Xair shock absorbers

[BrendAn]

36 minutes ago, facthunter said:

The single shock rear suspension is a link system The actual shock has only a short travel The dual shocks likewise attach about 2/3 the way down the swing arm.  This is related to motorcycle parts  A moe suitaable motorcycle soureced component might be using a front fork.  One side slider).  4 inches of wheel Travel  easily available and you need  good rubber bump stops. Nev

xair have them on the shelf and their prices are reasonable. if he buys and fits them it will operate as normal. 

Edited August 17, 2023 by BrendAn

[facthunter]

Well that's the way to go unless they need improvement. The design performance requirements for U/L's undercarriages  is not very stringent.  Nev

[BrendAn]

1 minute ago, facthunter said:

Well that's the way to go unless they need improvement. The design performance requirements for U/L's undercarriages  is not very stringent.  Nev

they seem to work fine . i assume mine are standard but i might be wrong. 

[facthunter]

I like to save weight and drag. It helps  all the time you are flying. I think the requirements are a drop from 4 ft and still be able to taxi it.  Nev

[facthunter]

IF you can damp the rebound that stored energy is reduced and doesn't propel you back up into the air so much.  Nev

[BrendAn]

45 minutes ago, facthunter said:

IF you can damp the rebound that stored energy is reduced and doesn't propel you back up into the air so much.  Nev

thats the great thing about the xair, the suspension keeps them on the runway. it absorbs the energy as you say.

[facthunter]

Spoilers would help too. The drag should help pin them on. Speed washes off pretty quickly.  Nev

[BrendAn]

24 minutes ago, facthunter said:

Spoilers would help too. The drag should help pin them on. Speed washes off pretty quickly.  Nev

its only doing 40 knts at landing

[facthunter]

But that makes them gust sensitive. They've been around a long time and are not a difficult plane. The amount of downforce on the tail is a bit weird. That force has to be opposed by the wing's lift . Nev

[WinneyBuh]

As I promised- my opinion for pre-design calculations .
It's only "IMHO", no recommendations inside!😇

GearXair.pdf

[FlyBoy1960]

All this discussion over what ?, they are something like $180 each according to an owner, just buy the correct ones and move on ?

[BrendAn]

1 hour ago, FlyBoy1960 said:

All this discussion over what ?, they are something like $180 each according to an owner, just buy the correct ones and move on ?

You move on. Do we have to ask you before we post anything 

[skippydiesel]

1 hour ago, FlyBoy1960 said:

All this discussion over what ?, they are something like $180 each according to an owner, just buy the correct ones and move on ?

Do you not enjoy expanding you knowledge, through hearing others opinions/experience/ideas ?

[BrendAn]

I think the person asking for the information is in Russia. Might be hard for him to get genuine parts,

I know they are preferable if obtainable in his country.

[onetrack]

They might be $500 each by the time they get to Moscow, what with all the current sanctions!

[WinneyBuh]

13 minutes ago, onetrack said:

They might be $500 each by the time they get to Moscow, what with all the current sanctions!

...and there is no guarantees  that both customs will accept them as non-war parts...🤔

[FlyBoy1960]

7 hours ago, BrendAn said:

You move on. Do we have to ask you before we post anything 

I didn't mean it like that.

 

There is just so much effort going into what is available but there is a perfect model of shock absorber out there which are approved for the aircraft, they are built to the manufacturer's specification, they are easily available from what I can read, and they are inexpensive.

Everyone is trying to reinvent the wheel for something that has no problem.

 

If the standard ones were not up to the task then I could understand all of the research, questions and complications of finding an alternative product, but when the standard ones seem to work perfectly well, are not overpriced, and are approved by the manufacturer, then you should just use that product.  

 

In many different countries you don't have a choice, you have to use what the manufacturer supplies and you cannot substitute parts.

 

It's like me trying to find an oval tire for my motor vehicle even though I know a round one will work perfectly and is made to suit my motor vehicle.

Edited August 18, 2023 by FlyBoy1960

[BrendAn]

2 hours ago, FlyBoy1960 said:

I didn't mean it like that.

 

There is just so much effort going into what is available but there is a perfect model of shock absorber out there which are approved for the aircraft, they are built to the manufacturer's specification, they are easily available from what I can read, and they are inexpensive.

Everyone is trying to reinvent the wheel for something that has no problem.

 

If the standard ones were not up to the task then I could understand all of the research, questions and complications of finding an alternative product, but when the standard ones seem to work perfectly well, are not overpriced, and are approved by the manufacturer, then you should just use that product.  

 

In many different countries you don't have a choice, you have to use what the manufacturer supplies and you cannot substitute parts.

 

It's like me trying to find an oval tire for my motor vehicle even though I know a round one will work perfectly and is made to suit my motor vehicle.

No worries. I agree with you about genuine parts if available in that country.

[BrendAn]

On 16/08/2023 at 5:40 PM, WinneyBuh said:

Good days for All!😇 Can I pullup this theme again? Now I 'm repairing X-air S, and have the similar problem.

Can anybody say, what is the length of main shock absorbers? I need the distance between centres of holes, when aircraft is standing on the ground.(Now  I have set of some ones, looking like from 'Honda Dio', but they have 260mm in free state. My craft is now completely disassembled and I can't measure this distance in assembly). 

Another way to solve is to know the model of shock absorbers, described in upper messages or model of bike they are from.

Great thanks for any answer.🤝

[WinneyBuh]

Thanks!!!! I tried to recount spring stiffness whith measuring on photo- IT IS ABOUT 400 LBS/INCH. What about calculated 350 in my PDF-article? 😉

You wheels are excelent!
Now I'm starting attempts to find  anslogs. 
How can I ever thank you? 😇

 

[Methusala]

FWIW my VP-2 originally had an aluminium leaf gear braced with steel diagonal cables. as Nev stated this undamped spring gear would launch you high into the air on a heavy arrival. An SAAA engineer in Brisbane designed an alternative brace using rubber donuts in compression and also rebound. He said that, unlike steel springs, rubber has a progressive compression/decompression rate so provides natural damping. In practice it worked as well as described. Just an alternative idea if original dampers are impossible to source in Russia (though India does seem more friendly that other western countries).

[BrendAn]

On 17/08/2023 at 3:58 PM, facthunter said:

I like to save weight and drag. It helps  all the time you are flying. I think the requirements are a drop from 4 ft and still be able to taxi it.  Nev

old post but i have been doing a bit of research. the main gear coil overs are the rear suspension of a royal enfield motorbike. and the xair undercarriage is tested to 9g. don't know how high that would be. 

[spacesailor]

9G 

That's a lot More than most aircraft wings can stand!. My Hummel is 6 G .

So at 9 G the wings drop off .

spacesailor

[BrendAn]

1 hour ago, spacesailor said:

9G 

That's a lot More than most aircraft wings can stand!. My Hummel is 6 G .

So at 9 G the wings drop off .

spacesailor

i guess the suspension can absorb high impact loads to protect the airframe. the airframe is pos 4 min 2 g.

i wonder how many gs it takes to break a car rim on a pothole . lots of that going on around here. 

 

[FlyBoy1960]

I have an Enfield and they are different, not even close unless it is something from the 60s ?    

 

The ones on the motorbike holding 200 to 300 kg are not going to suit an aircraft which is 500 kg. They would be bottomed out as soon as they were loaded with the aircraft weight.