Spitfire retracts

[David Holland 2]

Afternoon forumites, I’m well on with my Warbirds Replicas Spit and would like to mimic that characteristic lag where both undercarriage legs would rarely retract or extend simultaneously. Is there any sort or electronic magic box I can fit in one arm of the Y-lead to delay the operation of one of the (electric, servoless) retracts to simulate this. Anal, I know, but it would look good curving round on finals with flaps down and wheels coming down.

Thanks in advance,

David

[leccyflyer]

You could fit a servo slow module to one of the retract units. Something like this Servo Slow

[Dickw]

I did that on my Warbird Replicas Spit for the same reason - it looked good.

The servo slow module in one of the retract leads should do it. Luckily I can do that in my Tx, but the module should work if you don't have a servo slow option in your Tx.

Dick

[Jon H]

electric retracts are not proportional so you probably cant use a servo slow on the tx or an inline servo slow either as they only have 2 states, up or down with nothing in the middle.

The simplest option would be to use air as, in my experience, they are much more reliable and give you the desired lag

Edited By Jon - Laser Engines on 16/05/2020 13:31:24

[David Holland 2]

I’m sure Jon is right, I tried from the tx but it has no effect. They move suitably slowly but I want one leg to move a few seconds after the other. I’ve pretty much finished the wing, including the retract install and I’m not sure I want to get involved in retro-fitting air retracts. I used a Horus 10 so I’m sure I could use two channels and mix them but I hoped there might be a simple delay type module that would just plug into the Y-lead.

David

[leccyflyer]

There are plenty of videos on You Tube showing the servo slow modules working on servoless retracts.

[leccyflyer]

If you fitted one into each leg of the retract lead, set for different delays, wouldn';t that do what you wish to achieve?

ISTR that Tim Hooper used one of these way back in the past and it caused some issues though. However they are pretty cheap and might be worth experimenting with.

 

Aasah I've just watched that video with the sound on and he's using a servo, not servoless retracts. My mishstake.

Edited By leccyflyer on 16/05/2020 14:08:46

[Bob Cotsford]

If you are using a Horus why not just put each leg on it's own channel and set a delay on that channel

[Martian]

I,ve used a servo delay on my mosquito in line on one leg it was very effective cycle it a few times no problem I bought mine from hobbyking can,t find on there now but Amazon has some in stock for ten pounds

[Dickw]

Posted by David Holland 2 on 16/05/2020 13:52:02:

I’m sure Jon is right, I tried from the tx but it has no effect. They move suitably slowly but I want one leg to move a few seconds after the other. I’ve pretty much finished the wing, including the retract install and I’m not sure I want to get involved in retro-fitting air retracts. I used a Horus 10 so I’m sure I could use two channels and mix them but I hoped there might be a simple delay type module that would just plug into the Y-lead.

David

Jon is partly right - they are either up or down and not proportional.

BUT

They are triggered when the signal crosses the midway point and they do move slowly, SO, if you introduce a delay in the signal to one leg it will start to move later than the first leg and they appear to be operating at different speeds.

I use two channels in my Tx and a delay through "servo slow" on one channel. Setting the "slow" to two seconds means it it takes 1 second to get to the halfway point and trigger the tretract. I know it works because I use it like that. I don't see why a servo slow module in one leg couldn't do the same (but am willing to learn).

Dick

[David Holland 2]

Yeah, Bingo, Result. I had a servo slow in my odds box from the days of steam radio and it worked just as Dick predicted. Thanks for your input, guys, this forum is full of really useful people.

David

[Jon H]

I used the just past centre trick on a retract servo once. I forgot all about it until you mentioned it. I cant for the life of me remember what or why.

I had also not come across proportional retracts before.

As i said before, i always use air retracts as i have just found them so reliable. The electric retracts on my sea fury cause me constant problems

[Martin McIntosh]

I wanted slow retracts on the last Spitfire I built because my other identical one uses air which just snaps them up and down. Adding restrictors lost pressure.

I had a set of 96 deg. Spit. gear so I cut off the cylinders and connected the units to metal geared servos. I used the Tx servo slow feature to get them as I wanted. Previously I have made my own slows when the Tx in use did not have this.

[Eric Robson]

Thanks for the idea Martin, I have a M.E.109E which had metal retracts in and one side failed, they were quite old and had been in a hurricane. They are no longer available so I had a set of plastic retracts these were bigger and needed to cut the bearers away to fit. I replaced the faulty one first and the speed difference was amazing. So now it has odd retracts in but looks great when they operate.

Eric r.

[robert chamberlain]

If your trans won't  do it, there is a product called "GO SLOW"---If I remember, there were 2 pots so you could adjust each gear  for different rates.--------------  Bob C

[Paul De Tourtoulon]

If you were still in Europe you could get this for 10.99€

https://www.flashrc.com/hyperion/3073-servo_rate_adjuster_slow_down.html

 

 

[GrumpyGnome]

Lots in UK model shops  - Model Shop Leeds, Kings Lynn etc.. Google 'servo slow'......

Edited March 3, 2022 by GrumpyGnome

[Frank Skilbeck]

Model Radio Workshop also do a servo slow, if you TX won't do it.

 

I have done this with an electric tricycle undercarriage (from my Tx) so the wheels all go up at different times, not only looks good but also reduces the instantaneous starting current compared to starting 3 retract units simultaneously. For bigger models air is the way to go.

[Paul De Tourtoulon]

Air, other than air up spring down NO THANKS, I do a lot of 'shows' and the number of planes landing with air retracts failing ?