Hatch Catch

[Tosh McCaber]

Hi- Just wondered if anyone has any advice on a secure, but easy to use, hatch catch suitable for battery compartments? Don't think that a mag catch is up to the job?

[Peter Miller]

These are the ones that I always use.

**LINK**

4Max sell them but they are available on EBay and other places

[Tosh McCaber]

Thank you Peter- It looks like the neater smaller brass one may not be spring loaded?  I presume that the L-shaped wire catch would rotate into a groove in the fuselage when  pushed home?

Edited By Tosh McCaber on 14/06/2020 08:27:03

[Engine Doctor]

I have just fitted type A shown in Pete Millers link . Worked great ten stared sticking. Beware the bolt slides in the plastic lever ! I hope the cyano will hold it ,otherwise it's a re-think .

[Bob Cotsford]

The brass ones are spring loaded, I've used them a couple of times and they are a little sturdier than the plastic body types.

or at least the slightly larger Logic RC ones sold by RC World are!

Edited By Bob Cotsford on 14/06/2020 11:53:25

[Dwain Dibley.]

A couple of pics to try and show how I do it. The sides of the hatch have vertical tongues, the hatch is a friction fit, and the latch is simply a suitable servo arm turnbuckle, they look like a part of the nacelle. you can enclose them in balsa if you wish.

[ken anderson.]

hello Tosh...have a look here,I've used this one...

ken anderson...ne..1..catch dept.

[Chris Walby]

Tosh, The neater smaller brass one is spring loaded.

Seagull do a neat trick where the canopy slides inside the cowl, then drops down and locks as it slides back. Its stopped from moving forwards by a magnet. Really quick to release and very little chance of it coming off in flight.

[Tosh McCaber]

Thanks for all the suggestions guys!

[Tosh McCaber]

Just another thing- I like the brass catch, but would think that it may need a little reinforcent in the way of a strap over it to hold it in on larger hatches?

[Steven S]

I have been making my own latches. A piece of bent wire and a spring rescued from a dried up ball point pen works.

I soldered on the washer, but a locking collar will work.

There was an article in RCM&E

 

Edited By Steven Shaw on 14/06/2020 16:33:54

[kc]

 

If it's an open cockpit model the method shown hides the release and avoids the strain on the balsa hatch which otherwise needs some strength added to resist the force of opening the catch.

 

Edited By kc on 14/06/2020 16:38:14

[Bob Cotsford]

I've made similar using a wheel collet clamped to the latch pin with a longer screw, you only need the screwhead protruding. These days with the lack of disposable retracting biros to source springs from I just buy the commercial catches.

As for the brass body ones, I just epoxy them in a piece of 1/4" balsa which is in turn glued in the hatch.

I like that one in the cockpit kc, very neat. You could also use a rubber band as a spring with that one.

[kc]

Bob, I hadn't actually noticed any lack of retractable 'biros', but another source of free springs- slightly larger - is old pump action liquid soap dispensers. I did experiment with rubber bands but decided it would likely perish and open the hatch at the wrong time.

The important thing is to put the catch in the fuselage so if the hatch goes missing you don't lose the catch too. After spending an hour unsuccessfully looking for a hatch missing in a large field of long grass, I eventually realised it only took half an hour to make a new one!

[kc]

The simplest, lightest, cheapest and quickest catch to make is the turnbuckle type. Just a cut off piece of servo arm pivoted on a tiny woodscrew with - and this is the crucial item - a thin leather washer to provide friction and a litle springiness. The leather washer is cut from a piece of thin leather like the tongue of a shoe etc etc. It only works if the turnbuckle can be screwed into ply rather than balsa.

[Bruce Collinson]

I’m with KC, the turnbuckle made from a servo arm is pretty bombproof, at slight cosmetic cost. I’ve recently fitted one to a mid size foam F3A by simply letting a short piece of 3/8 hardwood into the foam, I think I used polyurethane glue, 4 faces stuck to the foam and it works a treat. I used the same on my Acrowot, where the hatch is underneath and there’s a ply plate to fasten to. Too many hatches and canopies here parted in flight when relying on the maker’s ideas.

Spring loaded latches are prone to sticking and fracturing, at least in my hands.

BTC

[Dwain Dibley.]

I knew I had a good idea.. LOL

Here's one made from ply.

D.D.

Edited By Dwain Dibley. on 14/06/2020 22:38:04

[Keith Berriman]

I am a servo arm and small screw user just have to remember to turn the arm the same way as screw thread goes in