ATTENTION: All Top Flite Corsair, P-40, ROBART 615 & CJM Retract Owners !PLEASE READ!
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RE: Reponse from Sierra
Hello all! This thing is exploding!! I'm putting out several questions for the rcu gang and the scalebuilders group. I need all of your input, who build TF and similar planes. First, A quick first comment; the unit shown is NOT what the final version will look like, but is stricktly a prototype used to prove the geometry and examine methods of manufacture. The final unit will have tye gear at the leading edge as in the original. Now, the questions. The P-40 and Corsair call for 4" and 3.5" wheels respectively. What wheel are you using and what is its'weight? Next, the retract angle on the original Corsair was 87 deg with the same rotational angle! Now the use of wire gear required the gear to angle forward to reduce nose-overs. BUT-- the reason for the rollovers is the bending of wire struts backward toward the center of gravity, I.E. the cg moves FORWARD! With the oleo strut and ridgid tube legs, this doesn't happen. I would compromise at 90 deg. The plane would at least look like it should! Those of you with built and flying planes, what weight are your planes?
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RE: Robinair Rotating Gear
Depending on how far you are from Luke (dion . . . . . )-- can't spell the rest of it), he might be a willing guinea pig for testing them when ready for that stage.
#578
RE: Reponse from Sierra
Lee mine both weigh in on the light end at 10 1/2 # some go as high as 13#.
CJ gear in my corsair are abotu 93 degrees I think if you make the geometry a compromise of 95 degrees it will work well. The problem you run into, is the P-40 leg is longer than the corsair leg, so Corsair gear on a P-40 don't look the same as P-40 gear and vice versa. also I'm flying Robarts on my P-40 and they constantly bend on harder landings and have way too much slop in the scissors. The P-40 itself had 100 degree rotators. I have 4" wheels on the P-40 and the Robart tires are heavy probably 8 oz. each. the corsair I'm flying larger than stock 3.75" Robart tires on CJ gear to make it look more scale, and they're not much lighter than the 4" tires.
personally I'd like the Cj's better if they had brass bushings to eliminate the slop instead of chinsy plastic bushings. THE Cj's are much better than Robart but still leave a lot to be desired. also The Robart gear uses a short cylinder which doesn't extend beyond the back of the mounting plate. If Robart would modify the links and add real struts doing away with the wire the gear would be pretty darn good. BUT they Haven't LOL anyhoo
thanks sir I'll look forward to this since I'd like a good set of gear for my P-40.
CJ gear in my corsair are abotu 93 degrees I think if you make the geometry a compromise of 95 degrees it will work well. The problem you run into, is the P-40 leg is longer than the corsair leg, so Corsair gear on a P-40 don't look the same as P-40 gear and vice versa. also I'm flying Robarts on my P-40 and they constantly bend on harder landings and have way too much slop in the scissors. The P-40 itself had 100 degree rotators. I have 4" wheels on the P-40 and the Robart tires are heavy probably 8 oz. each. the corsair I'm flying larger than stock 3.75" Robart tires on CJ gear to make it look more scale, and they're not much lighter than the 4" tires.
personally I'd like the Cj's better if they had brass bushings to eliminate the slop instead of chinsy plastic bushings. THE Cj's are much better than Robart but still leave a lot to be desired. also The Robart gear uses a short cylinder which doesn't extend beyond the back of the mounting plate. If Robart would modify the links and add real struts doing away with the wire the gear would be pretty darn good. BUT they Haven't LOL anyhoo
thanks sir I'll look forward to this since I'd like a good set of gear for my P-40.
#579
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RE: Reponse from Sierra
Lee,
As you prob already know the 1/8 scale Corsair requires a 4" wheel. I think the issue you will find is that the wheels are too thick for 1/8th scale.
I agree with your issue on wire gear vs a strut type setup. The main gear strut dia at 1/8th is almost .5" so there is quite a bit of rigidity there as well.
As for the weights of the available wheels those are posted on the websites of Robart and DuBro. I think the DuBros are a bit lighter and look closer to scale.
If the real gear retract angle is 87 deg then the model should work the same right? The key word being should! Obviously there will be differences in the gear mount area due to manufacturers using different airfoils etc. There is also the issue of the end of the strut being "bent" just over 7 deg.
Don't have any info on the P-40. Maybe there should be a F4U gear and a P-40 gear?
Keep up the good work!
Jeff Stultz
As you prob already know the 1/8 scale Corsair requires a 4" wheel. I think the issue you will find is that the wheels are too thick for 1/8th scale.
I agree with your issue on wire gear vs a strut type setup. The main gear strut dia at 1/8th is almost .5" so there is quite a bit of rigidity there as well.
As for the weights of the available wheels those are posted on the websites of Robart and DuBro. I think the DuBros are a bit lighter and look closer to scale.
If the real gear retract angle is 87 deg then the model should work the same right? The key word being should! Obviously there will be differences in the gear mount area due to manufacturers using different airfoils etc. There is also the issue of the end of the strut being "bent" just over 7 deg.
Don't have any info on the P-40. Maybe there should be a F4U gear and a P-40 gear?
Keep up the good work!
Jeff Stultz
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RE: Reponse from Sierra
Lee, YOU ARE DA MAN!!!!!
Im flying a Hangar 9 Corsair ARF.
weight about 9 lbs.
wheels are 3.25" ( but can go bigger).
Engine will be a YS .91. I would like to go bigger on the engine to swing a larger prop though.
The length of the struts are 5.25" from the bottom of the retract mount to the axle.
90 degree will be fine for me ( but I am flexible)
Thanks
Jeff
Im flying a Hangar 9 Corsair ARF.
weight about 9 lbs.
wheels are 3.25" ( but can go bigger).
Engine will be a YS .91. I would like to go bigger on the engine to swing a larger prop though.
The length of the struts are 5.25" from the bottom of the retract mount to the axle.
90 degree will be fine for me ( but I am flexible)
Thanks
Jeff
#581
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RE: Reponse from Sierra
ORIGINAL: Robinaire
Now, the questions. The P-40 and Corsair call for 4" and 3.5" wheels respectively. What wheel are you using and what is its'weight?
Now, the questions. The P-40 and Corsair call for 4" and 3.5" wheels respectively. What wheel are you using and what is its'weight?
#582
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RE: Reponse from Sierra
Thanks to Jeff S, JeffyD and others who responded! I got wheels from under 4 oz. to about 10 oz, for 4" wheels! Quite a spread! for planes under 15 lbs, there should be no need for a 10 oz wheel. I am in the shop this afternoon cutting some parts to the approximate finish configuration, and will then try to fit the mechanics to them. --How did I get myself into this thing????? (I'm kidding, of course!!) I.m actually having a ball! Sometime this coming week I'll try to post a picture. (If it looks terrible, just close your eyes! Cosmetics have no place on protos!) Sincerely; Lee Robinson
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RE: Reponse from Sierra
I must be dreaming. Folks, we actually have PROGRESS on this issue after a year, umpteen bazillion postings and a gazillion viewings. Lee, consider running for office, I'd vote for you (if I could).
Don't wake me up until it's time to get my credit card out.
Don't wake me up until it's time to get my credit card out.
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RE: Reponse from Sierra
Finally a man with INTEGRITY [sm=RAINFRO.gif]
Thank you Lee!
I plan on using 3.5 inch wheels (easier fit in the wing) on my TF Corsair. I have Dubro and Dave Brown, both are the ultra lite versions. If I remember right the Dave Browns come in at about 2.5 Oz and the Dubros are around 4.0 Oz. Unfortunately I don't have a small enough scale to get the exact weight but I know they very close to these weights.
I am weighting (bad pun) with baited breath.
Thanks again for your commitment.
MV
Thank you Lee!
I plan on using 3.5 inch wheels (easier fit in the wing) on my TF Corsair. I have Dubro and Dave Brown, both are the ultra lite versions. If I remember right the Dave Browns come in at about 2.5 Oz and the Dubros are around 4.0 Oz. Unfortunately I don't have a small enough scale to get the exact weight but I know they very close to these weights.
I am weighting (bad pun) with baited breath.
Thanks again for your commitment.
MV
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RE: Reponse from Sierra
ORIGINAL: p-40_lova
Hi All,
Will I have any problems using the CJ p-40 retract kit with a Robart 121 tailwheel?
Also, how well does the tubing attach and stay on the cylinder fittings? Any kind of extra support (wire ties, etc) needed?
Thanks in advance!
Doug
Hi All,
Will I have any problems using the CJ p-40 retract kit with a Robart 121 tailwheel?
Also, how well does the tubing attach and stay on the cylinder fittings? Any kind of extra support (wire ties, etc) needed?
Thanks in advance!
Doug
Anyone????
#587
RE: Reponse from Sierra
Doug,
sorry man LOL
I'm using the Tailwheel with CJ's on my corsair, just plumb it in as bthe nosewheel would be plumbed. If you Tee it in downstream of your restrictors, it will automatically go up and down slow. PS I used restrictors in my lines for the corsair and they work great despite what CJ says.
sorry man LOL
I'm using the Tailwheel with CJ's on my corsair, just plumb it in as bthe nosewheel would be plumbed. If you Tee it in downstream of your restrictors, it will automatically go up and down slow. PS I used restrictors in my lines for the corsair and they work great despite what CJ says.
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RE: Reponse from Sierra
Hi all; Am sneaking in through someones reply! Need dimension not on 615 drawing. The distance from the front end of the mounting flange to the first mounting hole. Am trying to reduce the heighth a bit, as there is a small interference at the leading edge. Expect to have a functioning proto by the weekend. Whoever said something about this causing a heart attack---DON'T!! You'll miss out on the final fun!!! Is there anyone on here from the Palm Beach, Martin, St. Lucie or Broward Counties here in FL with a flyable Corsair or P-40??? Lee Robinson
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RE: Reponse from Sierra
Thanks, Richard L; The drawings had the distance between the holes, but no locating dimension! Just had some deliscious clam chowder for lunch, so I'm all stoked up to charge ahead! This thing really has me wound up!! I'm trying to find a plane in this area. (You didn't expect me to risk one of my own, did you???) Don't answer that!! Lee Robinson
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RE: ATTENTION: All Top Flite Corsair, P-40, ROBART 615 & CJM Retract Owners !PLEASE READ!
well here we go. it was hard but the best advice ive seen yet is to learn how to land your plane. my robarts work fine, i did however add the struts and foam inserts, presto, also I practiced landing on fixed gear first to get the landing down .
As far as damaging the gear teeth thats bologna, if you did that much damage you need to get you pt 40 out for a few flights.
I to was upset about my robart 615's but its like this LEARN TO LAND sorry guys its a big bullet to bite but bone appitet
As far as damaging the gear teeth thats bologna, if you did that much damage you need to get you pt 40 out for a few flights.
I to was upset about my robart 615's but its like this LEARN TO LAND sorry guys its a big bullet to bite but bone appitet
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RE: Reponse from Sierra
Watch the two landings on the videos found on this link THEN tell me that I need to land better. . .
www.rcsites.net/hroachen
If your Robarts are holding up then great, you should consider yourself lucky then. Of course, I understand that your landings are nothing but "on the numbers" with hardly a tire chirp right? Please . . .
Mark
www.rcsites.net/hroachen
If your Robarts are holding up then great, you should consider yourself lucky then. Of course, I understand that your landings are nothing but "on the numbers" with hardly a tire chirp right? Please . . .
Mark
#597
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RE: Reponse from Sierra
ORIGINAL: kram51
Watch the two landings on the videos found on this link THEN tell me that I need to land better. . .
www.rcsites.net/hroachen
If your Robarts are holding up then great, you should consider yourself lucky then. Of course, I understand that your landings are nothing but "on the numbers" with hardly a tire chirp right? Please . . .
Mark
Watch the two landings on the videos found on this link THEN tell me that I need to land better. . .
www.rcsites.net/hroachen
If your Robarts are holding up then great, you should consider yourself lucky then. Of course, I understand that your landings are nothing but "on the numbers" with hardly a tire chirp right? Please . . .
Mark
Good Job
Don
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RE: ATTENTION: All Top Flite Corsair, P-40, ROBART 615 & CJM Retract Owners !PLEASE READ!
As far as damaging the gear teeth thats bologna, if you did that much damage you need to get you pt 40 out for a few flights.
I to was upset about my robart 615's but its like this LEARN TO LAND sorry guys its a big bullet to bite but bone appitet
I to was upset about my robart 615's but its like this LEARN TO LAND sorry guys its a big bullet to bite but bone appitet
If you're going to talk smack, you should at least try to do it intelligently. What's a "bone appitet"?