Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[kallend]

AG, reading some of the reviews of the SU35 i became a little bit turned off on it. I read where it's made from EPS foam and not EPO and that it was much lighter (and therefore, more fragile?) than what an EPO foam version would be like. Being that i tend to break things off of these from time to time, i'm wondering if that also means it can't be mended with foam-tac adhesive...
in any case, do you have any thoughts on whether or not there's much difference in the two materials...?
I may be giving myself paralysis from over-analysis, but I just like to know as much as I can before I jump...

I like the EPS foam. It holds its shape better and is easier to repair than EPO. Just don't use an adhesive or paint with organic solvents.

My SU35 and Eurofighter are each 5 years old and look better than any of my EPO models of the same age. And they are LIGHT!

[Airguardian]

AG, reading some of the reviews of the SU35 i became a little bit turned off on it. I read where it's made from EPS foam and not EPO and that it was much lighter (and therefore, more fragile?) than what an EPO foam version would be like.

Contrary to popular believe, EPS is superior to EPO from a material's structural properties point of view. EPS can achieve the same rigidity with thinner walls which makes it much lighter in the end. This is one of the biggest reasons why the FW Su-35 pretty much kicks any other scale EDF jet in the market. (The other being that the Sukhoi design is godlike, ofc). ^^

If it was up to me, I'd have Freewing make all their jets with EPS and ditch EPO. Sadly, I'm told that, weird as it may seem, EPS is hard to source in China, so this increases production costs. Availability also seems to be limited so they save it for the Su-35. All other EPS models in Freewing have been discontinued but the Su-35 is still a bestseller as far as I can tell... after some 11 years or so since its introduction, it is still pretty much the top tier EDF. That should settle your mind about it. ;)

Being that i tend to break things off of these from time to time, i'm wondering if that also means it can't be mended with foam-tac adhesive...
in any case, do you have any thoughts on whether or not there's much difference in the two materials...?
I may be giving myself paralysis from over-analysis, but I just like to know as much as I can before I jump...

It is definitely slightly more fragile if it comes to the point of crashing, but you should try and not crash in the first place!
As Evan said, it often breaks clean which makes repairs easier. And EPS can be glued much easier than EPO. Epoxi and contact glues work wonders on it (where Epoxi fails miserably on EPO, by comparison). Foamtac... haven't tested on EPS but should be fine, same as Gorilla Glue. UHU POR is a good option for large broken chunks too as far as you have large surface areas to make contact between the pieces.

So indeed, there is a lot of difference between the two materials and I prefer EPS.
True that EPS gets dinged and scratched more easily too, but I choose performance over looks in this case. And if you treat the plane with some caution it ain't even that bad. ;)

It can't be boiled back in shape.

What, why?
I have done it.
It gators badly, true that... but you can easily use light spackle and sand it afterwards.

[jasmith41]

Contrary to popular believe, EPS is superior to EPO from a material's structural properties point of view. EPS can achieve the same rigidity with thinner walls which makes it much lighter in the end. This is one of the biggest reasons why the FW Su-35 pretty much kicks any other scale EDF jet in the market. (The other being that the Sukhoi design is godlike, ofc). ^^

If it was up to me, I'd have Freewing make all their jets with EPS and ditch EPO. Sadly, I'm told that, weird as it may seem, EPS is hard to source in China, so this increases production costs. Availability also seems to be limited so they save it for the Su-35. All other EPS models in Freewing have been discontinued but the Su-35 is still a bestseller as far as I can tell... after some 11 years or so since its introduction, it is still pretty much the top tier EDF. That should settle your mind about it. ;)



It is definitely slightly more fragile if it comes to the point of crashing, but you should try and not crash in the first place!
As Evan said, it often breaks clean which makes repairs easier. And EPS can be glued much easier than EPO. Epoxi and contact glues work wonders on it (where Epoxi fails miserably on EPO, by comparison). Foamtac... haven't tested on EPS but should be fine, same as Gorilla Glue. UHU POR is a good option for large broken chunks too as far as you have large surface areas to make contact between the pieces.

So indeed, there is a lot of difference between the two materials and I prefer EPS.
True that EPS gets dinged and scratched more easily too, but I choose performance over looks in this case. And if you treat the plane with some caution it ain't even that bad. ;)



What, why?
I have done it.
It gators badly, true that... but you can easily use light spackle and sand it afterwards.

thanks as always. su35 back on my radar...

[Hugh Wiedman]

Airguardian , I remember seeing an outstanding video you did some time ago when you first got the SU-35 with all the mods and reinforcements you did. At the time, it actually made me think twice about getting it only because you did quite a bit of work to it and I was (probably still am) a bit lazy. But now it's back at the top of my list for the next EDF after watching so many of your great videos on it! Assume you still recommend all the changes you made?

[Airguardian]

Yep, each and every one of them :)

Plus, installing FMS Pro 1900kv EDFs with 80A Hobbywing Skywalker or Premium ESCs.
And if you need a sturdier main LG, the Freewing F-15 mains seem to be a good alternative, judging by other people's experience.

[Airguardian]

Well, these were the last flights we filmed before I added the VT nozzles...

[Dazza18]

Hi, new to this site & this is my first aircraft with retractable gear. Setting the CG, gear up or down ? Thanks

[Evan D]

I do it gear down just to make it easy to check sitting there. But I determine what I want for a balance point by flying it and then seeing where it is setting on the ground on its gear. I then mark where that spot is under the canopy.

[Dazza18]

Ok thanks, i'll start there and see where it goes. Did your final spot end up aft of the recommended CG.

[kallend]

Hi, new to this site & this is my first aircraft with retractable gear. Setting the CG, gear up or down ? Thanks

How much does it move as you raise and lower the gear, ad is that likely to have any noticeable effect on the flight characteristics?

[Dazza18]

How much does it move as you raise and lower the gear, ad is that likely to have any noticeable effect on the flight characteristics?

I have only done the CG gear up & with two 6000 packs had no trouble getting in on the marks. This surprised me as i noticed many others had trouble getting there batterys back far enough to obtain the correct CG. I'll check tomorrow with gear down but my guess is it will change requiring me to slide the front pack back further, hence why i was asking it is done gear up or down.

[jetpltrich]

Gear up gear down, you will notice a difference between the two re: CG.

Rich

[kallend]

Gear up gear down, you will notice a difference between the two re: CG.

Rich

I'm sure, but HOW MUCH does it move, and is it significant enough to worry about it?

[radfordc]

Ok thanks, i'll start there and see where it goes. Did your final spot end up aft of the recommended CG.

Yes, it flys better with the CG 10-15mm aft of the marks on the wing. I added about 50g of lead to the tail and also have two afterburner units. Flys really nice on 5000mah packs that weigh 750g each. Flys OK on 6000mah packs that weigh 850g each. Beware of high alpha maneuvers with the CG aft of the recommended marks.

[kallend]

Ok thanks, i'll start there and see where it goes. Did your final spot end up aft of the recommended CG.

If you search on "CG" in this thread and the RCG thread, you'll see that people are flying it with anywhere from the stock marks to 25mm behind the marks, with the median being around 12mm behind the marks.

With that variation, gear up or down wouldn't seem to make much difference.

[Evan D]

Since I do my checks gear down and 5-10 behind I wonder how that translates to gear up check?

[jetpltrich]

I fly mine at 17mm aft of wing marks. How accurate can my fat fingers be? +-1-3mm right? I don’t do high alpha just rolls and putts around. If you have it on a CG jig and select gear up the nose will go down due to the mains going forward. Personally, as long as you have the CG as others have suggested you’ll be fine.

Rich

[kallend]

Well, these were the last flights we filmed before I added the VT nozzles...

I made these 3DP cosmetic overlays for the VT nozzles some time ago.

https://www.thingiverse.com/thing:4769774

Do you think 3DP fixed nozzles with modified thrustline (less "up") would be of any value in preventing alpha-lock with aft CG? Would be pretty easy to create.

[Dazza18]

OK, so i did some accurate checks, no fingers involved. There's not a lot in it but on the recommended CG marks with gear up, as soon as i put the gear down the tail dropped. To balance it again without moving my batteries ended up with the CG about 6-7mm further to the rear. Surprised me a bit as i thought it would go the other way. Anyway, in the end as others have suggested just fly it & set it to your flying style.

[jasmith41]

CG? We don't need no stinking CG...🤣