H9-F6F Hellcat 60 ARF
01-13-2007, 06:49 PM
#576
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RE: H9-F6F Hellcat 60 ARF
Setting up the retracts took some changes. You need to cut some wire off of the retract control wires in order to put the quick connectors on. Be careful you don't cut off too much. The 1" servo arem length recommended in the manual is too wide. it causes the rods to bow and keep the servo humming. I'm using a JR 791 retract servo and the out side holes on the round servo disc are 13/16" wide and worked perfectly. It provided a tiny bow in the rods which helps lock the gear and no servo humm.
I am going to fasten the wheel wells with 7 #4x 3/8 panhead screws. This will allow future access.
Looks like a really great model!![>:]
I am going to fasten the wheel wells with 7 #4x 3/8 panhead screws. This will allow future access.
Looks like a really great model!![>:]
01-13-2007, 07:42 PM
#577
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RE: H9-F6F Hellcat 60 ARF
tom I think we all experience that when it came to putting in the retract. I first went with a Hitec 75 BB that went dead before I even flew the plane. I changed out to a JR 791 and no problems yet in 40 flights as of today.
01-15-2007, 03:22 PM
#578
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RE: H9-F6F Hellcat 60 ARF
Finally got the airframe completed 
. Zen 20 engine installed, radio equipment installed (except for the ignition & receiver batteries). All thats left is to balance the airplane (adjusting the battery placements and add weight as needed) and adjust the control surface throws. Then i'll have to wait until spring before i can start hunting Zero's.
This thread has helped me with some ideas and find people that can help me solve some questions with the Zen 20 installation.
Thanks
. Zen 20 engine installed, radio equipment installed (except for the ignition & receiver batteries). All thats left is to balance the airplane (adjusting the battery placements and add weight as needed) and adjust the control surface throws. Then i'll have to wait until spring before i can start hunting Zero's.This thread has helped me with some ideas and find people that can help me solve some questions with the Zen 20 installation.
Thanks
01-16-2007, 03:00 AM
#580
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RE: H9-F6F Hellcat 60 ARF
ORIGINAL: TomTreese
What is the purpose of the 1/4" x 1/4" x 7 1/4" Basswood stick in the kit????
What is the purpose of the 1/4" x 1/4" x 7 1/4" Basswood stick in the kit????
01-20-2007, 06:10 PM
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RE: H9-F6F Hellcat 60 ARF
what you everyone think of retract on the hellcat. Reason for asking broke mine today on dead stick landing. It was a soft touch that hit the end of our runway and than broke.
01-20-2007, 09:52 PM
#585
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RE: H9-F6F Hellcat 60 ARF
I changed the way I secured the gas tank from the discription above. I reinforced the plywood on either side of the tank and screwed a strip of velcro strap to each side. I then inserted the tanks and put some foam rubber all around between the tank and wood. I then secured it with the velcro straps. A much neater job then rubber bands.
I have a question.?? When I move the gear up and down they retract servo moves a little bit from side to side. This is obviously putting some stress on the servo attachment?????
Is this acceptable???
I have a question.?? When I move the gear up and down they retract servo moves a little bit from side to side. This is obviously putting some stress on the servo attachment?????
Is this acceptable???
01-21-2007, 12:50 AM
#586
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RE: H9-F6F Hellcat 60 ARF
Patzane, what broke??? Did the gear collapse or did it rip the retracts out of the wings? I've run mine off the end of the field at a great rate of knots into Canola and nothing happened...save embarrassment. Alot of people seem really critical of the H9 retracts but I've never had a problem..so far..and I have 100+ cylces on the gear? I've done some not so smooth landings as well and no problems. Just how hard does one have to bang it on to cause an issue?
01-21-2007, 02:11 AM
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RE: H9-F6F Hellcat 60 ARF
Well a few week ago I had a dead stick land and came down hard on the right gear. I was about to run into a bush. At that time I bent to gear some, but it was a easy fix. Today I dead stick again and the same right gear came out. The other part of the gear is still in the plane. I think when I had the dead gear a few week ago I did some damage at that time but I did not check them. I order another set 2night from Horizon Hobby.
01-21-2007, 10:57 AM
#588
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RE: H9-F6F Hellcat 60 ARF
HEPDOG>>>>>Further on my retract problem. I am using a JR-791 with the round servo arm with the quick-locks mounted 13/16 th apart. It is fine at the end points but it pulls some pretty good torque when it's about 1/3 of the way around. It appears it happens when the lock-down release????? The servo looks like it wants to teist and it definatelly moves the mount arouns a bit. My concern is, will it hold and is yours doing this????
Thanks[
]
Thanks[
]
01-21-2007, 01:14 PM
#589
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RE: H9-F6F Hellcat 60 ARF
Well I'm no expert but I did set up another H9 cat and his gear was full of little issues that culminated in it barely working.
Mine go up and down real easy, servo isn't working that hard at all. I use a single JR RT88 - although duals are in the works.
Patzane if the retract body mechanism is still attached and the gear leg itself is pulling out it sounds like you've striped the holding collars. I'll take mine apart later and confirm what holds the legs on.
Tom, I think the 13/16 number was wrong. I used an inch AND changed the belcrank holes. The only really critical travel is for down and locked - the pin must be all the way against the stops. UP and locked occurs before the stops so that last little bit of pin movement isn't as critical - although we don't want G loading trying to pull the gear down and the servo fighting that!
First and foremost you need to make sure the gear itself is working okay. The other one I set up had a burr on the slider that caused it to bind about about 2/3's movement. The quality control on the stamped steel parts isn't exactly the best. Probably the best thing to do is pull the retract right out of the plane and test it out by hand. Another area it can bind in is the rod that comes out of the retract and connects to the bellcrank. The conector on the end can rotate and snag on the spar structure causing massive loads for the servo.
I'll try to take some pics of these areas so it makes more sense.
Mine go up and down real easy, servo isn't working that hard at all. I use a single JR RT88 - although duals are in the works.
Patzane if the retract body mechanism is still attached and the gear leg itself is pulling out it sounds like you've striped the holding collars. I'll take mine apart later and confirm what holds the legs on.
Tom, I think the 13/16 number was wrong. I used an inch AND changed the belcrank holes. The only really critical travel is for down and locked - the pin must be all the way against the stops. UP and locked occurs before the stops so that last little bit of pin movement isn't as critical - although we don't want G loading trying to pull the gear down and the servo fighting that!
First and foremost you need to make sure the gear itself is working okay. The other one I set up had a burr on the slider that caused it to bind about about 2/3's movement. The quality control on the stamped steel parts isn't exactly the best. Probably the best thing to do is pull the retract right out of the plane and test it out by hand. Another area it can bind in is the rod that comes out of the retract and connects to the bellcrank. The conector on the end can rotate and snag on the spar structure causing massive loads for the servo.
I'll try to take some pics of these areas so it makes more sense.
01-22-2007, 12:21 PM
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RE: H9-F6F Hellcat 60 ARF
Ok.......how much do you guys out there trust the stick on weights from Great Planes?
I just added 2.5 oz's of these weights to the bottom of the Hellcat and positioned them all the way to the back (in front & behind the tail wheel). This is my first time using them without epoxying them. Not sure if the double backed tape is up to the task.
I just added 2.5 oz's of these weights to the bottom of the Hellcat and positioned them all the way to the back (in front & behind the tail wheel). This is my first time using them without epoxying them. Not sure if the double backed tape is up to the task.
01-22-2007, 04:31 PM
#592
Senior Member
RE: H9-F6F Hellcat 60 ARF
Flight Hawk they will stay on for about 2 or 3 flights. Then fuel residue and vibrations will make them fall off - usually in flight[:@]
Pantzane and Tom here are some pics of the gear. I took mine all apart today to see what's inside. Teh C clip is what keeps the gear leg from pulling out but more important to smooth action is the collar that holds the C clip firmly against the gear block. If you have too much play, the top of the gear leg will hit against the "down" allen stop.
Bascially, the only good way to make sure the gear is working well is disconnect the servo and play with it. If it doesn't move smooth by hand look for binding spots and interference points - there's lots of em.
Pantzane and Tom here are some pics of the gear. I took mine all apart today to see what's inside. Teh C clip is what keeps the gear leg from pulling out but more important to smooth action is the collar that holds the C clip firmly against the gear block. If you have too much play, the top of the gear leg will hit against the "down" allen stop.
Bascially, the only good way to make sure the gear is working well is disconnect the servo and play with it. If it doesn't move smooth by hand look for binding spots and interference points - there's lots of em.
01-22-2007, 04:47 PM
#593
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RE: H9-F6F Hellcat 60 ARF
Flight Hawk. I have used these weights for a long time and never have any come off. I drill a 3/32 hole in the center of the weights ( I have used a strip of up to 4) and a 1/16 hole in the plane(CA this hole). After I stick it on the weights, I secure them with a servo screw. If your not sure about the exact weight don't stick them just use a screw or two. No way there coming off!![>:]
01-22-2007, 05:02 PM
#594
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RE: H9-F6F Hellcat 60 ARF
I went to a fellow pilots, with 30 years experience, today to check out the retracts.
The torque occurs only when the gear is coming up just after the lock-down when there is the maximum (weight)pressure on the servo. It lasts about 1/10th of a second. Both gears seem to work smoothly by hand. We did remove the servo and reinforced the servo bracket. We also trimmed a little wood away from the pushrod connection and the push rod to the retract. When I use a 1" servo arm it bends at both ends at the end points and the servo hums. The round 13/16 th servo disc shows no sign of stress at the endpoints and no servo noise.
How much of the cowl did you cut out around the exhaust pipe for air escape??? I read you need twice as much as the intake???? There is a lot of intake but I think in this case twice is more than needed. I plan to cut an oblong slot to allow the pipe to clear and maybe a 1/2" clearance around the pipe. I want to leave the back edge of the cowl in tact so this will be an enclosed oval.
Thanks
The torque occurs only when the gear is coming up just after the lock-down when there is the maximum (weight)pressure on the servo. It lasts about 1/10th of a second. Both gears seem to work smoothly by hand. We did remove the servo and reinforced the servo bracket. We also trimmed a little wood away from the pushrod connection and the push rod to the retract. When I use a 1" servo arm it bends at both ends at the end points and the servo hums. The round 13/16 th servo disc shows no sign of stress at the endpoints and no servo noise.
How much of the cowl did you cut out around the exhaust pipe for air escape??? I read you need twice as much as the intake???? There is a lot of intake but I think in this case twice is more than needed. I plan to cut an oblong slot to allow the pipe to clear and maybe a 1/2" clearance around the pipe. I want to leave the back edge of the cowl in tact so this will be an enclosed oval.
Thanks
01-22-2007, 06:34 PM
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RE: H9-F6F Hellcat 60 ARF
Thanks Hepdog & TomTress
Iv'e never needed weights on any of my aircraft until now. With the Zen 20 on hanging on the nose, i had to do it [&o], it's just that i had to put them on the outside of the airframe [:@]. No way to secure them back far enough inside the fuse (it was tough enough just getting the batteries back there).
Iv'e never needed weights on any of my aircraft until now. With the Zen 20 on hanging on the nose, i had to do it [&o], it's just that i had to put them on the outside of the airframe [:@]. No way to secure them back far enough inside the fuse (it was tough enough just getting the batteries back there).
01-22-2007, 07:54 PM
#597
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RE: H9-F6F Hellcat 60 ARF
Tom it does need a fair amount of airflow - depends on the motor and how hot it gets where you fly. The H9 cowl lets a little bit of air out around the circumfrence but not enough for big motors or hot days
I'm using a 2C 90 and we see ambient of 95+ so alot of airflow was needed for me. My first version had an oblong slot on each side - one for the real pitts muffler exit and another was on the other side but fake. I also had 4 - 1/2" holes on the bottom and a 1/2 by 1" slot cut into the fuse behind the head with baffles to direct air around the head and out the slot. NEVER had an overheating issue once all that was done but it was kinda ugly.
The rebuild I'm doing is to clean all that up, and make it a little more scale. Cutting up the fuse is actually a much nicer option than big holes in the cowl and isn't all that hard. There's room between each stringer to build in ducts and in the end I think the firewall is actually stronger.
I guess I forgot to mention if you use 1" holes on the servo, you need to move the pushrod out to the outer holes on the bellcrank. I tried 13/16 and couldn't get it to work without buzzing etc. Moved to where I have it now and super smooth. PLUS the mechanical advantage gained by moving the rod out helps as well.
If there is a momentary loading on the servo when the gear is coming UP, don't worry - air pressure in flight will help that out! I find I have to slow down quite a bit to get the gear to come down and lock. I usually do a slowish flyby, hit gear down while pulling up and they slam down every time.
I'm using a 2C 90 and we see ambient of 95+ so alot of airflow was needed for me. My first version had an oblong slot on each side - one for the real pitts muffler exit and another was on the other side but fake. I also had 4 - 1/2" holes on the bottom and a 1/2 by 1" slot cut into the fuse behind the head with baffles to direct air around the head and out the slot. NEVER had an overheating issue once all that was done but it was kinda ugly.
The rebuild I'm doing is to clean all that up, and make it a little more scale. Cutting up the fuse is actually a much nicer option than big holes in the cowl and isn't all that hard. There's room between each stringer to build in ducts and in the end I think the firewall is actually stronger.
I guess I forgot to mention if you use 1" holes on the servo, you need to move the pushrod out to the outer holes on the bellcrank. I tried 13/16 and couldn't get it to work without buzzing etc. Moved to where I have it now and super smooth. PLUS the mechanical advantage gained by moving the rod out helps as well.
If there is a momentary loading on the servo when the gear is coming UP, don't worry - air pressure in flight will help that out! I find I have to slow down quite a bit to get the gear to come down and lock. I usually do a slowish flyby, hit gear down while pulling up and they slam down every time.
01-22-2007, 08:12 PM
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RE: H9-F6F Hellcat 60 ARF
Hepdog the part I have circle in red is what broke on mine.
TomTreese
here is pic of my opening. In the air it does not appear as big as the pic here and when on the ground no can see the open when right side up.
TomTreese
here is pic of my opening. In the air it does not appear as big as the pic here and when on the ground no can see the open when right side up.
01-23-2007, 09:58 AM
#600
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RE: H9-F6F Hellcat 60 ARF
ORIGINAL: Hepdog
Tom it does need a fair amount of airflow - depends on the motor and how hot it gets where you fly. The H9 cowl lets a little bit of air out around the circumfrence but not enough for big motors or hot day.
******I'm Using a Saito 100 and thimk a nice neat cutout around the pipeShould do it. ****
I'm using a 2C 90 and we see ambient of 95+ so alot of airflow was needed for me. My first version had an oblong slot on each side - one for the real pitts muffler exit and another was on the other side but fake. I also had 4 - 1/2" holes on the bottom and a 1/2 by 1" slot cut into the fuse behind the head with baffles to direct air around the head and out the slot. NEVER had an overheating issue once all that was done but it was kinda ugly.
The rebuild I'm doing is to clean all that up, and make it a little more scale. Cutting up the fuse is actually a much nicer option than big holes in the cowl and isn't all that hard. There's room between each stringer to build in ducts and in the end I think the firewall is actually stronger.
I guess I forgot to mention if you use 1" holes on the servo, you need to move the pushrod out to the outer holes on the bellcrank. I tried 13/16 and couldn't get it to work without buzzing etc. Moved to where I have it now and super smooth. PLUS the mechanical advantage gained by moving the rod out helps as well.
******I read earlier on this thread about using the outer hole of the bellcrank and you must have read my mind because I was going to ask you today about doing that. It maks sense for the mechanical advantage and it will take the 1" arm to move it the whole way. I'll try it tonight. THanks*****
If there is a momentary loading on the servo when the gear is coming UP, don't worry - air pressure in flight will help that out! I find I have to slow down quite a bit to get the gear to come down and lock. I usually do a slowish flyby, hit gear down while pulling up and they slam down every time.
Tom it does need a fair amount of airflow - depends on the motor and how hot it gets where you fly. The H9 cowl lets a little bit of air out around the circumfrence but not enough for big motors or hot day.
******I'm Using a Saito 100 and thimk a nice neat cutout around the pipeShould do it. ****
I'm using a 2C 90 and we see ambient of 95+ so alot of airflow was needed for me. My first version had an oblong slot on each side - one for the real pitts muffler exit and another was on the other side but fake. I also had 4 - 1/2" holes on the bottom and a 1/2 by 1" slot cut into the fuse behind the head with baffles to direct air around the head and out the slot. NEVER had an overheating issue once all that was done but it was kinda ugly.
The rebuild I'm doing is to clean all that up, and make it a little more scale. Cutting up the fuse is actually a much nicer option than big holes in the cowl and isn't all that hard. There's room between each stringer to build in ducts and in the end I think the firewall is actually stronger.
I guess I forgot to mention if you use 1" holes on the servo, you need to move the pushrod out to the outer holes on the bellcrank. I tried 13/16 and couldn't get it to work without buzzing etc. Moved to where I have it now and super smooth. PLUS the mechanical advantage gained by moving the rod out helps as well.
******I read earlier on this thread about using the outer hole of the bellcrank and you must have read my mind because I was going to ask you today about doing that. It maks sense for the mechanical advantage and it will take the 1" arm to move it the whole way. I'll try it tonight. THanks*****
If there is a momentary loading on the servo when the gear is coming UP, don't worry - air pressure in flight will help that out! I find I have to slow down quite a bit to get the gear to come down and lock. I usually do a slowish flyby, hit gear down while pulling up and they slam down every time.