All Day Dan

My Feedback: (5)

Thanks for the reply. It does make sense that a significant amount of the testing would be performed with an electric system because of the convenience. I have two Astroflight brushed marine 25s installed in a Dumas 48 inch PT boat. The motors are counter rotating and each one is run separately by an Astroflight 408D reversible speed control and its own 14 cell nickel cadmium battery pack. They are turning at about 8000RPM according to my calculation. The controls are connected in parallel to the throttle channel. They are not necessarily synched as each motor and controller are slightly different. When they get out of synch, the boat runs tilted to one side and digs in on the same side during a turn. I’ve uploaded a couple of images to show you the installation. From what I have read, the Twinsync should help. Do you see any problem with the counter rotation?

Dan Reiss

yl5295

My Feedback: (1)

No problem with counter rotation. RPM limit of the Twinsync is about 23,000. So as long as you stay below that you are fine. Exceed 23,000 and it declares deadstick (idles both). With electrics you can speed up the response time quite a bit for instant sync but you can here a little oscillating.

All Day Dan

My Feedback: (5)

Just what I wanted to hear. Thanks a lot. Dan Reiss

Mac Hodges

Bill,

Help me out....installing a new unit in a Cessna 310 with G26EIs. In hooking things up initially, LED 5 has a green glow that brightens when the sensor is passed by the magnet but the light never goes completely out. LED 6 is not lit at all and goes green only when the sensor passes the magnet and this, I assume, is as it should be. What's causing this with LED 5 and is it a problem? Also, any tips for mounting the sensor to read the ignition magnet on the rear of the G26?

Thanks, Mac Hodges

yl5295

My Feedback: (1)

You've got enough going on that it is probably best that we speak by phone when you are at the unit. I have a few simple tests I want you to run (see if the problem follows the sensor). I have only had 1 out of 1000 sensors turn out to be bad so far and it was because the cable company reversed the red and black wire in the male connector. So I want to get to the bottom of this problem.

All Day Dan

My Feedback: (5)

I got the Twinsynch but it did not include the 1/8" X 1/4" diametric magnets. They would adapt to my installation a little easier. Thanks. Dan Reiss

yl5295

My Feedback: (1)

That is correct. They are sold seperately for $2.50 a pair. email me at [email protected] and I can get you some or you can get them from RCShowcase.

Mac Hodges

Bill,

Reversed the component and all is well. LED 5 is off and comes on as it should when the sensor passes the magnet. Thanks for taking the time to help me.

Mac Hodges

All Day Dan

My Feedback: (5)

I figured out the rcshowcase website and got a pair of the magnets on order. Thanks, Dan.

Mac Hodges

Bill,

Got everything working. Really maintains the rpm between the two engines when moving the throttle slowly up and back. Move the throttle a little faster and it seemed a little slow to syn the G-26s. Went up one step and then another......I'm at the LED 1 and 2 on, LED3 off, LED 4 on now. Seems better, still no oscillating. Thought I would try next step even thought directions indicate my setup shouldn't require that. Any thoughts?
I have all my nine channels in use so don't have a channel for the Aux. connector. I would like to try the Sync Defeat mode. I have Aux 4 turning on a landing light. Could I use a Y on this channel and turn the light on and that would also turn the twinsync off at the same time?
When doing a loop and throttling back to say, half throttle, on the downhill side it seems the engines are going to nearly idle. I assume the unit is reading rpms that are spooled up by the dive and cutting power to maintain the rpm?

Mac

All Day Dan

My Feedback: (5)

One more question. Should I inhibit the BEC from the two Astroflight 408D reversible speed controls before I connect them to the Twinsync? I can do that by removing the red, plus, wire. I'm not too sure what the voltage is since I use a separate battery pack for the receiver. Thanks again, Dan.

yl5295

My Feedback: (1)

Mac,

There is no problem with you increasing the response time. What will happen as you make it faster and faster is you will see the throttle arms moving back and forth arround the "sync position". The faster you go the more the arms move. It tends to blend the RPMs together so that you might not be able to hear the osciallation (because that depends on the response time of the engine) but you can see it if looking at the throttle servo or throttle arm.

Another important thing to remeber is that when you are testing response time settings you need to test it at several different throttle positions. The Walbro carb is very sensitive from high idle to just above half throttle (this is why they are so difficult to sync mechanically or with curves). I also hear that pop-off pressure settings have a ton to do with mid throttle response. So just be sure to try it out throughout the throttle range after changing response time - since the engine response time and rpm change per 1 degree throttle servo movement is different through out the throttle range. (not to give away any secrets but the response time of the twinsync is different based RPM/stick position).

As for a "Y" cable. Yes you could use a "Y" cable off any channel. However, it seems to me that you would want the TwinSync turned on during approach and landing. I guess you could turn on the landing light once on the ground?

As for RPMs during a loop.... Let me explain how the twinsync works and then maybe we can figure it out. When you move the stick the Twinsync disengages and moves both servos to the new stick position and then after giving the servos enough time to move there (assumes about 0.3sec/60 deg) it starts the sync process. The sync process speeds up one and slows dow the other equally until they are synchronized.

So I would actually expect the reverse... A good test would be to put it in a dive and throttle back to mid stick. I would expect the RPM to be higher in a dive at mid stick than in level flight at mid stick. The reason is because it is easier to speed up and engine in a dive than it is to slow it down. So if left throttle servo pulls back 1 degree and right throttle servo increases 1 degree I would expect more of an increase on the right than decress on the left in a dive compared with level flight.

Play with it in a dive compared with level flight and let me know.

yl5295

My Feedback: (1)

All,

You may have seen that above a Problem was found (by Mac) with a component being placed on a Twinsync backwards. We have identified root cause of the problem with the assembly contractor and identified 21 twinsyncs that were shipped that may have had this problem. All inventory now will not have this problem and shipments after today are fine. We know who these 21 were shipped to and are contacting them for instructions to identify if they have the problem and how fix or replace the unit. There should not be any concern of a problem if we do not contact you today.

Thanks Mac for helping us catch this one.

yl5295

My Feedback: (1)

Dan,

The twinsync is powered by the receiver (red wire from the throttle channel). So if the receiver is on a seperate battery then you need to pull either the red wire from the throttle or red wire from the BECs. You can power it from either one.

BTW you are one of the 21 people and will be getting an email from me in a couple of hours to check something on your unit.

Kickin Chicken

Hi Bill,

Have a problem with Mode 2 -- Independent Run Up Mode --

Assign to 'G' switch - all positions moves both servos full travel

Everything else seems fine but haven't run engines yet.

Equipment
ZDZ 60's
TX - 9C Futaba
RX - 149 DP

Version 2.0 board
top/bot hookup
7 Aux1
3 Throttle
1 Servo
2 Servo
2 Senor
1 Senor

Thanks,
Charlie Evans

All Day Dan

My Feedback: (5)

You're right. One of them is in wrong. I'm using the Twinsync on electrics so I'll remove the diodes. No problem. Dan.

yl5295

My Feedback: (1)

Ah yes... My old friend the FP-149DP.

Great receiver -- but very unique in many ways (2.5V signal levels to the servos, < 20ma drive capability, and outputs all servo pulses at the same time, a very long time after reset until servo signals come out)... I have found lots of interesting things about this receiver that have required special treatment. As a mater of fact the only updates to the Twinsync the last 12 months were all because of this receiver.

The first 25 or 50 version 2.0 boards that shipped had a pull up resistor on the aux channel that was too strong for this receiver. You simply need to cut a trace on the back of the board with an exacto knife to fix it that removes this pull up. I can not post a pdf file to this forum so I will email it to you. All boards shipped since then already have this trace cut. When you get the drawing see if this trace is cut on the back of your board. If it is already cut then you have another problem. The only down side to doing this is the aux channel must be connected if it is in a mode that uses the aux channel. Otherwise it will get erroneous readings for the AUX channel.

I will email you the drawing of the cut to make.

Kickin Chicken

Hi Bill,
Cut the trace this morning, no change, everything looks the same.[sm=drowning.gif]
Have a Safe Trip, will check back next week.
Thank You Again,
Charlie

yl5295

My Feedback: (1)

The next step is to verify the mode the unit is in by powering it up in position 6 and compare it to the manual. If you have done this feel free call me this weekend since I am back in thr country now.

jbwilhelmi

My Feedback: (1)

What is the physical size of the circuit board with mounting holes? Am laying out radio installation and need to leave room.
Thanks

yl5295

My Feedback: (1)

board is about 1.7" x 2.1". Hole dimensions are 1.375" x 1.8" to centers.

Kickin Chicken

Hi Bill,

Hope you had a good trip, reason for being AWOL [sm=52_52.gif]for the last few days, I had a test done Monday morning at the hospital, that took a couple of day prepping for, if you know what I mean, couldn't get too far from the bathroom for two days and Monday afternoon just layed around [sm=what_smile.gif]. "The older I get, the stranger the test are becoming, either up or down!!!" Also, I started working on my plane trailer adding two shelves, where I took everything out and piled it all in my shop and really lost sight of my "Hornet", but I did finally get to it this afternoon and did the Mode 6 check ---- all the LED'S are lit ---- I will get with you tomorrow afternoon if thats OK, Sorry about all this time delay.

Charlie

MLDELARUELLE

All,

I bought the 1.0 version(I think, it was just when RC Showcase began to send them in august 2006) but never used it yet.
What important issue must I know ?
I intend to use it with 2 OS 46AX without glow monitoring with a standard FM radio (futaba or JR) on the topflite B25

I would like to know how to securely attach the sensors. I already bought the cylindric magnets, but .... how to do for the sensors ?
I saw that some of member of this tread screw it using a black stuff I don't know. I'm very surprise to see screew directly in the engine.

I read too use glue (epoxy) to secure the wire and the sensor. But what is the best way to install the sensor ?
In the documentation, I saw something else, but what about vibrations.


I read the review on rcshowcase site, but I can't find such clamps (in France) to hold the sensors

Thanks

2engsout

My Feedback: (2)

Hello, I was a beta tester and found this to be the most simple and reliable way as pictured below. 1st mark the half of the cyl. magnet that illuminates the green LED's on the twin sync unit, and mark that half. That will be the half that faces OUT. Then you can use 3/8" square hardwood stock or 1/4" ply ( NOT METAL or carbon fiber) to bolt to the bottom of the engine mount. Then epoxy the hall sensor to the wood with a 1/16" air gap between the magnet and the hall sensor face with the writing on it. 1/4" ply ensures that vibration will be kept at a minumum. This method works with magnets in the spinner backplate or in the prop driver (hub). This is MUCH better than trying to mount the hall sensor to the cowling (NOT recomended). Hope this helps. Rick Simmons

All Day Dan

My Feedback: (5)

I am setting up the Twinsync with two Astroflight controllers. They are off at a pulse width between 1.45 and 1.5 milliseconds. Above that, they are full on at 1.85 milliseconds. Below that they are in reverse up to 1.1 milliseconds. Right now the motors are doing as commanded by the throttle stick, for the small amount I can use when on the bench and not in the water, but one of the yellow LEDs stays on at idle or off. At full throttle, with the motors disconnected, they are both off. Does it make a difference if the yellow diode stays on? Dan.