HobbyKing 1/5 50cc Spitfire Mk IX Group Build Tips/Mods
08-25-2013, 06:29 PM
#126
So basically for your props, they cost a total of $15 each
No tax either. Pretty good! I should get a rpm test of the 20x10 on the turnigy 50cc within a couple days and ill report what I get.
Last edited by kahloq; 08-25-2013 at 06:41 PM.
08-27-2013, 08:23 PM
#127
Well.... I wasn't able to get the spitfire out to test the 20x10 yet, but was able to bench run my eme55 using the same prop. So...brand new eme55 with turnigy 20x10 2 blade.....max rpms of 7300 without touching the needles at all. This is better then my friends DLE55ra @ 7000 on a 20x10(different brand prop though).
Anyway......the eme55 test will be a good benchmark to compare the turnigy 50cc in the spitfire since both will be using the same exact prop. The 20x10 is also 2oz lighter then the biela 3 blade 19x10. I should expect a decent increase in rpms using the 20x10 on the turnigy motor. Lots of stuff going on build wise at the moment since Warbirds over the Rockies is only 2 1/2 weeks away....but I will get the spit engine prop test done as Id like to know how she'll do before the Warbirds event.
Anyway......the eme55 test will be a good benchmark to compare the turnigy 50cc in the spitfire since both will be using the same exact prop. The 20x10 is also 2oz lighter then the biela 3 blade 19x10. I should expect a decent increase in rpms using the 20x10 on the turnigy motor. Lots of stuff going on build wise at the moment since Warbirds over the Rockies is only 2 1/2 weeks away....but I will get the spit engine prop test done as Id like to know how she'll do before the Warbirds event.
09-08-2013, 02:20 PM
#128
Well.....the 20x10 definitely improved the flight performance relative to the biela 19x10 3 blade. It flew a lot better even with almost the same rpms. The 20x10 2 blade got 6700 on the turnigy while the 19x10 3 blade got 6500.
Plane flew very nicely and had plenty of power for loops and rolls.........
And that's the problem.............
This was the 3rd flight of the plane. During the flight, the gear wouldn't come down. Doing numerous rolls had no effect to release the gear. I was then advised to try a loop and gain speed on the backside and pull up. Yeah...sounds good.
But on THIS plane, it is absolutely the worst thing you can do and as such, I do not recommend ANYONE buy this plane.
Here's why.....
The plug in wings are held against the fuse by two small hex head bolts that, instead of biting directly from inside the fuse into the wing sidewall, there are two small wood tabs on each wing panel and the bolts run up thru the bottom of the fuse into those tabs that have blind nuts in them. Pretty easy installation, but not at all a good design because those wood tabs aren't very thick. This is a pretty bad design flaw because any high G maneuver will more then likely snap those tabs and allow that wing half to slide right off the aluminum spar tube. And that is what happened to mine. There is probably good reason why there aren't any other threads on this plane. Structurally, its a weak spot and would take some good engineering to alleviate this problem.
Aside from that, its a much better looking plane then the TF offering, but, with less work then fixing the design flaw, a TF could be made to look decent.
Id actually recommend the ESM Spitfire above all others in this size range. The only thing on that plane to avoid would be using the cylindrical motor mount thing and just build a wood motor mount box as the cylinder prevents air from getting to the carb if there is a muffler any where near the carb.
If you already have this plane.....find a way to secure the wing panels to the fuse other then those little wood tabs. I do have a video as I had a helmet cam going, but didn't bother uploading to youtube.
Plane flew very nicely and had plenty of power for loops and rolls.........
And that's the problem.............
This was the 3rd flight of the plane. During the flight, the gear wouldn't come down. Doing numerous rolls had no effect to release the gear. I was then advised to try a loop and gain speed on the backside and pull up. Yeah...sounds good.
But on THIS plane, it is absolutely the worst thing you can do and as such, I do not recommend ANYONE buy this plane.
Here's why.....
The plug in wings are held against the fuse by two small hex head bolts that, instead of biting directly from inside the fuse into the wing sidewall, there are two small wood tabs on each wing panel and the bolts run up thru the bottom of the fuse into those tabs that have blind nuts in them. Pretty easy installation, but not at all a good design because those wood tabs aren't very thick. This is a pretty bad design flaw because any high G maneuver will more then likely snap those tabs and allow that wing half to slide right off the aluminum spar tube. And that is what happened to mine. There is probably good reason why there aren't any other threads on this plane. Structurally, its a weak spot and would take some good engineering to alleviate this problem.
Aside from that, its a much better looking plane then the TF offering, but, with less work then fixing the design flaw, a TF could be made to look decent.
Id actually recommend the ESM Spitfire above all others in this size range. The only thing on that plane to avoid would be using the cylindrical motor mount thing and just build a wood motor mount box as the cylinder prevents air from getting to the carb if there is a muffler any where near the carb.
If you already have this plane.....find a way to secure the wing panels to the fuse other then those little wood tabs. I do have a video as I had a helmet cam going, but didn't bother uploading to youtube.
09-08-2013, 02:50 PM
#129
So what happened?
Unless you are very confident in the structure of your wing and mounting, that tactic of pulling hard "Gs" at the bottom of a loop is not a very good idea. With what these planes weigh, there is a strong possibility of a wing folding.
I am going to assume you lawn darted it. That sucks. Sorry for your loss. It was a nice plane.
Unless you are very confident in the structure of your wing and mounting, that tactic of pulling hard "Gs" at the bottom of a loop is not a very good idea. With what these planes weigh, there is a strong possibility of a wing folding.
I am going to assume you lawn darted it. That sucks. Sorry for your loss. It was a nice plane.
Last edited by vertical grimmace; 09-08-2013 at 03:02 PM.
09-09-2013, 07:41 PM
#131
Not a total loss.....the servos still work, the retracts are undamaged, the rx is fine and I have already used the tail wheel setup from the wreckage on another plane. The spitfire itself was completely destroyed when it hit the ground. Im actually glad it happened when it did instead of during our Warbirds over the Rockies event this coming weekend and the wing come apart throwing the plane into a spectator or someone else. As it were, it went down on the other side of the barbwire fence.
VG....I never actually got the chance to try to pull HARD g's on the plane. The right wing let loose at the first hint of elevator input on the downside of the loop.
BTW....the motor looks to be ok as the plane hit tilled dirt. Im sure it will run fine once cleaned up, but the electronic ignition will need to be replaced. I just don't have another large airframe to put that motor in. The ESM me-109G I have already has a 65cc rimfire motor NIB waiting to be installed.(im not putting the turnigy 50cc in the me-109 so don't bother saying I should).
OH.....on another note relating to the spitfire, my friend and fellow club member Fred also lost his HK spitfire the same day about 20 mins before mine went in. In his case, it started over rotating on the takeoff and during the attempt to correct and keep the prop from hitting the runway, the plane veered towards the left edge of the runway. Fred pulled the plane off of the ground too soon and resulted in a sustained multi occurrence stall that led to a significant cartwheel. His plane didn't suffer near as much damage as mine, but it was still too much to fix. Fred has since ordered a Top Flite spitfire. I may also at some point, but, not top on my list of things to worry about any time soon. Ive got the ESM ME-109G to do, finish my airworld me-262 and a few other EDFs. I'll give it some time to decide what, if any, plane I acquire to use the turnigy 50cc in.
VG....I never actually got the chance to try to pull HARD g's on the plane. The right wing let loose at the first hint of elevator input on the downside of the loop.
BTW....the motor looks to be ok as the plane hit tilled dirt. Im sure it will run fine once cleaned up, but the electronic ignition will need to be replaced. I just don't have another large airframe to put that motor in. The ESM me-109G I have already has a 65cc rimfire motor NIB waiting to be installed.(im not putting the turnigy 50cc in the me-109 so don't bother saying I should).
OH.....on another note relating to the spitfire, my friend and fellow club member Fred also lost his HK spitfire the same day about 20 mins before mine went in. In his case, it started over rotating on the takeoff and during the attempt to correct and keep the prop from hitting the runway, the plane veered towards the left edge of the runway. Fred pulled the plane off of the ground too soon and resulted in a sustained multi occurrence stall that led to a significant cartwheel. His plane didn't suffer near as much damage as mine, but it was still too much to fix. Fred has since ordered a Top Flite spitfire. I may also at some point, but, not top on my list of things to worry about any time soon. Ive got the ESM ME-109G to do, finish my airworld me-262 and a few other EDFs. I'll give it some time to decide what, if any, plane I acquire to use the turnigy 50cc in.
02-24-2014, 02:41 AM
#132
Haven't got the time to read the entire thread yet, my apologise if I repeat something. I would like to buy this Vantex 89" Spitfire but the one with the white-black strips on the wings that Hobby king doesn't have. Is that the same as the one hobby king has? Because it has the same specifications. Where can I buy one? greatwesthobbies has it at 670$ but they only ship to Canada and USA and I'm from Europe. I also find it on http://www.rchobby.com.cn/rcgasoline...cc-p-1016.html Do you think it's a good place to buy it? I emailed them asking about the price, they told me that 299$ is the 1,6m Spit and the 89" 2,2m is 399$ and the shipping to my country I saw that is about 215$ a little..double as I was hopping but I would still buy it mostly because I can't find it anywhere else on a more known sitte. What to you think?
04-09-2014, 07:23 PM
#137
I'm back on this project, I just got sidetracked with getting into turbines and getting my turbine waiver.
As far as the wing tabs are concerned, I agree that they are a weak spot and also easy to fix with a screw into the wing tube on each wing panel. This is a standard practice on most wing tubes I've seen, my BVM Bobcat will do 220mph and take a 50G pull out and it has 1 screw holding each wing panel on.
There is no way you will force stuck retracted gear down with a high positive G maneuver, this will only put more force on the up lock. A very gentle negative G maneuver is the ONLY way to relieve pressure on the uplock and get them down but I do not recommend this either. If you lost air pressure then you would have hanging gear legs that may not lock down. Belly land in the grass, that is what you do.
The manual clearly states and I completely agree: Never attempt to make full throttle dives!
Large models perform much more like full-size airplanes than small models. If the airframe goes too fast, such as in a high throttle dive, it may fail. The model should be flown like a full-scale airplane. Throttle management is absolutely necessary.
Cheap ARFs are always going to be a little more work to assemble, I personally don't mind this, I like this plane and I like the looks of it. I like to make changes to suit my tastes, I'm not saying what I do has to be done for the most part, just those areas that need attention to be safe. The one mod you must do for example is a screw thru the wing tube.
I used the plastic parts as molds and made fiberglass parts. The scoops are now held on with 4 screws and I positioned the flap servos and linkage so they are hidden in the scoop. My retracts hold air forever, all of the nipple threads need to be sealed on the air cylinders and I used a BVM fill valve and a Jet Legend retract valve.
RCGroups has a good thread on this plane with some pretty extreme mods, but I'll post a few updates here to finish this thread and not leave it hanging.
As far as the wing tabs are concerned, I agree that they are a weak spot and also easy to fix with a screw into the wing tube on each wing panel. This is a standard practice on most wing tubes I've seen, my BVM Bobcat will do 220mph and take a 50G pull out and it has 1 screw holding each wing panel on.
There is no way you will force stuck retracted gear down with a high positive G maneuver, this will only put more force on the up lock. A very gentle negative G maneuver is the ONLY way to relieve pressure on the uplock and get them down but I do not recommend this either. If you lost air pressure then you would have hanging gear legs that may not lock down. Belly land in the grass, that is what you do.
The manual clearly states and I completely agree: Never attempt to make full throttle dives!
Large models perform much more like full-size airplanes than small models. If the airframe goes too fast, such as in a high throttle dive, it may fail. The model should be flown like a full-scale airplane. Throttle management is absolutely necessary.
Cheap ARFs are always going to be a little more work to assemble, I personally don't mind this, I like this plane and I like the looks of it. I like to make changes to suit my tastes, I'm not saying what I do has to be done for the most part, just those areas that need attention to be safe. The one mod you must do for example is a screw thru the wing tube.
I used the plastic parts as molds and made fiberglass parts. The scoops are now held on with 4 screws and I positioned the flap servos and linkage so they are hidden in the scoop. My retracts hold air forever, all of the nipple threads need to be sealed on the air cylinders and I used a BVM fill valve and a Jet Legend retract valve.
RCGroups has a good thread on this plane with some pretty extreme mods, but I'll post a few updates here to finish this thread and not leave it hanging.
04-10-2014, 03:06 PM
#139
The wing failure and crash on this particular Spit was a direct result of a lack of experience in recognizing bad design and engineering of a large model like this.
While it may not be a good idea to yank full elevator, coming out of a dive, that actually had nothing to do with the wing sliding off the tube. It was a lack of experience, thru a career of assembling ARF's, and accepting what was provided by the manufacturer as adequate, when it was not.
]A truly experienced modeler would have recognized the design shortcomings, and made proper corrections. Unfortunately, such large and powerful ARF's are getting into the hands of modelers with limited experience, leading us to some concerning safety issues. Thankfully, no one was hurt.
While it may not be a good idea to yank full elevator, coming out of a dive, that actually had nothing to do with the wing sliding off the tube. It was a lack of experience, thru a career of assembling ARF's, and accepting what was provided by the manufacturer as adequate, when it was not.
]A truly experienced modeler would have recognized the design shortcomings, and made proper corrections. Unfortunately, such large and powerful ARF's are getting into the hands of modelers with limited experience, leading us to some concerning safety issues. Thankfully, no one was hurt.
Last edited by vertical grimmace; 04-10-2014 at 03:09 PM.
04-10-2014, 05:38 PM
#140
My Feedback: (5)
The wing failure and crash on this particular Spit was a direct result of a lack of experience in recognizing bad design and engineering of a large model like this.
While it may not be a good idea to yank full elevator, coming out of a dive, that actually had nothing to do with the wing sliding off the tube. It was a lack of experience, thru a career of assembling ARF's, and accepting what was provided by the manufacturer as adequate, when it was not.
]A truly experienced modeler would have recognized the design shortcomings, and made proper corrections. Unfortunately, such large and powerful ARF's are getting into the hands of modelers with limited experience, leading us to some concerning safety issues. Thankfully, no one was hurt.
While it may not be a good idea to yank full elevator, coming out of a dive, that actually had nothing to do with the wing sliding off the tube. It was a lack of experience, thru a career of assembling ARF's, and accepting what was provided by the manufacturer as adequate, when it was not.
]A truly experienced modeler would have recognized the design shortcomings, and made proper corrections. Unfortunately, such large and powerful ARF's are getting into the hands of modelers with limited experience, leading us to some concerning safety issues. Thankfully, no one was hurt.
It amazes me that you guys blame the modler for not making every possible fix on a product that should never have been sold to any modeler.
Companies that sell this kind of trash should be clearly identified by everyone so if they are going to sell stuff like this they are forced out of the hobby market.
Ed
04-10-2014, 06:12 PM
#141
Ed, take a deep breath! There, that's better.
There is a difference between an ARF offered at $400 and one offered at $700. We do expect the "top of the line" products to be totally satisfactory...that's what we pay for. But, to spend half as much and expect the same quality is really not being realistic.
There is a difference between an ARF offered at $400 and one offered at $700. We do expect the "top of the line" products to be totally satisfactory...that's what we pay for. But, to spend half as much and expect the same quality is really not being realistic.
04-10-2014, 07:33 PM
#142
My Feedback: (5)
Ed, take a deep breath! There, that's better.
There is a difference between an ARF offered at $400 and one offered at $700. We do expect the "top of the line" products to be totally satisfactory...that's what we pay for. But, to spend half as much and expect the same quality is really not being realistic.
There is a difference between an ARF offered at $400 and one offered at $700. We do expect the "top of the line" products to be totally satisfactory...that's what we pay for. But, to spend half as much and expect the same quality is really not being realistic.
otherwise they are just ripoff products and not suitable for sale at all. So dont talk to me about taking a deep breath - thats an extremely arrogant statement. So you need to think long and hard before you write that kind of arrogant remark to me again.
Ed
04-10-2014, 09:40 PM
#143
No this crash was the directresult of a company providing a badly designed and built model that was not capable of flying in a totally reasonable manner, whether by a not totally experienced modler or by any modeler. Stop making excuses for this kind of garbage product. This just gives the hobby a bad name, and you are part of the problem not part of the solution.
It amazes me that you guys blame the modler for not making every possible fix on a product that should never have been sold to any modeler.
Companies that sell this kind of trash should be clearly identified by everyone so if they are going to sell stuff like this they are forced out of the hobby market.
Ed
It amazes me that you guys blame the modler for not making every possible fix on a product that should never have been sold to any modeler.
Companies that sell this kind of trash should be clearly identified by everyone so if they are going to sell stuff like this they are forced out of the hobby market.
Ed
04-14-2014, 11:35 AM
#147
Soooooo Luke, how goes the rest of the build oh sorry I mean assembly
Man there are just too many people out there that need to get a life. I have not built an arf yet in any price range that did not need some kind of bashing or modification. Bash on Luke!
Man there are just too many people out there that need to get a life. I have not built an arf yet in any price range that did not need some kind of bashing or modification. Bash on Luke!
04-14-2014, 04:58 PM
#148
I agree rapture, with a little work, most of these ARFs turn out to be wonderful warbirds. Luke has been an inspiration to many of us with what he can turn out. Kahloq has done the right thing by informing others of a potential weak spot. This is what this site is supposed to be about...sharing information and ideals.
Sorry about the derailing of the thread Luke...bash away
Casey
Sorry about the derailing of the thread Luke...bash away
Casey
04-16-2014, 05:23 AM
#150
Senior Member
Ed, take a deep breath! There, that's better.
There is a difference between an ARF offered at $400 and one offered at $700. We do expect the "top of the line" products to be totally satisfactory...that's what we pay for. But, to spend half as much and expect the same quality is really not being realistic.
There is a difference between an ARF offered at $400 and one offered at $700. We do expect the "top of the line" products to be totally satisfactory...that's what we pay for. But, to spend half as much and expect the same quality is really not being realistic.
