ 1.5V. .... I guess the easiest way would be to strap together 9, 5ah NiCds with individual leads. .


 
Ive often wondered why that low tech, dedicated 1.5v Ni* battery 'per glowplug' wouldnt be a good cheap solution. Are NiCds even sold anymore? Even NimH are getting harder to find these days. 

I thought a programmable RC BEC-type regulator might work, but I think their min output voltage is ~ 4 - 5V. 

From a battery standpoint, Lithium (polymer or LiFe) are dirt cheap & can handle the amps with ease. The challenge is matching plug voltage vs nominal cell voltage. My knowledge of step down regulators is zilch.

Could a 1S Lipo battery like this (3.7-4.0v nominal) be dedicated to a  bank of 3 plugs in series? (3.9v/3 plugs = 1.3A/plug). Its good for 88Amps.
http://www.hobbyking.com/hobbyking/store/__18559__Turnigy_2200mAh_1S_40C_Lipoly_Single_Cell_.html

Sorry for the tangent. These Cox engine assmeblies are awesome. I love that 9 cyl radial! Yes, this plug driver problem must be licked so we hear can that baby run!


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## deverett

I fancy building the Hex-4 from barstock.

Does anyone know of a source of the cylinder/crankcase tap?  Size is 17/32" - 40.  Googling doesn't bring any results.  I've contacted Cox concessionaires but they don't sell them.  I've contacted James Engines and he doesn't have any.  Specially made taps work out at $200 each from his original supplier unless he has a batch of at least 20 made.

Being somewhat lazy, I just don't want to try and cut 4 very fine threads.

Dave
The Emerald Isle


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## DICKEYBIRD

petertha said:


> Could a 1S Lipo battery like this (3.7-4.0v nominal) be dedicated to a  bank of 3 plugs in series? (3.9v/3 plugs = 1.3A/plug).


Sorry, just noticed your post.  I'm no electrical expert but wouldn't you have to somehow insulate the glow plugs from the cylinders to connect them in series?

Dave you could make a tap from 4140 prehard without heat treatment & I think it would do 4 holes OK in aluminum.

Or strap it in your CNC mill & threadmill it.:hDe:


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## mu38&Bg#

James Engines was probably the last source that stocked those taps. Might as well to a couple practice pieces on the lathe for that price. Internal threading isn't that complex. Buy a carbide internal threading bar and it will be fine.

I have many NOS NiCds from being in the RC business years ago. They are definitely getting hard to find now. Even good NiMH are not easy to find. Two plugs connected to a single cell should be fine so you just need a few cells. I wouldn't invest much in the glow circuit unless you plan on running it often.

Greg


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## mu38&Bg#

When all nine plugs have a common "ground" you don't have many options. One option is to drive two plugs from one circuit by connect current to two plug center terminals. However if one plug burns the circuit is open. We had some discussion on RCG There wasn't much of a solution there either.


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## petertha

DICKEYBIRD said:


> I'm no electrical expert but wouldn't you have to somehow insulate the glow plugs from the cylinders to connect them in series?


 
DOH! Exactly right. This should teach me to type when its already long after my bedtime. I started out wondering if any newer '1S' Lithium type cells were nominally close to 1.5-2.0v plug requirements. And then my brain slipped into series voltage sharing. But the common ground through the engine is not like a string of christmas bulbs on a wire, is it?  
LifePo4 is 3.2v/cell, LipO is 3.7v/cell, Lto is 2.4v (dont know anything about them)

Without a resistor or regulator to knock back source voltage, I guess the cheap solution is back to plan A: dedicated Ni* cell per plug, maybe a bigger C or D size for longetivity & current rating?
http://www.batteryspace.com/ni-mhbatteries.aspx


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## DICKEYBIRD

We need Greg to get on board as a project consultant.  I'm sure he can show how to convert all nine cyls. to diesel and be free of the need to light up those plugs.

Steve's sturdy crankshaft design and the inherent smoothing effect of the progressive firing impulses from the 9 radial cyls. will eliminate the obligatory crank failures of dieselized Coxes...no?


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## mu38&Bg#

I don't think i want to adjust 9 compression settings.


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## petertha

I'm not an electrical guy, so please don't chuckle to hard. My googling for low voltage regulators stumbled me onto this parametric product spec-er tool. 
http://www.ti.com/

I assumed (1S min, 2S max Lipo battery) input voltage of 3.7v, 7.4v respecively, 2.0v output voltage & 4A output. ie one regulator thingy per cylinder driven by a single Lipo pack.

You push the red Start Design button & it then spits out parts that fulfill the criteria in kind of a dashboard tool where you can further compare/refine. Not sure if the resultant little black bits would actually do what we want, but the 2-3$/per looked appealing.

And thats the end of the road for me, maximum limit of electrical engineering incompetence achieved!  Anyone else with knowledge know if a board/circuit could be built around this?


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## cidrontmg

dieselpilot said:


> James Engines was probably the last source that stocked those taps. Might as well to a couple practice pieces on the lathe for that price. Internal threading isn't that complex. Buy a carbide internal threading bar and it will be fine.
> Greg



Well, it's an excellent plan. I have 12 Cox cylinders + pistons + glow plugs, but no 17/32" - 40 taps or dies. I have a 1/2" - 40 tap - close, but no go. I tried twisting (with a big enough wrench) the threads into ali, brass and steel. Ali and brass mangled the thread, and steel mangled the cylinder :rant:. Not a famous result.
http://coxengines.ca or James Engines don't have taps or dies, so no one are available. Special taps are quite expensive ($200? of one each ), but if you contemplate to think about selling taps/dies, with a moderate cost, I'm willing. And I think there's many more who would buy it.  *discussion*


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## mu38&Bg#

I've done all sorts of special threads on the lathe manually. I did several 2 1/16"-24 internal and external last year. I can also CNC thread mill so that's what I'd end up doing in this case, but the hardest part of threading in the lathe will be mounting the crankcase to the spindle.

Greg


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## deverett

After failing miserably to source the 17/32-40 tap, I wondered about making one.  For four holes into a bit of ali, I reckon a mild steel tap case hardened would do the job.

However, I've had brain failure.  How do you calculate the depth of thread to cut the tap (Crest to Trough)?  I've looked through Machinery's Handbook - 21st ed, 1979 - there are loads of formulae, but can't find the one needed.

Someone put me out of my misery, please.

Dave
The Emerald Isle


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## barnesrickw

As a side note to this thread, I don't think Cox realizes more people are likely to buy more parts, for more projects,  if they would sell a tap and die at reasonable price.  I may suggest they scan the internet for threads tagged 17/32-40 tap for Cox .049.


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## barnesrickw

The response I got from Cox International.

Hello Rick

We do not have any plans to carry the tap and dies at this time, but I will keep your suggestion in mind when adding future products to our line up.

Many thanks!

Theresa


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## mu38&Bg#

Don't let the lack of a tap stop you. Single point threading not as bad as it seems.


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## barnesrickw

I just inherited a lathe that will do threading.  I'll give it a try as soon as I get it.


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## MCRIPPPer

very cool motors. 

why not just use a few D cell alkaline in parallel to get it going. those things store quite a bit of energy so should last a while. they can also supply pretty good current. 

or you could make a low voltage transformer by winding the secondary with only a few turns of big wire, and get about a volt at hundreds of amps capability.


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## stevehuckss396

MCRIPPPer said:


> very cool motors.
> 
> why not just use a few D cell alkaline in parallel to get it going.



Tried it on an inline 4 cylinder and the 4 D cells drained in about 5 minutes.


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## petertha

stevehuckss396 said:


> Tried it on an inline 4 cylinder and the 4 D cells drained in about 5 minutes.



 That doesn't surprise me Steve. Typical alkalines appear to have high nominal maH capacity, but that also presumes low current load. Great for LED flashlights, not so good for resistance heating elements. At increased current draw, alkaline capacity goes to pot in a hurry.
 These performance graphs show the relationship visually. 
http://data.energizer.com/PDFs/e95.pdf
 At 100mA load, capacity = 100 hrs. But increase the current to 1000mA (1 Amp) and capacity goes down to ~1 hr. Its log scale so at target 3A plug load, capacity degrades to mere minutes like you experienced. In fact their scale doesn't even exceed 1 Amp, because it's getting outside recommended limits.

 That's what cell C-rating is all about. Other chemistries can offer much higher current delivery capability due to lower internal resistance & other factors.  In this Alkaline example: C = 1 A-hr / 1 Amp = 1C ("one C"). Compare that to Lithium batteries that will do 45C continuous & 90C burst. Even low grade LI will do 25/50 continuous/max these days. 

 Unfortunately the issue with all these great (& cheap) Lithium based cells is not their ability to deliver current, that's fine. Its that their nominal cell voltage is too high, in the +3v range. Whereas glow plugs are designed around 1.5v range. So what is required is a regulator circuit to step it down. That's essentially what the commercial glow drivers are all about +/- some other fancy features. But they are orientated around typical single plug applications. The multi plug application requires a different solution. But hopefully someone out there that can figure this out.


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## derek999

Hi, I'm new here but have been reading your thread with great interest as I plan to build a multi cylinder engine using Cox or similar cylinders and pistons.

The required starting voltage of around 1.5 Volts would be easy using power diodes in series with the positive line from the cell. Each diode would drop the voltage by around 0.7 Volt, so 3 would reduce a 3.7 Volt cell's output to around 1.6 Volts.
Diodes of about 50-100 Volts & 5 Amp capability would be suitable, but in use could get a little heated so they should be insulated.
Almost any electronics component supplier should have suitable diodes for pennies, and they should be wired in series to give the required voltage drop.
As they only pass current in one direction, test for correct function and reverse the direction if no glow achieved.

I found this to be a reliable and economical answer to the problem.
I hope it halps.

Best regards 

Derek
St. Andrews, Scotland (Golf City!)


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## pacomb

cidrontmg said:


> There's also http://www.jamesengine.com ,especially the HEX-2, HEX-4 and Cox V-4. Drawings are included (free!), and there's also HEX-2 plans, published in Model Engine Builder Issue #9, HEX-4 plans were published in Model Engine Builder Issue #14.
> There are also Italian designs, 3- and 5-cyl. radials, but I don't think there are drawings, or plans, just the fully and ready assembled engines. Nice interesting engines.


 
That nice 5 cyl radial, should be easy to take it apart, and do reverse engineering to take all the dimensions. As it is a 2 stock engine, you have so many little parts compared to a 4stroke radial.


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## pacomb

Hello, 
maybe an old thread, but maybe someone who participated on the thread can help.
I and a friend are with the idea of building a radial engine using cox .049 engines.
We are stuck with the 17/32-40 tap, cant find a source for them. Does anyone know actually who is selling the tap?
If we are not able to find a source, maybe someone who has it could lend us his tap to make the threads?
regards
paco


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## barnesrickw

pacomb said:


> Hello,
> maybe an old thread, but maybe someone who participated on the thread can help.
> I and a friend are with the idea of building a radial engine using cox .049 engines.
> We are stuck with the 17/32-40 tap, cant find a source for them. Does anyone know actually who is selling the tap?
> If we are not able to find a source, maybe someone who has it could lend us his tap to make the threads?
> regards
> paco




They can be found but are expensive.  It's prevented me from making anything from my cox parts.  I'm planning on selling the parts on eBay and just make my own cylinders and pistons.  


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## pacomb

Newman tools sells it for $140, not cheap!
http://www.newmantools.com/price/taps_ns_pr.html

But what I see is that when ordering 6 units, the price drops to $50 which is more convenient. 

For you north americans, it should be easy to join 6 and buy the tap cheaply!

Is there any interest to joing a group??


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## barnesrickw

I will commit to one for $50. Good plan. You know, maybe I'll buy and sell at that lever and sell for $75. . 


Sent from my iPad using Model Engines


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## pacomb

I have found 2 USA companies selling the tap for arround $50 per unit. Once I have confirmed the price, I will post it so every one can benefit.


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## barnesrickw

pacomb said:


> I have found 2 USA companies selling the tap for arround $50 per unit. Once I have confirmed the price, I will post it so every one can benefit.




Thank you.  


Sent from my iPad using Model Engines


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## pacomb

I am starting with a friend a cox 9 radial. We have already bought 10 new piston/head assemblies, and 10 glow plug head adapters.

I had a long time search for the correct cox tap with the 17/32-40 thread, and was astonished with the quotations I received from several companies, up to $200. 

Speaking with the seller of the cox parts, we agreed that he will make an order of several taps to a company so we could have a final reasonable unit price.

The final unit price is below $55 which makes a good price compared to other options. 

http://www.exmodelengines.com/cox-.049-cylinder-glow-head-tap.html

Hope all the people that where searching for the correct tap, can now order it and start a new cox project. 

I will post more information of our project.


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## barnesrickw

Thank you, thank you, thank you.  Just placed an order for my tap.  I tried asking the same from another Cox distributor, and they were not interested.  Excellent work. 


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## pacomb

I am glad I can help others with just some work. Looks interesting that some companies are a little bit business short minded

What cox proyect do you have in mind?


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## barnesrickw

I have plans for a Hex two and four, but am also interested in trying some of my own.  I was interested in small two cycle "pods" independently carbureted, etc. that you could bolt together with mating output shafts.  Then you could make any inline combination you wished.  Just thought that would be something interesting to try.  


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## Tin Falcon

Midway USA 


http://www.midwayusa.com/product/954762/baker-carbon-steel-plug-tap-7-32-40-thread


$33.99 available ready to ship. 
Tin


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## barnesrickw

Thanks Tin for the info.  Patience would have saved me a few bucks I guess, but I'm really appreciative of both of you for the help.  


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## GailInNM

Tin,
That is a 7/32-40.  They need a 17/32-40.
Gail in NM


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## Tin Falcon

OOPs though that too easy sorry for the confusion
Tin


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## barnesrickw

Well at least I didn't spend $20 too much now.   


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## whitehouse260

i know this is an old thread but does any one have plans for a cox radial engine? 
thanks,
matt


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## kf2qd

A Cox radial - As in a mount for multiple cox engines that drive a common center shaft through spur gears?


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## whitehouse260

I guess I should
 have been more clear... I was hoping for like 3 cylinders sharing a common crank case.
Thanks!


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## stevehuckss396

whitehouse260 said:


> i know this is an old thread but does any one have plans for a cox radial engine?
> thanks,
> matt


PM me. I have some radial plans. Common crankshaft with a centrifical blower built in.


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## gadabout

stevehuckss396 said:


> The master rod is a Cox rod silver soldered to a machined part.
> 
> 
> 
> 
> 
> 
> 
> The crankshaft
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Drive shaft for the blower


Would love to know more on how you did the master rod modifications , like did you remove the rod from the piston, how you held it to machine and silver solder etc please,thanks
Mark


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## WOB

Another way to get power for glow-plugs is to rewind the secondary of an open frame transformer that has enough VA( watts) capacity for the total glow plug load.   I needed to power 4 glow-plugs for a 4 cylinder engine that needed 4 amps per plug(OS Type F).  This would require 24 watts.  Looking through my electronics junk drawer, I had a 50 VA transformer similar to this https://www.jameco.com/z/67-1123-36...AC-Power-Transformer-br-6V-0V-6V_2265679.html    The secondary winding was on the outside ( usually the case) so it was easy to remove it leaving the primary intact.  I wound a new secondary with #14 AWG insulated wire ( from a piece of Romex) filling up the entire space occupied by the old winding.  Testing the new winding allowed me to adjust the number of turns so that I ended up with 1.5V at 16A that I needed.   The open circuit voltage was about 2.0V  IIRC.   I put it in a PVC box with a toggle switch, line cord, and plug for the primary. The secondary was brought out with a piece of #14 zip cord  and banana plugs to connect to my engine's mount.   Much easier than batteries, but does tie you to a 120V AC circuit.  Not a problem for most of us, I would guess.

WOB


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## kadora

I use transformer soldering iron - see my thread
https://www.homemodelenginemachinist.com/threads/glow-plug-feeder.24480/


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## picks27t

GailInNM said:


> Tin,
> That is a 7/32-40.  They need a 17/32-40.
> Gail in NM


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## MickeyDD

stevehuckss396 said:


> PM me. I have some radial plans. Common crankshaft with a centrifical blower built in.
> 
> Hi Steve,
> I am looking for plans for a Cox radial and saw your posting on HMEM today.  Could you please send me some plans for a 3 or 5 cylinder radial.  Also, do you know where I can find the 17/32-40 tap that I would need for the cylinders?  Apparently they were available a few years ago.
> Thanks,
> Michael


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## MickeyDD

Hi Steve,
Thank you for your reply. My e-mail is: [email protected].  Do you also know where I can find a 17/32-40 tap for the cylinder thread?  Is that what you use to cut the threads or do you use an internal  threading tool?
Thanks,
Michael


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## stevehuckss396

I purchased a tap years ago when a member had a dozen made and offered them for sale.


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## Tony64

cidrontmg said:


> There's also http://www.jamesengine.com ,especially the HEX-2, HEX-4 and Cox V-4. Drawings are included (free!), and there's also HEX-2 plans, published in Model Engine Builder Issue #9, HEX-4 plans were published in Model Engine Builder Issue #14.
> There are also Italian designs, 3- and 5-cyl. radials, but I don't think there are drawings, or plans, just the fully and ready assembled engines. Nice interesting engines.
> 
> View attachment 65256
> 
> 
> View attachment 65257


Oh my God !!!! I built this 10 years ago View attachment 65257


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## pacomb

Just a few images on the engine my friend is building


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## SmithDoor

MickeyDD said:


> Hi Steve,
> Thank you for your reply. My e-mail is: [email protected].  Do you also know where I can find a 17/32-40 tap for the cylinder thread?  Is that what you use to cut the threads or do you use an internal  threading tool?
> Thanks,
> Michael


You make a form tap used on aluminum.  The very find thread used makes this tap great or single point the thread.

Dave


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## SmithDoor

MickeyDD said:


> Hi Steve,
> Thank you for your reply. My e-mail is: [email protected].  Do you also know where I can find a 17/32-40 tap for the cylinder thread?  Is that what you use to cut the threads or do you use an internal  threading tool?
> Thanks,
> Michael


You can use brass insert and standard thread for body and single point for the 17/32 x 40tpi in the lathe

Dave


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## Canyonman

Pacomb      Does your friend have plans or plans to offer plans or can I get a set of plans??
Ken


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## pacomb

MickeyDD said:


> Hi Steve,
> Thank you for your reply. My e-mail is: [email protected].  Do you also know where I can find a 17/32-40 tap for the cylinder thread?  Is that what you use to cut the threads or do you use an internal  threading tool?
> Thanks,
> Michael



Have you read all the posts on this thread???  Please read them





						.098 V twin using 2 Cox .049 Cylinder assemblies.
					

I will commit to one for $50. Good plan. You know, maybe I'll buy and sell at that lever and sell for $75. :-).    Sent from my iPad using Model Engines




					www.homemodelenginemachinist.com
				




I managed that a company made an order of taps very cheap


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## pacomb

Canyonman said:


> Pacomb      Does your friend have plans or plans to offer plans or can I get a set of plans??
> Ken



*stevehuckss396 *sent me the plans he had. I have to say I am unsure if the engine will run. Steve him self has not started the engine. I have seen several faults, and I am unsure it can run..... I would not recomend anyone spending money building this engine, until someone has proven it runs


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## SmithDoor

Why does everyone want to use Cox cylinders?

Dave 



pacomb said:


> Have you read all the posts on this thread???  Please read them
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> .098 V twin using 2 Cox .049 Cylinder assemblies.
> 
> 
> I will commit to one for $50. Good plan. You know, maybe I'll buy and sell at that lever and sell for $75. :-).    Sent from my iPad using Model Engines
> 
> 
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> www.homemodelenginemachinist.com
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> 
> I managed that a company made an order of taps very cheap


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## stevehuckss396

I know of a few 5 cylinder engines that run based on the same design. I have never tried to hide the fact that I haven't run mine. I tell everyone the deal.


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## pacomb

SmithDoor said:


> Why does everyone want to use Cox cylinders?
> 
> Dave


easy, because you already have 50% of the work when making a radial, and they are easily available and more or less cheap. Most of the people that want to make a radial, dont want to fly it, they just make it for fun and to make it run. And if the total cost is low even if the size is low, no problem.

One could make a radial using 5, 7 or 9 cylinder heads and piston from OS, or similar, but they are not easy to get hold of, and the cost is high....


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## pacomb

stevehuckss396 said:


> I know of a few 5 cylinder engines that run based on the same design. I have never tried to hide the fact that I haven't run mine. I tell everyone the deal.



Yeap, you always said it, so no one can say they did not know jajaja! 

But I really encourage you to try to make it run. What more do you need?? just a good variable power suply!! If you had the hability to design and build that  engine, dont stop at the last stage!!! 

Can you post info on those 5 cyl engines?? Only ones I have seen are geared, which I think although funny, it makes no sense...


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## Canyonman

stevehucks396   I echo the support of pacomb! I too urge you to try and get it running!
Here's to success!
Ken


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## stevehuckss396

I don't have time or the desire to do anything with it. If you don't think it will run, don't build it. Design something else and build that. I really have no interest in it and have sold all my 049 engines and glow drivers. I am focused on building a pair of 4 cycle, 9 cylinder engines. I gave the plans to anyone who wanted to use them. I don't sell them and don't promise anything. They were never meant to be released to the public and now i'm sorry i did. Lesson learned.


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## Shopgeezer

I have your plans and very much appreciate you giving them to me. I think it is great that this design is out in the community. If a bit more development is needed someone will do it and the design will mature. That is how our hobby works. I for one want to thank you for making the plans available. Don’t listen to the complainers. The quiet majority are happily at work on the engine.


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## Canyonman

Hi Stevehucks396, No need to be sour. Our support was sincerely meant to be positive. Please don't let this event prevent you from offering plans or resources in the future. We are a community here and sometimes our enthusiasm may come across wrong I guess. I Thank You for the plans and look forward to seeing your 9 cyl project.  Ken


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## stevehuckss396

Not sour. Just life has been kicking me in the nuts lately and have bigger things to worry about. I still stop by to help if I can. I get an hour or 2 a week on the shop if I even feel like going out so not been posting any build stuff. Wife still kind of likes me so I ain't complaining. Just working through it.

Sorry if I sounded bitter. I'm really not and I have a lot to be thankful for. 

Cheers.


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## Canyonman

Steve,  I hope things go well for you in 2021!!!!    Ken


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## SmithDoor

I do make for fun but I like build all parts. I had drawings on building 0.60 making casting in 1972. But life took over. 

Now setup a new work shop, my wife has new car and shop was in garage. Now a fully insulated work shop with cooling. 

Dave 



pacomb said:


> easy, because you already have 50% of the work when making a radial, and they are easily available and more or less cheap. Most of the people that want to make a radial, dont want to fly it, they just make it for fun and to make it run. And if the total cost is low even if the size is low, no problem.
> 
> One could make a radial using 5, 7 or 9 cylinder heads and piston from OS, or similar, but they are not easy to get hold of, and the cost is high....


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## SmithDoor

Here is my drawings for cylinder and piston 












Dave 



pacomb said:


> easy, because you already have 50% of the work when making a radial, and they are easily available and more or less cheap. Most of the people that want to make a radial, dont want to fly it, they just make it for fun and to make it run. And if the total cost is low even if the size is low, no problem.
> 
> One could make a radial using 5, 7 or 9 cylinder heads and piston from OS, or similar, but they are not easy to get hold of, and the cost is high....


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## a41capt

stevehuckss396 said:


> Not sour. Just life has been kicking me in the nuts lately and have bigger things to worry about. I still stop by to help if I can. I get an hour or 2 a week on the shop if I even feel like going out so not been posting any build stuff. Wife still kind of likes me so I ain't complaining. Just working through it.
> 
> Sorry if I sounded bitter. I'm really not and I have a lot to be thankful for.
> 
> Cheers.


Hiya Steve!
I for one appreciate your sharing your work.  I’ll never build (never say never, right?) a radial engine, but I found your plans very enlightening!  I especially enjoyed how you got around the crankcase pressure issue associated with a multi-cylinder 2-stroke.

As far as getting kicked in the nuts, you’re absolutely right, this past year sucked! It sucked so bad that I’ve taken to wearing a “cup” everyday to protect the family jewels myself!  However, like most model engine machinists, I’m sure you’re used to adapting, pivoting, and finding a new direction, and hopefully your solution-seeking mind will fix things up for the future.

once again, thanks for the enlightening plans, and here’s to a relatively pain free 2021!

John W


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