Buying a F7 Tigercat with DLE 20's on board. I have set up twins before and have been decent at synchronizing them. For this project I am considering using Sync device. Have been reading and the two units available are the

"Twinsync" From Down and Locked http://www.downandlocked.com/Home.php

Manual: http://www.downandlocked.com/uploads...manual_5-0.pdf

"MicroSync" from Oregon Scale Aviation http://oregonscaleaviation.com/Resou...icroSynch.html

Manual: http://oregonscaleaviation.com/Resou...ynchManual.pdf


I'd like to hear how these have held up over time. The good , bad and ugly. Prior threads are old and I didn't find as much on the MicroSync and didn't see a head to head comparison. I saw that the Twinsync can plug into the tach lead of the DLE 20 ignition module eliminating the task of placing Hall sensors a big plus.

Looking forward to hearing that sweet twin sound from the F7. Thanks,
Pete

Wow no response in a week.

Since the original post I have learned the Tigercat I'm getting has a Sync system in it but the manufacturer is unknown. Picking up the plane April 7.

Come on fellas throw me a bone

Pete

These are not needed at all. All they will do is cause problems. I have been flying twins for 39 years and have never used a Sync device. As long as they are close its not an issue. Go to my You-Tube location. Heli4213 Look at my Giant twin I slander. These gas engines are about 400 rpm apart that's just where they run great. There is no need in the world to try to get them right on. I fly real twins and they are always off a tiny bit to. Dont waste your money or time not necessary.
Bob

Bob,
Thanks for your response I thought I'd never get someone to chime in. Like I said in the OP I have tuned a few twins and have had good success with them. I am meticulous about the throttle geometry as that's what makes or breaks you to keep them closely matched through the whole throttle curve. Then tune each engine for reliable performance not trying to lean ever last rpm out of them. I can usually get them about 200 to 300 rpms apart at least. In doing research for the F7 I thought I would look into a Synchronize unit . I found out the one I'm buying has a sync unit in it so I am saving $ but I wont know the brand till I pick up the plane this Thursday.

A large part of me agrees with you that I am introducing another failure point in an already complex model. Any other opinions welcome. It will be a few weeks to sort through everything in the F7 so don't be afraid to jump in.

KISS is a beautiful thing

Pete

Ok good luck. it seems like you have plenty of skill not to need them. Keep me up to date

I too have flown twins off and on for a long time. My son and I tried both of those listed and while "micro..." Worked and his support was excellent we found it just too complicated.

You just don't have time to do throttle resets when you lose a motor especially if the plane is a long way out or close to the ground.

i always tried to get both motors running nice but not necessarily at exact sync. Reliable idle and consistent equal response is most important. You need to be a bit rich at full throttle on the ground as rpm picks up in the air and the motors lean out.

if I was to do anything I'd get the EagleTree Guardian stabilizer. This thing should give you a few more seconds to react on engine out. It should hold rudder long enough for you to make your choices. I flew
my big Corsair with only an early helicopter gyro on the rudder for many years. It worked great especially in cross wind takeoff and landings so this modern tech should work better with faster response. Check them out.

Before I fly twins or any plane I check out the field area and get some idea where I could land in emergency.

My my plan on engine out is cut the throttle and nose down to maintain air speed. If I can make the field safely fine but otherwise gear up and belly it in. I'd rather repair than build a new plane.

Sage advice, Thanks for the feedback

Pete

I picked up the F7 yesterday and wow what a deal.

The plane came with Twinsync but it is not installed. The manual is dated 10/12/09 and it's version 2.4

This project will be up next after I do some maintenance on a few birds in the fleet.

Pete

If you are going to test the engine sync once it is set up, fill the tank on one side and only put a little in the other. Run them at full throttle and see what happens. Let your helper select the fuel combination without telling you....see if you can react correctly and fast enough. Maybe have a plan and try to follow it.

Pete,

I've been searching "Twinsync" and came across your thread. How did the F7 turn out??

What are your thoughts on the synchronizer??

Thanks for for any insight.

Steve

Steve,
I opted not to use the Twinsync to keep things simple as this plane has a lot going on already. I felt the unit could be a failure point and I was able to tune and synchronize the engines with no problem after substituting the original Tillotson carbs with genuine Walbro carbs. The plane wound up having first gen DLE 30's. I was within 200 rpms from idle to full throttle. I'm very satisfied.

Pete

I cannot figure out why people talk about this topic. This is not important at all. I fly real airplanes to and when I flew piston twins engines were always a few hundred out. I have been flying g RC for 40 years and RC twins for 30 years. I have about at this time 13 twins from glow to super big gas twins. Working on a Hostetler Cessna 421 now the big one. It will have twin cylinder 3W twin 70s. What people always miss is this really IS NOT A PROBLEM ANYMORE !!!!!!!!!!!!! This was a problem when engines shared a fuel tank. This has not been done for years. Simple set the engines to run that's it. Don't go back and forth and adjust them I see guys doing this all the time and engines fail because they are so concerned about a few hundred rpm and not about the real issue running so one is lean. Not necessary EVER !!!!!!!!!!!!!!!!!!!!!!!! I log my flights and at this point have 3500 twin flights with glow and gas and to date never had an engine STOP !!!!!!!!!!!!!! If you like this device that's cool use it just telling you my experience with twins.
Bob

Bob,

Nothing sounds better than the sound a twin makes when they are properly synchronized. It's intoxicating (for me at least) and if they are out by more than a few hundred or not consistent through the throttle range you hear it. Will the plane fly? Yes it will. Will an engine be unreliable? Not if you didn't lean one too much. Do you need the twinsync? No you don't.

Why did I start this thread last year? Because I bought a plane with the option of using a Twinsync and wanted to know what others had experienced and get some feedback. I asked questions did some research and made an informed decision not to use it. I agree the availability of some of these gadgets are more fluff and niceties rather than a necessity. People may not have your depth of experience so they turn to trusted forums to get answers and be educated.

Pete

As Heliman.. Said leave the sync in the box. Get both motors running nicely. A few rpm out isn't going to hurt. It's a lot more important to have both run all the time. We had tachs mounted in the top turret of the B25 so it was easy to monitor rpm. We were fortunate that both motors ran pretty well out of the box with electronic ignition. We had scale functioning exhaust that caused minor problems until I equalized the pipe length. Not tuned pipes just equal length. They apparently worked very well as it was easy to get almost 500 rpm more than others got out of the same motors. We just ran a little richer on the top end and they ran perfectly. Easy starting and held adjustements like a lawn mower. Start them and go fly.
again I'd use an electronic stabilizer and have it on its own channel so it could be turned off and on.

It it was interesting to see how much rudder input the gyro put on my Corsair on take offs. I fly with rudder so the gyro just helps me. But I did try takeoffs without rudder input and let the gyro do its job. It would put 20-30 deg in at times if you just jumped the throttle. I'm sure it saved me a few times when we flew in really windy conditions.

Pete,

Sorry, I have been away. How is it flying????

Setup:
Everything stated above I agree with (2 properly set up engines mechanically and tuned for reliability).

Syncronizer:
I agree with Pete. NOTHING beats that sound!!!! Synced props through all RPMs is a sweet thing.

I get it that Bob doesn't like them. That's cool. It's not his thing.

For me, I really like the idea of using one, but my twin project is still far off.

Let me ask a question about the Twinsync....

1- Can you turn off the throttle-cut feature??? In other words, can the unit sync the props and if one does quit, leave the other engine up at power??? (Or will it cut back to idle no matter what, requiring stick movement to restore)????

2- Can it be turned on and off via the transmitter???

Last thing, if the F-7 is flying great, install the Twinsync for a while and see what you think???

Cheers,

Steve

Steve,
I never installed the Twinsync. After replacing the carbs with genuine Walbro ones the DLE's ran great and they synchronized very well. They are within 200 rpm's from idle to full power. Like I said in the OP it's all about the basics with the setup geometry.

After getting all the systems working and organized this model is almost as complicated as my Boomerang Sprint. So I didn't want to add another layer of complexity with the Twinsync. Read the manual for it lol.

I most likely will sell the one I have as it's NIB never installed. Take care,
Pete

Pete,

Ok, so I just did a speed read of the manual. I can see what you mean about a complex set up.

Sometimes we want to tinker, but most of the time .... we just want to fly!!!!

Thank you for your input. It has been valuable to me.

Steve

ABSOLUTELY RIGHT !!! I have been flying twin engine planes for many years, and there is nothing more annoying to have an awesome twin engine plane sound horrible just because the engines are out of sync.

Even though the planes will fly perfectly without sync, that horrible, annoying sound just RUINS one of the coolest parts of having a twin engine plane.

Even in full scale I would not accept such substandard operation, and would adjust the RPM so that engines sounded perfectly synced.

Unfortunately, the links for these devices do not work anymore, so I will have to search the web for a synchronizer.

Mike

In my opinion these are not needed ever. You should be able to set engines by ear that's the way I've done it for 40 years and even if they are a little out they still sound good and it's not an issue with them running it's just not necessary. In addition to that when they were more popular a lot of them they had problems with because they would lower the rich engine and make it to lean and it still have an engine quit so my opinion just not needed.

Thanks Bob

Just to add if you want to see an airplane that was adjust it by hand go to my YouTube channel and look for the Cessna 310.
Channel Name, Heli4213

Hello all

Will there be any difference if both engines are already twins?? my 3m beechcraft will have 2 30cc rcgf twins

From what I can read about the twinsync device, it idls the second engine if the first ones stalls, but I have been told that some devices, will also force tail ruddel some degrees to compensate only working engine, which I find it interesting. Will the twinsync device make it??

I have found it at https://wikesrc.com/shop/ols/products/twinsync for USA, and https://www.bigplanes.nl/contents/en...chronizer.html for EU customers.