Harlock RC Viper 140
02-17-2020, 09:36 AM
#201
Hi Noab, I think the 45size is best for this model. Mine has an X45 and the stock tank/pipe you can buy for an extra $70 is more than adequate. The X45 is so small the pipes basically a heat shield so the single wall is perfect. The quality of the kits is very nice and with the lighter motor stock gear will work.
I generally fly about 7 mins from start to finish and it still has almost half a tank. It’s a bit nose heavy with all that fuel on T/O so it takes a bit of speed. Don’t use the stock CG, most are using 110-115 range which seems to be okay. It will knife edge just isn’t pretty unless you’re really fast. I fly the model around half to 3/4 since full throttle seems too much.
I recommend a gyro and it will feel like a 2.5m viper jet
I generally fly about 7 mins from start to finish and it still has almost half a tank. It’s a bit nose heavy with all that fuel on T/O so it takes a bit of speed. Don’t use the stock CG, most are using 110-115 range which seems to be okay. It will knife edge just isn’t pretty unless you’re really fast. I fly the model around half to 3/4 since full throttle seems too much.
I recommend a gyro and it will feel like a 2.5m viper jet
03-12-2021, 08:28 AM
#210
Join Date: Apr 2006
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Does anyone on this thread know the exact components to purchase a set of Electron retracts for the Harlock 140. I just purchased the Viper direct from Harlock and did not realize there was no gear available.
03-12-2021, 09:56 AM
#211
09-20-2021, 10:00 PM
#214
CoG Surprise
I have just finished my build, it has a Kingtech K45 G2, stock thrust tube, stock fuel tank, mini UAT all the way forward and a 2200mAh ECU battery and a 2500mAh Rx battery as far up the nose as I could get them. I couldn't move the turbine any further forward as the thrust tube wouldn't exit the rear of the fuse, it just sits at the end now as it is and the turbine end wouldn't be in the thrust tube to a sufficient degree.
I measured the CG by string wrapped around the wing spar, the centre of which is 100mm from the leading edge where it meets the fuse, and its very tail heavy at this point. The manual calls for 90mm and some people are saying 100mm is a good point to start, so I don't want to maiden it any further back from 100mm.
Both the fuel tank and UAT are empty at this stage, but as you can see from the photo the UAT is a mini and it being full wouldn't move the CG any I don't think, and fuel in the tank would make have to move the CG back further.
Other than the obvious of a ton of lead in the nose I would appreciate the thoughts and suggestions of the experts and owners of this jet.
Cheers,
Phil
Two batts all the way forward, mini UAT, pump etc.
Turbine position
I measured the CG by string wrapped around the wing spar, the centre of which is 100mm from the leading edge where it meets the fuse, and its very tail heavy at this point. The manual calls for 90mm and some people are saying 100mm is a good point to start, so I don't want to maiden it any further back from 100mm.
Both the fuel tank and UAT are empty at this stage, but as you can see from the photo the UAT is a mini and it being full wouldn't move the CG any I don't think, and fuel in the tank would make have to move the CG back further.
Other than the obvious of a ton of lead in the nose I would appreciate the thoughts and suggestions of the experts and owners of this jet.
Cheers,
Phil
Two batts all the way forward, mini UAT, pump etc.
Turbine position
09-20-2021, 10:29 PM
#215
Further to my above post and for the record my current balance point is between 125 - 130mm rear of the leading edge. I just may have to add some adhesive lead blocks to the underside of my false floor I added to fit everything in. Also don't be concerned that the turbine doesn't appear centered in the jet, it appears so because the photo was taken from one side, slightly distorting it. I lined it up with a centered string line.
I just noticed how much of the main fuel tank is in front of the suggested CG (110-115mm), it would appear that about 2/3rds of the tank are forward of that CG, which would certainly see it balance with less than half a tank of fuel. Maybe that's how I see some guys with K60's and Jetmunts 70 and 80's still balance at around recommended.
Thoughts on this theory guys??
I just noticed how much of the main fuel tank is in front of the suggested CG (110-115mm), it would appear that about 2/3rds of the tank are forward of that CG, which would certainly see it balance with less than half a tank of fuel. Maybe that's how I see some guys with K60's and Jetmunts 70 and 80's still balance at around recommended.
Thoughts on this theory guys??
Last edited by Flying Fiz; 09-20-2021 at 10:53 PM.
09-21-2021, 03:27 AM
#216
My Feedback: (53)
Not sure….but here’s the photo’s of the one I build for a friend…the CG was just 37mm in front of the Center of the main axles….it flys nicely (it was on a k35g3 but since been upgraded to a k45g3)
09-21-2021, 03:37 AM
#217
First off, the book is flat out wrong. 90mm is so nose heavy it doesn't have enough elevator to flare.
110 to 115 is what you want to shoot for.
Second, mix some lead shot with 30m epoxy, pour it into the forward nose cone to get your balance, you will use less weight than sticking it on the radio tray.
110 to 115 is what you want to shoot for.
Second, mix some lead shot with 30m epoxy, pour it into the forward nose cone to get your balance, you will use less weight than sticking it on the radio tray.
09-21-2021, 07:08 AM
#219
09-21-2021, 01:10 PM
#220
Thanks for all the suggestions and thoughts guys, I'll take that all on board.
On the point of turbine orientation, I know that my two Xicoy turbines (a 45 & 90) stated a preference for orientation (and I installed them accordingly) but I didn't see that anywhere in my Kingtech Manual, so thanks for the heads up, I'll have another look. Having said that, just about every Kingtech I have seen installed is in this orientation, as it seems way easier to access the three connections to the turbine.
Cheers,
Phil
On the point of turbine orientation, I know that my two Xicoy turbines (a 45 & 90) stated a preference for orientation (and I installed them accordingly) but I didn't see that anywhere in my Kingtech Manual, so thanks for the heads up, I'll have another look. Having said that, just about every Kingtech I have seen installed is in this orientation, as it seems way easier to access the three connections to the turbine.
Cheers,
Phil
09-21-2021, 01:31 PM
#221
My Feedback: (53)
Thanks for all the suggestions and thoughts guys, I'll take that all on board.
On the point of turbine orientation, I know that my two Xicoy turbines (a 45 & 90) stated a preference for orientation (and I installed them accordingly) but I didn't see that anywhere in my Kingtech Manual, so thanks for the heads up, I'll have another look. Having said that, just about every Kingtech I have seen installed is in this orientation, as it seems way easier to access the three connections to the turbine.
Cheers,
Phil
On the point of turbine orientation, I know that my two Xicoy turbines (a 45 & 90) stated a preference for orientation (and I installed them accordingly) but I didn't see that anywhere in my Kingtech Manual, so thanks for the heads up, I'll have another look. Having said that, just about every Kingtech I have seen installed is in this orientation, as it seems way easier to access the three connections to the turbine.
Cheers,
Phil
09-21-2021, 01:49 PM
#222
I've just checked the manual and yes there is a reference to orientation stating that the glow plug should in the vertical position. I assume the glow plug is included in the various functions in the green MPX connector and not the black data terminal. I'll re-orientate it so the green glow plug is vertical.
Cheers,
Phil
Cheers,
Phil
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Flying Fiz (09-21-2021)
11-14-2021, 11:31 PM
#224
Harlock RC out of Business??
It appears that Harlock RC may be out of business, they are not responding to anyone's emails, their website has been suspended for some time, and no stock anywhere.
Maybe they are now concentrating on manufacturing SAB jets for SAB, which I understand they have made from the start for SAB. Shame as I think the quality of their Viper jet is as good as I've seen and I wanted to buy their 2.5 meter Viper if I could find one or if they start making them again.
Does anyone know anything definitive on this?
Cheers,
Phil
Maybe they are now concentrating on manufacturing SAB jets for SAB, which I understand they have made from the start for SAB. Shame as I think the quality of their Viper jet is as good as I've seen and I wanted to buy their 2.5 meter Viper if I could find one or if they start making them again.
Does anyone know anything definitive on this?
Cheers,
Phil