yl5295

My Feedback: (1)

OK "Twin-Sync" it is... some one want to volunteer some snazzy graphics for it now?

on 4 engines. The right way to do it is one unit for the left/righ inboard engines and one for left and right outboards. Do not hook up a third device behind the two that are connected. It will cause all kind of timing and oscillation problems. If a third unit is connected the servos are going to be constantly moving because the third unit changing the throttles trying to sync the inboards to outboards will be intrepted as throttle stick changes to the two units diretly connected to the engines. This is gaoing to cause them to move the throttle and start the sync process again. It may work but I don't think so. There are two options if I were to build a 4 engine controller.

Option 1: add a high speed communication link to connect two controllers together.
Option 2: design a new PCB with two ICs on it with the communication link on board.

I looked at it again and I don't have enough blocks in the gatearray to handle more than two engines. Although it doesn't really matter because I have decided I am not going to build a three or four engine sync unit. (untill some one or a group of people donate a B-17 to me - then I will do it. I may consider other scale airplanes but no way would I do it for a bashed ugly stick with (4) OS 15LAs if you get my drift).

fockewulf37

My Feedback: (102)

I would not want one for four engines. I would only do it like above, outboard and inboard. It crazy to try to sync all four. I could see you flying along on a low pass. you loose one engine and all four throttle back. Then a sudden gravity pocket......crash!!!!



Ty

twinman

My Feedback: (2)

So...uh...This is out too??
Tee Hee.
Is a B-17 with a TURBINE engine.
How about a five engine Kadet??
Twinsanity at it's finest!!
Twinman

yl5295

My Feedback: (1)

Guys,

I spent a good bit of the day today testing and working on this and I ran into a potential minor issue. You can not fast charge a remote glow battery while it is connected to the sync units remote glow driver. (i.e. I smoked one today). Do the typical onboard remote glow units allow fast charging of the single cell nicad/nimh battey while installed? I know what I blew and why but the question is the following:

The unit could be damaged by connecting a peak charger to the on board glow driver without disconnecting it from the sync. So my options are the following:

1. Spec this as a warning and deal with and return/warranty issues from people who don't read (I would probably fall into this class myself)
2. Delay release and redesign to handle a peak charger on the remote glow battery while connected to the sync.
3. Delay release and redesign with a built in charger for the glow driver battery
4. Eliminate remote glow from the first production release units - I hate this option but it sounds like a pain for the user and me (tech support if people kill units trying to charge onboard glow batteries while connected.

The problem is peak chargers put out a lot of voltage to get their target current. These high voltages are tough on new semiconductors that run on very low voltages and currents. So not that there was a problem with the unit but just this is a use case that could cause problems for me and users.

YL5295....

v22

My Feedback: (8)

Some guys just have way to much time on their hands... That is just awsome twinman... the only thing that would be more awsome is to actually have the center engine turbo prop like the real one was ( well I assume it is the middle one in the nose that is turbo)[&:]
Can you give us more information on the real thing ????
Larry

jfail1

My Feedback: (2)

How much will it raise the price if you go with number 3 (add a charger on board)? I can't remember what the specs on the on-board charger would be (a single sub-c, 4/5 cell pack) etc. It would seem to me that number 3 would be the best option to cut down the tech support/defective unit/replacement issues. I have no problem waiting for mine although I already use Maxx products on-board glow drivers on my inverted engines but no glow driver is needed on any of my twins in that they are all right side up or on their side (for now anyway). So I do not need the glow driver on the sync boards.

Parkerm

My Feedback: (6)

Reminds me of a program I once wrote in basic. Tested it for three weeks and it worked perfectly. I put it in front of the first potential user and he crashed it in 3 keystrokes. Just hang on everybody...these things take a little time to work out.

roltech

I would go with option 3 even if it would cost more and delay release. MHOP.

roltech

William Robison

My Feedback: (3)

I don't see it as a problem. Put a current limiting resistor on the connector for the glow battery, and a zener on the sync unit end of the limiting resistor. Select the zener for whatever voltage you decide for the battery, both components could be added to the board by cutting one trace. Simple and quick, a little safety for people too lazy to disconnect the battery for charging.

Of course the caution about charging in place should be included also.

Bill.

William Robison

My Feedback: (3)

Gentlemen:

Apologies to all, I had thought to be able to run the “TwinSync” today (Sunday) but fate, nature, and procrastination all took their toll.

My C-3/10v is the designated “Hurry-up” test bed, as it already has Hall effect sensors mounted from the Jomar sync unit. They do not have the same JEDEC number as the ones supplied by BillW, and digging them out will be a major operation. They did pass all the electrical tests that BillW suggested, but I’d rather wait until he checks the data sheets to be absolutely sure.

I didn’t even get to run the engines without the sync unit. Been five years since that particular plane was out to fly, and one of the pumps was stuck. By the time I got it working again it was too late to make the engine noises here.

So why didn’t I use a different plane? I’m certainly not going to use it on a Twin Stick, and putting it on my Twin Star would be a waste. The Cessna Bobcat is such that even getting to the throttle servos requires surgery, and running the sensor wires would too. So how about a Duellist 2/40? Mine are all set up mostly the same way, differing only in one having air operated gear, the next one is mechanical, and so forth. I’d have to rearrange the servos (new push rods etc.) as well as fishing the wires through the wings.

So. The TwinSync will either go on the C-3/10 when I get the word, or I may stick my one remaining Jomar unit in the C-3/10 for comparison and just put the TwinSync in the TW60 that is tracked to arrive tomorrow, Monday.

And, believe it or not, I have another 81” span twin due to arrive Wednesday. It definitely will NOT be ready for Multis over McDonough. I’ll probably take it along to show it off, but definitely not to fly.

Bill.

twinman

My Feedback: (2)

Hi v22 (Larry),
Sorry to the sync unit. If we need to continue the turbine conversion I will move to another post set and not interfer with the twin-sync project,,,but as long as you asked...Go to http://www.ww2forums.com/cgi-bin/ubb...;f=15;t=000952
for all the data on the five engine B-17. There were three built..before mine!! Tee Hee.
A real turbine??? Uh..no.
twinman

fockewulf37

My Feedback: (102)

I would drop the remote glow all together. The main thing is to have the Sync system. You can always add a remote glow as a stand alone system. I think the glow part is trying to add too many bells and whistles to a sound sync system. On all my glow engines I run constant glow power to the glow plug.
I did this to my 3 engine Savoia and did not have an engine out for 2 years of flying it. You can get up to 42 minutes of constant glow out of a AA nicad. So i use one per engine and with a simple switch to turn it on. My pic show a C-size battery but I have gone to a AA...

Ty

v22

My Feedback: (8)

Thanks twinman

yl5295

My Feedback: (1)

I think I have a solution to the charging problem. I thought of it this morning and logged on to update every one and I see William Robinson thought of the same thing. Thanks William...

I just need to make sure I can fit it onto the PCB now with no major changes. If so should not result in any delays.

yl5295

My Feedback: (1)

It fits. Just need to test it now.

twinman

My Feedback: (2)

Thanks for the drawing landrel t brown, but I would vote the keep the glow system if possible for increased reliability.
One thing on the onboard glow system, which is immune on the constant on proposed by landrel t brown. If other modelers use this and a micro switch, put a capacitor across the switch connection or you could very strongly could, get a glitch in the reciever as the system goes on an off.
Probably not an issue with electronic controls.
Twinman

William Robison

My Feedback: (3)

All:

The unswitched glow driver has many advantages that are often overlooked. The most basic is its self regulation.

We have all seen the meter on our glow driver showing three to four amps draw by the glow plug. With a four amp draw a 1000 mah AA cell would be dead in 15 minutes at most, yet they usually last for a full day’s flying. Ty Brown just said he got at least 42 minutes from a AA cell. How can this be?

Well, as some of us know and others will now learn, resistance goes up with temperature. Cranking the engine. With the battery as the only source of heat for the plug, you do have that 3-4 amps drain. Once the engine starts you also have the heat of combustion and the catalytic action of the fuel heating the element, less electric power is needed to keep the plug hot. At idle the current will drop to about ½ amp, and at high throttle the current drops to a few milliamps.

As I said, self regulating. The “Intelligent” glow drivers use this resistance change to sense when to turn the glow heat on, charging you $30+ to do what the plug will do all by itself.

Bill.

fockewulf37

My Feedback: (102)

The way I tested the 2000 AA battery is: I fully charged the battery. I hook the battery directly to the glow plug via 4-5" wires. The glow plug would stay bright red to semi red for about 42 minutes on adverage. I found no difference with the C sixe rechargable 2000 MAH battery.
This was not in a engine... I am not up on all the electronics but it works for me....

Ty

yl5295

My Feedback: (1)

Remote glow is back in and I don't see any issues at this point. If someone wants to post pictures for me I will email them to you of the final production unit (minus labels and wrong color - i.e. boards I have now don't have silk screen and solder mask). One going to Twinman tomorrow if I can get it to him before M-o-M.

William Robison

My Feedback: (3)

Okay folks, here are two pictures of the (current) production device, shown with the prototype for comparison.

First picture is the prototype. At the bottom left is the programming switch, with the buttons above it. Then the four LEDs, two resistor arrays (the blue and yellow lines), the ECU, and at the right top are the connectors with the voltage regulator for the ECU just below. At the bottom right are several traces with nothing in them, and a row of solder points along the right side,

Please note all comments are based on what I see, BillW sent only the pictures.

Next is the CU of the production unit. You can see the push buttons have been moved to the top left, the four LEDs have been replaced with LED arrays. BillW didn’t say so I don’t know if there are still four, or maybe as many as ten. That would be four in the orange one, four in the green one, and a double red between. The bottom right part now has more components added, I assume this is the glow control section.

Finally, an overview of the system board and the supplied wiring. Two cables are supplied, for connecting to the rx throttle and auxiliary channels, the two “Plugs” on the cords at the top are not plugs, they are the Hall effect sensors for the rpm input all made up and ready for you. I don’t know if this is good or bad, as you know, prefabricated cables are always too short or way too long. Futaba “J” extensions can be used, but I prefer soldering an added length of wire if needed.

Whether they are too short or too long, I like having them made up instead of getting two Hall effect sensors loose and a hank of wire as EMS/Jomar supplied theirs. If you weren’t relatively skilled at soldering on a PC board the Jomar was a guaranteed failure, BillW has spared us this.

Thanks, BillW.

Bill.

>>EDIT: Had to load pictures separately. wr.

yl5295

My Feedback: (1)

Bill,

Thanks for posting the pictures. I tried and couldn't. Now to explain in a little more detail what you are looking at but William pretty much got most things right.

The two pictures with the cables attached is a sample production unit minus silkscreen and solder mask (i.e. actual production units will be green (to protect circuit) with writing on them labeling things. Dimensions are about 1.6" x 1.9" x 1/4" (connectors stick up a little more than 1/4"). Weight much less than 1oz. (I can weight anything this small)

The production unit has 5 leds with a connector for a 6th on a tether (optional remote LED indicator for glow plugs so device does not have to be visible). The five LEDs are: two Green to indicate magnet infront of hall effect sensor for each engine. two yellow LEDs one for Engines being synced and the other for verifying correct throttle direction and adjustment of end points/expo for sync point. Two wires coming off to the side with no ends are the glow drivers (3 wires each. Battery +, Battery -, and plug tip - engine case also goes to battery -).

William had a good point on the wire length what length do you want. I am placing the order now for these out of asia. I was going to get 12" on the male-male connectors that go from sync to receiver and 20" on the hall effet sensors. You can alway use a standard aileron extension on any of these to make them longer.

I can have the devices shrink wrapped as well. This will require returning them for software updates rather than swapping the IC. I am currently not planning on shrink wrap.

I may try to get a video of one in operation today or Friday.

gsmith6879

My Feedback: (37)

I plan to install one of the first production units on my F83 twin to give the system a good test before mounting in my big Bronco. The F83 has 2 24.5 cc conversion engines with CH ignition system installed. I used 1/8" rare earth magnets from Radio Shack JB Welded into the prop shaft to trigger the ignition system.

Can I install the TwinSync Hall effect sensors to use the exsisting magnets? I know there is a positive/negative side and they will not work on the CH system if installed incorrectly.

William Robison

My Feedback: (3)

GS:

The sensors are also polarized. the N pole will trigger one side, the S pole of the magnet will trigger the other.

Connect both sensors to the sync unit, and plug a battery pack into any of the other connectors. Wave the sensors by the magnets you have installed. If you have the sensors turned the right way the yellow LEDs will switch on. If no light, turn the sensor over and try the other side - one way or the other will work. Just remember which way to install them. I go by "Flat" side and "Tapered" side. Or you can just look at the numbers on the sensor. They're on the tapered side - see the angled corners?

Bill.

gsmith6879

My Feedback: (37)

Bill,

Great. Thanks for the information. The TwinSync is getting more user friendly the more I learn about it. I can't wait to get my hands on the system.

Gaines

William Robison

My Feedback: (3)

Gaines:

That was just one of the nasties with the Jomar unit, and the yellow LEDs are one of the really great things about this one.

The Jomar told you how to put the sensors in, and the magnets were marked. But. If it didn't work, or stopped working you had no way to check anything unless you had a DVM and knew where to check for what voltages.

Bill.