siclick33

Would this model benefit from a gyro? Is there any tendency for it to fish tail? It looks a little short coupled so I don't know how 'solid' it will be/

I'm trying to decide between a Powerbox Royal SRS (with the integrated gyro) and a Cockpit SRS. I'm leaning towards the latter as the Royal is $$$ and I already have a spare Cockpit SRS, but if it would benefit significantly from a gyro then I might be tempted to go for the Royal.

siclick33

Well mine has arrived

First the bad points (and they're not really that bad):

1) The nose steering is pull-pull whereas I would have preferred direct drive, which seems to be becoming more common these days.

2) I bought the lighting set from Tomahawk. This is the same set that you can get cheaper from Emcotec and consists of 6 14mm landing light LEDs, some resistors and a Jeti (SP06) RC switch to turn them on and off. It will be functional and adequate but there is no 'proper' lighting controller and, more importantly to me, there is nothing to mount them with, no lens cover (or plastic sheet) and no fitting instructions. If anyone could give me a point in the right direction I would appreciate it - I'm happy with the wiring but don't want to make a mess of cutting into the wing and mounting them.

3) The tail bag is a bit odd as it is one piece for both tail halves. This means that you can't put them on when the model is assembled (you can put the fin cover on) and if you take the tail off and put it in the bag then the 2 pieces will bang against each other, thus requiring you to put them in a bag in the bag!! They are also closed by zippers whereas I prefer the clips used by pull-over-products. That said, the bags are quite reasonable quality.

On the plus points:

The model quality is excellent. Mine was painted in the mould and I couldn't be happier with it. I've had a Skymaster Viper before and it was ok for the money but this is in another league.

I can be a little fussy at times and want things to be right. There were some minor problems during the order (most notably delays caused by the JWM and Jetpower) but Thomas was excellent at replying to any emails and queries that I had. For people that are cautious about buying models that aren't in stock or are built to order, I would just say that I'd be happy to order again from Tomahawk. As an aside, this model was built to my spec with my requested colours and I didn't have to pay in full up front. I paid a fair deposit and the rest when it was ready to ship. As far as I can tell, everything that should have been in the box is in there.

With reference to earlier posts in this thread, it looks like Thomas may have made a change to the elevator mountings as the smaller 3401/3421 will no longer fit. Standard servos such as JR8321/8411 are drop in, which is good for me as that is what I wanted to use anyway.

I will post some photos in due course.

Zeeb

My Feedback: (41)

Well I cannot say my experience with Thomas was similar to yours. First is that he never told me (despite his claims, I have all the e-mails to prove otherwise) the color I wanted was not in stock nor would it be until he had sufficient orders to fill a full load from wherever these things are built. He never told me (although he says it's "on the order button of the webpage") that I only had to pay a deposit. So I ordered the thing,he sent me a bill for some $5100.00 and change (US Dollars) which I sent him. I had to pay for that wire transfer fee since he woudn't take a credit card or anything else, I also paid the conversion fee to Euros and then I didn't hear anything from him. Finally after about a week I asked if he got the money and he told me yes but nothing else. About three weeks into the process, Hammer had shipped my engine and still no word on my airplane from Thomas, so I e-mailed again asking where my model was. He replied in a rather "curt" fashion that it would not be built or delivered until the end of the year and in essence wanted to know why I was questioning him. A series of arguments ensued where I demanded a refund and he refused. He tried to sell me a different color, I told him no. He claimed I did not have to pay in full up front but has no evidence of that information being provided to me. He refused to refund my money, or even less a deposit as he claimed he'd already "ordered" the model.

I am NOT happy with him or his USA distributor who I tried to get a model from originally, but who did not seem to care if he sold me a model or not unless it was one he'd been flying for about 3 years from what I can tell with the YouTube videos of him flying said model.

All I can do at this point is hope I see something for my expensive adventure, but I have nothing except Thomas's word that I'll get the model and the actual delivery date is the subject of another arguement.. Soo.... IMHO it's "buyer beware" when it comes to Tomahawk Design.

siclick33

I can't really comment too much as I don't know the details of your transaction.

All I can say is that my one-off colour swap model was quoted as being a 12 week build. Due to Jetpower and the Jet World Masters it ended up being a little over 16 (from memory). If you ordered yours recently and it wasn't in stock then I'm not surprised that he is saying that you won't get it this year. He offered me a different colour that was in stock as well, to save me waiting (and no doubt also to move his stock) and maybe he was trying to help you by offering you the same?

I also had to pay the bank transfer fees but that was something that I just accepted as an understandable consequence of paying for something in another currency. It was much cheaper than if I'd been charged a credit card fee.

The fact that I have exactly what I ordered sitting here is proof that he does deliver what he says (to me at least) and I don't see why you have any reason to think that you won't get yours.

Der Goetz

My Feedback: (9)

That sir, is not true.
I send you eleven emails within the course of a week, two of them containing quotes for the ARF Viper 2m in blue.
I even got you in touch with two builders in the US as you were interested in having one build for you instead of building yourself at the time. Since you were looking for "bind and fly" I offered you my very own Viper 2m on top of things.

With best regards,

Gotz Vogelsang

lxfly

Hi,
1)The positioning of the nose gear and the shape of the fuselage doesn't allow a direct drive. I'm going to build now my 4th Viper, and there is no difference if it's the 2m or 2,5m, Tomahawk or CARF
2) I build some lights in a 2m Viper from www.hab.se and made a piece like http://www.hab.se/cnc-stralkastare-i...629-c-773.aspx. You have to cut in the wing to mount it and mold a plastic sheet to cover
3) Put the 2 halves on the tubes and then put it in the cover, fits perfectly. I also leave the fixing bolt on one side of the tail half.

Got 4 models from Tomahawk until know, normally no problem except sometimes delivery time.
For the elevator servos I think 8321 is a good choice, also you just need servos from min 4kg/cm torque with metal gear.
You don't need a gyro to fly this model; I also keep the power system at a minimum with just 2 batteries and a Powerbox sensor switch which is quite enough for these small models.

DrScoles

My Feedback: (18)

I've got 25 flights on mine with a P80. Awesome flying plane! I think it would be more fun with a 120, however, I think a little discretion is advised. Not sure if I should use a BVM product as the benchmark, but I can bank the bobcat as hard as I want with no fear of anything breaking. I was flying the viper and doing a few aggressive turns, tiny little stress cracks appeared on the fuse above the wing tube box. It was a sign that I needed to fly it with a little more reserve. It is not a fast airplane by any means. It just goes where you tell it and landings are effortless.

I don't think a gyro is needed on the ground or in the air.

siclick33

Thanks guys. I won't bother with a gyro then and will probably go with the Cockpit SRS Powerbox that I already have. I may leave the lights until a later date but I'll see how brave I feel!!

One other negative that I've just noticed is that the gear set doesn't come with any air valves, tubing or air tank, which I think is quite tight considering that it cost almost 800 euros, but the quality of the gear does look good.

Xantos

I had similar stress cracks appearing at the wing root on the fuse exactly above the wing tube .
I am flying with a 120 and i don't think it is because of aggressive flying.
I arrested the crack by drilling a hole to relieve the pressure. Drilling just a small hole at the origin will arrest the crack from growing

DrScoles

My Feedback: (18)

Interesting idea Xantos. I bought a carbon fiber tube to see if it would reduce the flex. siclick, do you think you need a powerbox for such a simple system? The viper I bought, had one, I pulled it. One fromeco regulator to the rx and that was it. Makes for much simpler install.

siclick33

Not really but I'm short of TX channels and the matching for elevators and flaps will be quite handy (and I like the look of the graphical battery monitor). I may yet change my mind again when I get to that point; I haven't even finalised what turbine I'm going to fit yet so there's still time

I think I've found one piece that's missing. I assume that the fuel tank cap is supposed to have a threaded ring that you glue to the tank? If so, mine's not there. It's not a big drama as the metal cap looks like a leftover part from a farm tractor so I'm going to use something else anyway. The canopy release latch is also a bit odd - how have people gone about fitting that? Have you used the bowden cable? If not, I assume that I need to solder a metal rod on so that it can be opened from the outside?

DrScoles

My Feedback: (18)

I use the futaba 14 channel RX's or sbus, so shortage of channels never comes to mind.... Makes sense to use powerbox then! My viper was done when I bought it, I only re-did the layout inside. I have this pull cable thing for the canopy release that is a mystery to me, but works very well. About three inches back from the canopy there is a little wire pull. I circled it in the pic.

lxfly

To the brass cap belongs an aluminium ring and finished it looks like http://www.rcmarket.net/cmsj/images/...dvpj25r018.jpg
If you bought the prepared latch from Tomahawk,it is working quite well, I glue first the latch in the upper side of the fuselage(with epoxy) , so that the moving pin overlaps it, than i drill a little hole on the lower(under) side of the fuselage just where the wing joins the fuselage and guide the bowden outside the fuselage. Than I guide the bowden inside the fuselage and glue it on the wall in a wide curve. Now I sold the little metal ball to the steel cable to pull the latch.
On the canopy frame I mark the place of the latch pin, drill a hole, mount the canopy frame as it fits later on and glue a brass tube in the frame (4mm diameter) over the pin, so I have a strong place for holding the canopy.
Best you prepare the frame with the 2 front pins a 2 latchs in the middle of the frame.
If not clear, please tell me and I put you some detail photos on my site.

siclick33

Thanks very much for the info. I now understand most of how the canopy latch mechanism works. Do you just loop the bowden cable though the spring? Does the ball outside the fuselage flap around? I want to make sure I get this right as if it fails, either the canopy may come off or I won't be able to get it off, neither of which will be good I'm tempted to file a slot in the top of the fuselage and solder a rod to the spring to open it.

My kit came with a square cut out already made for the noseleg. It is quite a big hole so I am considering adding the included door (which I hoped I wouldn't have to do). Have other people fitted a working nose door? If so, how?

Thanks,

lxfly

Hi,
Yes, the bowden passes through the spring and yes, the ball is soldered or bonded on the cable end and flaps 1-2cm around.

I tried to close my door with the front gear but had some problem with this an so took it off(makes no difference in flight). During winter I shall go to a solution with a servo and a sequencer.

siclick33

Could I please ask how people have routed the servo/air cables in the wing? I would like them to exit the wing root forward of the wing tube and I see many others have done this, however there is no obvious hole to pass the wires through.

Do I need to cut a hole in the forward wing spar? If so, do you think I can make the hole big enough to pass a Multiplex plug through without weakening the wing?

DrScoles

My Feedback: (18)

I bought mine used, but added the plug in air fittings and the red connector. I can't stand those little white air fittings. You could get away with much smaller holes than you see here. I did all the soldering after the wires passed through.

siclick33

Thanks very much for the pictures; that's pretty much what I want to do.

I assume that the cables pass through a hole in the forward spar? I can't see how else they can route from the gear/servo area to where you have them exit the wing.

BaldEagel

Cutting a hole in the centre of a beam (spar) should not cause a problem structurally as long as the hole is the smallest size possible, has smooth sides i.e. no crack inducing sharp corners, and is only in the web of the spar and does not touch the flange surface top and bottom, think of a castellated beam, I would be tempted to laminate a second piece of similar size timber to the area with the grain in the opposite direction of the original spar. full width of the gap between ribs on either side of the hole, belt and braces I know, but its the structural engineer in me, happens all the time even though I am now retried.

Mike

lxfly

Even no problem to open like this:

siclick33

But where do the wires go inside the wing?

Have you made a hole in the forward wing spar (e.g. near the aileron servo mount) or have you routed the wires over the outer wing tube?

lxfly

Sorry , have to recheck that for the 2.0 Viper I built 3 years ago; I just build the 2.5 last year and here there are holes in the wingspar.

Zeeb

My Feedback: (41)

Well I'm going to have to eat some crow as mine finally showed up but it was just two days shy of 4 months. I'd have never ordered it if I'd known I'd be waiting that long but in truth I wasn't exactly sure I was even going to get one. With that thought in mind I've bought two other jets since I ordered the ViperJet and figured if it ever did show up I'd probably sell the thing.

That said; the little sucker is just gorgeous, the workmanship is outstanding and that landing gear which I paid for the electric conversion is just a work of art. I may have to keep the thing.....

For siclick33; after your questions and Rene's responses I went and looked inside the gear wells of the model I just got. The spar is built solid outboard of the gear mouning area. But right there the thing looks like it splits into two pieces with one running down each side of the tube. Each of those sides has square holes cut out of them where they glue the tube and there looks to be enough room to run wires or airlines forward of the wing tube. The spaces on top of the wing tube are not very big, you may have to pull the plastic housings off your servo leads to get 'em through and put those back on later but should not need any drilling of the spar if done that way.

lxfly

Thanks Zeeb for setting the point. I couldn't find any photo of my tube rooting, but I think to remember that I passed servo cable and 3mm tubes through the spar just over the wing tube (about where the wheel opening is). As I use the MPX plugs to connect servos, I always cut off the original servo plug and as normally you also have to extent the cable, getting throug these small openings is no problem.
Zeeb: nice scheme, here is mine from the 2.5

Zeeb

My Feedback: (41)

Well I like the scheme and the colors too but I can't take credit for it; it's one of the new painted in the mold versions from Tomahawk.....