Official FlightLine 1600mm B-25J Mitchell PNP Thread

[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.

[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

[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.

[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]

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

good luck on the maiden!

[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

[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

[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

[zorkahn]

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

[Elbee]

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

ZK, Callie Graphics has the 'Placement Guide".

Double check her website to see if it is offered as a PDF file or similar download.

If not, simply send her an email about the guide.

It is possible she has just been too busy to post it.

Possibly it will come in printed form with your nomenclature graphics.

Best, LB

[Spad Driver]

Gentlemen,
I put the Robart 2.25 wheel on the nose and it fits just fine and will use it until I can get the rims 3D printed.
AND I think I found a solution to our tire problem.
Those of us that have upgraded our A-10's or B-24's suspensions have soft squishy tires already in our spare boxes!.
the tires off of the original stiff struts that we replaced are an exact match for the stock tires on the B-25's struts!.
And I'll bet they are available on MRC'S website as replacements for the A-10 and B-24.

[Fast N Light]

Gentlemen,
I put the Robart 2.25 wheel on the nose and it fits just fine and will use it until I can get the rims 3D printed.

Could you take a quick measurement of the OD for the Robart 2.25" rim? The 2.5" is 36mm. Hoping they are the same..

[Spad Driver]

Fast n light Sir,
the Robart 2.25 rim is 26mm in diameter. The axle shaft width is approximately .5mm wider than the stock shaft. So use the stock axle width so there is less chance of the wheel binding.
The stock main wheel is 50mm in diameter. The width is 25mm with a 3mm rim. Axle shaft is 26.5mm in width. Measurements made with dial calipers.
The tires that I'm using will peel off the stock rims with a little effort and should fit on your rims when I have them made.
Some pictures of the difference between the stock wheel and tire versus the B-24 wheel and tire.
trying to show that the tires are the same physical dimensions but have vastly different stiffness.
The first picture is showing them under compression.
Spad Driver

[Spad Driver]

Correction!.
The dimensions I gave for the main rim is correct for both the B-24 and the B-25. But the axle shaft diameters are different.
the B-25 shaft is larger than the B-24's so I will be using the B-25's rims with the B-24's tires.
perfect fit!.
Spad Driver

[Spad Driver]

Robart 2.25 nose wheel with stock wheel beside it.
B-25 rim with B-24 tire installed under compression.
Spad Driver

[Fast N Light]

Robart 2.25 nose wheel with stock wheel beside it.

Looking at the Robart website, it appears their rim for 2.25", 2.5" & 2.75" tires are identical. Therefore I am expecting that the rim I designed with a 2.5" tire will also work with the 2.25".
It looks like the tire shown on your nose gear is a Dubro low bounce tire. They perform well as a low bounce tire, but the rim diameter is too small to fit the rims which I have designed.

Updated .STL files are posted on Thingiverse with the modification I have made since I started fitting them to the B-25 model. Still a work in progress....

Front wheel from left to right, G16.STL printed rim, Robart rim & hub caps, Robart 2.5" tire, FlightLine OEM tire & rim



Main wheel from left to right G16.STL printed rim, Robart rim & hub caps, Robart 3.5" tire, FlightLine OEM tire & rim

[Elbee]

...rim...

FNL, Keep up the fine work, Sir. Best, LB

[Aros]

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.

Hey Neil! Sorry to say I am moving to Astoria so I won't have the pleasure flying with you again. You flew her like a champ. I can't wait to fly mine! Good luck to you and happy landings!

[davegee]

Hey Neil! Sorry to say I am moving to Astoria so I won't have the pleasure flying with you again. You flew her like a champ. I can't wait to fly mine! Good luck to you and happy landings!

Hi Aros: be sure to say "hi" to Lewis and Clark for me when you move to Astoria! (LOL) Sounds like a pretty neat place. We had it on our plan to visit years ago on a trip up to your area, but plans fell through. Would still like to visit Ft. Clatsop and the Astoria environs someday.

Cheers

Davegee

[Aros]

Thanks davegee! It's a beautiful part of the country and we feel blessed to move there!