Official Freewing T-33 Shooting Star 80mm EDF Thread

[BHChieftain]

LOL!!! Thanks,
Chief

[xviper]

Hi xviper,
Thanks for the comprehensive reply. I’m aware of c-rating and how that also impacts weight. My lipo choice would be the Admiralpro 4000 (60c-642g), admiral standard 5000 (50c-732g), admiralpro 6000 (50c-846g). I guess my question can be simplified to what’s the typical runtime difference between those 3 packs on average (say mixed flying style), and would the 6000 weight adder trade off too much flight performance to be worth the extra flight time (assuming I don’t remove nose weight).

Even at "mixed throttle" for the whole flight, 5 minutes may be hard to achieve with less than 6000mah. However, having said that, if you fly like a grandma driving to church on Sunday, you could squeeze out 5 min. on a 4000. I once flew my old Avanti S (all stock) on a 5000 for just shy of 10 minutes just to see how long I could stretch it out. With an onboard voltage telemetry sending readings to my hand held receiver, 1/2 flaps and puttin' along at just above stall speed, I went round and round till the alarm went off. I got so bored sitting there in my lawn chair, I could have slit my throat. These days, I'm satisfied with a 3:30 flight that doesn't put me to sleep. It's not that hard to land and throw in another battery and send it up again if that's what you want. Take offs and landings for me is 1/2 the fun anyway.
To further answer your question about the T-33, it flies well with almost any weight of battery. It seems to carry added weight without much hinderance to performance. What you add in mah weight can easily be offset by increased flight time.

[BHChieftain]

Hi Evan,
Thanks. By “20% reserve” I mean 20% reserve mah after I land based on the meter.

[Evan D]

I'm confused by "20% reserve" Do you mean land with a meter saying you have 20% in the pack? This would be about, or below, 3.7V per cell which is lower than I fly my batteries (I aim for 3.8V per cell after a flight or about 33%.

You could also be meaning a useful reserve of 20% above 3.7-3.8V per cell. Useful reserve for a go around or two and a last high speed pass.

Xviper's advice is right on. I have yet to buy a Spektrum or Admiral battery. I do not find them good values. It seems over the years I go from brand to brand as they change chemistry/ size/ apparent C rating/ etc. My current go to in the 5000 size is Power Hobby 5200 50C that are 645g on average and their 5000 100C which is 575g on average. The C is what's on the label and as Xviper says you shouldn't really trust what the label says. The 5000 is a really good battery in my opinion especially when you need it for a tight space or where a light weight battery is needed, it has replaced 3500-3600 packs in my 70mm jets. A battery I like in the 6000 range is the Socokin 6000 60C at 830g, maybe a bit heavy but they are on Amazon and on sale now and then, a good value. They also make a 5200 but while it performs well it's a little heavy.

These manufacturers change things without notice. My usual way to shop is to buy a couple and try them and if I like them I buy 10 or 12. I then fly those for a year or two and look for the a suitable replacement, repeat the cycle. If the old batteries are still performing well I may keep them longer. I take the old batteries to swap meets and will sell them for $20 or so, there are usually quite a few that don't need the latest greatest EDF battery.

[BHChieftain]

Hi xviper,
Thanks for the comprehensive reply. I’m aware of c-rating and how that also impacts weight. My lipo choice would be the Admiralpro 4000 (60c-642g), admiral standard 5000 (50c-732g), admiralpro 6000 (50c-846g). I guess my question can be simplified to what’s the typical runtime difference between those 3 packs on average (say mixed flying style), and would the 6000 weight adder trade off too much flight performance to be worth the extra flight time (assuming I don’t remove nose weight).

[xviper]

Hi,
I’m considering purchasing this plane with a set of Admiral lipos from MRC. I’ve read thru the posts here but am on the fence between 4000, 5000, or 6000 lipos. If I plan to leave the nose weight in place, what are the pros/cons of these sizes? I’d like a min of 5min flight time with a 20%reserve on average. Was thinking 6000 would be the no-brainer but does that extra weight (including nose weight) affect it much? I’m not planning on knife edges.
Chief

First, you must look at the weights of the batteries you are about to buy for this plane. Just looking at mah doesn't tell the whole story. I fly mine on a 5000may, 6s battery that is quite heavy (~850g). I have my timer set at 3:40 and flying a mix of throttle levels, it comes down with your desired 20% or so. However, I also have 6000mah, 6s batteries that weight just over 800g. With this one, I could get the 5 minutes you require but you'll need to stay away from high throttle flying for most of the flight. I also have some Gens Ace 5000's that weight only 725g and they perform just as well and just as long as my heavier brands.
Besides weight, you have to look at "C" rating. Take a look at the Admiral and Admiral Pro 4000mah, 6s. Why do they weigh so different? Higher "C" usually mean more punch, which a jet craves for, slightly more flight time, but at the expense of weight and higher cost. You can do the same comparison with the 5000 and the 6000. Keep in mind that different brands of LiPos will have a different "true" "C" rating. Most Admirals have tested closer to 1/2 of what the stamped "C" rating says, some a bit more. My 70C ChinaHobbyLine 5000s, in real world testing, only puts out maybe 40 to 50C. On the most part these EDFs like to have big batteries in the "true" 40C or more range. Additionally, the bigger mah the battery is, the less "C" rating is needed to do the same kind of performance.
To get what you want (performance, flight time), you might search for a lighter 7000mah battery. One example (and there are many others) would be the Spektrum 7000mah, 6s, 30C @720g. It will more than likely give you the 5 minutes (and then some) you want but do you really want to pay 190 bucks for one? Also check out brands like SMC, ChinaHobbyLine and HobbyKing Heavy Duty, Graphene and Panthers.
If you want to be a more informed LiPo buyer, here's a real world comparison test for what those "C" ratings actually mean:

https://static.rcgroups.net/forums/attachments/3/0/3/0/6/1/a15094071-220-All%202021%20LPB%20Results.Jpg

[BHChieftain]

Hi,
I’m considering purchasing this plane with a set of Admiral lipos from MRC. I’ve read thru the posts here but am on the fence between 4000, 5000, or 6000 lipos. If I plan to leave the nose weight in place, what are the pros/cons of these sizes? I’d like a min of 5min flight time with a 20%reserve on average. Was thinking 6000 would be the no-brainer but does that extra weight (including nose weight) affect it much? I’m not planning on knife edges.
Chief

[Corsair nut]

Much appreciated! The speed brakes actually work quite well on landing too :(

[EA-6B Geek]

Almost rtf. Just need to finish cockpit and weathering

The speed brakes and the intake mod are awesome.

[Corsair nut]

Almost rtf. Just need to finish cockpit and weathering

[WarbirdFan66]

T-33 grass field gear mod

---

For those who fly from grass- or sand-strips and such, and dont care that much about the scale looks of the front gear perhaps, here a smal mod suggestion.

First i changed the oleo leg from that of the original T-33 leg to the strut of the Freewing L-39 which is about 7mm longer (you can find it as a spare part / its a perfect fit and you dont need to change anything to install it, i even think it looks a bit better but maybe thats just me). That might does not sound much but it makes the take off look a lot more scale like not to mention way easier in my opinion due to the slightly changed AoA of the plane.
While at the same time the newly added mudguard helps to keep the sand, dust and grass bits that are often thrown up into the wheel well by the front wheel to a minimum ( by the way the mudguard also fits the original oleo leg of the T-33, just in case you still wanna use that one).

For those who are interrested, i will put the 3D files up on thingiverse in a few days (for none commercial use of course)... blue skys

[EA-6B Geek]

Getting close on my refinish.

Nice!

[Corsair nut]

Getting close on my refinish.

[Jogs]

I fly from grass as well and have the same experiences. Long take off run and a sudden jump in the air although full elevator seconds before.

I changed the CG (about 1,5 cm to the rear) which helped. The longer nose strut mod is on the list but not done yet. Other conclusions from my experiences are:

• never fly from wet or damp grass, it's a no-go because she'll never get airborne
• never fly from uncut grass because that's a huge drag and even leaves marks in the wings from single out standing blades of grass (see picture)

[EA-6B Geek]

Mine is balanced at the CG specified in the manual. I’ve been extremely pleased with how it flies there, but I supposed moving it aft would help with the rotation from the runway. I think I’ll try that next time it gets flown.

[timmybeetle]

i have always had trouble taking off from short grass here in miss it seems to get up to flying speed with take off flaps but wont lift the nose to fly today we tryed full flaps and finally after a long run it flew the nose came up at about 45 degrees right off the ground but we caught it in time to level it off..ive calabrated the throttle the cg is good useing a 4000ma 6s battery iam thinking about buying another 1920kv motor and see if that is the problem any suggestions? my f86 with same motor and fan has no problems getting off same field

Hello

I fly from grass.
It's mentioned before if you fly from grass you need to move CG 10-15mm aft (back), otherwise if its front heavy it will not rotate.
Because the plane is now a bit unstable I use a gyro to compensate this, works for me.
At my T33 I noticed that my front wheel jams a bit, I removed 2 washers which where installed between rim and strut.
Also I lubricate my wheels axle.
F86 do the CG check as explained in threat, it balanced on the main wheels, see
https://www.hobbysquawk.com/forum/rc...1359#post71359

I will check on my T33 if we can come up something like that too😉

grts Hans

[Corsair nut]

Is there a place where all the 3d printed files are for the t33? I need the seats. And did somebody do pilots to fit the t33?

Thanks!

[xviper]

I flew mine this morning for a couple of flights and after reading the last couple of posts about this plane "leaping into the air" on take off, I'm a bit surprised. Mine is stock and I fly off GeoTex and on 1/2 take off flaps, it rises quite gently into the air, with a very shallow ascent. I have not flown it off grass as I don't want to risk tearing off those strut pants.

[EA-6B Geek]

i have always had trouble taking off from short grass here in miss it seems to get up to flying speed with take off flaps but wont lift the nose to fly today we tryed full flaps and finally after a long run it flew the nose came up at about 45 degrees right off the ground but we caught it in time to level it off..ive calabrated the throttle the cg is good useing a 4000ma 6s battery iam thinking about buying another 1920kv motor and see if that is the problem any suggestions? my f86 with same motor and fan has no problems getting off same field

Hey Ron. I fly my T-33 off of a nicely paved asphalt runway, and I have noticed that it never just rises from the ground. Always seems to leap into the air suddenly. The results seem similar regardless of the flap setting. I think it’s an angle of attack problem. I tried increasing the length of the front strut, hoping for a smoother transition from the runway. Using an incidence meter, I noted an increase of 2 degrees after I lengthened the strut. Didn’t make a bit of difference. I still believe it’s an AOA problem. This thing really sticks to the runway after touch down on landing. Haven’t had a chance to try anything else, but I may install a set of smaller diameter main wheels, hoping to get that nose up some. I know smaller main wheels are no help if you are trying to get it off of a grass field, but this is all food for thought. Sure flies great!

[Ron1950]

i have always had trouble taking off from short grass here in miss it seems to get up to flying speed with take off flaps but wont lift the nose to fly today we tryed full flaps and finally after a long run it flew the nose came up at about 45 degrees right off the ground but we caught it in time to level it off..ive calabrated the throttle the cg is good useing a 4000ma 6s battery iam thinking about buying another 1920kv motor and see if that is the problem any suggestions? my f86 with same motor and fan has no problems getting off same field