Looking for ideas on mounting leds in vehicle

[East Coast]

Hello -
First post here !

I'm working on a small piece of electronics that will be mounted in a vehicle - mainly delivery trucks. For the most part I am lucky in that the electronics package is buried within the vehicle and I don't need to worry about operator interactions and the like. However, there are 2 leds that do have to be in view of the driver and we will have to mount them somewhere on the dash. I am trying to come up with the simplest way to do this that will not involve a lot of headache for the truck shop to install.

I have seen these little molded assemblies that are made by VCC that allow you to push the holder into a small hole and they lock in with barbs, but then there's the trouble of getting a connector on the other ends of the wires in behind the dash. If the hole is cut big enough to fish the connector though, then it's too big for the led assembly.

Here's an example of what I am talking about above - https://www.digikey.com/product-detail/en/5100H1/L10001-ND/59891
These things have been around forever and seem to be pretty widely available.

In some cases there is a knock-out panel in the truck dash that can be modified "on the bench" and then put back in place, but not all cases. I guess I am really just wondering if anyone else out there has faced a similar challenge and if there are other options that I might consider other than the product referenced above. It's got to be as simple as possible - there could be 1000s of these going out the door each year eventually.

Thanks !

 

[ericgibbs]

hi EC,
That type of LED [ according to the datasheet] will require a suitable resistor in series from the supply voltage.
Are your trucks 12V or 24V battery.?

EDIT:
Error
I see 5V or 12V supply!,, sorry

 

[East Coast]

hi EC,
That type of LED [ according to the datasheet] will require a suitable resistor in series from the supply voltage.
Are your trucks 12V or 24V battery.?

EDIT:
Error
I see 5V or 12V supply!,, sorry

Hi Eric -
They can be 12 or 24V but that's no matter - the leds are driven from the 5v supply in the electronics package that's buried in the vehicle and we'll have suitable limit resistors on the PCB assy.
Thanks

 

[tunedwolf]

If this is a commercial venture, I would be looking at having a small molded LED bezel made that can be stuck or screwed onto the dash. I wouldn't imagine that it will be too expensive in quantity after the initial tooling costs are met. That way all installations will be consistent at least, even if the dash layout means that the siting of the bezel changes

 

[East Coast]

If this is a commercial venture, I would be looking at having a small molded LED bezel made that can be stuck or screwed onto the dash. I wouldn't imagine that it will be too expensive in quantity after the initial tooling costs are met. That way all installations will be consistent at least, even if the dash layout means that the siting of the bezel changes

Hi -
Yes, this is something I have been considering, as it will be a production item in the future. At the moment I am trying to get some ideas cobbled together to get something reasonably professional looking for a trade show in a couple of months. Of course there will be the standard "let's just sell some of them this way" afterwards too Your comment has sparked another idea - I have a pal with a high end 3D printer. I can get him to whip up something in Solidworks, and print it out to try out the concept for little to no money (well, possibly a beer purchase....). I might try something with a combination of the leds that I referenced earlier, along with a little round holder that would hold two of them. It would then involve drilling a single hole about 3/4" diameter and pressing in the 3D printed bezel to snap into the hole, and the snap in bezel would house the 2 leds. Only downside is that the plastic in the 3D printer is a milky white color and I would prefer black.....still, it's a way to test out some concepts.

Thanks for the idea.

 

[tunedwolf]

3D printing a few prototypes would be advantageous, you can always dip coat a few in your colour choice of resin for the trade show and let the engineering team check it against your mold drawings, plus it also lets you work out the kinks of mounting it, wiring to it etc ahead of your first production

 

[ClydeCrashKop]

When I need to make a nice looking plastic part, first I figure out what general size and shape I want. Then I go to stores looking for a mold to use with plastic body filler. Boxes, balls, toy Easter eggs, etc. If you want an irregular shape or something special, look at the blister packs that products are sold in. You might have to buy a light bulb, toy or tool that you don't need to get its packaging. You could even position your LEDs in the mold and cast them in place. You can also use polyester or epoxy resins. They can be tinted any color you like. If you coat the mold with PVA, polyvinyl alcohol mold release, your part will pop right out.

 

[KeepItSimpleStupid]

These **broken link removed** should work for you. The ones shown already have the series resistor.

**broken link removed**

Way back when I used LEDS with wire leads, but mounted with a backing nut.

The only real suggestions that I have is nuts on the back sort of make sure your not drilling in a bad place and use a pilot or bullet bit to drill the hole. They will drill round holes and won't pull the drill in as bad as a simple Jobber's drill. **broken link removed** Too bad Dewalt's website isn;t working right. I have a whole set of these.

An alternative is to use a step drill Unibit combined with a regular drill bit. The Unibit deburs the hole a bit.

 

[Richard Mackay]

Are you still there??
I have been wrestling with this issue recently.
The last comment about a step drill interests me.
My LED is the standard 3mm device.
Is there a step drill available to mount the LED with the 2 diameters of the LED ? (i.e. fully recessed into the bezel)

 

[KeepItSimpleStupid]

The step drill has large increments. If your drilling plastic, the pilot or brad point drill should both work. See: https://www.ereplacementparts.com/article/2266/Drill_Bits_101.html

I'll keep looking for a source. 4 mm is close to 5/32, but you have 3 mm.

You do have some direct panel mount LEDS: https://www.mouser.com/catalog/catalogusd/648/179.pdf

Look at the T1 light panel clips and the light pipes. https://www.mouser.com/catalog/catalogusd/648/146.pdf
The light pipe is an interesting low profile indicator, but that needs more work to make it work

These https://www.jameco.com/webapp/wcs/s...productId=95513&catalogId=10001&CID=CAT152PDF aren't too bad. The T 1 3/4 versions have a ring on the back side. They will leave a black ring on the face of the LED.

Not exactly sure what your asking. There are drills that can drill and counter bore (2 diameters), but they are designed for screws primarily.

 

[Richard Mackay]

Thanks for your comprehensive response!
My application is a small PCB mounted (glued with a heat gun) onto the inside of the lid of this enclosure (attached). I simply drill holes in the lid for the LEDs and solder them so they are just protruding on the outside of lid where I have an adhesive label stuck with info on these. (They are the only components on the track side of the board)
This works fine but due to the shape of the standard LED I need to step drill a 3/4.5 mm hole. Drilling the holes with separate drill bits is tricky because if the 3 mm hole is already drilled the bigger drill snatches the epoxy and can make a real mess!
So I thought there might be a step drill already made for the job but I guess not.
I have bought a standard step drill bit which starts at 4 mm which I will machine it down to 3 mm and try that...

But for sure there are many ways to skin the cat so thanks again for all your ideas and links.

 

[ClydeCrashKop]

**broken link removed**
A 0-degree rake angle on the cutting edge eliminates grabbing as the drill exits the hole,

You could drill the large diameter first and use a Drill Bit Stop Collar.
https://www.amazon.com/Drill-Bit-Stop-Collars-7-Piece-Set/dp/B0039ZEZNG

 

[KeepItSimpleStupid]

See your PM (Conversation). Under your handle name, there is "conversations".

 

[Richard Mackay]

Thanks CCK for this info.
I thought there must be a drill bit stop collar somewhere..Thanks.
I have tried drilling the larger hole first and it does help with the snatching issue but the smaller drill can still wander so you can end up with non-concentric holes!
For now I'm going to try my step drill trick.
Of course these issues are due to working with hand controlled tools, not CNC machines.

 

[KeepItSimpleStupid]

They do make these things: https://www.mscdirect.com/product/details/56443963

Drilling, nearly always leaves you with "triangular" holes. Reaming or milling get you round holes.
The pilot point bits will generally get you a round hole.

Soapy water (dish-washing detergent and some water) worked very well as lubricant for plastic. I've made pilot point bits for 5/8" that worked in acrylic.

I could see milling the face; then use a starter drill and then finishing up with a pilot point bit or drill and hand ream.

The hard part is chucking the tools in place. It's not bad with an x-y readout.

If I now get what your doing, you want to counter bore the LED from the inside surface, so it's effectively flush on the inside surface where the leads are?

Are you or are you not using a clear lid?

 

[Richard Mackay]

Exactly! And I am not using the clear lid.
And thanks for this link. I was going to bet my bottom $ that they didn't make anything like it. Looks perfect for my application
The US should get into SI measurements I reckon. I think it's happening slowly...(citation needed!)
Apparently the ship that Revolutionary France sent to the US with the SI standards (kg/m/etc.) was blown off course and landed up in the West Indies.
Thanks again!