|
RE: Another Skymaster Viper
@Alessandro,
don't use those shims. Keep the turbine in parallel with the mounting rails, and align it with the pipe only. I've talked with a lot of people about this, some with lots of viper experience ;) The intake seems to be off-center, thrustline with the rails and pipe in one line is ok and inline. Hans |
RE: Another Skymaster Viper
ORIGINAL: DelGatoGrande ORIGINAL: Matt Chapman .... Will an incidence + or - have an effect on the pitch of the plane based on power in flight? ... Yes it can have an effect! like in prop planes we must fine tune the up down thrust of the engine.. same think in jets. its like you having a vector thrust set up whrong... start seting a degree lazer meter to zero on the wing ...then check engines mounts and pipe.. ..but if Matt Chapman enjoy fly this toy untill now..then it needs no corection:D forgive my poor english Besides the problem of the thrust line another problem could be the heating of the tube. With the incidence of my mounting rails of the turbine the bottom of the tube will be much more hot the top and we are speaking about many degrees... am I becoming paranoid? [&:] Alessandro |
RE: Another Skymaster Viper
Mount the turbine to the rails as they are supplied. Then line the tube up to the turbine ( Straight ) All is fine. The heat is distributed evenly down the pipe ( Dont worry this is no fry eagle pipe ;) ) There is no pitch change with power. I know it looks strange but all of the Vipers are like this and all work perfectly.
Regards Al |
RE: Another Skymaster Viper
The Man spoke,the issue end
time to fly[8D] |
RE: Another Skymaster Viper
1 Attachment(s)
ORIGINAL: NightSwan @Alessandro, don't use those shims. Keep the turbine in parallel with the mounting rails, and align it with the pipe only. I've talked with a lot of people about this, some with lots of viper experience ;) The intake seems to be off-center, thrustline with the rails and pipe in one line is ok and inline. Hans I've done a scheme... terrible! :D A |
RE: Another Skymaster Viper
ORIGINAL: DelGatoGrande The Man spoke,the issue end time to fly[8D] You are right! Thanks you all. |
RE: Another Skymaster Viper
1 Attachment(s)
ORIGINAL: f106jax ORIGINAL: DENTO ORIGINAL: kimba HI All and John I have finally finished the Viper no maiden as yet Temp here for the next week is going to be 39 to 41 C so there are fire bans in place have done quite a few mods some from this forum and some of my own which I have posted. It has been a big help reading what you guys have done thanks for all of the posts I will post a few pics that may be of help to others Cheers Bronte Sorry about the fire ban as you know ours has been lifted, Talking to Chris Venter larst night and he is close to finishing his, So I shall leave my maiden untill we can do both at the same time in maryborough maybe early feb,Could be as many as 6 VIPERS at wangeratta, Talk to you soon bronte shall add some shots of my craddle . REGARDS JOHN Would you be good enough to post the dimensions of your carrier and templates of the front and rear fuselage cradles? Looks great! Thanks, Shall post some shots of the craddle and try and explain BOTTOM PLANK 2.4 MTS LONG X290 MM WIDE BOTH FRONT AND BACK SUPPORTS 290MM WIDE 190MM H MIDDLE SUPPORT 1800 X 90 LONG I hope the shot will help you will have to allow for what ever tube you use apart from cutting templets and posting them by post this is the best I can do REGARDS JOHN |
RE: Another Skymaster Viper
Just a heads up chaps, if you do make a craddle don't leave your presious airframe on it for a long period of time, the paint will fade from UV exposure, but not under the straps, even under the bottom supports there will eventually be a colour difference, just thought I would mention it.
Mike |
RE: Another Skymaster Viper
Be carefull with thrust angle and thrust line height. Can be confused . A boomerang has the thrust line very close to the (vertical)Cg , changing its angle a little don´t change its height a lot with respect to the Cg ,that´s what really counts.
Ask a harpoonII owner how easy is to get into problems with thrust trim .... I have seen it flip on take off. Some cheap ducts can suffer from heat but normally thre is no problem,a lot of fresh air is bypassed into the duct. |
RE: Another Skymaster Viper
When I had the second flight on my Viperjet, the canopy was destroyed in flight (pictures a few pages back).
I got a new piece of plastic from Skymaster (quick delivery!), and installed it, no problem. However, today when cleaning the workshop, I looked at the old plastic, to see if a few pieces could be saved for other purposes, and I noticed that the plastic is VERY brittle at the edge where it was glued onto the canopy frame, just the slightest touch/twist, and it cracks! I cut a piece of it out, and tried on that, holds very well. So the glue Skymaster uses for fixing the glass to the canopy frame makes the plastic brittle, and I wonder how long the canopies out there will hold ?? Any of you seen similar stuff ? |
RE: Another Skymaster Viper
ORIGINAL: Ali Mount the turbine to the rails as they are supplied. Then line the tube up to the turbine ( Straight ) All is fine. The heat is distributed evenly down the pipe ( Dont worry this is no fry eagle pipe ;) ) There is no pitch change with power. I know it looks strange but all of the Vipers are like this and all work perfectly. Regards Al with a friend of mine that is building another Viper we measured the difference of degree between wing and engine mount... 4 degrees!!! Of course I swear I believe you (!!:)) about the strange absense of pitch change with power but what about the total power? Don't you think we can lose some of it? Alessandro |
RE: Another Skymaster Viper
Alessandro
mine also looked strange when i put a straight line on the rails, as it does hit the bottom of the rear of the fuz. However i checked Ali's model which has the same angle of the rails, but the turbine lines up perfectly when bolted in place. I bolted mine onto the rails with the bypass and it also works out fine. Weird i know, i wasn't sure if it was an optical illusion to start with lol Duncan |
RE: Another Skymaster Viper
ORIGINAL: Duncan Alessandro mine also looked strange when i put a straight line on the rails, as it does hit the bottom of the rear of the fuz. However i checked Ali's model which has the same angle of the rails, but the turbine lines up perfectly when bolted in place. I bolted mine onto the rails with the bypass and it also works out fine. Weird i know, i wasn't sure if it was an optical illusion to start with lol Duncan you are right, it seems in line, but you will agree with me that cannot... I think we will find an answer here http://www.youtube.com/watch?v=NzlG28B-R8Y :D Alessandro |
RE: Another Skymaster Viper
ORIGINAL: cgroen When I had the second flight on my Viperjet, the canopy was destroyed in flight (pictures a few pages back). I got a new piece of plastic from Skymaster (quick delivery!), and installed it, no problem. However, today when cleaning the workshop, I looked at the old plastic, to see if a few pieces could be saved for other purposes, and I noticed that the plastic is VERY brittle at the edge where it was glued onto the canopy frame, just the slightest touch/twist, and it cracks! I cut a piece of it out, and tried on that, holds very well. So the glue Skymaster uses for fixing the glass to the canopy frame makes the plastic brittle, and I wonder how long the canopies out there will hold ?? Any of you seen similar stuff ? |
RE: Another Skymaster Viper
Sorry to hear about that !
I ordered one middle of december, and received it approx 1 week after ! |
RE: Another Skymaster Viper
Yep it doesn't make sense, but Ali would notice if there was an issue with the thrust angle, if he can't notice any, there's no chance my dumb thumbs will lol
|
RE: Another Skymaster Viper
ORIGINAL: dubd ORIGINAL: cgroen When I had the second flight on my Viperjet, the canopy was destroyed in flight (pictures a few pages back). I got a new piece of plastic from Skymaster (quick delivery!), and installed it, no problem. However, today when cleaning the workshop, I looked at the old plastic, to see if a few pieces could be saved for other purposes, and I noticed that the plastic is VERY brittle at the edge where it was glued onto the canopy frame, just the slightest touch/twist, and it cracks! I cut a piece of it out, and tried on that, holds very well. So the glue Skymaster uses for fixing the glass to the canopy frame makes the plastic brittle, and I wonder how long the canopies out there will hold ?? Any of you seen similar stuff ? please send your address with telephone number to this e-mail addres , [email protected] we will send the canopy to you directly as soon, Best regards Anton |
RE: Another Skymaster Viper
I measured also the thrust line and i have got also the same problem as before. ( I think it is alessandro )
I think i will change the front ( of the mounting rail ) so the thrust line will stay almost the same as Ali says. ( with no pitch difference ) and after the turbine and thrustpipe are straight. Question to Anton, mine clear canopy is also broken. ( it is really very brittle ) can you tell me how much i have to pay for a new clear canopy? best regards,, Peterjan |
RE: Another Skymaster Viper
ORIGINAL: Duncan Yep it doesn't make sense, but Ali would notice if there was an issue with the thrust angle, if he can't notice any, there's no chance my dumb thumbs will lol Ali, the friend of mine is Marco Loreti that sends you a greeting! He works with Luca Friggeri that spoke to me about you. Alessandro |
RE: Another Skymaster Viper
Hi Alessandro, Hi to all my Italian friends!
I dont think it makes a difference with the thumbs. My Viper also has the turbine looking like the turbine is angled up at the front. We measured the same with Duncan's model. No trim or pitch change. The Intake to the turbine angle is not straight but the turbine to tailpipe is level. I am sure there is no problem to angle it either with Shims, but non of my Vipers have ever had a shim. Good luck. Regards Al |
RE: Another Skymaster Viper
ORIGINAL: Ali Hi Alessandro, Hi to all my Italian friends! I dont think it makes a difference with the thumbs. My Viper also has the turbine looking like the turbine is angled up at the front. We measured the same with Duncan's model. No trim or pitch change. The Intake to the turbine angle is not straight but the turbine to tailpipe is level. I am sure there is no problem to angle it either with Shims, but non of my Vipers have ever had a shim. Good luck. Regards Al Ciao Alessandro |
RE: Another Skymaster Viper
SM Viperjets experts!
Guys I am about to start working on the fuse as I already finished all moving surfaces. To my surprise the main large Kevlar tank doesn't fit at the bottom of the fuselage..... at the time I try to push the tank back to be under the intake bypass…. doesn’t fit….. it hits the intake.... it needs shim about 3 mm to able to fit. I am about to cut the tank in half at the seam…. remove the 3 mm and re glue the 2 pieces…. I know I can do a good job but what a pain. Question? have any of you guys had that same problem…. or I am the only un lucky? I am also considering moving that main tank on top of the bypass…… but I am concerned with having so much weight on top….. due to fuel. By the way I measured the capacity of both Kevlar tanks and they are huge…. Bottom=92 onz and Upper 56onz…. total of 148 onz! Any recommendations would be quite appreciated, Gonzalo Northern California |
RE: Another Skymaster Viper
Gonzalo,
in my viper SM glued some mounts for the air-tubes at the back of the fuse-bottom - my tank would not slide all the way back. Could this be your problem as well? I removed the airlines and re-located them - tank fits perfectly now.. Good luck! Hans |
RE: Another Skymaster Viper
1 Attachment(s)
I know of a builder who found his intakes were not glued in straight so had to do the same thing and put his tank on top of the intakes instead of under.
To make the best of this he just located his smoke tanks under the intake instead. Check the picture, you can just see the front of the smoke tanks. PaulD |
RE: Another Skymaster Viper
Thanks Hans and Paul for the info!
I am not planning so far to put smoke.... so I'm still on the side to cut the tank and redo the work.... is very little what I need to remove.... I am a little hesitant to have all that weight hi in the fuse...... unless I do most of my flight inverted :) I still curious how many had that issue. Regards, Gonzalo |
| All times are GMT -8. The time now is 08:32 PM. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.