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-   -   RS55cc (https://www.rcuniverse.com/forum/gas-engines-142/10727092-rs55cc.html)

Umran 09-21-2011 05:07 AM

RS55cc
 
Dear All,
Introducing the latest addition to 50cc class gasoline engine, the RS55.

If everyone in this forum doesn't mind, i would like to declare this is the first time in this world an engine being develop for RC usage with built in start system. It begin with my auto start system for dle111. After getting it done, a new challenge arose that was how to make a rear drive start system for a single cylinder engine which is having a float crankshaft?

Since early May, i started the designing work, maybe after 3 weeks, the initial drawings completed. I uploaded the video below which show the 3D rotation of this engine.

[youtube]http://www.youtube.com/watch?v=I6LGY8GUtrE[/youtube]


After which i sent out those drawings to our local manufacturer for prototype development. And today afternoon i received the built engine. What else can i say, it is simply superb!!!

[youtube]http://www.youtube.com/watch?v=GUPfBfZxNR0[/youtube]

The concept work as intended, the engine additional weight is basically very minimal when compared to current 55cc class engines yet you wouldn't have to worry about slapping those props anymore to get it to start.

mrbigg 09-21-2011 06:13 AM

RE: RS55cc
 
Pretty cool. Do you think the electric motor (looks to be brushless), will hold up in the heated cowl area?

Super08 09-21-2011 07:17 AM

RE: RS55cc
 
The scale guys will love that. :)

BadAzzMaxx 09-21-2011 07:35 AM

RE: RS55cc
 
Now do a 80cc twin and you will eat the market up.

I am not into scale and I love it. LOL

Milton

Umran 09-21-2011 08:40 AM

RE: RS55cc
 


ORIGINAL: mrbigg

Pretty cool. Do you think the electric motor (looks to be brushless), will hold up in the heated cowl area?

The cylinder temperature is roughly around 100 to 130 degrees C. The crankcase temperature is roughly 70 to 90 degrees.... the bl motor operating temperature is typically around 60 to 90... with silicon wires, i believe it should hold up. Anyway this engine will not go for full production yet until i have install it on an airplane and do further testing on it.


Umran 09-21-2011 08:48 AM

RE: RS55cc
 
1 Attachment(s)


ORIGINAL: Super08

The scale guys will love that. :)

yup true. attached are static photos which shows the actual weight of this prototype, with muffler and stand offs the weight is 1760 grams. In fact i will mark a few areas of this prototype where we can shave off in order to reduce the weight further.

As it is now, it can surely power up a 50cc 3D airplane (wingspan 87-88 inches), more so for a scale airplane. Tomorrow i will begin to power it up.... we'll see what the kind of power it has.

Umran 09-21-2011 08:49 AM

RE: RS55cc
 


ORIGINAL: BadAzzMaxx

Now do a 80cc twin and you will eat the market up.

I am not into scale and I love it. LOL

Milton
hehehe... you know my 60cc twin is in the pipeline, well.... up another 20cc... i'll see what i can do.

skip1320 09-21-2011 10:16 AM

RE: RS55cc
 
Make it starter generator,and ESC with bec volt drop for ignition,and a kill switch,C,mon!

clivemc 09-21-2011 10:47 AM

RE: RS55cc
 
yeah looking good - 70-80cc twin and you will be cooking :):):)

apalsson 09-21-2011 11:12 AM

RE: RS55cc
 
Excellent work Umran,
I agree with Milton and Clive, a 70cc or 80cc twin would be completely unique in the market space
Also - have you considered a rear exhaust version of your 50cc
The Scale boys would really love that! (50cc Mustang, Spitfire and all the other narrow-cowl warbirds)

coronabob 09-21-2011 04:32 PM

RE: RS55cc
 
Umran,

Put me down for one 60cc twin. It will do very nicely in my Pitts Python. Is it going to have DLE30 cylinders & pistons? Do you accept Paypal?

Looks like your 50cc weighs right below 4lbs with muffler. I already have five 50cc engines. Just can not see myself buying another 50cc. That's the only reason.

Umran 09-21-2011 05:05 PM

RE: RS55cc
 


ORIGINAL: skip1320

Make it starter generator,and ESC with bec volt drop for ignition,and a kill switch,C,mon!
Stater/generator - mechanically simpler than the current design but it will rob significant amount of engine power.

ESC with bec for ign - yup that is the idea!

kill switch - i have already mentioned it to RCEXL to have it custom built into the ignition unit, but i did not pursue it at this moment.


The starter generator concept - the electronic part of it is tricky. Imagine the if using the current brushless motor, the output is 3 phase AC with wild frequency(depending on engine rpm) and voltage. This needs to be regulated before it can be use. On this i'm not an expert, i need the help from electrical/electronic engineers to get around it. But it is a good concept for UAVs.

Umran 09-21-2011 05:06 PM

RE: RS55cc
 


ORIGINAL: clivemc

yeah looking good - 70-80cc twin and you will be cooking :):):)

yup noted. like my previous response, will see what i can come up with in due time.

Umran 09-21-2011 05:08 PM

RE: RS55cc
 


ORIGINAL: apalsson

Excellent work Umran,
I agree with Milton and Clive, a 70cc or 80cc twin would be completely unique in the market space
Also - have you considered a rear exhaust version of your 50cc
The Scale boys would really love that! (50cc Mustang, Spitfire and all the other narrow-cowl warbirds)


Your idea on rear exhaust is simply superb! i did not think of it previously. Was so used to side portings...

Umran 09-21-2011 05:13 PM

RE: RS55cc
 


ORIGINAL: coronabob

Umran,

Put me down for one 60cc twin. It will do very nicely in my Pitts Python. Is it going to have DLE30 cylinders & pistons? Do you accept Paypal?

Looks like your 50cc weighs right below 4lbs with muffler. I already have five 50cc engines. Just can not see myself buying another 50cc. That's the only reason.

it took the manufacturer a full 3 months to come up with this prototype, and i was told by them that the 60cc haven't started anything physical yet. So chances are it will only be around in 3 months time, i hope.... can't pressure them too much afraid that they might back-off... hehehehe...

aussiesteve 09-21-2011 05:14 PM

RE: RS55cc
 
As usual - Great Work Umran. Keep it up mate.

Get it made anywhere other than China and you will be leaps ahead. There are some great companies in Malaysia that are more than capable of producing this engine :D


a1pcfixer 09-21-2011 11:21 PM

RE: RS55cc
 
I really like your remote start system!!!

What are the specs for the battery used to power the bl start motor?

2s1p/7.4v -or- 3s1p/12.6v?

Mah/capacity?

Weight of battery + ESC?

IF (big if) it's 2s1p/7.4v then a LiFe/A123 (6.6v) ignition battery might be able to serve
double duty & power the remote start sytem + ign.......maybe?

IF it requires a 3s1p/12.6v battery, then we're looking at dead weight to carry around.

Umran 09-22-2011 06:18 AM

RE: RS55cc
 


ORIGINAL: aussiesteve

As usual - Great Work Umran. Keep it up mate.

Get it made anywhere other than China and you will be leaps ahead. There are some great companies in Malaysia that are more than capable of producing this engine :D


Yes there are many who can mass produce this engine... The concern here is casting molding tool, it cost a lot...

Umran 09-22-2011 06:25 AM

RE: RS55cc
 


ORIGINAL: a1pcfixer

I really like your remote start system!!!

What are the specs for the battery used to power the bl start motor?

2s1p/7.4v -or- 3s1p/12.6v?

Mah/capacity?

Weight of battery + ESC?

IF (big if) it's 2s1p/7.4v then a LiFe/A123 (6.6v) ignition battery might be able to serve
double duty & power the remote start sytem + ign.......maybe?

IF it requires a 3s1p/12.6v battery, then we're looking at dead weight to carry around.
The system being designed based on 3S li-po with a fall back on 4S li-po. We are not looking at battery storage capacity here, our concern is only the potential different between the motor poles. Therefore a small 1300mah 4S will do the job as well as a larger capacity one.

To regulate the ignition system to 5V, it is advisable to use at least 3S. The reason is simple, li-po is known to have a single cell went dead suddenly, if this were to happen on a 2S li-po, the supply voltage to a regulator will drop below the regulated voltage i.e. 5V this will spell doom to the engine.

Umran 09-22-2011 06:31 AM

RE: RS55cc
 
And today manage to power it up.... below are the resuts using XOAR 23 x 8 prop,

Minimum idle - 1400 rpm
Peaked rpm (23 x 8 prop) - 7140rpm
Average maximum with the same prop - 6900 rpm

Re-start capability for a very warm engine - satisfactory

[youtube]http://www.youtube.com/watch?v=OOOX8-CbQFU[/youtube]


all in all, myself satisfied with the result, now will take to the air. But unfortunately it can only be done in November as this coming weekend i'll be leaving to Toulouse, France to oversee our Malaysia Airline A380 production there. And will only be back in late October.

What to do....

Super08 09-22-2011 06:42 AM

RE: RS55cc
 
No good pictures of the top end. What are you using a DLE based cylinder and piston assembly?

a1pcfixer 09-22-2011 06:58 AM

RE: RS55cc
 


ORIGINAL: Umran

The system being designed based on 3S li-po with a fall back on 4S li-po. We are not looking at battery storage capacity here, our concern is only the potential different between the motor poles. Therefore a small 1300mah 4S will do the job as well as a larger capacity one.

To regulate the ignition system to 5V, it is advisable to use at least 3S. The reason is simple, li-po is known to have a single cell went dead suddenly, if this were to happen on a 2S li-po, the supply voltage to a regulator will drop below the regulated voltage i.e. 5V this will spell doom to the engine.
You might want to steer clear of using LiPo's, not a great battery for use around gassers.
Li-Ion is much better, reliable, and safer than plain LiPo's.
LiFe/A123 batteries are considered by many as the very best of the group.

So it basically looks like you're wanting around 12 v for best torque (from the bl motor) to spin the engine over.
Such a source needs some form of BEC added to run the ignition off your start system battery, so users can eliminate the ignition battery.

I'm just looking at how excess weight (batteries) can be reduced -or- do double-duty,
and therefore reduce overall weight of your system.

Umran 09-22-2011 11:04 PM

RE: RS55cc
 


ORIGINAL: Super08

No good pictures of the top end. What are you using a DLE based cylinder and piston assembly?
The top end, at this moment for this prototype, we use the most common 55cc jug not DLE though. Perhaps later when it enter full productions, we are looking into getting it locally produced. The reason is simple, we want to cut down R&D cost...

Umran 09-22-2011 11:13 PM

RE: RS55cc
 


ORIGINAL: a1pcfixer

You might want to steer clear of using LiPo's, not a great battery for use around gassers.
Li-Ion is much better, reliable, and safer than plain LiPo's.
LiFe/A123 batteries are considered by many as the very best of the group.

So it basically looks like you're wanting around 12 v for best torque (from the bl motor) to spin the engine over.
Such a source needs some form of BEC added to run the ignition off your start system battery, so users can eliminate the ignition battery.

I'm just looking at how excess weight (batteries) can be reduced -or- do double-duty,
and therefore reduce overall weight of your system.
Yes sir, 12 to 14V. Li-Ion is very good, however it is slightly on heavy side for the amount of capacity it can carry. At this moment i'm thinking of this start system battery to act as ignition supplier as well.

Later if i can find a perfect voltage regulator (which doesn't ripple out the voltage and maintain constant output) even when the battery output is being used for ignition system which is constantly cycled between drained and stop based on engine rpm setting, then perhaps we can use only 1 battery onboard for a gasoline set-up.

At this moment i have not found it yet.

Umran 01-01-2012 11:48 AM

RE: RS55cc
 
Dear All....
Finally this engine made it to air.....

Thanks to Mr. James from Miri who is willing to install it on his brand new Katana S for further testing.

Refer below video...

[youtube]http://www.youtube.com/watch?v=8JaGG48m1co[/youtube]


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