Makri Free Flight Timer

[g_kandylakis]

"Makri Timer"... That is the fancy name for the electronic timer for indoor scale F4E models as developed by Matthias Kritzler (Matze" here) of Germany.

We have been in contact over the matter for a few weeks now and he has just completed the first sets and was able to send me the ones I ordered to test/use.

It has already been mentioned / presented in the related topic on indoor timers,
https://hpa.aeromodelling.gr/index.php?topic=226.msg3516#msg3516

but I thought it deserves a dedicated topic for more detailed description.

So, what follows is a sort of review / description from the user side.

There are two versions available:
the normal mini timer, for motor control only and
the timer+, for two motor operation, 2 servo operation and LED operation

The grid is in milimetres, so you get an idea about their size.

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For programming they require a small programming device that is connected to a 4 pin female connector.

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The device recognises the type of timer and shows the already programmed values for each parameter, which can be changed very easily as we will see.

This is not a proper business, more like a side hobby of Matthias, however since there is quite some time he devoted into this and the materials themselves do not come free.

The prices he gave me were
40€ for the programming unit (which can be used for an endless amount of models and both timer types

25€ for each timer, regardless of type

2,5€ for a small extension to the timer, in case it is mounted in a way that makes it not easily accessible for plugging in the programing cable.

The timer price is more or less market standard (if there is such thing as a market for these things).

The programming device is an extra investment, true, but well worth the cost, considering what capabilites it provides. More on that later.

The parameters are all saved in the timers, so there is no chance of miing them for different models by mistake, unless you enter them wrong to begin with.

[g_kandylakis]

Weights:
As delivered, the simple timer weighs 0,64 grams, the larger timer weighs 0,88 grams.

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They have soldering pads for wires to solder on but I prefer to solder pin sockets, to allow for ease of assembly disassembly.

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With these soldered on, the single one weighs 0,75grams, the double one 1,06 grams.

[g_kandylakis]

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The timers do not have an integrated brushed ESC, like the Atomic Workshop Zombie does.

Such an esc weighs about 0,35 grams.

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But on the other hand, they can be used for either brushed or brushless motor operation with no problem. And the larger one for two separate motors as well, not to mention the servos...

Next picture shows the programming unit with the black cable and the yellow flexible extension that can be stored in the model at a very low weight penalty.

The unit just came out of the bag and still has the protecting membrane on it...

[g_kandylakis]

A nice diagram at the rear of the instruction sheet helps understand the various electric connections

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[g_kandylakis]

I will make a video of the actual programing process that will better show the ease and accuracy of programming, it will take some days though.

I can describe the operations at least, with text.

The small timer, as already stated, has a single motor function. It receives + and minus cables and has a signal output at the top right corner.

It can have a start button if you like, or the timing starts automatically once you plug in the battery. Because the start time can be individually set, there is little stress involved. You can choose 60 seconds for example, plenty of time to plug the battery in, put the cover panels back on, put the model on the ground and then wait another 40 seconds for it to start...

For this timer there are three introductory settings and 6 distinct power phases, each with three parameters, meaning a total of 21 parameters.

General parameters:
ESC initialise time (in seconds)
Start Button yes/no
Start delay (in seconds)

To go to the next parameter you just press the second button on the device (from the left).

To go to the previous parameter, you press the first button from the left.

To increase the value of seconds, you press the fourth button, each press results in increments of 0,2 seconds.

To decrease the value by 0,2 seconds, you press the third button.

And that is it...


For each of the six motor phases, you can define a ramp (seconds), the power percentage you want (from 0% to 100% in 1% increments) and the time / duration of the phase in seconds (0,2 increents).

when finished with the first phase ramp, % and time, you press the next button and go to the ramp for the second phase.

Each parameter is very well named and described so you always see what you are doing. The video will help immensly here to make this point clear.

So,

secs  %   secs
R1,   P1, T1
R2,   P2, T2
R3,   P3, T3
R4,   P4, T4
R5,   P5, T5
R6,   P6, T6

another 18 parameters, plus 3 from the start, a total of 21 parameters.

You do not need to use all the phases of course. Leave them at zero time and they get ignored.

I was thinking of someting like this:

phase 1 = idle motor run
phase 2 = take off
phase 3 = climb
phase 4 = cruise
phase 5 = descent
phase 6 = flare or zero or something else

When time for phase zero expires, the motor stops...

[g_kandylakis]

The larger timer has more, of course.

I asked Matthias and he did it, to have a separate parameter set for each motor output instead of the same one for both motors.

I have seen how more manouverable rc models with differential thrust motors are in small halls and think it would be most helpful to have the option. Worst case if you do not want that, you manually dublicate the values from ESC1 to ESC2. But you retain the flexibility.

So, 3 + 18 + 18 parameters so far.

For each servo there are 7 parameters and a last one for the LED lights.

Total 3 + 18 + 18 + 7 + 7 +1 = 54

Sounds a lot initially but it is so easy once you have done it once or twice.

And that is all for now, the next step is to make a proper video of an actual programming session and the resulting run.

The accuracy of 1% in power setting and 0,2sec increments in ramp and time is incredible, compared to the tedious job with tiny screwdriver potentiometers of the previous generation timers.

True, they might be considered simpler and quicker to adjust on  field but for fine tuning there is no doubt about the best option. To me at least.

George

[g_kandylakis]

And a short ( ) video of only 16 minutes. But it should clarify quite a lot, I hope.

[g_kandylakis]

The Zombie timer came from my Avro 504 O hydroplane.

The settings are from the last round at the BMFA Indoor Scale Nationals, where for the first time it took off rather well and slower than before, but when the 2nd phase kicked in, again it decided to go straight to the partition.

Interestingly, despite the head-on collision, there was zero damage to the model this time.

My plan, already in progress, is to use the large timer and add the aileron servo to it, to make the bank steeper during the descent, hopefully avoiding walls forever, if it works. It should work, only things have a habit of not going according to plan, in my case...

To sum it up, my first impressions of the timer of Matthias are more than good.

Highly recommended and I imagine it will become a hit (in our limited aeromodelling world). Very well done!

George

[Jmk89]

George

Thanks for making that video. It makes it much clearer how the timing process works

[PeeTee]

Hello George

The Makri FF Timer seems to do many of the options I had with the Dan FF Timer fourteen or so years ago. Dan Kennedy produced these and they were used by a number of people on HPA. The timer was programmed by a separate unit but you had to put it in a separate box. I understand that the timers are still used by competition modellers in the UK.

Peter

[g_kandylakis]

Hi Peter,

I am not familiar with the Dan FF timer you mention. From what I understand it is used for outdoor free flight duration models.

What do you mean, "put in a seaparate box"?

In any case, this timer is made primarily for indoor scale models and that is why I am using the Atomic Workshop Zombie timer as a benchmark.

The single timer as seen on the video is fairly simple and straightforward.

It gets more interesting with the larger version, for twin motor operation and two servo operation, for example landing gear and elevator.
(when the gear goes up the aerodynamic balance is disturbed and you might need some down elevator)

The biggest problem with the Zombie timer is not its capabilities or programming difficutly (very fine hand adjustments are needed), after all it has served many well, me included, for almost 20 years now.

The problem is it is impossible to find and buy it as no more have been made for years now.

So the addition of a newer, better and available timer is most welcome.

Participation in the CO2 electric class competition, whether in the UK nationals or in the IIFI in Holland is quite low. I imagine in no small part becuse of the lack of available timers. Hopefully this might change a bit.

George

[PeeTee]

Hello George

The thing in a separate box is a programmer which one uses to set up the run time etc. It's disconnected before flight ! I have asked some of my friends who are members of HPA to try and give me a hand posting photos.
p.s What about the K&P timer which should still be available

Peter

[g_kandylakis]

Hi Peter,

Regarding the separate box, I understand it more or less as the similar programming device shown in the video. You plug it in, do the programming and remove it for flight. Would love to see pictures for comparison.

About the K+ P timer, I have had it too.
You can adjust power time and decay, which however gives a resulting power curve that is rather difficult to predict.

You might say it is also a two phase timer in effect.

But it is definetely heavier and again needs adjustment through the tiny potentiometers where you can never be exactly sure how much you put in while you are doing it.

And as with the zombie one, you have no servo programming capability or twin motor operation.

Having used/tested all three (Zombie, K+P, Makri), the way I see it, the only drawback of the timer of Matthias is the extra cost of investment in a programming device.

If you have more than one models to fly then this becomes less of an issue.

In all other terms of practicallity, weight, programming accuracy and capabilities it is far more superior than the currently known existing alternatives.

George

PS. I tried to go to kpaero.com and cannot access the page. Wonder why.