jack744

My Feedback: (60)

Henry check Altercare rc in canada they have alot of options for electric gear and brakes. The down and locked are great products and Mitch is great to work with but they don't currently offer electic brakes.

Jeremy_D

Henry, I believe JL are still testing their version, there is a video of it early in the thread. I'll see if I can find out more info on it

A4Driver45

My Feedback: (7)

Hey guys, this is about the go juice burn, I have a Rabbit in my Viper, using the two tanks that comes with the bird, I fly between 1/2-3/4 power after runup for takeoff I fly for 9 min and have 1/3 both tanks left...the Rabbit is very good on go juice, both tanks draw even, I set it up as shown in the pictures and have no problems, the only problem I do have is during de fueling my uat tank wants to suck in, i believe it is the pump drawing at a high flow.......if anyone has any info on the uat tank sucking in please reply.

thanks
Rocky Kranz
Navarre, FL.

Jeremy_D

Mine did, I dropped my battery voltage to the pump to 6.6v and that did the trip

A4Driver45

My Feedback: (7)

Thank you for the tip on dropping the pump Voltage.

Rocky Kranz
Navarre, FL.

VF84sluggo

My Feedback: (55)

I'm considering either the RTF version, or a "turn key" version, of this jet. I'm curious how the Global Jet 20kg HV servos compare to the JR DS8425 servos.

The $200 lower price if picking GJ servos is appealing, but I don't want to risk being penny wise and pound foolish.

Thanks

essyou35

My Feedback: (11)

Not answering your question but I used futaba s3001HV on everything except the elevator. ON a 2s LIPO they give about 140 oz/in and they cost 39.99USD. If you want to go cheaper on servos there is a good option. On the elevator I used a 7954SH hitech servo for over 400 oz/in on a 2s lipo.

I got my 2nd flight yesterday. Flew about 5 mins with some WOT passes and landed with under 1/2 tank left. Can probably go 6 mins but I may be pushing it. I tend to fly 1 or 2 clicks over half throttle. Had a fuel issue yesterday I got worked out, one of my rear tanks would not fill. Nothing like taking the jet half way apart at the field and reassemble.

One issue I have with the viper is that it seems very touchy on the controls, and yet I dial down the throwns and it is still touchy. My throw extremes leave me really pulling hard on the elevator in turns and my roll rate is about 1.5 seconds or so per roll. On landing I am very pitch sensitive, and CG is not tail heavy. I am more nose heavy than some of you guys. Its almost like my expo is reversed but that is not the case. My throws are less than the recommended right now.

I only have 2 flights so maybe my perception will change. Very easy to fly jet much easier than my f-86D I had.

I increased my crow and I have to come in under power. I cut power yesterday too far out and it slowed FAST, I had to apply power again and it hovered for a second then came in. My f-86D would of snapped hard. With crow you can land in 50 feet assuming you get the throttle right.

Bob_B

My Feedback: (11)

essyou35 I think you meant 3051HV servos

jack744

My Feedback: (60)

can anyone give me some help on installing the smoke tanks into the viper. I can't get them to go between the side of the fuse and the turbine rails,they wont slide up to the sides of the turbineoutside the mounting rail and fuse. Am I missing the way to have then sit back there?

Chris Pyrah

Hi JackThe turbine Rails are removable just take out the allen bolts on each rail remove the thrust pipe screws and the rails will come out,I fitted my tanks into place and just held them with a tiny blob of silicone to stop them rattling about.One thing, if anyone is in the process of building or working on a Viper then just take a bit of time and read this thread from the beginning,there is all the information you will /should need on building and setting up the viper.quite a few guys have took time to post a lot of useful information on this model now, Cheers Chris

jack744

My Feedback: (60)

Thanks so much Chris for the help! I have read this thread from front to back and a few times and it is one of the most helpful threads on rcu. All of you that have the viper and flown it and poasted comments I thank you! I think I am going to plump the smoke tanks and one of the forward fuel tanks all together for turbine fuel and use one of the front tanks as smoke oil. I have a Kingtech K -100G turbine to install and I am using 2 batteries for the radio that are A123 2300mah 2s 6.6 volts and a Life 4400mah battery for the turbine. Hoping that I won't have to put all the batteries in the nose. I would like to have them behind the nose gear and the ecu battery under the tray that the UAT is on. Hoping it will balance at the 35 mm behind the center of the wing tube. Again thanks to all that have poasted in this thread all your posts have been very helpful!

VF84sluggo

My Feedback: (55)

I asked for a quote from GJC on a "turn-key" version of this jet with a P100. The paint job called for +$50, and I wanted the smoke tanks and wand (I have a Tam's pump to use.) I also asked for the electronic brakes to be removed as I plan on using a Smooth Stop.

From the website:
Turnkey P100RX = RTF 1 + Jetcat P100RX (100N/22LBS) turbine installed. (RX & Batteries Sold Separately)
Price: From low $5000.00, varies depending on options.

My quote came in at just under $6800!!...a far cry from "low $5000", even considering "varies depending on options." Shipping is listed as $165, so that's reasonable. Labor to assemble is listed at $650. We're still a ways away from the "low $5000"...which I suppose I naiively assumed included the labor cost as this is the "turn key" option.

Ok, maybe someone here can explain this, as I've not heard back from the GJC rep that gave me the quote.

Sluggo

mikedenilin

My Feedback: (67)

Hi Randy,

I saw your email and also replied moment ago.
Here is a copy of it
"
Hi Randy,

The biggest difference is the type of servos we use. The quote that you got is for JR servos. We do offer Global Jet servos that will cut the cost down. You also add smoke system, and Hanson UAT, and also the installation is to be done in the USA.

If you would order a Kingtech K100 and use our Global Jet/XT high torque servos, then we can cut the cost down a lot. It would also be assembled in our China facility. If you like, we can give you a quote for that.

Thanks,

Mike"

Originally we were able to install these Jetcat turbine there but we faced the import tax and export tax problems there in China. We have less problems with Kingtech as it's made in Taiwan and easier to get their engines in & out of our facility in China. We have an assemble line set up for RTF on these engines with many standard parts, so the labor cost is a lot less. We can pass the saving to you.

Mike

VF84sluggo

My Feedback: (55)

Mike, thanks for the reply and your email. I think I'll pass on the turn-key option and do the building/assembling myself.

Randy

madmodelman

Randy, it'll only take you a few hours.

VF84sluggo

My Feedback: (55)

Exactly! I was just being lazy After seeing the turn-key quote, I've found new motivation and will get either the ARF PRO WIRED or the RTF1/RTF2 version.

Don't know anything about the Global Let servos, though. That was the resason for a post I made a little while ago. But, are JR DS8425's really needed? 7 of them at $114.99 each adds up. But, then again there's only a $200 difference between the RTF1 (GJC servos) and the RTF2 (JR servos) versions, which is not huge in the overall scheme of things. I don't particularly enjoy servo installation, so for me getting a kit with this work done would be nice.

Randy

Jeremy_D

One of my flying mates has the arf pro wired with the GJC servos and he is quite happy with them. They came installed from China. He only had to adjust the flap linkage, everything else was fine

essyou35

My Feedback: (11)

1X Hitech 7954SH: $70
6X Futaba S3051: $240
2X Hitech 430-BH for valves: $34

Servo total: $344 all were free shipping and found on amazon.com

All servos are HV servos so I use a 7.2V 2s Lipo to power these, from Hobbyking. Its a 30C lipo and with two of them its serious power.

The only downside I have to using these lipos is the wire guage is quite thick, and going from that wire to a servo connector is a challange. I just made an adapter using servo wire into bullet connectors and then into a servo connector, using heatshrink the whole length of the wire.

Also for anyojne having pressure issues, I removed my tanks and got rid of the stock clunks. I used the large dubro tanks and all my problems went away.

madmodelman

Randy, I stuck a Savox 20kg in the tail, 6.5 to 10kg fine for the rest.

VF84sluggo

My Feedback: (55)

Thanks for the info guys.

I like the idea of being able to use 2s lipos straight to the servos for power, and not needing a regulator. Anytime I can eliminate a gizmo or gadget, that's one less failure point, and a little less weight, even if it is just ounces. My question is, ok, the HV servos can hack the higher volts, but what about the receiver?

Randy

mikedenilin

My Feedback: (67)

Hi Randy,

Attached are pictures of a turnkey jet we just finished for a jet member. It's equipped with k100.

Installation of servos is really easy. All servo trays are injection molded ABS plastic. You just need to screw the servos onto the rails and do that 6 trays. each tray has identical size, so it's easy to replace or swap them.

Either ARF PRO WIRED, RTF etc. you will find this plane really easy to put together.

Mike

VF84sluggo

My Feedback: (55)

Thanks Mike. Either it's my computer or RCU, but I only see pics in threads, or in the Marketplace, every now and then. Most are just squares with a red 'x' in a box that does nothing if I click on it except for saying "loading".

madmodelman

Yep, me too!

essyou35

My Feedback: (11)

Randy I am using a Futaba R6014FS and have no problems with the 7.2 lipos so far, charged to 8.4V. My previous setup used LIFE packs at 7.2V charged with lots of flights on it. If you are using futaba there are several threads about this. You do have me thinking I should buy a new RX I am reading the HS versions now can use 8.4V. I only have 2 flights on my viper and now you got me thinking...

http://www.rcuniverse.com/forum/m_10.../printable.htm

VF84sluggo

My Feedback: (55)

Good to know. Yes, I use Futaba and a 6014HS receiver. I know it's good for unregulated power from A123/Life packs, and I've used them with no trouble. My concern has usually been with the voltage tolerance of the servos with unregulated LiFe's. With HV servos that is moot, but it looks like it's also a non-issue with the 6014HS.

On a different note, I have a Tam's smoke system that I used in a Baby Boomer, but from the pics it looks like the smoke system sold for this jet has a longer smoke tube, which I assume is to pump out the oil near the exit of the thrust tube and not just aft of the engine exhaust cone (as it was with the Boomer.) Is that correct?

Since I have no experience with a smoke system in a jet that uses a thrust tube, I've wondered if using the standard Tam tube causes a mess inside the thrust tube (and possibly the inside of the jet). Is that why a long tube is needed, to avoid oil residue in the smoke tube? And, is the exhaust still hot enough at the thrust tube exit to fully burn the oil...if my assumption in the previous paragraph is correct.

Randy

P.S. From the link in your post, you can see I've been down this confusing and contradicting Futaba receiver/servo/battery/regulator voltage road before.