CARF Mephisto Build thread
06-30-2018, 05:34 AM
#152
My Feedback: (21)
Great thread guys on a fantastic kit! I really appreciate all of the build photos. I bought a white one and painted it. Today I finally put all the pieces together for the first time to see how the color scheme worked out. It's ready for final graphics now and clear coat this weekend. I can't wait to get it in the air. 
07-02-2018, 08:33 AM
#157
Thread Starter
It's something you must do with the 300's. CARF have done a lot of testing.
We did something similar on the P-300 Pro Andrew Bird is flying and he has better performance than the KT310 and BF 300's we have flying here.
Dave
We did something similar on the P-300 Pro Andrew Bird is flying and he has better performance than the KT310 and BF 300's we have flying here.
Dave
07-02-2018, 11:11 AM
#159
Thread Starter
If you want to hover it you need to keep the weight down. Andrew Bird used a length of thin walled square carbon tube cross the fuselage to attach the bottom of the bell. Turbine tailcone to start of steel tailpipe I gave Birdy a distance around 50mm. He’ll jump on here soon and confirm final distance, but it works well and is quiet.
07-02-2018, 12:23 PM
#161
Dave's right - I ran 55mm on the tailcone gap and did what I could to keep the weight out of the plane.
Power does seem pretty good so far. Now I've got the base setup more nailed down I'll be investigating the vector a bit more in the next flights. The brief bit of hovering I've done with a decent fuel load on a hot day, the plane still drove out of it ok. Hopefully find out more in the next few days.
My initial set up was rubbish and it's definitely worth taking the time to get the plane properly trimmed, mixed and find the correct control balance with the gyro's off. It was a huge transformation in the course of a few flights with the tweaks.
Power does seem pretty good so far. Now I've got the base setup more nailed down I'll be investigating the vector a bit more in the next flights. The brief bit of hovering I've done with a decent fuel load on a hot day, the plane still drove out of it ok. Hopefully find out more in the next few days.
My initial set up was rubbish and it's definitely worth taking the time to get the plane properly trimmed, mixed and find the correct control balance with the gyro's off. It was a huge transformation in the course of a few flights with the tweaks.
07-07-2018, 04:56 AM
#165
We trimmed the length of the front of the carbon bell mouth as it was restricting the airflow around the rear of the turbine. I cut mine so it is flush with the leading edge of the carbon support which is holding it at the top. It means you get good airflow in around the tailcone now with the larger diameter turbines.
07-10-2018, 08:01 AM
#167
Thread Starter
Most of the guys are using them in the 3-D mode, so when you switch on full vector and gyro. It helps when hovering. I’m not hovering, so don’t use tailerons.
07-18-2018, 06:00 AM
#171
Hi Fellows, I'm going to need a little help to clarify how to do the mephisto setting, something like “setting mephisto for dummies”
.
I am building this Mephisto for a good friend and I am soon to delivery, We look forward to the maiden next week, but I have some doubts with the setting.
I already set high rates as recommended in the manual, as well as the low rate. No gyro, no expo for now.
I would like to know if you have any recommendations as how much expo to use.
My doubts are about the particular configuration of the BD Cortex pro.
The Cortex normally has 3 positions Bank1, (low gyro, dump mode), OFF and Bank2 (High Gyro, Heading Hold, Hold mode).
In the Carf manual it refers to the programming only of Bank1 and recommends using this same configuration for both normal flight and 3D, modifying the sensitivity (Low and High) in the assigned switch.
I understand then that Bank2 (hold) is not used, am I correct?
On the other hand, can someone explain to me how to adjust “the sensitivity” on the switch in a mz18?
The owner request is to assign the three flight conditions to a three-position switch Gyro off, Gyro Low, Gyro High.
I will be happy to listen to your suggestions.
Thanks
.I am building this Mephisto for a good friend and I am soon to delivery, We look forward to the maiden next week, but I have some doubts with the setting.
I already set high rates as recommended in the manual, as well as the low rate. No gyro, no expo for now.
I would like to know if you have any recommendations as how much expo to use.
My doubts are about the particular configuration of the BD Cortex pro.
The Cortex normally has 3 positions Bank1, (low gyro, dump mode), OFF and Bank2 (High Gyro, Heading Hold, Hold mode).
In the Carf manual it refers to the programming only of Bank1 and recommends using this same configuration for both normal flight and 3D, modifying the sensitivity (Low and High) in the assigned switch.
I understand then that Bank2 (hold) is not used, am I correct?
On the other hand, can someone explain to me how to adjust “the sensitivity” on the switch in a mz18?
The owner request is to assign the three flight conditions to a three-position switch Gyro off, Gyro Low, Gyro High.
I will be happy to listen to your suggestions.
Thanks
07-18-2018, 09:54 AM
#173
07-18-2018, 10:25 AM
#174
My idea was that other users could share their different settings or ideas about setting Mephistos....I imagine that not everyone follows the manual instructions "by the book".
regards
07-18-2018, 11:23 AM
#175
I'm not a cortex user but here's my 10 pence worth:
I only have 13 flights on mine but I have worked pretty hard on the set up. This plane really benefits from taking the time to get the base set up to your liking before switching on the gyros. I haven't even looked at the set up in the manual so not sure what they recommend but have found the ailerons soft compared to the elevators so am running max throw and around 10% expo aileron with the elevators knocked back at 60% travel and 30% expo. I suspect this will be more twitchy than many would like but hopefully it gives an idea of control balance on the two surfaces. The rudder is pretty sensitive as well so I'm running 30% expo there as well. I'm running 16% differential to get it axial as well (not using tailerons).
Mine required mixing Rudder / elevator and rudder / aileron in knife edge flight and some time playing to get the trim of the tail pipe reasonably close. There is a decent Flap elevator mix needed as well.
Gyro wise I've kept it simple - a 3 position switch, 1 Off, 2 low gyro mode vector off, 3 max gyro and vector. I'm not using any heading hold at the moment. My low rate gyro is helping stabilise in wind etc but gives the model a bit more feel and feedback. My high rate gyro is mostly max'd out on each surface - please take care with the elevator set up here. Mine seemed to still have a very small amount of hunting from the elevators at high speed which wasn't always that easy to spot so keep a good eye on it - my elevator gain is the lowest of all the gains for reference.
I was really disappointed with mine after the first flight - my base set up was awful! Now I've worked it through and kept tweaking I'm really enjoying it. I'm still refining things and still learning the plane - I have to admit I'm not a big gyro user so am trying to find a balance where the gyro isn't killing all the feel and feedback this (or any!) plane can deliver.
I only have 13 flights on mine but I have worked pretty hard on the set up. This plane really benefits from taking the time to get the base set up to your liking before switching on the gyros. I haven't even looked at the set up in the manual so not sure what they recommend but have found the ailerons soft compared to the elevators so am running max throw and around 10% expo aileron with the elevators knocked back at 60% travel and 30% expo. I suspect this will be more twitchy than many would like but hopefully it gives an idea of control balance on the two surfaces. The rudder is pretty sensitive as well so I'm running 30% expo there as well. I'm running 16% differential to get it axial as well (not using tailerons).
Mine required mixing Rudder / elevator and rudder / aileron in knife edge flight and some time playing to get the trim of the tail pipe reasonably close. There is a decent Flap elevator mix needed as well.
Gyro wise I've kept it simple - a 3 position switch, 1 Off, 2 low gyro mode vector off, 3 max gyro and vector. I'm not using any heading hold at the moment. My low rate gyro is helping stabilise in wind etc but gives the model a bit more feel and feedback. My high rate gyro is mostly max'd out on each surface - please take care with the elevator set up here. Mine seemed to still have a very small amount of hunting from the elevators at high speed which wasn't always that easy to spot so keep a good eye on it - my elevator gain is the lowest of all the gains for reference.
I was really disappointed with mine after the first flight - my base set up was awful! Now I've worked it through and kept tweaking I'm really enjoying it. I'm still refining things and still learning the plane - I have to admit I'm not a big gyro user so am trying to find a balance where the gyro isn't killing all the feel and feedback this (or any!) plane can deliver.