Suggestions on designing component of IP67 enclosure - Page 1
Forum section: electronics / projects

author: Martin F
author_rank: Regular Contributor
timestamp: August 07, 2025, 10:57:52 am
content: Hi all,ContextWe develop data loggers, including a device called the CANedge3.The device is IP40, but some users would like to be able to easily install the device inside an IP67 box/enclosure. We would like to offer a tailor-made solution for this to make it easy and convenient for users to do so - without them having to build it themselves.Importantly, our device should remain inside the current aluminum enclosure, meaning the box should fit the full product as-is (rather than attempting to extract the PCBs from our device). The CANedge3 has 2 x DB9 connectors and 2 x SMA connectors that need to be mated inside the box with waterproof connectors on the outside. At the same time, the CANedge3 should be stress-relieved inside the box.The illustrative concept is seen in ‘ip67-box-concept-illustrative.png’. Note that the SMA connectors here are placed on one side of the connector - but it could also be that they are placed on either side (one on each side).For the enclosure box itself, we expect that we can fairly easily create that on our side. Similarly, we expect it will be possible to find a suitable front end plate using a standard version available. The illustrative concept is one way of solving the challenge we have - but it may be that a completely different solution exists. If so we are open to suggestions.Our main challengeOur main challenge is to create the small 'bridging' PCB between our device 2 x DB9 and an external, compact IP67 connector. We have created a 1st draft of this in the 'ip-enclosure-draft.step' file. The PCB needs to enable the following:- Provide 2 x DB9 connectors that can mate with the CANedge- Provide 1 x IP67 connector with 8 (or more) pins for providing the external interface- Enable the user to ‘lock’ the CANedge to the PCB by screwing in hex screws to the two outer mounts- The PCB should be easy to produce via standard PCB assembly solutions- The connectors should be easy to source (e.g. via mouser) and low cost (ala the examples below)- The footprint of the connectors should ideally be similar or less as in the example STEP- The overall solution needs to stay as compact as possible, practical to produce and easy to assembleThe current version uses the below connectors:- DB9:https://www.norcomp.net/series/191-series-vertical-low-profile- An alternative might be e.g. press fit DB9s:https://www.norcomp.net/series/191-series-press-fit- DT:https://www.te.com/en/product-DT15-08PA.htmlWhile the current solution "almost works", it has the problem that the connectors conflict when mounted as in the current solution (because of the PCB thickness, which uses a standard size). See some of the closeup pictures attached.However, we believe this may be solved via the use of some alternative connectors (e.g. different DB9 types and possibly an alternative waterproof connector type, or simply alternative variants vs. the ones we use now).Our questionsDo any of you have suggestions on alternative types of connectors we could consider for this which would allow us to solve the challenges with our 'bridge PCB'? And if so, can you share example part numbers of these?If you have alternative suggestions overall on how to solve this more creatively, we are also very interested!Thanks!

author: Terry Bites
author_rank: Super Contributor
timestamp: August 07, 2025, 04:30:04 pm
content: Maybe get custom flexible pcb made up by jlcpcb.com or similar to make the conversion between your pcb mounted D9's and the external connector.Costs very little. Use SM female D9's. I think those Norcomp parts are a good choice.

author: Poroit
author_rank: Frequent Contributor
timestamp: August 08, 2025, 04:31:30 am
content: G'day Martin F,Consider using an off the shelf Waterproof enclosure like Pelican or similar to house your existing logger.The enclosure could also be fitted with waterproof connectors.Offer it as an option to customers with the requirement.https://www.rugged-box.com/alternative-hard-case-brand-list/

author: Martin F
author_rank: Regular Contributor
timestamp: August 08, 2025, 08:37:47 am
content: Thanks for the suggestions.To clarify, our challenge is specifically on how to design the bridge PCB without the current 'conflict' issue between the connectors on each side of the PCB. The rest of the enclosure design should be fairly straight forward assuming we can solve this part.Our hope is that there might be a special variant of DB9 connectors and/or waterproof connectors that could together be used in a similar way as in our STEP file - but without creating the connector conflict shown (where the pins from each connector type are too long). Any suggestions on this are welcome.Martin

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 08, 2025, 09:15:13 am
content: It would be impossible to make it shorter than you are currently thinking and fit it into the case.

author: Martin F
author_rank: Regular Contributor
timestamp: August 08, 2025, 09:27:03 am
content: Can you clarify what you mean by "shorter" in this context? Just to understand if the challenge we are outlining is unclearly described.Again, the bridge PCB solution we're outlining here is illustrative of the concept we are trying to achieve. It would work if it was not because the connectors on each side of the PCB conflict with each other given their type/position/design. It may be that alternative connector types would enable us to get around this (potentially combined with a slight adjustment to the PCB design itself) - but it may also be that there is another solution entirely, which still achieves the same goals as this current design draft.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 08, 2025, 09:47:57 am
content: I think there are two issues.1. It is impossible to fit DB9 and Deutsch onto a single board.2. current design cannot be fitted into an IP67 case.fitted. But if design are changed, won't fit it.Even if the board is changed to FPC or the connector is changed, I don't think it will fit into the case. angled SMA connector makes the waste space.

author: Terry Bites
author_rank: Super Contributor
timestamp: August 08, 2025, 01:18:58 pm
content: Do you have to use the DT06 Deutch/ TE connector? What about other IP67 automotive connector types? Eg TE "SUPERSEAL 1.0 Connectors"A custom cable (that you can sell on to the customer!) will allow for a wide choice of connector types.There are many low cost Chinese custom cable sources.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 08, 2025, 01:24:38 pm
content: I just got home, so I'm checking the step file.I think the enclosure you are trying to use is the EEC-325X4B-E016. There is a reinforcement structure inside, it hitting with the CAN device case.considering the availability of the enclosure you are thinking of using, I think it would be better to use a more readily available IP67-compliant case. I think there are better enclosure available at a lower price.if you use this enclosure, will need to replace the SMA connector of the CAN device from a right angle to a straight connector that extends straight upward, and you will also need to consider using a fully surface mount connector from HARTING for the DSub connector.

author: Martin F
author_rank: Regular Contributor
timestamp: August 08, 2025, 01:39:57 pm
content: Hi again,1) The use of enclosure in the illustration is just conceptual, we have not locked down the actual enclosure yet - it may also be that we do a customized one. The tricky part for us is primarily on solving the challenge of creating a very compact bridge PCB that also allows us to lock our device to the PCB for stress relief.2) We are not locked to the DT connector - it could basically be any other connector that is IP67 and provides 8-12 pins. The DT connector is just common in automotive applications, but we will anyway most likely provide an adapter to go from the IP67 connector to some other alternative options for adapter compatibility.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 08, 2025, 01:47:29 pm
content: Isn't the enclosure decided yet?I think everyone is basing their thinks on the concept illustration.using FPC will solve the problem.advantage of FPC is its flexibility. It can mitigate mechanical shock.

author: fchk
author_rank: Frequent Contributor
timestamp: August 08, 2025, 02:26:58 pm
content: I did it like this:Connector: CONEC 15-000633, IP67 ratedAttached is an apdaptor board with serial resistors and ESD protection and a ffc connection. The ffc cable goes to the main pcb. This ensures mechanical isolation from stress etc. This did the job.

author: Martin F
author_rank: Regular Contributor
timestamp: August 08, 2025, 02:30:42 pm
content: @squadchannel: The idea is to use an enclosure in the style of the illustrative one, but potentially customize it fully to adapt to our device requirements and dimensions. That part can be fairly flexible. We are, however, looking to make it more in the style of the concept illustration vs. e.g. switching entirely to a junction box design - though if that turns out to be too impractical we may pivot.So in short, sorry if the enclosure in the concept illustration causes confusion - it is not meant to be taken 100% literally, the form factor of that may change as needed. But the concept remains the same: We are trying to design a simple PCB which has an IP67 connector on one side and 2 x DB9 connectors on the other side - both sides ideally mounted directly onto the PCB so as to enable a compact design without e.g. additional cables inside the device.@fchk: Thanks for the suggestion - do you have a picture/illustration that shows this solution in the broader context? It's a bit unclear to me how this would connect to the device while ensuring stress relief, but I am probably missing something on this. Would be very interested.Really appreciate the inputs on this - thanks for taking time out.

author: fchk
author_rank: Frequent Contributor
timestamp: August 08, 2025, 02:50:05 pm
content: Quote from: Martin F on August 08, 2025, 02:30:42 pmSorry, I can't add more pictures - this was a customer project. But the idea is simple. The whole connector assembly you see is screwed to the case via the sunb-d connector's two bolts (you see the empty holes for the bolts). The main pcb has its own bolts. Connetion between the two is a ffc cable, which decouples both parts mechanically.

author: Poroit
author_rank: Frequent Contributor
timestamp: August 09, 2025, 07:13:35 am
content: How about Amphenol C16 series connectors and use interface cables between the existing DB9 as Terry Bites suggested?https://www.amphenol-industrial.de/en/products/eco-mate/c16-familySome old project pics attached showing these connectors.Pasternack offer SMA bulkhead connectors so you could use a short flexible RF cables (RG178) for comms.https://www.pasternack.com/nsearch.aspx?keywords=sma%20bulkhead%20connectors&view_type=grid

author: Martin F
author_rank: Regular Contributor
timestamp: August 09, 2025, 07:24:35 am
content: Thanks for the suggestions and examples!The main reason we're trying to avoid having cables between the DB9 and the IP67 connector inside the box is to retain compactness of the overall solution. The device itself is 5 x 8 x 2 cm and we're looking to create the most compact IP67 box possible that users can insert the device into, while also making it both practical to produce and install (the end users will be putting the device into the IP67 box typically). This is something that might be used by 5-15% of our end users, hence why we're looking to make it a 'modular' solution (rather than design new IP67 variants from scratch). At the same time, we're trying to make it so that the final solution can still be mounted on e.g. two-wheelers like e-Bikes, where the design has to be quite compact.To recap, we're open to pretty much any IP67 connector solution - the key thing just being that it's ideally something that will allow us to create the bridge-PCB displayed in the STEP file for a compact mounting solution. It may also be that there's a different type of DB9 connectors (like the press fit version I shared) that could be used, which could help solve the issue.

author: Martin F
author_rank: Regular Contributor
timestamp: August 09, 2025, 08:17:37 am
content: I've also added some extra pictures of the 'bridge PCB' specifically and the collision challenge. Perhaps the issue can be resolved via another type of IP67 connector entirely, e.g. a circular connector, but we've not been able to find examples that would fit.

author: Poroit
author_rank: Frequent Contributor
timestamp: August 11, 2025, 05:48:28 am
content: I saw your website Case Studies link....very impressive!!!!I now understand why you need a compact solution.

author: Martin F
author_rank: Regular Contributor
timestamp: August 12, 2025, 09:22:04 am
content: Hi all,An update on this:We are now looking into using an M8 connector instead of the DT connector, as this enables a much smaller footprint that might 'just work' between our DB9 connectors. See attached the images and STEP file.We are currently looking at using an M8 connector with shielded brackets as per the STEP in order to make it more robust vs. vibration.The problem currently is that the DB9 connectors we are using will slightly conflict with these shielding brackets as shown in the image. As a result we are therefore considering if alternative DB9 connectors would exist, which still allow us to screw in the DB9 connectors via the two outer-most screws to our CANedge - but which are perhaps more "low profile" so as to increase the gap between the DB9 connectors and the shielding flanges. Does anyone have suggestions for specific DB9 types that may allow for this?

author: Martin F
author_rank: Regular Contributor
timestamp: August 13, 2025, 02:01:36 pm
content: We solved the conflict issue simply by rotating the M8 connector 90 deg as per attached image/STEP.This leaves a concern regarding stress relief: Currently the M8 is the only thing connected directly to the IP67 enclosure end plate. The data logger is going to be mounted inside an IP67 enclosure (e.g. like a STEP ME enclosure attached or similar), but even though the enclosure design can be fit to match the data logger flanges, we expect there will be some gap/slack that exposes the bridge PCB and the M8 pins in particular to vibration stress in this design.Any suggestions on alleviating this in a practical, low cost manner in the current model?Thanks!Martin

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 13, 2025, 02:37:06 pm
content: we have mentioned many times that FPC should be used.