Retract's. What is the difference between 85 degree and 90 degree?

[Kevin Fairgrieve]

I am looking at fitting to an existing model a set of either.

E-Flite 60-120 Size Electric retracts - 85 Degree

E-Flite 60-120 Size Electric retracts- 90 Degree

Simple question.

What is the difference between the 85, and 90 degree ones. (apart from the obvious 5 degrees)

Is it the rake the angle?

I know not.

Might help if i said they are too go into my Kyosho TA-152, which currently has mechanical retracts, which are a pain as I have to realign them every time I assemble the model. Wings need to be stored as two pieces.

 

Thanks in advance.

 

Kev

Edited By Kevin Fairgrieve on 15/03/2017 21:12:51

[Martin Harris - Moderator]

Different angles are available to accommodate different amounts of dihedral and leg angles while down e.g. FW190 -  the Ta152 has a similar inward stance so probably the 85 degree ones would be better but still a little too much for scale?

Edited By Martin Harris on 15/03/2017 21:44:50

[Denis Watkins]

Yes Kevin, as Martin has said, the wheel ideally, to run true and support weight correctly is set perpendicular to the ground, with 90° simply hanging straight down

Either retract can be mounted on plates in such a way that even the 90° with modest dihedral, would reach the ground at right angles

The 85° gives much more leeway with dihedral, and maybe obstacles, but nothing a modeller cannot sort out.

[Martin Harris - Moderator]

The FW 190 / Ta152 has a rather extreme undercarriage angle although many models don't attempt to recreate it.

[onetenor]

Why does the FW 190 have such an angle ? Anyone know ?

[Martin Harris - Moderator]

These might be a little lightweight but E-flite do a 74 degree retract primarily for the FW190...

I've never seen a definitive reason but the geometry would allow sharing landing loads to the main spar via both the main leg and the operating link attachment, which is directly above the wheel.

[Piers Bowlan]

Good answer Martin. I was asking myself the same question.

[Kevin Fairgrieve]

Thanks for all the reply's.

Now I understand. think the 85 degree ones will be the way to go.

Not sure the 74 degree ones would cut it as the model weighs in at a little over 5.5Kg.

This is a stand a long way off scale so not looking for that. I just want to fit a set of retracts that are fit and forget. No joining pushrods as is the case with the manual ones, each time you want to fly.

Kev

[Tim Flyer]

Hi chaps . I have another question. Sorry if I'm being silly as retracts are a fairly new subject for me. On my World Models Spitfire 60 it seems the retracts are a "dog leg" type and not straight running into the wheel well. I want to fit electric retracts and oleos but I have not seen dog leg type retract on HK. Does it mean that I will need to move the wheel well to use them. Please see photo and thanks in advance for advice. At the moment I'm using the World Models mechanical ones that came with the kit but they are unreliable and I want to fit proper oleos.

Edited By Timothy Harris 1 on 25/05/2017 22:00:12

Edited By Timothy Harris 1 on 25/05/2017 22:03:20

[will -0]

Hi, it's all about pintle angle (look it up)

http://www.modelflying.co.uk/forums/postings.asp?p=14&th=43843

[Tim Flyer]

Thanks Will that Pintle angle bit will also be useful when I build my LA7 . My Spitfire does have the correct angles at the moment but reason for the upgrade is more Thant the mechanical mechanism needs rather too frequent adjusting and the solid wire legs bend very easily.I notice on the sketch in the thread from the link you sent that the Spitfire oleo shows a 5deg bend . Maybe the retracts are ready drilled with this ?

Edited By Timothy Harris 1 on 26/05/2017 10:19:21