Official FlightLine 1600mm B-25J Mitchell PNP Thread

[zorkahn]

I've ordered the B-25 nomenclature from Callie Graphics. Has anyone found a good guide for placement for the nomenclature?

[Fast N Light]

I got this link from MRC.eu: https://www.hobbywing.com/en/uploads...7152905f10.pdf
It is for the ESC with UBEC but it should be the same for the other one.

Luc - I later found the ESC instructions on a separate sheet placed in the B-25 user manual. The calibration is same basic one listed in my earlier post. Thanks for your assistance

[Elbee]

This would be me. I've been flying mine almost every weekend since Sept 2. I plan to put PBJ clothing on it, so going shades of blue instead of olive drab. Cheers, Neil

Neil, really looking forward to seeing your PBJ version. Lots of pictures, please. Best, Steve

[Seahawk One]

Brought my P-38 out to the field this morning for a quick sortie. Met Neil (he says he is a member here but doesn't post much), nice guy...Had the FlightLine B-25 with him so I got to watch him fly it. Really nice looking model in person, flew great! Has a little pep to its step! Looking forward to getting mine. Another beauty from FlightLine.

This would be me. I've been flying mine almost every weekend since Sept 2. Video of my first flight is below. Sadly, no other videos since. The first flight as seen in the video was just a typical maiden and trim. She rivals my EC-1500 on landing- albeit with a little more weight. I seem to like 90% flaps for everything. Normally have two settings (three if you consider flaps up as one), but for this plane she seems happy to do scale with one. No more bounce (as seen in the video on my runway after using flaps. Don't think it will go as slow as the P-38, but she's good for scale bombing runs. I've been using a SMC 5300HV pushed all the way forward. I plan to put PBJ clothing on it, so going shades of blue instead of olive drab. Definitely one of my favorite planes! Glad to see everyone getting their B-25's now.

Cheers, Neil

https://youtu.be/qynTQ_k6e-Q?si=IQ0suq_lA2fgyRy6

[Evan D]

Yes, don’t make the low rate elevator really lo.

good luck on the maiden!

[desertdrifter7]

Thanks everyone for your input related to the CG. I balanced the CG with wheels down. It does show it's tail heavy with the wheels up but that is expected since the wheels retract aftwards. I balanced my P-38 with the wheels down and never checked it with wheels up. I am sure it is tail heavy as well with the wheels up. Someone stated that the B-25 does not have a lot of elevator response and I was worried that balancing with the wheels up would cause a problem getting off the ground. The weather is crappy but I am hoping to get to the field tomorrow. If not, then Monday.

[Evan D]

That's the one I use for the reversing ESCs. not sure if it's right for the plain ones. But calibration is the same.

I got this link from MRC.eu: https://www.hobbywing.com/en/uploads...7152905f10.pdf
It is for the ESC with UBEC but it should be the same for the other one.

[Elbee]

I haven't done any mod to my B25 gear. The results are based on FnL's testing. What it sounds like 3.5" is gonna be a little tight for the main. NG will be fine with 2.25"

I've been using Robart tires on many of my scale models. Have yet to notice the "ballooning" at landing speed RPMs.

EK, thanks, I haven't either and like you, I have used Robart's tires wherever I can for years.

My presumption is Fast N Light might still be tweaking his 3DP wheel set.

I know I had to do some sizing changes when I used my own wheel designs for the Robart Tires on my FL 1600mm Corsair.

Best, LB

[Enzo_K]

Enzo_K Fast N Light ,

So just for clarity, both Robart 3.25 and 3.5 are good-to-go for the MGs, and Robart 2.25 for the NG.

Have either of you noticed the Robarts 'ballooning' some at landing speed RPMs and interfering with the struts?

Best, LB

I haven't done any mod to my B25 gear. The results are based on Fast N Light's testing. What it sounds like 3.5" is gonna be a little tight for the main. NG will be fine with 2.25"

I've been using Robart tires on many of my scale models. Have yet to notice the "ballooning" at landing speed RPMs.

[LucB]

Anyone have the ESC calibration instructions? I didn't see anything on the Motion site. My 1st twin engine plane so I want to minimize the chances of messing up the beep, beep, beep...

Did the basics: Tx on, 100% full throttle, motor on switch. Connect battery to ESC, beep beep, move throttle to 0%. Heard beep beep beep beep beep beep. Seems to be working OK.

I got this link from MRC.eu: https://www.hobbywing.com/en/uploads...7152905f10.pdf
It is for the ESC with UBEC but it should be the same for the other one.

[Elbee]

Enzo_K Fast N Light ,

So just for clarity, both Robart 3.25 and 3.5 are good-to-go for the MGs, and Robart 2.25 for the NG.

Have either of you noticed the Robarts 'ballooning' some at landing speed RPMs and interfering with the struts?

Best, LB

[Fast N Light]

Really appreciate the effort.

Some experience sharing. Robart wheels are also a bit thicker than the stock wheels. But if you make the rim thinner. When you squish the rubber tires, they "zoom-out" some. So I think the 2.25" will probably be a better choice for the nose. Same goes for the mains.

Best of luck with the mod. Looking forward to getting this mod for mine.

Yes the 2.25" is the better option for the nose to prevent radial interference with the strut. Motion shipping those Robarts my way at the moment.

A bit of tuning the main rim design and the 3.5" looks good to me. The clearance might be too tight if your going to get mud on the tires, but I won't be doing that. 3.25" should also work fine and no one will notice the difference unless your parked next to me. lol

The tire to rim interface I am using is similar to the Robart rim which only provides lateral tire support at the center-line. Currently testing thinner gap geometry there to see what effect it has.

[Enzo_K]

Evan, I had a cerebral flatulence not to mention I was in the Army and not the navy and had my fore and aft confused. I think I was task loading today. RR. I was thinking the same thing. I would rather have it balanced while in flight and use a little elevator when landing. It balances perfectly with the battery all the way forward and wheels up. I will try it with moving the battery back and see what it does to the the CG with the wheels up and wheels down.

Had mine balanced on CG mark with the wheel down. And it flies great. I did not notice any tail-heavy tendency after the wheels were up during the flight. It does not have a ton of elevator authority. So balancing it nose-heavy with the wheel down may not be a good idea.

[themudduck]

Evan, thank you. I am sorry I failed to mention I have the battery as far forward as I can get it. I use a Great Planes CG Machine to check the CG on my planes. Maybe I will just use my fingers and see it it comes out right.

What battery (mah size) are you using and how much does it weigh?

[desertdrifter7]

Evan, I had a cerebral flatulence not to mention I was in the Army and not the navy and had my fore and aft confused. I think I was task loading today. RR. I was thinking the same thing. I would rather have it balanced while in flight and use a little elevator when landing. It balances perfectly with the battery all the way forward and wheels up. I will try it with moving the battery back and see what it does to the the CG with the wheels up and wheels down.

[desertdrifter7]

Evan, thank you. I am sorry I failed to mention I have the battery as far forward as I can get it. I use a Great Planes CG Machine to check the CG on my planes. Maybe I will just use my fingers and see it it comes out right.

[RRHandy]

The B-25 is like flying the Corsair, Balance with the gear up for flight because the gear swing behind the CG and a nose heavy plane will fly again. Evan is right. My .02

R.

[Evan D]

Mine flies well balanced at the marks gear down.

But for the sake of discussion if you have the battery all the way forward why add tail weight instead of moving the battery aft?

[desertdrifter7]

With a spectrum smart battery 5000mAh all the way forward and the plane upright, since it is a mid-wing (not low or high), I opted to balance it upright. With the gear up it balanced perfectly but with it down it was very nose heavy. To balance it with gear down will require tail weight and I am very reluctant to do that. I would appreciate any input.

[MikeT]

A friend received his B-25 and brought it by the shop for help with programing the radio. I was really impressed by it.

Mike