viperjet questions
01-23-2007 | 09:51 PM
#1
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viperjet questions
Need some answers to help a friend get his Cermark Viperjet put together:
What's the servo requirements / recommendations ?
Nose gear doesn't fit the installed mount (steering arm binds hard against the lower fuselage), so the mount will have to be redone. To get this right, should the aircraft sit level or slightly nose high ?
All wing / stab etc mounting screws are missing. Anyone know what the right sizes are ? (I'm guessing they're probably some kind of metric thread).
For gluing the control horns into the ailerons, flaps, etc., are there hard-points already in the surface ? If so, where are they so that we can ensure that we cut the slots in the right places ?
Thanks in advance for any answers you can provide. There may be some more questoins coming soon...
Gordon
What's the servo requirements / recommendations ?
Nose gear doesn't fit the installed mount (steering arm binds hard against the lower fuselage), so the mount will have to be redone. To get this right, should the aircraft sit level or slightly nose high ?
All wing / stab etc mounting screws are missing. Anyone know what the right sizes are ? (I'm guessing they're probably some kind of metric thread).
For gluing the control horns into the ailerons, flaps, etc., are there hard-points already in the surface ? If so, where are they so that we can ensure that we cut the slots in the right places ?
Thanks in advance for any answers you can provide. There may be some more questoins coming soon...
Gordon
01-24-2007 | 05:25 AM
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From: Mother Earth, the Sunny side!
RE: viperjet questions
Gordon: is this 2nd generation (I am familiar with) or the 3rd and last generation? The wing screws are a strange size. Tam must have some around. MY Viper sat level on the ground and it flew great. I think I used 3421 on the tail, 9411 on the rudder, and regular size for flaps and ailerons(8411 or better). I still have some remains of my Viper and the wing servo hatch is the same so you can look at it and find the hard points. Make sure you double check the stiffness of the stab/stab mounts/rudder areas. I also added some CF cloth to the side of the fuse behind the engine former all the way to the fin area. Get a lot of flap deflection. Glue the winglets...
01-24-2007 | 07:45 AM
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RE: viperjet questions
Gordon, I think most of the changes were "internal". I can tell the difference by looking, but can't really tell you what to look for off the top of my head. I think (I use this loosely) that you can tell by looking at the wing spars. If it has normal "blade" style, it is a 1st or 2nd Gen. I think the 3rd Gen. utilized spars that looked more like a "T". But as I said, I may not be exactly right; it has been awhile since I've dealt with the Viper Jet.
George
George
01-24-2007 | 07:47 AM
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RE: viperjet questions
ORIGINAL: George
Gordon, I think most of the changes were "internal". I can tell the difference by looking, but can't really tell you what to look for off the top of my head. I think (I use this loosely) that you can tell by looking at the wing spars. If it has normal "blade" style, it is a 1st or 2nd Gen. I think the 3rd Gen. utilized spars that looked more like a "T". But as I said, I may not be exactly right; it has been awhile since I've dealt with the Viper Jet.
George
Gordon, I think most of the changes were "internal". I can tell the difference by looking, but can't really tell you what to look for off the top of my head. I think (I use this loosely) that you can tell by looking at the wing spars. If it has normal "blade" style, it is a 1st or 2nd Gen. I think the 3rd Gen. utilized spars that looked more like a "T". But as I said, I may not be exactly right; it has been awhile since I've dealt with the Viper Jet.
George
Thanks,
Gordon
01-24-2007 | 07:50 AM
#7
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RE: viperjet questions
I would say yes, 3rd generation then. You should not have to do anything special then if this is the case. ENJOY!
George
P.S. I meant to say you don't need to the same mods that were required on the earlier birds. Sorry I can't help you with your existing problems.
George
P.S. I meant to say you don't need to the same mods that were required on the earlier birds. Sorry I can't help you with your existing problems.
01-24-2007 | 07:55 AM
#8
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RE: viperjet questions
gordon
i am on my second viperjet loved the first one so much had to get a second (losted first one to pcm lockout)
both are first generation the first had reg size hitec dig in ele-rud-flaps-aler i used todds bobcat covers on the tail
servos they stuck out a little it had sping air gear/ robart struts/ bvm brakes futaba radio ram 750p auto start
for power 21 lbs is just right for this plane was radar gunned at 187 full power get as much flap as you can
second one has jr 3421s in the tail /hitec digs in the wings/robart gear and struts bvm brakes
ram 750 p auto this one i am going to setup crow per tams photos
use the cg per book and get the most flaps you can
also both i filled the tail with 2 part foam to stiffen it a little
george from va told me about that mod
plane flys like a fast pattern plane
good luck with it
vinny
i am on my second viperjet loved the first one so much had to get a second (losted first one to pcm lockout)
both are first generation the first had reg size hitec dig in ele-rud-flaps-aler i used todds bobcat covers on the tail
servos they stuck out a little it had sping air gear/ robart struts/ bvm brakes futaba radio ram 750p auto start
for power 21 lbs is just right for this plane was radar gunned at 187 full power get as much flap as you can
second one has jr 3421s in the tail /hitec digs in the wings/robart gear and struts bvm brakes
ram 750 p auto this one i am going to setup crow per tams photos
use the cg per book and get the most flaps you can
also both i filled the tail with 2 part foam to stiffen it a little
george from va told me about that mod
plane flys like a fast pattern plane
good luck with it
vinny
01-24-2007 | 08:13 AM
#9
RE: viperjet questions
ORIGINAL: Gordon Mc
Need some answers to help a friend get his Cermark Viperjet put together:
What's the servo requirements / recommendations ? JR 3421 or Hitec 5245 for elevators. The 3421 is a better fit being narrower and that is what I used. JR 9411 on the rudder. Anything standard size on the ailerons and flaps. I had 8231s lying around and used those.
Nose gear doesn't fit the installed mount (steering arm binds hard against the lower fuselage), so the mount will have to be redone. To get this right, should the aircraft sit level or slightly nose high ? Level
All wing / stab etc mounting screws are missing. Anyone know what the right sizes are ? (I'm guessing they're probably some kind of metric thread). 5-40 for the wing mount bolts but may be different on the gen 3 you have. The Cermark Aermacchi and the other Viperjets used the 5-40 bolts. You can find them in the car department of hobby shops.
For gluing the control horns into the ailerons, flaps, etc., are there hard-points already in the surface ? If so, where are they so that we can ensure that we cut the slots in the right places ? I don't recall that there were any specific hardpoints.
Thanks in advance for any answers you can provide. There may be some more questoins coming soon...
Gordon
Need some answers to help a friend get his Cermark Viperjet put together:
What's the servo requirements / recommendations ? JR 3421 or Hitec 5245 for elevators. The 3421 is a better fit being narrower and that is what I used. JR 9411 on the rudder. Anything standard size on the ailerons and flaps. I had 8231s lying around and used those.
Nose gear doesn't fit the installed mount (steering arm binds hard against the lower fuselage), so the mount will have to be redone. To get this right, should the aircraft sit level or slightly nose high ? Level
All wing / stab etc mounting screws are missing. Anyone know what the right sizes are ? (I'm guessing they're probably some kind of metric thread). 5-40 for the wing mount bolts but may be different on the gen 3 you have. The Cermark Aermacchi and the other Viperjets used the 5-40 bolts. You can find them in the car department of hobby shops.
For gluing the control horns into the ailerons, flaps, etc., are there hard-points already in the surface ? If so, where are they so that we can ensure that we cut the slots in the right places ? I don't recall that there were any specific hardpoints.
Thanks in advance for any answers you can provide. There may be some more questoins coming soon...
Gordon
You can always bug Jimmy or Tam (at the expense of green bottles
). Mark
01-24-2007 | 09:13 AM
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RE: viperjet questions
Thanks guys !
Do you know what rating of Hitec digitals you used ?
I may try asking Jimmy as suggested. I already emailed Tam the questions, but I know he's really busy right now so I don't want to bug him too much.
Cheers,
Gordon
Do you know what rating of Hitec digitals you used ?
I may try asking Jimmy as suggested. I already emailed Tam the questions, but I know he's really busy right now so I don't want to bug him too much.
Cheers,
Gordon
01-24-2007 | 09:26 AM
#11
RE: viperjet questions
I think I am the only one that mentioned the Hitecs. The mini size HS5245 was originally an option for the elevator. It is nearly the same size as a JR 3421 but it was slightly thicker and harder to fit. For convience and a flush cover the 3421 was the best choice.
Not sure if that is the one you were asking about, but here are the 5245 specs from Tower
Operating speed: 0.15 sec @ 60 degrees at 4.8V
Torque: 61 oz-in (4.4 kg-cm)
Weight: 1.12oz (32g)
Length: 1.27" (32.4mm)
Width: 0.66" (16.8mm)
Height: 1.21" (30.8mm)
Wire length: 12" (305mm) approximate
I used all JR.
Mark
Not sure if that is the one you were asking about, but here are the 5245 specs from Tower
Operating speed: 0.15 sec @ 60 degrees at 4.8V
Torque: 61 oz-in (4.4 kg-cm)
Weight: 1.12oz (32g)
Length: 1.27" (32.4mm)
Width: 0.66" (16.8mm)
Height: 1.21" (30.8mm)
Wire length: 12" (305mm) approximate
I used all JR.
Mark
01-24-2007 | 09:56 AM
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RE: viperjet questions
ORIGINAL: BlackCloud
I think I am the only one that mentioned the Hitecs.
I think I am the only one that mentioned the Hitecs.
I have just found the following spec's though:
Elevator: 2 JR 3421
Rudder: 1 Jr 9411
Aileron: 2 Jr 2721 or any good standard size servo.
Flap: 2 Jr 2721 or any good standard size servo.
Retract :Jr 341 or any mini size servo
Nose steering: Standard size servo
So that seems to answer my servo-requirements question.
Thanks a lot for the help guys.
Gordon
01-24-2007 | 12:54 PM
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From: Mother Earth, the Sunny side!
RE: viperjet questions
Gordon: the last gen Viper does NOT have live hinging! One has to hinge the surfaces with robarts hinges. there are more CF in the fuse and the body. If you wish, I can come by your house and check it out....
01-24-2007 | 01:31 PM
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RE: viperjet questions
ORIGINAL: Ehab
Gordon: the last gen Viper does NOT have live hinging! One has to hinge the surfaces with robarts hinges. there are more CF in the fuse and the body. If you wish, I can come by your house and check it out....
Gordon: the last gen Viper does NOT have live hinging! One has to hinge the surfaces with robarts hinges. there are more CF in the fuse and the body. If you wish, I can come by your house and check it out....
I don't think ther's any actual "need" for you to come by to check it out, but you're always welcome to come by and visit any time you want.
Gordon
