[US] Main Board Rev 3 — looking for participants

[wjtrotman22]

I am looking to build 5 as gifts for Christmas and would be willing to add another 5 ( or more ) if anyone would be interested to buying them. I took the latest information from the v2 board and added to jlcpcb. Figure it would be about 25 bucks a board plus shipping if anyone is interested. I am just loading the files provided by jamro with the double sided assembly so assuming the files are correct, I am not an electrical engineer so no guarantee on my end :-) Looking to order them in a week or so. Let me know if there is interest in combining order or if I am ordering for myself.

[wjtrotman22]

I had loaded the rev2 of the board and just saw there is a rev3 coming. Not against trying that one if it looks like it will work.

[jtruland]

Would you be open to mailing one or two out to NJ?

[wjtrotman22]

I have nothing against the great state of NJ and would be more than willing to mail 2 boards. Thanks!

[William-A8571]

Are you fine with waiting for the Rev 3 board or are you looking to get started before then?

[jtruland]

I don't have immediate plans for the next couple, I can wait.

[jamro]

Thanks for organizing this! Really great to see the community helping each other out! 🙂

Just a heads-up: Rev 3 is still in production, so I'll probably need another 2–3 weeks to receive and test it. No guarantees on that timeline or whether everything will work as expected.

I've been using Rev 2 for quite a while now, and it's been working well, so it's a safe choice if you don't want to wait.

[jamro]

Hey! Thanks, glad you like the design!

I ordered Rev 3 from PCBWay, mainly because I wanted to test another manufacturer. JLCPCB should work perfectly fine too! Actually, I have found the whole ordering process with JLCPCB smoother and faster so far, although I have only placed two orders with them, so it's not exactly a huge sample size :)

One thing worth checking before you start 3D printing is ⁠PR #87. It introduces an improved joint for the body servo. I'm still testing the design, but the initial results look promising! The original design works too, though, so there's no need to wait if you are eager to get started.

Looking forward to seeing your build!

[wjtrotman22]

I will try printing the new design and even without the board I will see if I can run basic movement using the servos I ordered which should get here today. I will let you know if I have any issues with the 3d part.

It seems like there might be some interest in basically turning this project into kits where we bulk order the PCBs and the components (screen, motor, esp, hardware ) and package/ship them out. I know this is not my design so I do not want to over step.

[William-A8571]

[jtruland]

I'd join for a parts order, as well. With such small quantities, the shipping is generally the killer.

[heytastyfood]

Same. Rev 2 or 3

[DoWhileGeek]

I'm in for 2 boards, 3 depending on the price per unit. I'm in California.

[trhooper]

I'm down for a board if you have room shipped to Indiana

[wjtrotman22]

Of course.

[jamro]

Quick update: Main Control Board Rev 3 is in: boards ordered, assembled, and tested on a real robot (USB, boot, servos, OLED, audio, plus the new J4 expansion header). Design is merged in
#66.

If you’re planning a community / regional batch, feel free to target Rev 3... same stock build, plus the 12-pin extension port for future mods (mic, sensors, buttons, etc.)

[wjtrotman22]

Nice. After trying both which manufacturer would you recommend (quality and price taken into account)? Also do you have any issues with us bundling the parts as kits ( with all the parts needed) to cut down the price of small build numbers ( assuming people are interested).

[jamro]

After trying both, I personally recommend JLCPCB.

PCBWay was slightly cheaper, but JLCPCB was faster, and the whole ordering process felt much smoother. Everything happens through online forms, while PCBWay required some back-and-forth emails.

Quality-wise, both boards work perfectly fine! I am definitely not a PCB manufacturing expert, though, so I can’t really judge beyond that.

One interesting cost optimization I noticed: if you leave the ESP32 headers unassembled, you can go with single-sided PCB assembly, which can significantly reduce the price. The trade-off is that you’ll need to solder the headers yourself. JLCPCB makes it really easy to experiment with different configurations using their instant online quotation tool.

As for bundling parts into kits, I’ve only ordered assembled PCBs myself, so I’m not sure whether JLCPCB or PCBWay can supply complete kits with all the additional components. Since you’re organizing the group order, feel free to explore whichever ordering options work best for everyone involved. It would be great to hear what you find out!

[wjtrotman22]

Thanks for the feedback back. Think I will be going with jlcpcb. For the part bundle I was referring to bundling the board with the oled, servos, etc. Basically everything you need to assemble the robot minus the 3d printed parts ( which after talking to my son, for a price he wouuld be willing to customize and print :-)).

[jamro]

Ah, got it! 😄 I think bundling everything into kits is a great idea and could make building Tiny Engineer much easier for others.

Since you’re organising the group order yourselves, feel free to bundle the components however works best for everyone.

[namrop]

I'd like in for 1 board, shipped to Florida. Rev 2 or Rev 3 is fine with me. Let me know how you'd like to handle payment and shipping.

[TheMarcusLee]

I'm in for 2 or 3 Rev 3 boards depending on final cost, shipped to Illinois.

[barch95]

I'd like 2 boards, shipped to Long Island NY if possible.

[lockettks]

I’d love to get in on the group order! I’m in Virginia and would definitely be interested in a complete Rev 3 electronics kit if that becomes an option. This will be my first robotics build, so having the components bundled would be awesome. I’d also be interested in an assembled board if the full kits don’t work out. Thanks for organizing this!

[benbrulotte]

If there's still room on this order I'll take 3, shipped to Utah. Thanks!

[wjtrotman22]

Hi Everyone,

So I said I would give it about a week and it looks like we have about 20 boards requested. I will buy a few more just to handle any late additions to the order. Using the new Rev 3 and jlcpcb.com I got the following prices. Side note sending to the US there was a Duty and taxes cost I was not expecting :-( This brought the total to 23.16 per board. Lets say 25 to cover my re-boxing fee. I did pay a bit extra for the individual wrapping in bubble wrap and anti-static for my own sanity when reshipping to ya'll. Anyone that knows something about ordering PCBs please double check the settings and verify I did not select anything incorrectly for fully assembled PCBs:

For shipping I checked the cost of small shipping boxes and it looks like those are about a dollar each. To estimate max shipping cost I used my cousin's address on the other side of the US in Seattle and it was 9.48 USPS ( 5 day) and 11.32 UPS ground (4 day) with tracking. I used Stamps.com to get prices and was planning on printing labels and shipping that way.

So for those wanting to know the pricing before settling on a number, 3 boards would be about 85 bucks.

Also as a side item my son and I took a look at bulk ordering the main components to see how low we could get those.

I have ordered examples of these items and will be running a test to make sure they work with the existing 3d printed item. I can tell already with the oled I found a minor change to the head will be required due to the pin placement. It came to a base total of 17.67 per kit for the 5 SG90, 1 ESP32-C3, .91 oled, 1 speaker. Once I test this these components with my non PCB test ( minus the speaker) this may be an additional option my son may be willing to take on but I need to check his price for doing the work. He is a Sr in HS and is very busy but also needs college money so more to come.

I think this is a list of all replies so far for the thread. Now that we know the price, for those that provided a range let me know your final count if you are still in.

@jtruland 1 or 2
@heytastyfood not sure I think I lost your total in the mix
@DoWhileGeek 2 or 3
@trhooper 1
@namrop 1
@TheMarcusLee 2 or 3
@barch95 2
@lockettks 1
@benbrulotte 3

We can handle payment details over email. Please email me at wjtrotman714@gmail.com with your address and final order count. Also let me know if you are interested in the possible parts order. None of this weighs much so other than me reusing an amazon box I would not think shipping is going up much. After the test is done I will confirm if that is an option and final cost.

I will wait to order the PCBs a few days to let anyone that knows more about the PCB confirm my settings on the JLCPCB site. @jamro if you have a minute let me know if you see an issue with my settings.

Please note I am ordering the boards as designed and take no responsibility on the final product. That is my best legalese to say I hope these all work but don't come after me. :-)

[wjtrotman22]

LOL not sure why the tips showed up on the screen shots. Trying again:

[jamro]

These are pretty much the same settings I used for my PCBAs orders, and everything looks good to me. The only thing I would consider changing is Depanel Boards & Edge Rails Before Delivery to Yes, so you receive individual boards without having to separate them yourself.

[jamro]

Just a heads-up for everyone considering the parts bundle: it looks like the OLED display might be the same one discussed in #94 (would be great to confirm!).

I want to officially support this OLED variant as a Tiny Engineer robot mod, but it hasn’t been implemented yet.

Maybe someone here would like to pick up #94 and contribute? 😁 It could be a great first contribution for anyone interested in robot modifications!

[wjtrotman22]

Thanks for the feedback. Changed the price a little but well worth it as I assumed the boards where already separated so they could be individually wrapped. That would have been a big disappointment to get just a few large sheets. Looking the image you posted above and my rendering on the site I think the parts look ok:

Was using female connectors for the J4 just a design choice since they may not be used and would be better protected or is there another reason. I am more asking to see if my assumption as to why they are that way is correct and not suggesting they should be different. Still learning :-)

[jamro]

Yes, exactly! I chose female headers for J4 to avoid accidental shorts when those connectors aren’t being used

[wjtrotman22]

Greetings,

I have gotten confirmations from 3 people who stated they were still interested. Please email me to confirm you intent and how many you want. Once we get closer to the 20 board number I will collect the money and place the order. Do not want to order too many if there is not a demand for them here in the US.

[heytastyfood]

Hello 1 for me thanks

…

On Wed, Oct 28, 2026 at 2:31 AM wjtrotman22 ***@***.***> wrote: Greetings, I have gotten confirmations from 3 people who stated they were still interested. Please email me to confirm you intent and how many you want. Once we get closer to the 20 board number I will collect the money and place the order. Do not want to order too many if there is not a demand for them here in the US. — Reply to this email directly, view it on GitHub <#82?email_source=notifications&email_token=AJSEMWNUS4JVHB6VXP4Q7ET5WGOGVA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJSGM3DOMBRUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-19236701>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AJSEMWPXDAQRQCK6FAB5CCD5WGOGVAVCNFSNUABJKJSXA33TNF2G64TZHMYTGNBRHE4DMNJQGQ5UI2LTMN2XG43JN5XDWMJRGA2DMMBSGWQXMAQ> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AJSEMWPB76FQGSTCHET4DYD5WGOGVA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJSGM3DOMBRUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSVGM33PORSXEX3JN5ZQ> and Android <https://github.com/notifications/mobile/android/AJSEMWJLJEBI2ZSNB3BPWXD5WGOGVA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCOJSGM3DOMBRUZZGKYLTN5XKO3LFNZ2GS33OUVSXMZLOOSXGM33PORSXEX3BNZSHE33JMQ>. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.***>

[wjtrotman22]

Shoot me an email at the address wjtrotman714@gmail.com so I can keep track there. Thanks

[jtruland]

I'm still in for 2. Thanks for coordinating this!