Lymow One contacts covers

Due to charging issue on Lymow One mower as contacts get dirty, I designed these contacts covers.

It took me lots of time and lots of "print, test and scrap" to achieve a proper and functional design. (Maybe I could reuse scrap parts as Santa's sleighs for Christmas decorations 😁).

This design is probably not perfect, but I think I have maximized the design optimization and reduced the overall dimensions as far as possible. However, I am hitting the conceptual limits, as I want to avoid altering the mower or the charging base.

I share it for free, but please respect my work, effort and time and do not make money with it.

You’re welcome to give a small contribution on my paypal (DenisPicard366 or [email protected]), if you enjoy it.
Thank you for support.

22nd April 2026 update*
Modify Rails-link print orientation for better strength ...(or try to get better strength)

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Tests were performed with parts printed with PETG (nozzle 0.4mm, layer thickness 0.2mm, 3 walls, 30%infill, wall generation: Arachne)
Arachne wall generation is an important setting, for good results in some very thin areas.

You’ll also need:
-1.5mm stainless steel axis. (2x 94mm and 2x 98.5mm)
-4 compression springs
-cyanocrilate glue (or strong glue compatible with printing material)

Springs i used (required):
-Material: stainless steel
-External diameter: 6.8mm (6mm to 7mm)
-Free length: 65mm (60mm to ??)
-Solid length: 17.4mm (17.4mm or less)
-Wire diameter: 0.5mm
-Compression load: 0.11N.mm (something similar. 0.10 to 0.14)

I use these springs:
RS-PRO spring 821-352, you can find on many website.

Free length and compression load will impact load needed to keep close, open and maintain open flaps. It could have an impact on charging behavior.

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Pre-assembly instructions:
Rails-link, cover and pusher need to be print twice.

-fixe rails on rails-link (with strong glue)
-assemble cover, with steel axis and ball-end.
-insert cover in rails.
-insert springs
-install srping retainers.
Rails are marked with numbers to ensure correct location positioning on rail-link.
Take care to make 2 symmetrical assemblies.

Installation on mower don't need any modification in order to keep warranty.
It only use existing screws.
Just need to remove the 4 front screws under the mower, and install covers using these four screws.

Install "pushers" on docking station.
"Pushers" can be fixed with piece of double-side adhesive.

There is still a gap between flaps and contacts area where grass can go. So i use a longer "mud flap" on mower deck and it realy increase efficacity. (My mud flap on deck is about 15mm longer than original one). I made it with a piece of PVC trim and some duct tape (See pictures).

The hole in "spring retainer" is intended to allow easy removal for maintenance ( if grass gets in spring housing).

On docking station, mower can't move fully forward, due to clash between rails and docking station.
I made 2 stops to add on docking station to avoid overstrength on other printed parts.

Charging should work fine with "hanbreak: OFf", but if mower randomly stop charging you can try with "handbreak ON".

Use it ON YOUR OWN RISK. I am not responsible for any damage caused by using this model to your robot or any other object.

Feel free to give feedback, if it works or if any fails or just if you have any remarks or suggestions.

My concept is share under "NON COMMERCIAL" licence and i will not provide any licence for the following reasons:
-it is not infaillible and i'm aware of its limitation.
-It works very well for me and a few others, but success often depends on the specific context, and sometimes it fails.
-I don't want any people to make money with my work and with something which can break quickly depending on the situation.

You can sell printed part at production costs or either sell complete kits to help other people, but without making a profit. Please, just tell people who use it and enjoy it, to make a small donation for the design work.
Thanks