Asif

My Feedback: (30)

Hi, here are some pictures. No smoke on this jet. Out of 6 jets, I have smoke installed in one which I rarely use.... just not a fan of smoke. I have 3 Powerbox batteries ( two for RX, one for retracts and brakes). Will be installing cockpit from Scale-cockpits once it shows up. I have Intairco stand for storage and transport, very convenient.

https://www.scale-cockpits.at/eshop/...er-mk2-skygate

Regards
​​​​​​​Asif

ECalderon

Hi

I have the same scheme. With those two batteries in the front, its definitely going to be nose heavy. My turbine batteries are located in the back of the fuel tank, and receiver batteries on the sides just in fron of the fuel tank.

Regards
Eduardo

Dave Wilshere

The tail servos used make a big difference in the balance requirement, since the manual balance is so nose heavy, with JR servos in the tail we have Vipers with all three batteries on the fuel tank (with some cockpit) with metal case servos like Savox the batteries are in the cockpit in front of the tank.
Because the Viper flies OK with the forward balance many people leave it nose heavy...but it’s so much nicer with my rear balance!

Skunkwrks

Hello fellow pilots. I have a Cayman painted Viper that I'm starting to assembly.
I'm going with the JetsMunt M166TS turbine for power and using the Electron ER40eVo gear and a GS 200 control as I have replaced the original controller.
Going with some new JR 8911 servos on the aileron elevator and rudder should have enough control. Flaps I'm using some Savox 1230 also for steering.
Radio is Jeti DS16 with a CB 210 central box using the thrid-receiver as the power switch and staying with all of the CARF hardware as it's quality is good.
I'm going to run some Navi lights on the wings with a strobe and a beacon for those overcast days flying.

Are there any issues/ problems I should be aware of this build I would greatly appreciate your point of view?

Russ

skunkwurk

My Feedback: (18)

Hello Skunkwrks - I think our screen names may create confusion....

Skunkwrks

Well Hello skunkwurk- It may, as mine is Skunkwrks named after Lougheed's the special project.
I will help in regards to redirecting fellow FCU members to the USA skunkwurk and the Canadian Skunkwrks member....

Skunkwrks

Hope the Avitar photo helps ..

Dave Wilshere

Ignore the manual balance point, it needs to be way behind where the designer put it. I think I put my figures in an earlier post. You may struggle to get the 8911 in the tailplane, it will need some work as it was designed for a 19mm 8411. The electron gear will require packers in the mains.
Otherwise it’s an easy build.

Canadian Man

My Feedback: (1)

Glad you found this thread Russ. I was just going to message you to check it out.

Agrav8ed

I could be wrong but I also seem to remember that the nose opening is a little small for the electrons nose gear. But I agree, is a good build and a great flyer.
Tone

Dave Wilshere

Yes, also for the original Air leg. Unless a manufacturer only offers the design with one choice undercarriage its best to have it undersized...without making opening the hole an impossible job!
Once we are confident all the original Air gear has gone into retirement we can redesign the gear mounts for Electron.

Skunkwrks

Good to hear about the front gear tolerance, I haven't tried fitting the front gear. The whole airframe was designed around the german air retracts it seems, until CARF does a refresh with the Viper these issues will be addressed by guys like me preferring to Electron gear over the factory air set..

Thanks Agrav8ed and Dave for the help, looking for to flying this bird in May..

Skunkwrks

Thanks, Jonathan it's the only forum offering good information about this Jet venture I'm going into of course with a lot of guidance from you,Yoda

Russ

pfact

My Feedback: (92)

Skunkwrks -

I tackled the same issues when I built my son's Viper in 2013. We chose to try Behotec electric retracts & brakes - they are an easy fit (no modification required) and after 111 flights I can say they work at least as well at electron. The cool thing about them is they use stepper motors which permits the user to define up and down endpoints rather than relying on changes in current draw to stop.

Phil

Skunkwrks

Checked the gear in the bracket and had to narrow the support bracket with some plywood and hysol fastening to the bracket. The wheel looks like it will touch the fuse with the gear swing. Might have to get a 65mm wheel as the re40 gear have a 75mm wheel. The Behotec are good gear and having adjustable limits are great.

Dave Wilshere

The door is supplied long enough to open the hole to suit, we take out the steering servo mount rail..

Skunkwrks

Thank goodness the door is long to cover the notches in the fuselage. I'm leaving the servo bracket on 4MM blind nuts are mounts with some Goop to ensure they don't move.
The gear swing now is unobstructed and operates smoothly, had to shorten the steering arm so it would clear the fuse side

A7Bldr

My Feedback: (40)

Here's a unigue video of the Viperjet.

Skunkwrks

Great video of your Viper flying from a frozen lake.
What size turbine are you using and what is your elevation from that lake.
Thanks Rusty

A7Bldr

My Feedback: (40)

Hey Rusty, that is not my plane or video, I just saw it myself and was amazed at how well it worked off the ice.
I think he is using a -180 size turbine.

I do have one to try this year on a -14o JetMunts engine, though.
Jim

Skunkwrks

Okay, it's the same paint scheme as mine and is easy to see in the air.

Mine is just about ready for test runs and soon first flight.
I'm using the Munt 166 for power but my elevation is 3400ft so 18% less trust than sealevel at 30.7N of thrust

Skunkwrks

I need some help with CG on my Viper. The manual says it should at the front of the wing and it can move forward 10-15mm from the tube front.

The issue I'm having is I need to add 848g to the nose to balance out on the Xicoy scales.

Seems to be a bit excessive for the weight with a full UAT tank and 2.5cm of fuel in the tank .

Would like to hear what other have done to get a neutral flying Viper.

Thanks Russ

DUCMOZ

You can go back in this thread and read Dave’s comment. He has clearly advised where the balance should be.

Behzad

Skunkwrks

Thanks DUCMOZ for the obvious answer .........

I move the CG point to the rear edge of the spar,30mm and now the balance weight is very manageable.

Should fly get in this range for aerobatics manoeuvres, thanks Asif for your input here?

Peter A

My Feedback: (34)

The Skygate/CARF Viper is very flexible on the CG. I flew mine with no weight in the nose just the batteries located above the nose wheel for 5 years and I sold it and it is still flying today.
You really need NO extra weight at all in the nose. You can pushback to behind the wing tube also, 800gr seems excessive nose weight.