Mirage vs. Mig 21 (and maybe the A4)

[SanExup]

I know there are a couple of newer, perhaps more glamorous planes than a few of the older EDF'S, I'm sure I will end up with them. But I'm looking for a winter project, a third Edf, with speed and performance. Non-avanti.

I was wondering, to those that own and have flown the Mirage and the Mig 21, how would you compare them? I am looking for a comparison of the high performance versions with the 9 blade fan. And I guess I would throw the A4 into the mix but from what I've read so far might not be as similar to the Mirage and Mig21.

So what I'm hoping to compare are:
Flight Characteristics- high speed, low speed, not necessarily which one can fly high alpha for 3.5 minutes. More how they are throughout the flight envelope, aerobatics, scale flight? Maybe differences in thrust to perform vertical maneuvers?

Flight Times- Since they use the same motor, are you getting similar flight times? I know their are different variables to this but generally how do the flight times compare.

Quality- How would you compare the assembly? The finish quality? Foam, paint, landing gear, or anything else that might stand out for you? Are there out of the box upgrades that just seem mandatory to get the most out of the plane?

[Mizer67]

The Mirage is faster, more nimble, climbs better, has better T/W ratio for verticals and is more aerobatic. Plus it'll high alpha better too. If pure performance is what you're after, the Mirage is far better. It's significantly lighter, so it doesn't retain it's energy as well though.

The Mig is still fun. It's more stable on the ground and the barn door flaps slow it down really well. Plus it has a ton more room for batteries and gear. Of all my planes, I think I've made the fewest repairs to the Mig, but it doesn't get flown as often as my Mirage(s). I have about 20 hours on the Mig, 60 hours on the Mirages I've had.

The Mig has more durable gear and you don't have to deal with the sometimes wonky nose gear door on the Mirage.

I don't have the 9-bld. fan, I use the FMS 2100kv 80mm, so can't give you flight times for that. I set my timer to 3 min. on a 4000. The Mirage will need narrow 4000's to be able to CG well.

[SanExup]

Thanks Mizer67 That is exactly the information I was looking for! And I should have included the question of, what do you fly more. So thanks for that. What your saying doesn't make it any easier though. I do think I'll eventually end up with both if they keep carrying them. Most of the 6s that I have are 4000s and 3500s. I'll have to compare sizing, that might be a deciding factor.

[Mizer67]

Thanks Mizer67 That is exactly the information I was looking for! And I should have included the question of, what do you fly more. So thanks for that. What your saying doesn't make it any easier though. I do think I'll eventually end up with both if they keep carrying them. Most of the 6s that I have are 4000s and 3500s. I'll have to compare sizing, that might be a deciding factor.

The Mirage needs a battery that's <=42mm wide to get the most rearward CG in the manual. I flew it for a couple of years on 3600's when it first came out, but flight time will likely suffer by ~:30 seconds vs. a 4000.

Depending on the exact plane, battery and motor you use, you may need to (carefully) shave the interior of the battery compartment to get the CG back a few more mm. The new 9 bld. motor is lighter than the old one, which is usually good, but in this case will make achieving neutral CG more difficult.

Or, you could add the 3DPUP nozzle, which adds about ~40 grams to the rear. It's not a well made part, but it puts the weight right where you need it to get extreme rear CGs. I think it flies fine at the back of the manual recommendations and chose to save the weight vs. installing it.

[Mizer67]

Also, to give you an idea of performance differences (on the FMS 2100kv fan on a fully charged battery):

Mig / Mirage

Max vertical (from level flight at full speed): ~650 ft. / Unlimited other than by LOS (I start to lose orientation about 900 ft.)
Max speed (sea level, level flight): ~111 mph / ~125 mph

The biggest difference between the Mig and Mirage though is the weight. Because of it they behave totally differently.

The Mig carries energy better, but once it dumps it in a turn, which it does fairly easily being a delta, it takes a while to get it back. Whereas the Mirage can turn/loop etc. consecutively and just power right out and accelerates back to speed much quicker. It'll also accelerate straight up when completely stalled. The Mig doesn't have the T/W to pull that off.

[Evan D]

Lt me add that the Mig and Mirage have the same wing outline (airfoil might be a little different). The difference is that the Mig has a tail with rudder and elevators so it can have flaps. Makes it totally different flying and landing.

The A-4 again is different than both the other two.

[SanExup]

Well, and as much as I would love an A4, the dirt road I fly from would destroy the nose gear every flight probably.

Evan, I assume you own both or have flown both? Which one do you fly more often or are inclined to bring to the field more often?

[Evan D]

All three... It may be telling that I've had 3 Mirages and sold my Mig after about 100 flights... Not that it did anything bad, just the Mirage is so much more high performance.

[SanExup]

Thanks Evan! Did you swap the nose gear on the Mirage at all? I saw somewhere that the T33's nose gear might be a clean swap.

[Evan D]

No, still stock and mine are the older non tiger meet but with higher power setups.

[SanExup]

I wish they still offered the non tiger meet but I would probably modify that one as well. Did you change the stock camo pattern or decals?

[Evan D]

Stock camo, put in the A-4 outrunner and 100a ESC.

[Mizer67]

Thanks Evan! Did you swap the nose gear on the Mirage at all? I saw somewhere that the T33's nose gear might be a clean swap.

I don't find the durability of the Mirage nose gear itself to be much of a problem.

If your field is very rough, it's good to reinforce the nose gear retract with a small, flat piece of carbon fiber. I do that for mine before I fly them by cutting a small slot and inserting it just above where the rear of the nose gear retract sits. The plywood tray that's above the (rear portion of) the retract will crack if you hit hard the nose hard enough without it as the forces bend the whole assembly backwards. Landing in too high of alpha will also cause this as the tail drags and slams the nose gear down. It's best to land more flat.

Now, if you're flying from dirt, the nose retract will eventually fill up with dirt, or in my case sand...and clog the worm screw. This will cause the nose gear to stall and not fully close the spring loaded door. But it's usually possible to clean them out and get them to work again for a while. Or, it's a pretty cheap fix as it's a ~$12 part to get a whole new retract if needed.

PS - the Mig is an excellent runway vacuum, much better than most of my other jets. If you're flying from dirt with rocks, I'd suggest a FOD screen.