yl5295

My Feedback: (1)

There are a couple of other things about the near future that I thought I would let people know:

1. There will be a price increase coming after RC Showcase sells out of their inital inventory at the "Introductory" price. This is my doing and not theirs. Pricing will increase to at least $99 and maybe more for the TwinSync with glow drivers. I expect to continue to offer a TwinSync without glow drivers for the $89 price.

So the good news for people getting one of the early units and having to deal with software updates is the lower price...

2. I will be coming out with a remote display that will work on the current twin sync with a return to the "factory" (my basement). It will have a four digit LED readout that will display engine rpm (alternating between each engine) and will have the six leds on it. It will be design to mount in your cockpit dash board.

It will probably sell for about $39 and will require your unit to be returned to add the remote display. The display will be connected to the TwinSync via the two pin connector that is currently for the remote glow LED and will have a second connector that you need to attach a servo connector to for power. I can see adding indepenant plug control to devices with the remote display since they will have two RED leds for glow plug status.

William Robison

My Feedback: (3)

BillW:

I still say the timer is redundant. From your email you said the glow routine runs once per second. With one engine running less than 3500 rpm the plug will be heated in the dead engine, switched on every time through the routine. All the timer does is duplicate the switching already being done.

Remote rpm and status display? Needless bells and whistles, in my opinion. Why should we want an rpm display except to impress onlookers? The engines are in sync or not, your ear will give you that status. Remote mounting of all five (or six, with dual glow display) is more than sufficient, and could be done at near to zero cost by using a ribbon cable and a small PC board.

Bill.

yl5295

My Feedback: (1)

I am not disagreeing with you but I have to build a remote intelligent display for another upcoming product anyway. So why not offer it to twinsync owners as well. Anything besides a two wire interface will require the PCB to be redesigned and will not work with the currently shipping devices. That is why it is an option and not included with the Twinsync. Besides I ordered 200 PCBs and those have to sell before I even consider a new PCB design.

The 30 second timer is for guys who don't use an electric starter. They would have to constantly be flipping the prop at > 1 revo/sec to keep the plugs hot without a timer. I could reduce the timer to 5-10 sec which 2 rev/sec every 5-10 seconds would be easier for a guy to do without an electric starter.

Kmot

My Feedback: (24)

How about a glow driver and I can switch on and just leave on all the time if I feel like it?

roltech

I don't know about 2 stroke in twins my own opinion I think that most twin would run 4 strokes, even if it 's just for how they sound.

roltech

yl5295

My Feedback: (1)

That is already there. Mode 5 is a switch/AUX channel controlled glow driver. The aux channel switch turns it on and off.

William Robison

My Feedback: (3)

Rol:

I don't know for sure, but I'd suspect there are far more two stroke twins than four stroke powered. Of all mine, only one has four stroke engines. I am putting another together now, when it's finished I'll have seven (I think) two stroke, and two with four stroke engines.

TomK:

One mode in the TwinSync is already set to allow tx conttol of the glow heat.

Bill.

roltech

You probably right! I'm putting together a B 25 and will install 2 - 4 stroke RCV 91 CD mostly for more realistic sound. If anyone think I should not I would like to know why. Every thing I will install in this model will be first class, after all it cost enough in the first place,and I want to do it right.

roltech

pc55bomber

Hi Bill
To sum up the software upgrade in relation to the glow plug driver:

Engine running --Glow on both plugs if RPM <3500
Starting -- Rock prop to start glow, Engines not started 30 sec timeout turns glow off.
Engines running -- RPM <3500 glow on until RPM >3500 (does the timer kick in here?)

Is my summary correct?

I cant see the point in having independant glow sensing when in practice if you loose an engine
you will want to land as soon as possible so the drain on the glow battery is not important.

From a practical viewpoint IMO there is no need to go any further with the device its great.


Cheers
Paul

William Robison

My Feedback: (3)

Rol:

The first and most important consideration in selecting engines for a twin is reliability.

To me reliability is Saito, K&B, and Magnum. I have only one twin with another brand, that one has the Russian AMD 0.061 engines, none of the others were small enough.

The latest plane I’m putting together was supposed to get the K&B ringed 61 engines, but when I started to fit them the amount of wood that had to be removed changed my mind. Tried a Saito FA-72, looked great, so I ordered a new pair of FA-82 engines for it.

The K&B engines were (and are) ready for installation, the new Saitos mean a fair delay getting them run in and set as well as a goodly chunk of added money. But I think the result will be worth the expense and delay. I’ll use the K&B engines in the Super Duellist and the new Tigercat. They will both accept the two stroke engines without a lot of cutting. And I have a pot full of the K&B engines.

So what I’m saying is this plane was intended to be a two stroke also, just the nacelle design made me change my mind and go with four stroke engines.

I think the pictures will illustrate my point here.

Bill.

yl5295

My Feedback: (1)

Roltech,

in response to post #301... I guess it depends on scale flyers versus sport/speed loving flyers. I personally would not build a twin with four stokes because the sound of synced screaming 2 strokes is why I build twins. I would build a gas powered twin though for many reasons.

I have twin engine combat planes and eveyone at the field thinks they are very fast (many estimate about 90MPH). They are 2548 legal and are not fast- 17.5K rpm on an 8x3 prop puts them at probably 60mph is my guess. The only thing that turns more heads than a low flyby with twin two stokes in sync is a turbine. I often take my twin engine combat planes sport flying - just because I like the way they sound.

I think I probably have an example of every other single engine flying model available like big gas 3D aerobats with smoke, WWI and WWII scale planes, pattern, Q500, helis, turbine jet, etc., etc. Twins excite people including the pilot when they scream by in sync. But that is hard to do and many have really nasty habits when one dies. (I spent hours getting a P-38 out of a tree one time) that is why I sunk the time into this device even though I have higher volume, more profitable, and easier products that I could have introduced first.

I am building a scale twin now and I may eventually go to 4-strokes for it but they are 2X the price. I saw a piped duelist fly once and it seemed like the echos lasted for about 5 seconds after a highspeed pass. There are probably more scale twins out there than than anything else but I think we are getting ready for increasing populatiry of twins because of increasing reliability and arf companies trying to differentiate. I bet that it is about even now (2S/4Stroke). I predict in a year there will be 2X-4X more 2 stroke twins than 4stoke twins flying. Gas twins will always dominate scale events.

Just my opinion.... At my field the crowd argued whether I should put 2-stokes or 4-stokes in the Cessna 310 I am building and it was about 3:1 in favor of the 2-stokes because of the sound. The guys that wanted 4-stokes were the full scale pilots.

yl5295

My Feedback: (1)

In response to PC55 post #305...

Great question... I actually had to look at the code to answer it...

The timer kicks in every time the plugs are turned on. The plugs are only turned off by both engines going to >3500 RPM or 30 seconds later and both engines engines are not running yet.

So now I realize that I was thinking when I wrote this code. In the event of a dead stick the plugs will come on but will go off after the timer expires in 30 seconds.

I think I like this plan/software right now... very simple and easy to use.

The other thing that I saw when looking through the software tonight that I thought I should point out is that the plugs will never turn on if a TX signal is not present. So no worries about turning over the props with handling unless you have a PCM receiver. Then you can turn plugs on if the RX is powered and failsafes are set.

Bill

Kmot

My Feedback: (24)

Good enough for me. Thanks fella's!

Jim Reeves

Silly question here ...what if my receiver has not got an aux socket, where do I put that plug..

Thanks

Jim

William Robison

My Feedback: (3)

Jim:

"AUX" channel just means any channel not used for the primary flight controls. If you’re using AUX for the glow control as an example, channel five which is usually retracts can have its on-off switch used. If your transmitter has a three position flap witch, that could be used for the independent engine run up, and so forth.

Bill.

Jim Reeves

Many thanks Bill, retract switch it is, I'll be using the proportional flap control.........for flaps!!

Thanks

Jim

roltech

One of the reason of choosing the RCV CD .91 is that other than the muffler there is no cutting on the cowl for the motor
hence CD stands for Compact Design.This motor was recommemded by the MFG of the B 25 . but after reading the post I will give it a good thought about what I will install.
Thanks guys.
roltech

drifter

My Feedback: (53)

Bill,
Here is a situation I have not seen a comment on.
I have an OV-10 Bronco fitted with two receivers, one in each boom. Each engine servo is connected to the throttle channel on it's respective receiver. Both are on the same frequency. Will the Twin sync function with each engine controlled by the throttle function on each receiver, or do I have to use an auxillary channel on one of the receivers? Since the Twin sync controls the channel plugged into it , can they both be throttle channels or must the Aux on one be used?

yl5295

My Feedback: (1)

I have not considered this mode of operation. Is the reason you have two receivers due to wiring difficultly or safety?

If it is safety then having two throttle signals going to the twinsync will not make it "safer". The throttle signals should be the same. If they are not something is wrong? What should you do if something is wrong? Well you want the engines matched. The worst thing you could do is idle one and have the other at full power. The best thing to do probably is to idle or kill both engines. The device will do that now with only one throttle input if it is an FM recevier and it looses throttle signal.

If it is a problem of running wires there is no way arround having to run a wire between booms regardless of the design of a syncronizer because both booms have to know the RPM of the other boom to sync the engines. So there has to be at least one or more wires between the booms.

I guess I don't see a reason to run two throttle signals to the device? Control surfaces I understand how dual receivers add safety and simplify wiring. (actually interference is more likely with two receivers than one). But for throttles on a twin seems to me like one is better or at least as good?

Am I missing something here?

drifter

My Feedback: (53)

I run two receivers because of the numerous connections that must be made otherwise. Each is independant with it's own battery and switch. Each controls 2 flaps 1 aileron 1 rudder 1 elevator 1 throttle 1 onboard glow and either nose gear steering or the retract servo. Interference has not been a problem (yet).

I know there has to be a connection from both engines to the twin sync. My only question was whether that signal must come from a throttle and Aux channel, or if the throttle channels on both receivers could be used. As I understand it the Twinsync senses the info from the respective sensors and sends a corrective command if needed to one output or the other. Does that output signal have to go to a throttle and Aux channel or can it go to two throttle channels if they are on different receivers? Since it is the twinsync sending the signal and not the transmitter does it matter?

My explanation is probably cam (clear as mud).

yl5295

My Feedback: (1)

OK I think I understand.

You don't need to connect two throttle connections and there is no reason to do so and actually you shouldn't. The reason is if you connected throttles from each receiver you are effectively connecting the two RX batteries in parallel together (a no-no with NiCads and NiMh batteries).

The correct way to do what you want to do is to run a servo wire and a sensor wire from one boom to the boom with the twin sync. The servo in the boom without the twin sync will be driven by and powered by the other side and and driven by the twinsync receiving signal from receiver that it shares a boom with. This is the best solution. Aux channel is optionally connected depending on the mode you put the device in.

I still can't think of a reason to connect two throttle connections to the twin sync and actually see a couple of problems in doing so.

yl5295

My Feedback: (1)

Guys,

Just an update on how things are going with the first units out the door. There is an osillation or "hunting" for the sync point that is due to a "software bug". I found the problem and am shipping about about a dozen replacement ICs or units to the people that I have been talking to and trading emails with the last week or two or who have returned their device or IC.

EVERYONE NEEDS a software update regardless of the type of engine and servos you have...

A couple of people have flown with it and have noticed a little tail wagging because of the "hunting" for sync. DON'T fly with it at this point without an update. Send the IC or complete unit back to me and let me get you a new one with the software working correctly. All failsafes are working but the syncronization is not working like it should due to control algorithms response time issues.

People with orders with RC Showcase... I have their units ready to ship and that they will ship to you upon arrival at RCS. I am just holding them to make sure they have the latest software with no issues at this point.

The new software that should go out tomorrow has user programmable throttle response curves although I don't recomend using them. What I am saying is... if someone does see any hunting or oscillation you can get me on the phone and we can change the response times and curves of the device without having to send in a chip or the unit for a software change.

The glow plug driver is now based on RPM rather than timers and deadstick/run/not run.

The only other reported problem was with a multiplex radio that I have not gotten to the bottom of yet. JR throttle settings need to be reversed and Futaba's need to be normal. The bottom line on radio brands is that the yellow led should be off at idle and come on a stay on at 20% to full throttle.

It feels a little painful with any new product intro but this is going to be a great thing to have on any twin engine plane once everything is how it should be... we are at 95+ % the way there... the last 5% is always the hardest...

yl5295

My Feedback: (1)

All,

I shipped out a bunch of ICs yesterday (and a few replacement units) with the new software. So I thought I should post instructions on installing the new ICs before people start receiving them the next day or two. Below are the instructions.

As per the picture below install the IC with the notch (half round indention on one of the short sides with no pins) toward the top of the board. The top side of the board is the side facing up when the connectors are on the right hand side and the buttons are on the left hand side.

To install the IC make sure all of the pins are in the corresponding hole and push the IC down into the socket. This is easiest with the device laying flat on a bench. Check afterwards that all pins went into the holes and none of them bent and did not go into the hole.

I will try to get updated instruction guide out today.

yl5295

My Feedback: (1)

GUYS,

If you are sending just ICs back to me, stick them in STYROFOAM at least 1/4" thick -- NOT FOAM RUBBER. I am getting some back in foam rubber or very think styrofoam with the legs all bent up. I straighten them out before returning them but if you bend them and straighten them a few times they will break off and then you will have to buy another IC.

eagledancer

does anyone have a ETA of the backordered units from showtime?