Ok, our new "jet shop" is ready and full equipped [sm=thumbup.gif], Alex's was out on weekend so as Jaime (the 3rd Buddie)...So on Saturday I took a break with the Europort and decided to lay my hands on my Viper.-

For those who has not have the chance to check on the new Viper there is a big difference with the old version, so the effort of giving us a better structural plane is notable and archived.

This is my second Viperjet....and you know...."the second half of the wing always is better build than the first one[&o]" ...So the idea of starting this thread is to share step by step my joy [&:] of putting this jet together.
I'll start posting picture tomorrow....due I did not have my digi camera at the shop on Saturday....[&o]

Regards,

Miguel.-

Miquel, here is my Viper (latest old version) with the struts I got from you-THANKS! I love the way it flies, but it took a few rough landings to figure out how to land it.

What's the difference between the old and new versions besides the wing construction?

George

George,
Cool and clean job!
I'm glad you are happy with the struts.-

Landing the Viper is not difficult...after your learn It took me 3 set of struts.....but anyway....I'm not a super pilot either. I use 15 or 40 degrees flaps deflection... I do the approach always with the nose level or down and go to1/4 of power when in the runway axis. At about 30. feet hight I go to idle and let the Viper fly down with level or down nose nose....never nose up... Start to flair at about 5 feet of the ground....The flair is the trickie part....careful. You'll need pull the stick to slow descending speed.... I decided not to use exponentials.....feel better for my taste.
I do not use flap-elev mixing (personal choice) and always land on hight rates mode....better yet, after testing I only use one rate setting and do the rest with the fingers.....with the rudder don't.

Regarding the differences between the new and previous Viper version, I'll point them out during the building process.- Last Saturday I started with the rudder and also glued all hinges to the moving surfaces......and noticed:

* that inside there is a new layer of carbon fiber cloth.
* Also the rudder as all other flying surfaces, feels heavier and the skin is veeeery much stronger
* all notches and holes for the hinges are ready.....I just did some minor work to push the hinges more inside to get the proper location of the pivoting point of rotation....not big deal at all.-
Lets wait till tomorrow....a picture is 100000000000 times better than my writing....Imagine this: Tam's English is better than mine [X(], and this is not science fiction

Thanks,

Miguel

Lets wait till tomorrow....a picture is 100000000000 times better than my writing....Imagine this: Tam's English is better than mine [X(], and this is not science fiction




I agree you with 100%. That why I'm not doing the instruction for my Super Hornet.
Tam

Great timing on this thread! I'm also getting ready to build my ViperJet.

George, which SimJet are you using? I have a 2300 AES & a 3000 AES, which would be a better fit? Are you guys using real carbon plates for your component mounting, or is it plywood covered with Ultracote or similar? I ask because there's been serious talk about Rf interference when close to carbon parts...

What servos are you planning on using/ currently using? I'm a JR guy, so if you have suggestions for JR components, let's hear 'em.

Miguel, I'm also planning on installing a Tam's smoke system & lighting like George, are you going to include this in your build thread?

Thanks in advance!

Edit: grammer....[]

Mark, I have 2300 AES. I think this is plenty of power. You could always try both. I have 1700 also and may try that at a later time. These particular tray are the stock plates covered in Ultracoat. I also have some ABS in there as well. I have 8411's on the ail. and rudder, 9411 on steering, 3421's on elev. and HS 5645's on flaps which are not used but would go with something big on the flaps perhaps in an analog.

George

Mark,

I'll go with plastic simulating carbon fiber.....but anyway I had use real carbon fiber for same purpouse in other pojects,,,,and not problem at all with the radio.-

Regardig the servos and despide arguments...I'll go with Hitec 5945 for flaps, 5245 for Aile, elev and rudder.- I been using these servos WITH NO problem at all.-

The smoke is the tie of the Viper's suit.- I'll be using an preasurize system with 20 onz capacity tank. Is my own made and works perfect at 70 PSI....Tam's works pecfect too, is just that I enjoy doing some stuff on my own...[&:]

The lights will go also. Strobe and landing lights sytem, with the touch of a micro switch to turn the landing lights on when the wheels goes down.

Regards.-

Okay guys, let's get it on!!!!

Just got off the phone with Tam, and he's sending me the rest of the stuff I need to get the ViperJet together. Should have it all in a couple of days......

I'm feeling the temperature raising a few degrees up, all right [sm=thumbup.gif]

THE VERTICAL FIN & RUDDER:

IMPROVEMENT # 1
Yesterday I compared both fins (new and old vertion) and for sure the new one weight much more that the old due the reinforcements made (carbon fiber layers). With a digital caliper I measured the thickness of the rudder wall at the servo bay openning. The old one measure 0.036" and the new 0.060"...big diference, but only in that area. In others they have the same.


ASSEMBLING

Material used:
4 units 4-40 socket head screws cutted to lenght.
2 units 4-40 bllind nuts
2 units 4-40 flat washer
1 set on BVM servo mount
3/16"plywood.

Attatch the servo to the mount. Only one pair of screws, nuts and washer are require.
Cut 3/16"plywood base as per the servo side size and with 4-40 blind nuts to hold the servo mount. Glue that base with Hysol and don't forget to do it archiving 90 grades with the fin trailing edge.

.....to be continue....have to go now

Miguel

I was wondering....and I'm goig to refer in this thread only to the important details the can make difference in the asembling process. If not this is going to be endless [&:]
Anyway, if someone have a particular questions, comment, sugestions, then we could cover those details...
Later,
Miguel.

Miguel,

I built the Viper a month ago but elected to paint it in different colors, by doing so it added some weight to it. Hence, I had to add a pound of weight to the nose for balance, even with all the batteries up front. The new Viper is beefed up with corbon fiber and resin in stress points adding to the overall weight.

Use the servos Tam suggested, he has been through it. By using different servos that are stronger, they are taller for some use. I had to make servo covers out of .010 BVM polly ply besause the ones supplied are set inside the cut out. Then I used clear silicon to attach them.

I powered mine with a P120 turbine, this is plenty of power, the model is a great flying plane. With the wing loaning keep the speed up and watch the nose attitude. On the second flight I dropped the gear and pulled the nose up before the flaps, to my surprise it did a half snap. I keep the speed up from now on and not had a problem.

Good luck,

Ken.....

Yeah Kevin, I already noticed the new Viper has tendency to be tail heavy due all new structural reinforcement and for having the new main gear almost 1" aft the original location.....[sm=frown.gif] happiness is never complete right...[&o]
I'm going to use 2 cytoys pilots....instead of one, and also plan to go with all details possible at the cockpit...
Also, instead of using standard size servos for the ailerons, is better to use HS-5245 or similar size & weight servos. They weight half and are located behind the balancing point.
Regarding the way to secure the elevator and rudder servos, I'm not sure but have the feeling that you need a good amount of silicon glue to hold them in place....and this way is heavier than using screws....right?
I use screw in my previous Viper and the set up was light and removable. At the elevators I had the same problem you had with the hatch, but now I reduce the problem to 0.25mm....that can me solve making a notch at the under side of the hatch cover.
Also installing the turbine & bypass as close as possible to the nose side (with some small mods []) could be a way to.....
If you don't have plans to fly off grass field, then use 2 5/8 inches mains wheels instead of 3 inches.
If you are using Y harness (without matchbox) to connect the elevator servos, then try to have the split of the Y as aft possible to reduce the weight of 2 servos extensions all the way from the tail.
Installing the light system will also help to balance.
I hate the idea of carrying dead weight on a plane....[>:]

As per the flap issue.....if you want to drop flaps without having problem regarding speed or nose level, then mix it with down elevator. As said before I prefer not to mix mine....I just drop the flaps at about 3/8~1/2 throttle stick position.

Are you going to be at FJ?
I'm 100% agree with you,,,,this a a beautiful plane and never going to get tire of telling to Tam to make a BIGGER version with All scale details [sm=thumbup.gif][sm=tongue.gif]

Miguel.-

Nice thread you have started, Miguel.....

Three of us up here in Wisconsin are building Vipers......

We did swap out the 3421's in the elevators for 9411's which are a little taller....to solve the cover problem, we are using plastic hatches from Todd at Dreamworks that he originally did for the Bobcat when the issue of 9411's replacement came up....they are $9.95 for 2 of them.....just tape them in place....you can leave them clear or paint them.....

We fly off grass most of time up here so for the last 8 years we have learned to beef the gear plates, BEFORE they crack.....

We add 1.5 mm Carbon Fiber plate to the top of the nosegear plate and 3.0 mm to the bottom and then tap into it for the retract machine screws.....no need for blind nuts.....

For the mains, we just added a lower plate(closest to the top of the wing, also 3.0mm and we tap into that again for the mounting screws.....no room for a top plate facing the retract....it elevates the cylinder enough to hit the former it rests under, so just gonna put some resin on the wood to keep it from getting soft on wet grass or asphalt.....

Thanks for tips on flying and on preliminary C.G from you and Ken.....

I can post pictures of our C/F plates if its O.K. with you....don't want to hijack your thread.......

Tom/Dave/Bob
Fond du Lac Viper Builders

If you guy need help. Just ask me. I only built about 20 Viper myself.
I didn't add any nose weight on my. Ofcourse the battery carry onboard can fly for 20 flight for RX and 9 flight for ECU before need to be rechard.
I love to use battery for balance.
My camo Viper Jet is already it way to Florida.
See you guys next week.
Tam

Tom,
Glad you like it
I don't want this to be MY thread. Lets put together here all info that might orientate everyone interested in the Viperjet.

We have here an asphalt runway, but with my previous Viper I involuntarily tested the main gear bases... and they are veeery strong... As per the nose gear, I was thinking in the possibility of using a flex plate that can act as a fusible (not sure yet).....I had the experience of having my nose plate broke...and change it was complicated....and also affected the outside cosmetic of the fuselage nose [&:][].-

So, post what ever you want [sm=thumbup.gif] and lets all enjoy this Viperjet festival
[sm=bananahead.gif]

Regards,

Miguel.-

Thanks for the comments Miguel......as all 3 of us are building independently, we do things slightly different.....as soon as I get a chance, I will snap a few more photos of how we have mounted servos, etc......

I would be interested in where everyone is planning to mount the batteries......sounds like everything should be way up forward in the nose.....I was going to build a little platform that extends into the nose cone for one of the packs, sort of like the KingCat, but much shorter of course....enough for one Lithium or NiCad pack......it will just clear the top of the N/G retract.......lots of thick epoxy around the nose ring on the fuse to tap into for the platform.......not sure yet where I am going to mount the other battery(ies)........

I did find, like you did, that the hinging was a bit of a PITA......although the hole were pre-drilled, a couple of mine were off, and the depth of the aft spar was not quite right, especially the rudder.....like most things I do, the first time takes forever with lots of headscratching and wishing evil thoughts on the kit manufacturer, but the second time, I can do it blindfolded......

If anyone is able to post photos of how you set up the nose gear door actuation, I would also appreciate that.....I am planning at the time to do it much like I have seen on Tam's photos, sort of like the Bandit with a hinged front 1/2 of the door attached to the strut, and using a cylinder on the aft portion.....not sure about cylinder location.....

Tom

hi Guys i am new to this group and there seems to be a lot of talk on the Viper. I have just completed the first part of a article for the english mag RADIO CONTROL JET INTERNATIONAL ON THE Viper mk2 which will be published next month. i am soon to do the test flying so we will see if there is a real problem with it . My impressions of the kit are good and if it flys as good as it looks there should be no problems .

I'll use 2 battery packs Nicad ( 2400 & probably 1000 Mamps) (Flat shape pack for the big one, bump for the smaller if go into the nose cone or flat if go on top of nose gear area.....I guess.)

The big one goes under the rear servo tray, right behind the front former.
The small one....find a way to mounted in the nose cone of right above the nose gear retract area.

And of course...the ECU batt at the nose cone too.

For the nose gear door actuartor....I did some real head scratching trying to fin a systems works and also with a nice design look....I was complex to do....but I worth the effor [&:]
These picture does not show up to much.....but I'll take a few more pictures this fternoon for you.


As per the cilinder location for the aft nose door....you are lucky I found an old picture....: - ). If I'm remeber correctly ( ???) use a cilinder shorter then 1".... to avoid over traveling issue. But anyway I'm sure you will know how to deal if so.

Good luck.-

As per my experience with this plane ( I had one and re-order the 2nd) all I can tell this is an
excelent plane and you'll not have any problem at all ...

Good luck and keep us posted with your article....

Miguel

I was going to try doing it similar to my Bandit.....don't know if the geometry will work yet....I haven't got that far yet in my building......

Tom

This is how I set up for nose gear door air switcht close the door. This photo is Super Hornet photo. The Viper Jet set up the same way.

The gear door aircylinder down side Tee off from the retract down side.
For up. Tee off from retract up and go to the air swicth. When the wheels go up and hit the switch to close the door.
I use gear door offset hinges to set up this.

Maybe the photos can explain better than my Vietenglish.

Tam

Tom,
The front door I just let it hand loose like the Kingcat set up. When inflight. The air will close that door.
Bring some tape to up the door when transport.
Tam

Very slick Tam......could you post a shot of where you have the cylinder mounted and it's connection to the door.....

I know this is on the Supa Hornet, but it does look very similar.....

I also sent you a P.M.

Tom

Yeah, that's a simple way to install the front door....not headache....but you know me Tam...I was not going to leave that door loose [&:]

As per the air valve, another idea is to mount it in the other side ( right of left?) of the air cylinder location at the former.
I used a piece of cable crossing one side to another that activate the trigger when hit by the struts. I did it that way to avoid having the air valve on top of the tray taking useful space....[]

This is a picture of my old tray....the new one will be....different [&:] You see my concern regarding space....?

Some compulsive guys fit a little spring made out of a single loop of fine music wire to keep tension of the front 1/3 of the nose door........so not to hang loose at any time....on the KC, when the gear is down, it actually overextends the door to about 110 degrees and keeps it tight against the strut with a little block between....up in the air of course you can't really see much, except that it does close completely.....

Tom