I found the lines others drawn on the maze floor very helpful in determining when the mouse is correcting, if the position has any errors, etc.
I used this straight edge and a Sharpie pen. Because of my floor panel dimensions, I was able to do all my work with one four foot section. I tried three or four other pens but none worked as well as the good old Sharpie. The only “problem” with the Sharpie is that with use, the tip wears our and so you end up with lines that are 2mm thick.
I think for this purpose the 2mm is fine but if you would rather have thinner lines, you can use the silver version of the DecoColor pen.
On my small maze, I used this pen and it gave me really crisp lines. The issues I ran into were that you have to press down a bit to get the ink to flow into the “nib”/tip and I ended up with a couple of splotches and also the pen stopped writing after a bit even though it still had ink.
Since availability varies, I suggest checking your local arts and craft store. I was able to get a good selection of pens (five) from the store and I tried them on the edge of the maze until I found the ones I liked.
If you look closely, you’ll see that some of the walls are in upside down. When I was putting the walls into the maze, I found that the walls went into the posts easier when they were upside down! I think this is because of the molding draft angle of the notch in the post and the tongue in the wall. Since mice only look at the sides, I’m going to use the walls upside down!
The gaps between the panels are approx. 1mm to 1.5mm. I think if I want a smaller gap than that, I will have to use a latch. I’m thinking of attaching latches but if I do, then I’ll need to raise the maze floor from the floor of the room. Also, I’ll have to make sure that the latches align on all the different floor sections. The mouse seems to run fine, so until I find a problem, I’m probably not going to reduce the gap.
NOTE: I realized I made a big error in my lines. I have the diagonal lines going from peg center to peg center rather than edge center to edge center. Since I don’t want to repaint the floor, I will most probably just add additional diagonal lines.