New E-flite P-51D 1.5

[davegee]

If you look closely, there are like 8 tiny molded dowels that fit into the holes on the other side of the wheel. They are not glue. So gentle prying, a little bit all the way around, and they'll split for ya.

Hi Blues Dragon: Thanks for the update on the tires mod. One question: did you have to slice through the E Flite hard plastic tires to access the rims so you could pull them apart, or were you able to work a screwdriver in there somehow to pull the rims apart? I have an E Flite P-51 tire that I'm ready to experiment on, but want to go the easiest, best way, as you did. Thanks for any tips on doing this.

davegee

[BluesDragon]

Hi Dave; I just worked the screw driver under the lip of the rim and used the tire for leverage to gently lift and separate one side of the wheel off. Then popped the tire off the other half. Just work the screw driver all the way around, lifting a little bit at a time. You can slice the tire to make it easier. I just have a habit of saving everything I can. never know when something may be useful one day. The Robart wheels pinch the tire between their two halves of the wheel. So, as Ron mentioned, you do need to trim some out of the center as to not pinch them on the stock wheel. You wanna be sure the stock wheel closes back up securely.

[davegee]

Hi Dave; I just worked the screw driver under the lip of the rim and used the tire for leverage to gently lift and separate one side of the wheel off. Then popped the tire off the other half. Just work the screw driver all the way around, lifting a little bit at a time. You can slice the tire to make it easier. I just have a habit of saving everything I can. never know when something may be useful one day. The Robart wheels pinch the tire between their two halves of the wheel. So, as Ron mentioned, you do need to trim some out of the center as to not pinch them on the stock wheel. You wanna be sure the stock wheel closes back up securely.

Thanks so much, Blues Dragon! I'm going to give it a go with my stock E Flite P-51 wheel and tire to see if it will work for me. Worth a try. Thanks for explaining it in detail to me.

Cheers

davegee

[SanExup]

I just received two pair of Robarts yesterday and will be switching out the tires for both the P51 and the Fw today. Thanks for the tips!!!

[davegee]

I just received two pair of Robarts yesterday and will be switching out the tires for both the P51 and the Fw today. Thanks for the tips!!!

I just completed changing over from the stock wheels on my E Flite 1500mm P-51D to a "hybrid" tire and wheel assembly where the wheels are the stock pull apart ones in the kit, and replacing the hard plastic or rubber tires with the much softer 3.5" Robarts. This idea is the courtesy of BluesDragon, who explains what he did and shared it with us here on Hobbysquawk. I had just a few minor differences how I did it, and I'll explain below:

1) BluesDragon explained that he was able to pry a small slot head screwdriver past the hard rubber or plastic tires to reach the seam on the rim to pry them apart. I did try this, but wasn't successful and was worried that I would only damage the thin plastic rims of the wheels in the process. So, I made four cuts with my hobby jigsaw in the wheel every 90 degrees from the outer part of the tire as close as I could get to the plastic rim without cutting too far. I was then in a position to take a pliers and gently pull on the segments until they came free. I wasn't planning on using those OEM nasty tires for anything, anyway!

2) I heeded the admonitions above from Ron1950 about not chopping off your fingers cutting the inside rubber rim parts of the Robart tires down to fit the two E Flite wheel rims that go on either side of the opening in the Robart tire. I started using my exacto knife, but then chickened out and used a coarse rotary sanding tool on my Dremel and easily got rid of those unwanted rubber parts on the Robarts tires, and a smooth finish. And, I am happy to report I still have my fingers intact!

3) The E Flite wheel rims fit together onto the new Robart tire pretty well. Just as an added safety precaution, I added a bit of all purpose foam glue onto the surfaces of the wheel rims before sticking them together. As long as the C clip doesn't come off the end of the axle the tire will stay on the plane, but I thought a little extra insurance was better, plus I can still easily pull them apart someday if I change out the Robarts.

4) For the most part, the new "hybrid" wheels went on smoothly and I attached the C Clips to complete the process. Or so I thought. One of the rubber Robart tires started to rub on a little part of the inside curved plastic covered strut of the landing gear. One gear was just fine, but I had to make a little change to the other. Even adding the thinnest of washers that I had as spacers was too thick to have the grooved end of the axle show where the C clip goes. So, I used my Dremel again to gently wear down slightly the area where the tire occasionally touches the strut when it is under a load taxiing. That seemed to do it.

5) I did a number of taxi tests, some very sharp turns in the street and got satisfying results. The acid test will be to fly it, hopefully early next week to see how well everything works on a real flight. I have had a number of issues with ground control problems with the old setup, and I'm hoping this will be more docile regarding sudden left or right excursions on takeoff roll or landing roll. I was using the full Robart tires and wheels as of late which did help out a lot, but it had an annoying wobble using the RC Geek method of adapting the Robarts that I didn't find satisfactory. The RC Geek method worked, but I think this is a better solution, hopefully.

6) Last point, the Robarts being hollow and soft rubber are slightly "fatter" than the OEM hard rubber tires, and I think that is why one of my struts was rubbing with the tire. Just something to double check when you do this mod.


Thanks again to BluesDragon for this idea, or at least sharing it with us if he found it from someone else. It is a great idea, and I'm sorry I didn't think of it myself! I'll report back my flight-test findings once I'm able to get out to the field again next week.

cheers

davegee

[SanExup]

Yeah, it was an easy swap for both the P51 and the Fw190.

[davegee]

Does anyone have the Flightline F4U Corsair? I would like to do the same thing as the E Flite P-51, haven't measured the axle diameter to see if the E Flite P-51 and the FL Corsair have the same axle diameter. I briefly tried to fit the P-51 wheel onto the Corsair axle, but it seemed the Corsair axle was slightly too large, or I had junk like tape from the previous RC Geek procedure that kept it from going on. Not sure.

If that won't work, I have been able to use the RC Geek technique on the Corsair, and while not perfect with a little side wobble of the tires, it is still much better than the OEM wheels that come with the plane.

davegee

[xviper]

The only reason I see for changing out the stock wheels is to moderate the bounce. This Eflite P-51 is the worst plane I've had in regards to the landing bounce. (Till I get the proper Robarts, I land on the grass - no bounce even with the stock tires.) Yes, I have the FL Corsair and IMO, it doesn't have the bounce problem to speak of, so substitute wheels are not necessary. If you are changing them for looks, then that's another story, but really, this is only important if it's a display model. Otherwise, you can't really see that the wheels are any different, especially when it's rolling or flying (when they're hidden anyway).

[davegee]

The only reason I see for changing out the stock wheels is to moderate the bounce. This Eflite P-51 is the worst plane I've had in regards to the landing bounce. (Till I get the proper Robarts, I land on the grass - no bounce even with the stock tires.) Yes, I have the FL Corsair and IMO, it doesn't have the bounce problem to speak of, so substitute wheels are not necessary. If you are changing them for looks, then that's another story, but really, this is only important if it's a display model. Otherwise, you can't really see that the wheels are any different, especially when it's rolling or flying (when they're hidden anyway).

Hi XViper: My main reason for wanting to look into compatibility of The "hybrid" E Flite/Robart wheel/tire combo for the Corsair is to eliminate an annoying "wobble" or looseness of the wheel on the axle using the Robart wheels. There is still "slop" and you can wiggle the wheel left and right a bit with your hand. I have used a 1/4" diameter aluminum tube to substitute for the wheel bearing of the Robart, but it isn't perfect. I haven't tried something like brass yet, a little harder metal than aluminum, to see if that might work better for a tighter fit.

That can lead to some directional control problems if it gets worse for takeoffs and landings. I don't have any issues at all with bounce with the Robart tires, going back to a previous FL Corsair that I had changed out but later crashed a few years ago.

At this point, using washers to get the right spacing on the axle, the wobble is minimized, but I would still change out with the nice bearing the E Flite wheels have if they were compatible with the diameter of the Corsair axle. I still haven't confirmed if they are, or not.

Regarding bounce with the stock OEM Corsair tires, I have to admit with this new Corsair I didn't really fly with the stock tires very much. I think I changed them out right away with the Robarts. I fly strictly on rough and uneven hard surfaced fields, and based on my experience with my previous Corsair with OEM tires, bounce on hard surface runways was definitely a problem. Thus, the reason for changing out to Robarts right away. I'm glad you don't have bounce issue on grass fields with your OEM tires; unfortunately, I don't have that option at the moment.

Cheers

davegee

[davegee]

I took up my E Flite P-51 1500 mm with what I call the "hybrid wheels"; that is to say the stock wheel hubs on the mains and the 3.5 inch slightly modified Robart tires. I did several flights with them, lots of taxi tests, hard turns, etc., and had about 6 takeoffs and landings, all without any problems. I did have a quartering headwind from the left and the plane wanted to veer left on takeoff, but that's more my problem than anything to do with the wheels. Landings and rollouts were pretty consistent with better, straighter rollouts than before the changes, and with the Robarts, no bounce on landings at all.

The only minor issue I had was some rubbing of one tire onto the curved part of the landing gear strut when full weight is on it setting on the ground. But I don't think the rubbing caused any directional control issues.

I'll continue tests with it, but I think so far it is a winner, IMHO.

cheers

davegee

[davegee]

I took up my E Flite P-51 1500 mm with what I call the "hybrid wheels"; that is to say the stock wheel hubs on the mains and the 3.5 inch slightly modified Robart tires. I did several flights with them, lots of taxi tests, hard turns, etc., and had about 6 takeoffs and landings, all without any problems. I did have a quartering headwind from the left and the plane wanted to veer left on takeoff, but that's more my problem than anything to do with the wheels. Landings and rollouts were pretty consistent with better, straighter rollouts than before the changes, and with the Robarts, no bounce on landings at all.

The only minor issue I had was some rubbing of one tire onto the curved part of the landing gear strut when full weight is on it setting on the ground. But I don't think the rubbing caused any directional control issues.

I'll continue tests with it, but I think so far it is a winner, IMHO.

cheers

davegee

Well, after several test flights with what I call the "hybrid" wheel (i.e., OEM wheel hubs from E Flite and using a 3.5" Robart rubber tire) I have had mixed results. I flew the P-51 again this morning, a slight left crosswind, but I didn't get any sort of nice tracking down the centerline on takeoff roll, and landing ended with a very sharp groundloop near the end of the landing roll. It went over on its right wingtip momentarily on that sharp low speed groundloop, minor damage to the foam. I think the problem using the Robarts is that because they are hollow, when the weight of the airplane is on the tires, they get a bit "squatty", enough to rub slightly on the curved landing gear strut. This causes the airplane to act unpredictably, like putting a brake on the left or right gear suddenly, causing directional control issues.

The problem with what I thought was a very promising solution to improve ground handling on this E Flite P-51, is not sorta muddled. I don't really feel comfortable putting this bird into the air again until I have a better solution for this problem. I have the 1500mm FMS P-47, and the Flightline 1600mm Corsair, and they track beautifully for both takeoffs and landings. All three of these airplanes are tail draggers, of course, have wide tracked main gear. Even my big Flightline Spitfire with its narrow track main gear performs well for takeoff and landings, probably in part due to the fact that I have flown it for several years and am pretty comfortable with it.

Does anyone have any success or improvements for the E Flite P-51 wheels that you find it fairly comfortable to takeoff and land? The airplane is superb in the air, but the way it handles on the ground for me is discouraging.

Thanks,

davegee

[xviper]

Does anyone have any success or improvements for the E Flite P-51 wheels that you find it fairly comfortable to takeoff and land? The airplane is superb in the air, but the way it handles on the ground for me is discouraging.

Thanks,

davegee

I have the softer tires as well. Taking off has never been a problem for me, even with the hard stock tires. I've learned to slowly get up to take off speed so that I can control the "wandering" better. Keep the tail wheel on the ground with UP elevator till it starts to get light, then let off the elevator and let the tail come to its natural level. At that time, there's enough airspeed for the rudder to work and keep the plane straight. Continue to add throttle slowly till it just lifting off, then add more throttle to speed up but not so much as to torque.
Landing is another story. With the softer tires, I can do a near perfect landing on the GeoTex runway 75% of the time. If I land on the grass, I can grease it 90% of the time. Using the proper amount of throttle, dependent upon how much flap is used, is important. Too little and it will drop suddenly and bounce back up. One has to "fly" this plane onto the ground. Trying to stall it onto the ground almost never works well.

[davegee]

I have the softer tires as well. Taking off has never been a problem for me, even with the hard stock tires. I've learned to slowly get up to take off speed so that I can control the "wandering" better. Keep the tail wheel on the ground with UP elevator till it starts to get light, then let off the elevator and let the tail come to its natural level. At that time, there's enough airspeed for the rudder to work and keep the plane straight. Continue to add throttle slowly till it just lifting off, then add more throttle to speed up but not so much as to torque.
Landing is another story. With the softer tires, I can do a near perfect landing on the GeoTex runway 75% of the time. If I land on the grass, I can grease it 90% of the time. Using the proper amount of throttle, dependent upon how much flap is used, is important. Too little and it will drop suddenly and bounce back up. One has to "fly" this plane onto the ground. Trying to stall it onto the ground almost never works well.

Thanks, X Viper. I'll try your technique you described to try and keep it straight down the runway before lifting off. My landings are ok, I fly with power on a bit to touchdown on the mains with the tail low but not touching the runway. I then bring the power to idle and lower the tail and steer it straight, or try to. I get these very hard uncommanded turns at a very low taxi speed on the rollout, regardless of what I try to do to control it with the rudder to keep it straight. Not sure why that is happening.

Thanks for your input.

cheers

davegee

[paladin]

Dave, is it possible the rubber tire is walking over the rim? then the oleo is acting as a re-rimmer.

Joe

[davegee]

Hi Paladin: in my experience, the rubber tire is NOT walking over the rim. It stays on the rim just fine, The problem is that the rubber tire is soft, which is great for cushioning landings, but for ground operations, the weight on wheels with the airplane setting on the runway causes them to bow out ever so slightly, to the point that they (mostly just on one side) rub on the curved part of the landing strut. On landings, this action can momentarily act like a brake on that side, and causes a sharp turning moment, usually as the airplane is slowing down to a stop. Landings have generally been smooth, I've got that down, but the rollout is a problem.

I think that although the tire is never in jeopardy of coming off the rim, it probably still allows the tire to sway a bit left and right, when under a load. I tried using some rubber type glue on the inside edges of the tires to try and secure the tires from possibly spinning inside the plastic wheel hubs, but that didn't seem to have any effect.

I have flown tailwheel warbirds for a long time, mostly foamies, and have some of my favorites today, the 1500mm FMS P-47, and the Flightline Corsair, both wonderful performers on the ground and in the air and don't exhibit any of these bad tendencies on hard surfaced runways. But this E Flite P-51 is becoming a big disappointment for me, using OEM tires, or these other experiments I've been doing. In flight, I have Zero problems with it, a wonderful scale performer.

I've ordered new OEM main wheels/tires since I cut mine up as a part of these experiments. I'm hoping I might be able to master control of this airplane using them, even though I don't like the idea that they are so hard and cause bounces and other undesirable things when using them.

[paladin]

I've had those robart wheels on a lot of planes. i had a model tech 90 P-51d and it would also rub against the wheel yoke when landing cross wind. that plane was 66in ws and 13-14# so the wheel rubbing did not change its direction. but it removed enough rubber that it was obvious what was happening on cross wind landings, the up wind wheel. if it were me i would paint the side of the tire nearest the yoke and go fly. that will tell you where its contacting. in my case i added three washers between the yoke and wheel, cant do that hear.

Joe

[SanExup]

davegee I had the eflite soft tires for my FW190 on backorder, they've just come in and shipped. The robarts fit the Focke Wulf better so I'm just going to leave them on. But I am going to see if the eflite soft tires fit the P51 better than the Robarts. I'll let you know. But for around $10 it might be worth picking up a set before they sell out, just an idea. They might also be the most expensive pieces of foam that don't remedy the issues.

[davegee]

davegee I had the eflite soft tires for my FW190 on backorder, they've just come in and shipped. The robarts fit the Focke Wulf better so I'm just going to leave them on. But I am going to see if the eflite soft tires fit the P51 better than the Robarts. I'll let you know. But for around $10 it might be worth picking up a set before they sell out, just an idea. They might also be the most expensive pieces of foam that don't remedy the issues.

Sounds great, SanExup! I have a buddy in Denver who has the E Flite P-51 and the FW190, too. I thought he looked into the idea of putting the FW tires/wheels on the P-51, but I think he said that they weren't compatible, but I'm not totally sure on that. I'll ask him again on that, but would very much appreciate your take on whether the soft FW tires might be adaptable to use on the E Flite P-51. I sure hope so. I love flying the P-51, and sometimes with these experimental wheels they sorta worked ok, but I'd like a better fix than what I've found so far.

Looking forward to hearing what your take is on them. Thanks!
Cheers

davegee

[davegee]

I've had those robart wheels on a lot of planes. i had a model tech 90 P-51d and it would also rub against the wheel yoke when landing cross wind. that plane was 66in ws and 13-14# so the wheel rubbing did not change its direction. but it removed enough rubber that it was obvious what was happening on cross wind landings, the up wind wheel. if it were me i would paint the side of the tire nearest the yoke and go fly. that will tell you where its contacting. in my case i added three washers between the yoke and wheel, cant do that hear.

Joe

Hi Joe: thanks for that input. I still have the Robarts on my Flightline Corsair, use a combination of washers and wheel collars to keep them set in the right place. Still have a little bit of wobbling left and right on the axle, but performance is generally very good, nice realistic takeoff runs and landing rollouts. I can see exactly where it was rubbing on the Robarts when I had them on my E Flite P-51. I tried very slightly taking a dremel tool to the exact spot where it was rubbing, going about as far as I dared on the plastic covered metal strut. For some reason, it didn't rub on the other side. I might even look into buying a couple more Robarts 3.5" tires as one of them seems to have developed a warp of some sort where it doesn't spin true on the axle but on occasion touches that one spot on the gear strut.

I'm still hoping that I'll find a reasonable solution to the problem. It's not acceptable to me to have a warbird taildragger performing on the ground like it is. I can't rule out that I might be part of the problem the way that I fly, but I don't have any issues with my P-47 or Corsair, or any other taildraggers that I have had through the years like this E Flite P-51.

cheers

davegee

[paladin]

the one spot rubbing in the robart hubs i definitely know the fix. if you have one spot that seams to not track with the rest of the wheel its because the rubber flange that is captured between the two hubs has pulled out slightly on one side. i found i had to completely remove the tire to push it back into the correct form. sounds like you have been experiencing some cross wind too.

joe