Official FlightLine F4U-1A Corsair 1600mm (63") Wingspan

[Elbee]

davegee , Dave, what is the axle diameter of the Flightline Corsair's MG? Best, Steve

[davegee]

davegee , Dave, what is the axle diameter of the Flightline Corsair's MG? Best, Steve

Hi Steve: I just took my rather crude caliper to an extra axle I had in my box. Looks to be .1875" or 3/16" diameter.

Regards,

Dave

[davegee]

I will come up with something. The downside is keeping things light and sufficiently strong. I have been messing with printing CF filament, though it isn't as strong as you'd think. I will also try PET-G and nylon-based filament. We'll see, until then, more when there is more. Best, Steve

Sounds worth a try, Steve. The material like the Robart wheel bearings looks to me to be made from nylon, hard for me to say. But hopefully you'll find a material suitable and strong enough to slip right on those 3/16" Corsair axles! Good luck!

Dave

[nuts-n-volts]

Those wheels are Chinese so pretty sure they're 5mm which is a bit larger than 3/16. I have not measured.

[Elbee]

Hey NV, A&A, so I figure the diameter is what passes for 5mm. .1875=4.7625mm rounded to 4.8mm. Certainly not 4mm, so I am guessing 5mm since most of the Freewing/Flightline axles are called out as 4 or 5mm. Agreed? Let me know.

[davegee]

Those wheels are Chinese so pretty sure they're 5mm which is a bit larger than 3/16. I have not measured.

Hi nuts-n-volts: If you get a chance and have a Corsair axle available, if you could verify my reading of .1875" or 3/16" from my analog caliper, that would be great. If Elbee is to make an accurate axle bushing for the Robart tires, we'll need to be confident we have the correct diameter. I just remeasured with the same caliper, and I'm pretty sure it is 3/16 inch diameter, but always good to have another reading to confirm that.

Cheers

Davegee

[Elbee]

I have not unpacked the wings from the shipping box, so any verification as to the actual axle diameter is greatly appreciated. Not certain whether to mod the Robart OEM hub or design something new. Again issues will be which print filament to use either way. I do think it was quite clever of Robart to design the wheel as to make it difficult to use anything other than their parts. Great vertical integration technique, but limits usage for us modelers.

[nuts-n-volts]

Ok... Corsair main axle is 5.03mm/.198". Wheel hole is 5.16mm/.202". Mind you that it's a bit more difficult to get a consistent measurement on a small hole like this, but I think I got it pretty close. Digital Caliper

Btw... the FMS F7F main axle that I showed you the wheel for is 4.92mm/.1935". A little smaller, but very close. Could be made to work. ...I know, that's probably my deal. Your hubs look great LB!

[Elbee]

Thanks for checking that and foro the compliment. I presumed 5mm. The OEM Robart hub drilled to that spec would make the wall pretty thin. I will noodle on it. And the FMS Wheels do look the part. Best, Steve

[starcop]

Absolutely one of my all-time favorite warbirds. Pretty cool bird guys. The details are fantastic. A+! Matt

[nuts-n-volts]

Thanks. If you glued, maybe screwed the tires, would the inner axle wall stand a chance?

[davegee]

Ok... Corsair main axle is 5.03mm/.198". Wheel hole is 5.16mm/.202". Mind you that it's a bit more difficult to get a consistent measurement on a small hole like this, but I think I got it pretty close. Digital Caliper

Btw... the FMS F7F main axle that I showed you the wheel for is 4.92mm/.1935". A little smaller, but very close. Could be made to work. ...I know, that's probably my deal. Your hubs look great LB!

Hugh Weidman and I both independently experimented with slightly reaming out the largest of the Robart axle bushings. Hugh said his works fine and he has many flights on them. I can report that I have had probably a couple of dozen flights with my Corsair with the modified wheel bushings and so far, they work ok. The only complaint I have is that the wheels don't "free spin" when pushed by hand, they rotate about a half of a turn, or so. Still, they roll just fine for taxi, takeoffs, and landings. Seem to be holding up so far.

It's not perfect, that's why I was enthused on the possibility of printing some that fit better on the Corsair axle. If not, I plan on continuing flights using what I have set up on mine.

[Elbee]

davegee,

.25" OD K&S Brass Tube has an ID of .205-.215"+/- which is 5.2mm-5.45mm.

I don't know if that would be too sloppy a fit, but a bushing from that stock would be both inexpensive & easy.

Best, LB

[davegee]

davegee,

.25" OD K&S Brass Tube has an ID of .205-.215"+/- which is 5.2mm-5.45mm.

I don't know if that would be too sloppy a fit, but a bushing from that stock would be both inexpensive & easy.

Best, LB

Thanks, LB. That was one of the first avenues I went to to try and use the Robarts wheels. For some reason, I found they didn't work out so well, and then started routing out the Robarts bushings that I am still using on my Corsair.

But you have a point. I think I'll try some new tests with brass bushings again to see if I can come up with something better than I had with the last attempt. Robarts definitely improve ground tracking and cushion landings better than stock tires. I especially found this true with the E Flite 1.5m P-51D that made a world of difference for that plane.

Will report back any progress I have on the brass tubing for the Corsair. Oh, and I finally broke down and ordered a digital caliper. The analog one I've had forever must have some errors in it that the digital ones don't. Plus, it's easier to read on aging eyes!!

Cheers

Dave

[Elbee]

Good purchase. Order a card of the batteries that your caliper uses. Trust me: invariably you will forget to turn "Off" the read-out. LOL

[Elbee]

Thanks, LB. That was one of the first avenues I went to to try and use the Robarts wheels. For some reason, I found they didn't work out so well, and then started routing out the Robarts bushings that I am still using on my Corsair.

But you have a point. I think I'll try some new tests with brass bushings again to see if I can come up with something better than I had with the last attempt. Robarts definitely improve ground tracking and cushion landings better than stock tires. I especially found this true with the E Flite 1.5m P-51D that made a world of difference for that plane.

Will report back any progress I have on the brass tubing for the Corsair. Oh, and I finally broke down and ordered a digital caliper. The analog one I've had forever must have some errors in it that the digital ones don't. Plus, it's easier to read on aging eyes!!

Cheers

Dave

Hey Dave, I had an "Ah-ah" moment, does the Robart wheel use 'wheel collars' to attach to the Flightline axle or a "C" Clip? And if it is a "C" Clip, did you or Hugh Wiedman regroove the axle? Best, Steve

[davegee]

Hey Dave, I had an "Ah-ah" moment, does the Robart wheel use 'wheel collars' to attach to the Flightline axle or a "C" Clip? And if it is a "C" Clip, did you or Hugh Wiedman regroove the axle? Best, Steve

Hi Steve: It was a solid axle with a larger flange to keep the wheel on on one end and a flat spot on the other end for the set screw on the bottom of the gear strut to attach to. No C-Clips as I recall.

Dave

[Elbee]

Thanks, Dave, the reason i asked was I did not leave any tolerance between the 3DP hub insert and the back of the opposite Robart PEM wheel hub. I was concerned that the 3DP insert would interfere with the axle. Easy enough fix in the design by creating a space should that be the case. You might let me know when you reassemble your Robarts. Best, Steve

[davegee]

Hi Steve: that sounds excellent! Although my plane works fine with the drilled out Robart axle bearings, I would be very interested at any time to test out anything that you might print up. This might also give you confidence that when you assemble the wings on your beautiful Corsair that you will be able to use the Robarts without unforeseen problems.

Please PM me sometime if you get a few completed for test. You can let me know the details like cost for the parts, shipping, etc., if you are amenable to that.

Cheers

Dave

[Abwagner121]

OK, Abwagner121 and John Wood, (clever Mod though) maybe adding gasoline to the fire and I'm sure I'm going to "ruffle some feathers", but if you learn to land consistently with power and ease it on the runway perfectly flat at around 28%-35% throttle (depending on flap deflection and wind) with the mains touching first, then reduce throttle and let it settle in, you shouldn't have a problem cracking the gear casing or bending the worm screw. I've probably got over 70 flights/landings with my current gear and they're still in one piece (probably just jinxed myself). As I've said before, I probably went through at least 6 main gear retracts in my first 15 flights trying to 3 point it in or just not landing correctly that way. After watching tons of videos and listening to pilots experienced at scale landing of warbirds, I changed my landing technique and it's been smooth sailing ever since. You can 3 point the Spitfire (but it too likes to land flat, with some speed, on the mains and sure looks more scale) with no gear issues due to the landing force not being taken on by the worm gear, but this Corsair will just not let you get away with that more than a few times, or even once. I used to call the Corsair retracts my "Independent and Unbiased Assessment Meter of my Landing Technique". I even set my timer to tell me when the throttle is at 40% (approach throttle setting) and 34% and 28% for landing speed. The throttle does not go below 28% until it's rolling on the runway, flat for about 10-15 feet.

Yes, that reply does "ruffle my feathers" a little bit! I'd like to tell me where the airfield exists that you don't have any wind issues of any kind. The club that I fly with has an airfield off of a lake so you can get wind gusts at ANY time. I've also had the retract servo crack with a perfect touchdown. Now, if you fly this bird off of grass, that makes it even more likely that you'll have issues. While your landing style may work for you, it may not work for everyone because all airfields are not the same & have different variables involved.

[Hugh Wiedman]

Hey Dave, I had an "Ah-ah" moment, does the Robart wheel use 'wheel collars' to attach to the Flightline axle or a "C" Clip? And if it is a "C" Clip, did you or Hugh Wiedman regroove the axle? Best, Steve

Elbee, for some reason I seem to remember that I used a collar with a set screw and some nylon washers to make it fit right, then just put the Robart wheel insert in. Wings are in bags now so next time out I'll drop the gear and check, but pretty sure I used a collar as I remember it was a little difficult getting the correct allen wrench in that was short enough to fit since the collar was recessed in.

[Hugh Wiedman]

Yes, that reply does "ruffle my feathers" a little bit! I'd like to tell me where the airfield exists that you don't have any wind issues of any kind. The club that I fly with has an airfield off of a lake so you can get wind gusts at ANY time. I've also had the retract servo crack with a perfect touchdown. Now, if you fly this bird off of grass, that makes it even more likely that you'll have issues. While your landing style may work for you, it may not work for everyone because all airfields are not the same & have different variables involved.

Didn't mean to, but just reporting what I've found. And my last 70 flights are all on grass and the runway is not level at all. Constantly hitting "pot holes" made from red ant hills as well as holes dug by our Everglades deer, alligators and other critters as the field is located next to a canal and some swampy areas. We haven't rolled it in years so it definitely is not smooth in any way. In fact about 25% of the time on take-offs with my jets, I'll hit a hole/bump and it jumps in the air. Maybe I just have a set of retracts that were unusually better than their typical manufacture run. This time of year our typical winds are about 10-15 mph with gusts up to 20 and it constantly shifts direction. Summer is a bit different, calmer winds, less gusty conditions, but that lasts only 3 months and then it's 98 degrees. Was out today and we had shifting winds 12 mph, gusting to 18, but that's typical. Right in the middle of landing into the wind, it would shift 90 degrees and gust up to 18. Kept us on our toes, but better to be flying than working!

[Elbee]

Elbee, for some reason I seem to remember that I used a collar with a set screw and some nylon washers to make it fit right, then just put the Robart wheel insert in. Wings are in bags now so next time out I'll drop the gear and check, but pretty sure I used a collar as I remember it was a little difficult getting the correct allen wrench in that was short enough to fit since the collar was recessed in.

Yeah, that's kinda how I remember it, too. No worries, I am not there yet. Thanks for quick reply. Best as always, Steve

[Elbee]

Hey Corsair Crowd, I have updated the Robart 3.5" wheel insert.. I created a void in the Inner Hub to allow for a wheel collar. Shoulda seen that coming, my bad. You can download the upadted STL files which are available in the "Official 3DP Printing Forum" here at the "Squawk". Best, Steve

[RodgerC]

Maidened my Corsair this morning. Flew fantastic. Just a few clicks of up trim needed. I had mixed in a tiny bit of down elevator with the flaps but this caused it to nose down slightly so I removed it on the 2nd flight. Great companion for my Spitfire. The FW190 is another members. Best of WW2 together!!!