LAM (Large Area Mower) - Project Update

Latest News on the LAM (Large Area Mower)

I created a new part of the site dedicated to this project.  Please visit for the latest updates on the project. Plan is:


1. Update the LAM to the monster design - Done!

2. Get the GPS capability up and running.



Working on the GPS. Please visit the GPs updates page to see more,



LAM Monster Charging station is completed.



The STL pack has been updated with the Monster version of the LAM.  The new version is shorter due to moving the 3rd cutting disc to the back of the mower.  This this aid with turning and keeps the overall build more compact.


I will now work on updating the build instructions and designing the new LAM charging station.






Added the charging station to the LAM STL Pack


I moved the GPS development to a new area of the website




Finally a dry day to test the new front casters.  They work very well and I have released the STL files in the store and the electronics bundle to buy and download.

H A P P Y   C H R I S T M A S !  !

I will continue to work on the GPS as this needs to be tested with different modules before I release the code.  This will then be a small electronics upgrade to the mower but wont affect the design of the mower.



19.12.2019 - GPS - Multi Point

It seems like the logic does scale up to allow a Multi Point GPS fence to be used.  Heres the field again with 8 GPS Points and a cut in area.

By limiting the area of the fence being monitored by the location (X,Y) of the Mower (Yellow Triangle) and by limting the theoretical extension of the boundary line to just the length of the line it was possible to make logic for each type of line (direction from the last GPS point to the next).



 Anyway the main Thing is it works.  Now I just need to find a logic that Arduino can select the right equations based on the type of line inputted.

My goal is that the operator can Input the GPS X and Y coordinates in the code

Point 1 X Coordinate 1 Y Coordinate 1
Point 2 X Coordinate 2 Y Coordinate 2
Point 3 X Coordinate 3 Y Coordinate 3


The code will then use the coordinates to generate the boundary equations.

Well thanks to Excel I managed to get this to work.  Without the visual aid it would have been impossible :)

Now I need to test the logic for various shapes and make sure there are no exceptions for other boundary line directions.





18.12.2019 - GPS  

I'm working on a GPS system for the LAM.  I want to have a GPS fence system available which is easy to use.  Lots of hurdles to cross here but I think it can be done.  My initial calculations are done in Excel as its easier to visualise whats happening.

I've seen GPS systems with 15mm accuracy for about €250.  Im not sure if this accuracy is needed.  Otherwise systems with 5-10m accuracy are less than €30.

Here's a local football field which Im using to make the calculations.  I hope this can be transferred easily to Arduino as it uses equations and not arrays for the GPS data.

Green Triangle is the Mower.  The squares represent the limits of the mower when the boundary of the fence is projected out along the boundary line.


Another Test area to see if the equations are transferable to any field

Again with different 1, 2, 3 & 4 starting points


As the mower leaves the fence the square crosses the exact same point as the green triangle and then if it continues to move the mower doesn't have 2 squares either side of it anymore. (now only 1 to the left and 3 to the right).

So a logic to detect this must be possible to program.


4 GPS points as a fence seems to be possible using the X boundaries as stops for where the mower needs to turn.  Im not sure how this will pan out when more than 4 points are used....  Hope everyone has big polygonal gardens with 4 points.... 


16.12.2019 - First Tests

So Ive been driving the LAM around my wet, leafy, soggy garden and trying to get some test driving behind it.

I really wanted to keep the compatability between the 330 and the LAM components so Im glad the 12V motors seem enough to climb and push through bushes even with the extra weight of 3 mower motors and larger frame...

Improvements need to be made on the front wheel casters.  They sometimes block when turning the LAM. (I guess due to the larger footprint and weight).  I will increase the caster offset to try and get more moment on the turn so that wheel doesnt stick in the sideways position.

Im a little off my original plan but I want to make sure its tested and working before relasing any STL files.






09.11.2019 - LAM v Standard Mower

This should give an impression of the size difference between the 2 mower variants:

Standard ReP_AL Mower :  Cutting Diameter = 220mm / 8.7 inches

ReP_AL Large Area Mower : Cutting Diamater = 530mm / 20.8inches               



08.11.2019 - Main Covers Test Print & Fit.

First test of the large main covers:





Main Cover Improvements to make:

The rear section of the cover reuqires more structure to hold the shape and give good fixing points to the rear control panel cover.  This will be updated in the design.



02.11.2019 Base Plate Test Prints and Fit

The distance between the blades measures just over 530mm.  The blade discs and cutters will need some clearance so the end cut width will probably be around 520 - 530mm.


The linking plates were modified from the original plan to give more fixation points to the base plates.

The overall construction feels extremely solid :) which im very happy with.






I've been working on a design for a Larger Area Mower (L.A.M.). Im trying to use the same back end of the mower for power and trying to keep as many parts as common as possible.  This design would have 3 cutters.

Please let me know if this design would be of of interest by sending me an email or giving it a like in Thingiverse.