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why do you guys suggest modifying planes that are straight from the shop?

eagle4

New member
#1
I've noticed a lot of times people will buy a plane and straight away start adding modifications to it, eg bigger battery to help with nose weight, add a spar to help with rigidity etc.

Why is this? shouldnt the stock setup from the factory have the CG in the right place and have enough rigidity in the wings?

or is there something I'm missing

I'm new to the hobby and i'm not keen on buying a plane then having to modify it so that it actually flys correctly.
 

lobstermash

Propaganda machine
Mentor
#2
A lot of planes are built to use particular (brands of) components. Modifications are often required to improve the compatibility with more universal (cheap) components.

Also a lot of models we get nowadays with brushless motors and lipos used to have much heavier brushed motors and nicad batteries, but manufacturers are too lazy to change the moulds, or are making a cheap copy of someone else's design. A lot of manufacturers don't air test their planes much or at all either to keep costs down.

RE rigidity, most planes are fine for the first few flights, but a few crashes or some aggressive aerobatics later things start to soften up. Prevention is definitely better than cure when it comes to even model aircraft (let alone real ones).

You'll rarely find beginners modifying their planes, due to lack of research, ignorance and lack of confidence. If you've got lots of money, you don't need to bother with any of that, but if you don't have as much to spend on the hobby a small amount of work early saves $$$, enhances enjoyment in the long and short term and keeps the mrs off your back for longer (she told me to write that last bit).

There are a number of models that don't need modification, but you'll pay a lot more for those and you'll have to utilise some external expertise to pick them (you've come to the right place). Start another thread asking how to choose a model that's easy to learn on and doesn't require modification and you'll probably get 3-4 pages of answers in 24 hours (that's a challenge, people!)
 

earthsciteach

Moderator
Moderator
#3
Unfortunately, it isn't uncommon that the CG recommended by the manufacturer is not ideal. It is always a good idea to do some research on the internet to see how those who own the airplane found it to fly best. The lower priced airplanes seem to have equally lower quality control, as well. Never trust it out of the box!

Aside from that, I think there is a history rich in tinkering and tweaking airplanes in this hobby to get better performance. Its fun to make it fly better!
 

FlyingMonkey

Stuck in Sunny FL
Staff member
Admin
#4
There's several reasons why this could be, here's a few that...

1) Poor quality control. Some planes look good, but have imperfections that cause balance issues, trim issues, or even problems with the electronics.

2) Cheap crap. Sometimes there's a really good RTF airframe that is only available as a RTF or "Ready To Fly". It's sold at a really low price, so the electronics inside it are the cheapest available. It might be worth it to a pilot to buy the RTF version, gut it, then replace everything with higher quality components.

3) Personal preference. Some people just like to fiddle with things. They want more power, they want different flight characteristics, they want their plane to look different than everyone else's.

4) Availability of on hand supplies (consumer). In some cases, you might have a plane that calls for a certain sized battery, but you don't have it. So you can combine two battery packs, to do the same thing, either more voltage, or more mAh.

5) Availability of on hand supplies (manufacturer). Sometimes the manufacturer puts together a plane package, that when designed, intended to use a certain motor and battery combination, but when it was produced, and was ready for market, went with a different combination due to availability, or cost. The change in motor or available battery, might have ended up being heavier, or lighter than it was originally designed for.

6) Lost in translation. Much of what we're flying is made in China. Keeping costs down, lots of corners are cut. One of these corners seems to be the quality of the directions, and to compound that, the quality of the translation of these directions.

There's a few things that come to mind. Hope this helps.
 

Brian fred carr

Site Moderator
Mentor
#5
I agree with all of the above.....I think it is an integral part of the hobby to tinker and change things
part of the pleasure of this great hobby...buy an rtf fly it a few times and i guarantee you will want
to tweak and change things...its in our nature
 

pgerts

Old age member
Mentor
#6
I've noticed a lot of times people will buy a plane and straight away start adding modifications to it, eg bigger battery to help with nose weight, add a spar to help with rigidity etc.

Why is this? shouldnt the stock setup from the factory have the CG in the right place and have enough rigidity in the wings?

or is there something I'm missing

I'm new to the hobby and i'm not keen on buying a plane then having to modify it so that it actually flys correctly.
I expect an RTF or PNP or ARF to fly as expected wit the recommended setup - like you do.
There is no reason to fix something that works OK.
Buy something with reasonable quality and you will fly as it is supposed to do.

But as many modelers have noted - buy cheap crap and you have to adjust and repair - or adjust just because they believe that they are better than all other to design the plane.