M99T Alarm, Square Fob, Button (3D Print file)

This evening i handed the bro my M99T fob to design and 3d Print a replacement button for it. i am aware you can 3d print rubbery items. but this has been designed for PLA. i do not know if it works with other materials.

Heres what he came up with

https://www.printables.com/model/594028-fiat-coupe-alarm-replacement-button

Thought some of you may appreciate the option.

Edit: ill host the file indefinitely on my nextcloud the first time i get the chance and post the link incase printables link becomes dead

For future reference, many years ago i started to model the case.

One day i will get round to finishing it im not sure how many are left in the wild but may as well give back a little something

That's a nice bit of work! I think it'll work fine with other materials; just a case of having the machine setup and the 'slicer' calibrated for it. You could use TPU, but like any rubber there's different shore ratings. So I'd think you'd spend a bit of time and money finding one that's right. Plus PLA comes in loads of colours so you can coordinate to the car

thank szkom, wife said the exact same thing 30 secs before i logged on.

Hello Richy

Yes, this is the future !

There's bound to be loads of odds and sods needed around the cars.

Paul

The rubbery centre button of the later (round) M99 T2 fobs also disintegrates readily and the fobs are getting quite expensive to replace (£125 from Abacus Alarms). A much easier design to replicate, if the button is made without the text...

good job Meta

sadly i dont have a round fob to test else id have modelled that too.
im super fortunate to have the skills and access to kit to do small dev work like this but time is something that isnt as kind to me. (see previous comment about having half modelled square case for 6 years)

Is it something you could measure and md post a couple of pics, Dave?

If it's not too complicated a shape then it might just need digitising?

Thats the plan, as i find stuff, get it modelled & printed.



It may be pertinent to grab PCB microbutton depth from case too, helps with allowing it to "click" properly when pressed. ideally would need PCB Pics with a measurement reference, and as many other measurements and pics as possible.

I had the same problem a few years ago and superglued a large black grommit onto the fob - so far it's stayed perfectly attached.

It's not the case that is the issue. It is the rubber buttons that perish unfortunately

That button needs to be printed out of TPU 95a filament, it's softer.

Anyone got the stuff to print these? I would be interested in buying one please let me know how much it would cost.

Failing that, presumably an old TV remote might provide a button of suitable material that could be doctored to fit… anyone tried that before?

I've asked a mate to CAD draw and try a print so I'll update the thread if they're any good.

Problem with TPU is that different brands give different results. You might find you need to use a multiple material print to achieve the correct squish when you press. Perhaps PETG for the bulk of the button and then a thinner top piece made of a softer TPU

The issue is also the size but if it's printed in single layers of said thickness it might work if they're glued together after with harder base layer as it needs something solid to act against the button

Size shouldn't be a problem as most FDM machines with a typical 0.4 mm nozzle will manage 0.1mm layer heights so you're able to print very small items quite successfully. It's normally the issue that you lose fidelity at that size but not necessarily accuracy. It's really a job for a twin idex/ extruder machine as you then orientate the differing materials to suit. However with some clever slicing of the gcode I reckon it'd be possible to retract material and print straight on top with the next material on a single extruder.

The other way perhaps to approach this might be if you can access a resin printer to print a mould. You could then cast the buttons in a polyurethane or similar

You know when you think you're quite intelligent about technical things with a degree and all but then someone starts talking about something quite technical and you just have absolutely no idea what on earth they are going on about?

That's a good shout, mould would work better for this

No, and yes..

A colleague at work very kindly printed one of these buttons off for me last week using PLA. It certainly does the job so thank you @richydraper for sharing the files!

If there is some feedback I can offer it would be that I found the button to be quite a snug fit both passing through the top casing and fitting onto the microswitch on the circuit board so possibly those dimensions could be tweaked to give a slightly looser fitting. I did wonder if the button might get stuck when pressed down but it doesn't seem to. The button does sit almost flush with the top of the casing but I have no point of reference for how it would have originally been as the button was completely gone on mine and I was having to press the switch directly through the holes in the case.

I was also wondering how the case came apart and expected there to be a few clips to unhook (and not break in the process!) but it's actually an interference press-fit so it's just a case of working around the gap between the two halves with a screwdriver gently prising it apart bit-by-bit.

Now I need to come up with a good way to attach a chain of some kind to it so it can be attached to a keyring...

That's great news that it works!

If I could offer some insight into resizing; it probably isn't something to be too concerned about. If you resize the CAD model then it may not print properly on another machine. There are loads of factors that affect the finished X,Y and Z dimensions that all come from inaccuracies in the machine, the software, setup and even the material used