As usual, I am playing a bit of catch up... :/ I maidened my new F18 V4 about 4 days ago and have now flown a total of about 16 flights on this great little plane.
Another awesome plane in the V4 lineup for sure! In all honesty, the improvements on the F18 V4 didn't jump right out like the improvements on the Mig29 V4, but as I flew it more and more, the amazing improvements became more and more evident.
Unfortunately I cannot really give much feedback on high alpha capabilities just yet, winds were 10-15 mph every time I have flown it, so very tough to get any consistent high alpha.
Build - Very straight forward, maybe a little bit more challenging dependent on your build experience than the V3, but only the part with the KF2 and slats/fronterons, but the new instructions are very straight forward and helpful.
Stability - More stable in all areas of the flight regime than the V3 especially at very slow speeds and higher speeds. Even in a wind with no lift aids like flaps, spoilers, etc I felt comfortable flying it down to about 30% throttle, it stayed very well behaved and then as speed increased, the stability just continued to get better. Although not as stable as the Mig29 V4 in the wind, overall at close to the same weight, it handled the wind better than the F18 V3.
Speed - The F18 will really not be a speed demon, but that is probably what the Mig is for if you really want to burn up the skies. However, at first I was skeptical that the leading edge slats/fronterons were going to significantly impact speed, but I noticed no apparent difference in speed and acceleration between the V3 and the V4 and they have the exact same power setup. I would not recommend loading the F18 V4 up with an NTM Prop Drive 2700 and big ESC, too much weight and excess wing loading. Similar to the V3 in my humble opinion, any prop/motor/ESC/battery combo that allows you to have decent punch out from high alpha or good pop for aerobatics is all you really need dependent on your final weight. Again, just my opinion.
Overall handling - Just like the V3, the V4 is a "smart plane" with even better self-stabilizing tendencies, however the really cool thing I found is with the motor moved a bit forward and the redesigned control surfaces it was more responsive and agile in all three axes, so aerobatics are even crisper and quicker...yay! It took me a few flights to get used to the slight "floatiness" of the KF2 airfoil as all my other F18s have all had KF4, but after about 6 flights or so, I wasn't really noticing the floatiness anymore.
So once again, Dave Powers and Scott Lott managed to take one of my favorite park jets of all time, the F18 V3 and make it better, amazing... :)
Hopefully this video will cover anything else I have forgotten to mention. Lots more flights to come as I take the F18 and Mig29 V4s to the field and "fly the wings off" them... :)
Cheers,
Scott
Hi Scott,
ReplyDeleteI know this thread is back in the blog a little bit and not the most current subject of your intrest but I was thinking about the F18 V3 the other day. Having only built the Mig 29V2 my experience data base for RCPower planes is somewhat limited. I've read everything on the RCP forum including all of what you have written, so I know its not easy choosing between the Mig and the F18.
While I was watching over this walkaround video again I was wondering how the solid rear stab section might work out for this V3 version and if it would make for a nice modification. I've also read how in alot of situations the battery on the V3 need's to go all the way forward against the bulkhead in order to get proper CG. I wonder if moving the motor mount forward an inch like RCP did for there V4's, as well as shortening up the nose section in front of the canopy would help create more flexability regarding the battery and its placement in the electronics compartment.
The F18V3 might just be something I would also have some fun with as well...
talk to you soon,
RT
Hi RT -
DeleteAfter seeing what I have seen in building and flying 4 Mig29 V4s and an FRC Su35 MK2 with the fixed horizontal stab, it is something I will put on every park jet I build from now on. Not only does it add stability, but it very easily reduces the moving surface of the elevon which helps reduce drag and turbulence when maneuvering the plane.
I have given a lot of thought to building another F18 with NAMC mods and in all honesty would probably build another V3 with mods before building another V4. The more I flew the V4, the less I liked it, those slats or "fronterons" just didn't do it for me. To set it up the way I want, it would take more work to mod a V4 than it would a V3, so I think another NAMC modded V3 will be one of my winter builds.
Just before the V4s were released, I built a modified F18 V3 with smaller elevons and ailerons, modified rudders and KFs, I wrote a couple posts about the mods and how they affected it's flight performance here http://migsrus.blogspot.ca/2014/05/rc-powers-f18-v3-modification-tests.html http://migsrus.blogspot.ca/2014/05/rcp-f18-v3m3e3-flies-great.html
I think moving the motor mount forward on the V3 is a good idea, as well as concentrating the aileron and elevon servos close to the CG, something I will also do on all future planes I build. This should allow you to draw the battery back somewhat. It would mean running your servos externally like I did on the F18 V3M3e3 in the posts above, but if you put the fixed horizontal stab at the back, this is very easy to do.
The F18 V3 is one of my favorites as it helped take my flying skills to a whole new level, it is stable, maneuverable, but does things just a little slower than the Mig, so you can relax a bit more and work on your skills and confidence at a slower pace. I have over 350 flights on my current F18 V3 and will fly it forever if it lets me.
A couple things I would say is that it is a plane that likes full controls, elevons, ailerons and rudders, how you set those up is up to you. It is very lethargic elevons only, it needs ailerons to help in the roll and rudders for slow speed flying. It is not the most stable plane in the wind, even with a 2200 battery with my weight around 21.5 oz it gets bounced around a lot because of the angled vertical stabilizers.
I found about 20-22 oz the ideal weight to give good wing loading and performance if you match it with the right motor (Focal Price or Deal Extreme 2700 is an excellent choice). Over 23 oz and performance starts to drop off considerably. I flew it as light as 17.8 oz with the MJV3, but would only fly it at that weight in dead calm conditions.
I think the F18 V3 is an excellent choice for someone for a second park jet, as I mentioned, I owe a lot to it for helping build my skills and confidence immensely.
Good luck with your build and don't hesitate to ask if you need help.
Cheers,
Scott
Then there's the MANY cool paint schemes to choose from that our northern neighbors have incorporated into there CF-18 fleet. Canada most definitely has the best looking F18's by far! Two of my favorites are the 20th Anniversary Edition, and the CF-18B AETE.
ReplyDeletehttp://i60.tinypic.com/35iq1zp.jpg
http://i57.tinypic.com/20r1o0.jpg
CAF-18 Pictorial - http://lemdecal.com/F-18%20PICTORIAL.html
Hi RT -
DeleteThose are some very nice paint schemes, many if not all of the CF18 paint schemes (other than the normal operational grey scheme) were designed by an amazing artist named Jim Belliveau who was in charge of the Base Graphic Arts section in Cold Lake when I was stationed there, he has designed some true masterpieces over the years. But then we have had the CF18 for 32 years now, so he has had plenty of time and opportunities to paint them, they have seen a lot of history and a lot of combat.
Cheers,
Scott
Hi Scott,
ReplyDeleteBecause I opened this dialog here I figured it would be alright with you to continue it. I probably should have started it in the post where you already did modifications to the F18 V3 to keep things more in order .... ;-/
Recently when I got the plans done at Office Max for the Mig V3 I didn't carefully check the scale pattern in the store, probably due to the girl that was behind the counter distracting me. As I was assembling the modifications on paper I kept running into problems with fit until I finally noticed that the 2" scale was almost 1/16 of an inch off on one of the printout's. My fault as a printer (my profession) for not checking more closely in the store... lesson learned.
At this point I shifted my focus towards the F18 V3 for a change of pace and decided although its more work, I'd print the tiled plans at home so I would have more control, plus I have access to paper cutters at work which make the task a little more accurate, and easier.
I'm working on modifying the F18 V3 plan before I start cutting and wanted to ask you a couple of thing's. We both agree the fixed stab is a must modification these day‘s, but I was also thinking of the tail heavy condition a lot of builder's were experiencing and thing's I could do to make it better. Without rocking the boat too much on an already excellent plane of coarse that means centered component’s around CG like you've mentioned for best performance and battery flexibility. My mind is still wrestling with a couple of other idea's so I'll list them below and maybe you'll have some helpful insight for me ?
*The Fixed Stab would also allow the hinge line to be moved forward slightly shortening the wheelbase a little, and making the tail (and plane) more Mig like. Care would have to be taken to not close that gap so much that it reduced rudder surface performance. I'm thinking with this modification that some of the rearward nacelle pieces under the elevator could now be shortened a little, which I'm assuming were there originally to protect the full moving elevator from digging into the ground on landing's.
* Regarding the motor mount I'm thinking of just printing pg 5 of the planview which has the motor cutout and moving it forward by 1". I would probably have to move the carbon wing spar slightly forward as well.
*I'm debating on weather or not to extend the top KF to include the LERX, or just build a stock KF4 and save a little weight.
* I'd like to shorten the distance from the front of the canopy to the tip of the nose like RCPowers did on there F18 V4. I haven't gotten to this stage yet (and could use some idea's) but at some point will be looking for the path of least resistance if I decide to add this modification.
I cant really ask these question's too easily in other places (and don’t even want too) because some would say I could [maybe should] just build it stock and have a great time with it as intended by RC Power's. IMO there's nothing wrong with adding some minor well thought out modification's that have been proven by other's, that might make things a little more fun for the guy who's plane it is.
talk to you soon,
RT
Hi RT -
DeleteSorry to hear about your Mig plans... :/
I'll try to answer each of your questions in order.
Yes, you could move the hinge line forward right up to the back of the vertical stabilizers/rudders if you wanted to, you will lose some scale look to the plane, but the surfaces shouldn't interfere with each other. Part of the tail heavy conditions people might have been experiencing could be caused by where RC Powers recommends putting the elevon servos behind the prop slot. If you are going with a fixed horizontal stab setup, it makes it much easier to run the servos outside, then you can move them forward quite a bit. Even though I didn't use the fixed horizontal stab on this modified F18, I put the servos outside as you can see in this video https://www.youtube.com/watch?v=4OT5a2BQokw#t=14
Those big long triangular shaped pieces that extend back on the side pieces/nacelles are strictly aesthetic in my experience, they do nothing to protect anything on landing and add more weight to the back end. On all my F18s, I cut those off just ahead of the elevon hinge line as you can see more closely in this video on a couple of occasions. https://www.youtube.com/watch?v=C2TPIgB0QCw&list=UUfPZvAvwOjP9Kjv84ajANVg
Perhaps it is too much for what you want to achieve at this point, but if you really want to shorten the wheel base, you could cut an inch out of the side plates, move the whole rear end forward like we did with the Mig 29/35 NAMCV3, especially if you are going to move the motor forward by an inch. Whatever you are comfortable with. This post shows the pics and diagrams used to modify the first Mig29/35 NAMCV3 if it helps give you ideas. http://migsrus.blogspot.ca/2014/10/rcp-mig29-v4-namcv3-mod-picsdiagramsinfo.html
If you are wanting to move the motor mount forward by an inch, I would just draw it out on the plans you are going to use once you have them all together, it helps keep things in better perspective in my experience to have the whole piece I am modifying together on the plans before drawing lines to modify it.
You probably would have to move your carbon wing spar around somewhat, but moving the motor forward will bring more weight up closer to your CG which should help the plane be more responsive in all axes. Even if you end up shortening your wing spar somewhat, you will still get some added strength by using the KF4 airfoils. Don't forget, you will also need to remove at least an inch from the back of the score and fold portion of your nacelles if you move the motor forward, otherwise the nacelles will interfere with the prop.
I can tell you from personal experience that extending the top KF forward on the LERX is well worth the few extra grams in foam. It makes the plane fly much smoother and more stable, I will build all my planes in future with the top KF extended forward even if the plans don't call for it.
Shortening the nose might require a little creativity, but when I shortened the nose a bit on the Mig29/35 NAMCV3, I simply measured back from the sharp point on each "finger" on the nose assembly the distance I wanted to shorten the nose and made a small mark. Then by hand redrew the curved lines in proportion to how I thought the nose should look. The nose will end up having a bit "stubbier" look, but I always felt the F18 V3 nose was too "pointy", but just my opinion.
Don't ever worry about asking your questions or posting your thoughts here, we certainly agree people should be free to build and modify their planes how they want and don't judge how folks build their planes.
Hopefully this has helped you somewhat with your thought process on modifying your F18 V3, I look forward to seeing/hearing what you come up with. Good luck... :)
If you want to e-mail pictures of any part of the build to get my feedback or a second opinion, please feel free to do so at migsrus@outlook.com and I will do what I can to help.
Cheers,
Scott
Hi Scott,
ReplyDeleteI never even considered how moving the motor forward would effect the prop area, thus reducing the size of the nacelles on the bottom. I probably need as much landing area on my planes as possible, and should leave the motor mount where it is and look for saving tail weight elsewhere. I could move the elevator hinge line forward to meet up with the vertical stab reducing the rear deck plate like you suggested. That might be my best option and within my skill level at this point. That along with building light, centering the mass around the CG, and rounding off the nose section a little might make for a nicely finished F18 V3.
Let's take a look at the untiled drawing for a minute. I simply moved the elevon surfaces forward to meet the rear of the vertical stab just to see what it might look like. My concern would be going to far forward and blocking airflow to the rudders during high alpha, or high AOA scenario's. It’s not so easy looking at a 2 dimensional drawing and trying to anticipate 3 dimensional problem’s, so I figured I’d better have an expert take a look and tell me what he‘s thinking.
Below are 2 quick drawings using shapes from the untiled plan. One drawing is the top view so you can see the rear stab section and the distance between the elevons and aileron’s. The other is the top view with the rudder shapes in place showing what it would look like from above. I colored the shapes to make it easier to cut and paste them. I’m curious if it looks to you like there is enough space there for the rudders to work effectively?
http://i57.tinypic.com/4lsw41.jpg
http://i57.tinypic.com/2ec43s7.jpg
talk to you soon,
RT
*edit*
ReplyDeleteI forgot to included the stock views for comparison on the previous post.
Below are 2 stock views, and 2 modified view's, both with identifying text so it should be easier to compare.
http://i59.tinypic.com/2mcghfa.jpg
http://i57.tinypic.com/suxaxl.jpg
http://i59.tinypic.com/2hs5jyr.jpg
http://i59.tinypic.com/24yvluf.jpg
Hi Scott
ReplyDeleteHere's another quick comparison of the FRC SU35 Mk2 using the untiled plan. It's interesting how the modified tail section of the F18 above slightly resembles the stock version of the SU35 Mk2 now, regarding the distance between the elevons and ailerons. That doesn't necessarily mean its a good idea or anything... it was just something I noticed and was thinking about.
http://i58.tinypic.com/2qjj3ic.jpg
http://i62.tinypic.com/nl7gqq.jpg
Hi RT -
DeleteI don't know if it will be as much of an issue if you shorten the tail section of the F18 without moving the motor further forward, but one of the issues I find with the Su35 is that it feels a bit "short coupled", especially in the pitch axis perhaps because the elevon hinge line is so close to the prop.
The prop slot is between the vertical stabilizers on the Su35 which does tend to funnel and concentrate the prop wash directly back to the elevons which may also lead to this behavior, you may not experience that as much with the F18 since the prop slot is ahead of the vertical stabilizers.
Some more thoughts on moving the motor forward. For both the F18 and Mig29 V4, RC Powers moved the motor forward from the V3s. Obviously there was no Su30 V3, but if you look at the Su30 V4, it's motor is quite far forward, almost right on the CG and it seems to be a very stable yet nimble plane. Our recent experimenting with the Mig29/35 does prove to me that having the centers of mass, thrust and gravity closer together make for a more stable, well balanced yet very maneuverable plane. Additionally, because it feels so well balanced, it almost has the same "self correcting" tendencies that I find with the F18 V3, the latest NAMC Mig is very forgiving in it's handling and performance.
The FRC Su35 I think is a candidate for having the motor moved forward to try and bring the centers of thrust, mass and gravity closer together. When I do get around to building my next one, it will have a big modification to it's motor location to try and accomplish this.
The F18 V3 is certainly not an unstable plane, but with the motor moved closer to CG would become more stable and a much more nimble plane in my opinion. This can also be achieved by arranging your other components, servos, ESC, Rx as close to CG as possible even if you choose to keep the motor where it is.
Anyway, just food for thought.
If you shorten the tail like you are looking at doing and leave the motor where it is, you might end up being a bit more responsive from a thrust vectoring standpoint even with reducing the elevons by using the horizontal stabilizer. You might have to be a little more careful about thrust vectoring stalls as the moving surface is still going to be fairly big and they will be closer to the prop. Again, just food for thought, not anything that should stop you from doing the mods you want to do, but things you might need to factor into the plan.
Cheers,
Scott