Log in
Search
Latest topics
» COX .020 RC PROJECTby 1/2A Nut Today at 2:49 am
» Project Cox .049 r/c & Citabrian Champion
by MauricioB Today at 2:10 am
» Irvine Mills .75 replica
by Coxfledgling Today at 1:54 am
» **VOTE-ON-THE-NEXT-COX-ENGINE-OF-THE-MONTH** (October 2024)
by GallopingGhostler Today at 12:01 am
» WILLY NILLY
by MANDALAY Yesterday at 10:56 pm
» Happy Birthday Robert ( Rsv1cox )
by Cribbs74 Yesterday at 7:50 pm
» Stick built rubber powered Scientific ME-109
by DPCM Yesterday at 5:36 pm
» The Cabin.........A carpenters nightmare.
by rsv1cox Yesterday at 5:26 pm
» Cox 020 PeeWee rebuild questions
by rdw777 Yesterday at 2:12 pm
» I Got Cheated!
by GallopingGhostler Yesterday at 2:06 pm
» PSA propellors!!!
by robot797 Yesterday at 6:24 am
» "Rodd-O-Gyro"
by Oldenginerod Yesterday at 4:54 am
Cox Engine of The Month
R/C TD.010 plane
Page 1 of 2
Page 1 of 2 • 1, 2
R/C TD.010 plane
G'day folks,
Just joined up and thought I'd show you this little model I built from scratch a long time ago.
Originally I designed it for .049 power which I used for many years with a Medallion R/C 049 until I crashed it.
I bought the 010 in the early 90's(I think) and so I scaled down the plans to suit this little engine.
The only thing I couldn't bear was no throttle so we made one. It's along the lines of the exhaust throttles of the other Cox engines but of course it was much more tricky as we couldn't(wouldn't) machine the step off the bottom of the cylinder where it meets the crankcase. So we had to slit the tube, lap the mating halves smooth,weld it together, machine the outside then bore the inside before breaking it apart again to fit it to the engine.
Here's some pics...
Just joined up and thought I'd show you this little model I built from scratch a long time ago.
Originally I designed it for .049 power which I used for many years with a Medallion R/C 049 until I crashed it.
I bought the 010 in the early 90's(I think) and so I scaled down the plans to suit this little engine.
The only thing I couldn't bear was no throttle so we made one. It's along the lines of the exhaust throttles of the other Cox engines but of course it was much more tricky as we couldn't(wouldn't) machine the step off the bottom of the cylinder where it meets the crankcase. So we had to slit the tube, lap the mating halves smooth,weld it together, machine the outside then bore the inside before breaking it apart again to fit it to the engine.
Here's some pics...
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
Wow!
Nice plane but, even nicer is that throttle ring. I was hoping it was a bit more rudimentary so I could do one myself. You did it the right way though. If you ever want to cobble up some more of them I will be your first customer!
Bravo!
Nice plane but, even nicer is that throttle ring. I was hoping it was a bit more rudimentary so I could do one myself. You did it the right way though. If you ever want to cobble up some more of them I will be your first customer!
Bravo!
Cribbs74- Moderator
-
Posts : 11907
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
Re: R/C TD.010 plane
Second
John Goddard- Diamond Member
- Posts : 2447
Join date : 2011-11-24
Age : 60
Location : Leyton North East London
Re: R/C TD 0.010 plane
You could put me down as a third. Is the circlip the only thing holding
two halves of throttle ring together? John
two halves of throttle ring together? John
proctor- Gold Member
- Posts : 199
Join date : 2012-01-31
Location : Scottish Highlands
Re: R/C TD.010 plane
FIXR7 wrote:G'day folks,
Just joined up and thought I'd show you this little model I built from scratch a long time ago.
Originally I designed it for .049 power which I used for many years with a Medallion R/C 049 until I crashed it.
I bought the 010 in the early 90's(I think) and so I scaled down the plans to suit this little engine.
The only thing I couldn't bear was no throttle so we made one. It's along the lines of the exhaust throttles of the other Cox engines but of course it was much more tricky as we couldn't(wouldn't) machine the step off the bottom of the cylinder where it meets the crankcase. So we had to slit the tube, lap the mating halves smooth,weld it together, machine the outside then bore the inside before breaking it apart again to fit it to the engine.
Here's some pics...
damn that looks great, love the throttle ring and welcome to the forum
mitchg95- Diamond Member
- Posts : 2103
Join date : 2011-12-19
Age : 29
Location : Geneva, mn, USA
Re: R/C TD.010 plane
Glad you like it lads!
I have to admit I have only run the engine in without a throttle back in the mid 90's.
So I suppose I better try it soon eh?
Yes the circlip holds it on and it is a very tight fit.
I remember back in the day, a hobby shop owner told me it wouldn't work because of the porting of the TD engine!? Wtf?
I said; what's the porting got to do with it? If you restrict the exhaust you restrict the flow regardless of what's inside the engine!
Anyway you guy's have proved it works.
I have to admit I have only run the engine in without a throttle back in the mid 90's.
So I suppose I better try it soon eh?
Yes the circlip holds it on and it is a very tight fit.
I remember back in the day, a hobby shop owner told me it wouldn't work because of the porting of the TD engine!? Wtf?
I said; what's the porting got to do with it? If you restrict the exhaust you restrict the flow regardless of what's inside the engine!
Anyway you guy's have proved it works.
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
Oh yeah they work!FIXR7 wrote:Glad you like it lads!
I have to admit I have only run the engine in without a throttle back in the mid 90's.
So I suppose I better try it soon eh?
Yes the circlip holds it on and it is a very tight fit.
I remember back in the day, a hobby shop owner told me it wouldn't work because of the porting of the TD engine!? Wtf?
I said; what's the porting got to do with it? If you restrict the exhaust you restrict the flow regardless of what's inside the engine!
Anyway you guy's have proved it works.
I think he meant the exhaust ports or something.
Re: R/C TD.010 plane
FIXR7 wrote:...I remember back in the day, a hobby shop owner told me it wouldn't work because of the porting of the TD engine!? Wtf?
I said; what's the porting got to do with it? If you restrict the exhaust you restrict the flow regardless of what's inside the engine!
Anyway you guy's have proved it works.
Does an .010 have sub piston induction? Maybe he was talking about the exhaust ports. A lot of times SPI and throttle rings or mufflers don't work well together, since it sucks hot exhaust gasses back in to the crankcase instead of cold fresh air at TDC.
I'm not a .010 expert, so if there's no SPI, then you're right, no problem.
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: R/C TD.010 plane
Maybe that was what he was referring to?
I don't know, are the .049's and such the same in terms of porting?
I don't know, are the .049's and such the same in terms of porting?
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
FIXR7 wrote:Maybe that was what he was referring to?
I don't know, are the .049's and such the same in terms of porting?
the .010 does have SPI but throttle rings are still OK on them if you can get the fits right.
Re: R/C TD.010 plane
First be sure not to confuse exhaust ports with bypass ports, which are fuel delivery channels inside the cylinder.FIXR7 wrote:Maybe that was what he was referring to?
I don't know, are the .049's and such the same in terms of porting?
There are several different exhaust port configurations for the .049s and they later changed the method of obtaining SPI. Originally the port was set low enough so the piston skirt had a gap under it at TDC, for cold air induction. Some cylinders had it, and others did not. They basically all used the same piston.
But later the exhaust ports were all the same height and you then used a shorter piston to obtain the same gap at TDC. That made it easier to manufacture and mix and match parts for different performance levels. Putting a short piston in an old style SPI cylinder will make too much SPI and hurt performance.
There are several different configurations of bypass ports also.
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: R/C TD.010 plane
I think he(the shop owner) was referring to the bypass ports.
Thanks for the info on the SPI RknRusty!
Thanks for the info on the SPI RknRusty!
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
Here's some more on SPI in a thread at RCGroups.com. It went on for 4 pages, but the first post pretty much tells the story.FIXR7 wrote:I think he(the shop owner) was referring to the bypass ports.
Thanks for the info on the SPI RknRusty!
http://www.rcgroups.com/forums/showthread.php?t=1538781
There is a similar one here, but I couldn't find it.
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: R/C TD.010 plane
Ok so it stands to reason that the exhaust throttle could upset the inward flow of air to the crankcase? Enough to cause poor operation? Possibly? You could argue though, that the exhaust throttle is deliberately causing poor operation.
The problem would not be there at WOT therefore.
Does anyone have an original exhaust throttle engine with SPI? I'd say most likely.
I'll have at look at mine.
The problem would not be there at WOT therefore.
Does anyone have an original exhaust throttle engine with SPI? I'd say most likely.
I'll have at look at mine.
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
FIXR7 wrote:Ok so it stands to reason that the exhaust throttle could upset the inward flow of air to the crankcase? Enough to cause poor operation? Possibly? You could argue though, that the exhaust throttle is deliberately causing poor operation.
The problem would not be there at WOT therefore.
Does anyone have an original exhaust throttle engine with SPI? I'd say most likely.
I'll have at look at mine.
Good Luck with it Pete.
If you do a little research you'll see the recurring theme is lower top end on all the throttled Cox's.
I'm not sure what fuel supply is like down under but do yourself a favour if you can't find some fresh stuff
buy some new plane or car fuel and knock up a bit of castor into it.
I've been faffing around with my 010 since before Christmas and have only just realised the problem
has been dud fuel. Compounded by the fact it actually ran OK(ish) in my Cox 049's.
John Goddard- Diamond Member
- Posts : 2447
Join date : 2011-11-24
Age : 60
Location : Leyton North East London
Re: R/C TD.010 plane
That is true, but if it all works fine despite what we think, just fly it and think no more of it.FIXR7 wrote:Ok so it stands to reason that the exhaust throttle could upset the inward flow of air to the crankcase?
Enough to cause poor operation? Possibly?
WOT is where the sub induction is greatest, so watch out for overheating, especially while bench running. The effect on idle, I hear, is that sometimes it won't run slow enough to suit your needs.FIXR7 wrote:...The problem would not be there at WOT therefore.
As far as I know Cox only ever sold non-SPI engines with mufflers or exhaust throttles.FIXR7 wrote:Does anyone have an original exhaust throttle engine with SPI? I'd say most likely.
Am I getting on your nerves yet?
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: R/C TD.010 plane
Nope rusty, I asked the questions because I don't know and it's all good info! Thankyou.
So you're saying that even though there is no restriction in the exhaust ports by the throttle sleeve at WOT it still adversely effects the SPI operation? Because of the extra thickness of the sleeve creating an effectively longer port?
Ok, everyone who has made an exhaust throttle for one of these .010's lets hear the details about your engines' running?
I've heard about the high idle...Large sleeve tolerances perhaps?
and how about fuel? The last lot I got was a blend of Klotz and castor with 25% nitro...twas good.
So you're saying that even though there is no restriction in the exhaust ports by the throttle sleeve at WOT it still adversely effects the SPI operation? Because of the extra thickness of the sleeve creating an effectively longer port?
Ok, everyone who has made an exhaust throttle for one of these .010's lets hear the details about your engines' running?
I've heard about the high idle...Large sleeve tolerances perhaps?
and how about fuel? The last lot I got was a blend of Klotz and castor with 25% nitro...twas good.
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
Oh thanks also John.
btw, I remember an old RCM mag with an article about "tarno" carbs being available for .010's and, was it Clarence Lee who ran one on a tiny little sea plane? Rare as rocking horse [bleep] no doubt?
btw, I remember an old RCM mag with an article about "tarno" carbs being available for .010's and, was it Clarence Lee who ran one on a tiny little sea plane? Rare as rocking horse [bleep] no doubt?
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
Exactly. The crankcase vacuum caused by the ascending piston is suddenly relieved when the SPI gap cracks open. Instantly the vacuum inhales whatever is right outside the exhaust port. In the case of a muffler or exhaust throttle, that "whatever" consists of poorly oxygenated hot spent fuel and dirty castor oil, rather than the cold clean oxygen rich air it was designed to use for boosting the next intake charge.FIXR7 wrote:...So you're saying that even though there is no restriction in the exhaust ports by the throttle sleeve at WOT it still adversely effects the SPI operation? Because of the extra thickness of the sleeve creating an effectively longer port?
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: R/C TD.010 plane
Righto, just took this pic of my Medallion .049 by shining a torch up it's date. You can see the gap between the bottom of the piston and the exhaust port. Does that mean it has SPI?
Also checked the Black Widow I just bought and it's the same gap on this non throttled engine.
Also checked the Black Widow I just bought and it's the same gap on this non throttled engine.
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
That's it. Some have more than others. Is there a number stamped on that Medallion cylinder? The #1 on BW cylinders is usually a tiny stamp on the corner facing of one of the exhaust ports. Hard to see. The Medallion might be stamped on the barrel. For a non throttled Medallion the old originals had #2., usually on the barrel between the ports. That was a single bypass cylinder.
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: R/C TD.010 plane
I'll have a look.
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
They both have a 1.
FIXR7- Bronze Member
- Posts : 31
Join date : 2012-04-04
Age : 59
Location : Perth, Western Australia
Re: R/C TD.010 plane
Someone put a Black Widow cylinder on your Medallion. That's good, it's considerably more powerful than a #2. I have one of the new type SPI sets with the slit exhaust ports and the short piston on my Medallion. It really woke it up.
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Page 1 of 2 • 1, 2
Page 1 of 2
Permissions in this forum:
You cannot reply to topics in this forum