CSM Carbsmart setup

[huskynox]

Bob, please keep us informed if you have any sensor problems, like if it fails... If you get a ton of flights out of yours we will all know that your install is the way to go with the silicone trick. Thanks!

[magicmalik19]

how do you guys actually know that your running full lean while your flying? Are you flying without a canopy and sorta trying to peak at the servo horn in a hover or something? Im guessing that the carb smart doesnt actually show the fullest lean and rich position it recorded during a flight, does it? I would think that its kinda hard to see where the servo horn is during flight.
Also, Bob at the mid position of the carbsmart, how many turns out is your needle?

[Finless]

Was there a particular reason that you shortened the link instead of readjusting the servo horn on the needle valve knob, or was it just the quicker thing to do? It seems to me that you'd no longer have parallel horn throws (assuming the radii from center to ball were the same).

I could have MOVED the arm on the mixture knob but I only need to ge a little more lean so I just shortened the link which did the SAME thing... You can do it either way my friend! They both achieve the same result.

Bob

[Finless]

Bob, please keep us informed if you have any sensor problems, like if it fails... If you get a ton of flights out of yours we will all know that your install is the way to go with the silicone trick. Thanks!

Will do! If it fails I for sure will let you know as I know you have had some issues man.... If mine does please trust that I will be honest about it! So far so good with 7 flights.

Bob

[TheBum]

I could have MOVED the arm on the mixture knob but I only need to ge a little more lean so I just shortened the link which did the SAME thing... You can do it either way my friend! They both achieve the same result.
Fair enough. It's just that you're normally such a stickler about keeping everything at 90 degrees that I was surprised you made an adjustment that was contrary to that stance.

[Finless]

Fair enough. It's just that you're normally such a stickler about keeping everything at 90 degrees that I was surprised you made an adjustment that was contrary to that stance.

Well that is a good point! But because I adjusted the servo travel for the Carb Smart and lowered the throw, I felt this simple adjustment was all that was needed. But YES... if you want it right and 90, then move the arm on the needle valve. :)

Bob

[TheBum]

how do you guys actually know that your running full lean while your flying? Are you flying without a canopy and sorta trying to peak at the servo horn in a hover or something? Im guessing that the carb smart doesnt actually show the fullest lean and rich position it recorded during a flight, does it? I would think that its kinda hard to see where the servo horn is during flight.
That's a very good question and I haven't seen an answer yet. I'm assuming you could see the position of the horn on the needle knob while in a hover or immediately after landing, while still idling.

[magicmalik19]

yea I would like to know.. even if you looked at it while idling, the engine would have enough time to cool down some while you walk to it and get a chance to look. Im sure the carbsmart reacts pretty quickly to temp changes so i doubt you would be able to see where the needle was before you landed. Im just curious how you guys are coming to the conclusion that its flying full lean the entire time and that you need to add more travel.

[lakespinner2]

It is a little hard to see it moving in flight unless you're comfortable flying it very hard and very close (which I'm not). :P

One thing I tried that works pretty well is to take a bright yellow zip tie (tiewrap), cut it in half and fasten it to the carb needle (with string and tape) and let it stick down below the edge of the canopy. It will read kinda backwards since it's sticking down instead of up like the needle horn. But, it does let you see it moving at much further distances.

It's not an elegant way to see it moving but it works pretty well.

[Finless]

I land quickly and look where it is. It doesnt change all that fast at 50% gain.

Bob

[KORN]

QUOTE "One thing I tried that works pretty well is to take a bright yellow zip tie (tiewrap), cut it in half and fasten it to the carb needle (with string and tape) and let it stick down below the edge of the canopy. It will read kinda backwards since it's sticking down instead of up like the needle horn. But, it does let you see it moving at much further distances."

Sort of like this wiretie pointer and rich/lean marks on my Bergen...the little metal JR wire ties work good also and just bolt on the carbsmart arm

[skigolfmike]

I think CarbSmart is pretty neat. If/When I get a nitro heli, I'll definitely have that on my short list of accessories.

I've got a ton of 2 cycle tuning experience with models and racing karts. My only concern is starting up lean. All the 2 cycle engines I've tuned need to be rich when they are cold and lean when they are hot. (To a point - too lean is always bad.) I can tell you from experience it's very easy to cold stick a kart engine because it's too lean. Other than that, once the engine is running and is up to temp, IMHO, the CarbSmart is a good thing.

From my experience, the ideal way to do this is to measure cylinder head temperature (CHT) and exhaust gas temperature (EGT). OTOH, a system like that would be pretty complex and would probably be overkill. Anyone here know what it means when the CHT goes up and the EGT is going down. What about when the CHT goes down and the EGT goes up.

[montarok]

Thanks Bob, for all the info and especially the videos, they made things a lot easier for a guy like me that has no patience. This hobby is fun because of guys like you.

[TheBum]

Bob: Were you able to install the sensor with the engine still in the heli or did you pull the engine to install it?

I'm trying to decide if having the engine still in the heli would likely hinder my sensor installation. I hate the job of pulling and reinstalling the engine, so if I can avoid it, I'd be quite happy.

[Finless]

I installed it while still in the heli. Did you watch my video? I show where I installed it on the bottom of the heli. You want to use a good cleaner to get the head clean. I used a spray can of brake cleaner.

Bob

[TheBum]

I installed it while still in the heli. Did you watch my video? I show where I installed it on the bottom of the heli. You want to use a good cleaner to get the head clean. I used a spray can of brake cleaner.
Yeah, I watched it and maybe I just missed where you said you left the engine in the heli while installing the sensor. The sensor was already installed in the video, although the RTV was stick tacky.

I've never used brake cleaner, but I assume it has degreasing agents in it and has a "straw" to get into the gaps. I'll look for some the next time I'm out and about.

[snappa]

left the arm off as I wanted to see how it would react first however I have one query about the needle, on my older motor (tt50pro) I noticed the needle with the "clicker" removed had quite alot of slop? on the redline 53 I havent removed the clicker yet but do you really need to remove it? it seems to provide a sort of preload on the needle stopping it from moving surley a servo would be ok puching through the clicker? I did read elsewhere someone who put some heatshrink in the slot for the o ring to tighten it up a little I dont know how much slop the redline will have but could you end up with vibration damaging the seal or needle?

[Finless]

Leaving the clicker on made it so my servo worked TOO HARD trying to run in between clicks! It had no purpose with a servo controlling it.

Bob

[snappa]

thanks Bob I will remove mine next time I get near the garage.....

[snappa]

A nice feature for this would be to see what the max lean and max rich settings would be when you finish? could be done with software ie first the arm moves to max lean then max rich? what would be the thought on having the sensor in the exaust gas ? more accurate or not needed

[forjer]

A nice feature for this would be to see what the max lean and max rich settings would be when you finish? could be done with software ie first the arm moves to max lean then max rich? what would be the thought on having the sensor in the exaust gas ? more accurate or not needed
I was thinking the same thing. I've got an eLogger that can monitor servo position. I'm wondering if I'll be able to calibrate the logger properly...should be able to. One of these days I'll give it a try.

[snappa]

let us know if you do it

[forjer]

This weekend while installing an RPM sensor, I decided to try capturing the Carb Smart mixture servo's position with the eLogger. Unsure if I could properly calibrate the eLogger, if the eLogger would even see the servo, or if plugging into the C.S.'s circuit would just freak out the C.S., I figured, "What's the worst that could happen?".

Well, the heli flew fine and the servo seemed to be moving, so all seemed well...until I got home and downloaded the data.

The first image shows the first flight. Not so great. Temp on the right (lighter line) and servo position on the right (darker line). It appeared that the servo's position didn't get logged correctly. Just a few spikes here and there while the temp leisurely wandered up to about 200 deg F.

The second flight (which I didn't upload) showed the same.

But...the third flight's graph is different! There you can see two distinct spikes in each curve. When the temp started to rise above a certain point, the C.S. servo started richening (down on the graph).

The fourth flight's graph has one additional spike.

So...why only two or three spikes on the last two flights and none in the first two flights? Well, I flew harder on the last two flights...not uber hard, but harder sport with some light pumping thrown in. As the temp climbs to around 206 deg F the servo starts richening the needle and it stops the temp from rising above what the C.S. was set at...212 deg F (100 deg C)! If you look at the max temp on each of the last two flights, you'll see 211.5 and 211.0 deg F respectively. By the way...the C.S.'s gain is at 50%.

Pretty damn impressive. Way to go CSM!

Looks like I can afford to go leaner. Next time out I'll lean 'er out a bit so I can get some more needle movement action and also get the temp to rise up earlier in the flight.

[livinma1]

Is this the same stuff. http://www.radioshack.com/search/index.jsp?kwCatId=&kw=arctic%20silver%205&origkw=arctic%20silver%205&sr=1

I would prefer to pick it up locally today so I can install my carbsmart but if not I will just order from Grand Rc.

[Animal]

Is this the same stuff. http://www.radioshack.com/search/index.jsp?kwCatId=&kw=arctic%20silver%205&origkw=arctic%20silver%205&sr=1

I would prefer to pick it up locally today so I can install my carbsmart but if not I will just order from Grand Rc.

No its not,, the carb smart uses the two part epoxy that grand r/c is selling. the arctic silver that radio shack is selling is only a paste, for thermal conductivity between your computer processor, and the heat sink.