On HDPE, I can supply the stuff easely enough. But P&P is an additional cost from Belgium. PM me about sizes and cost.
On HDPE, I can supply the stuff easely enough. But P&P is an additional cost from Belgium. PM me about sizes and cost.
Hi all!
I will pm you when I solved some other things.
Meanwhile what material should I make the base?
I'm thinking of steel, but what thickness?
A full steel baseplate is heavy. Thinner than 2mm is just waiting to be crumbled like a tin can.
Best case is to use 3.2mm Hardox, still the weight of steel, but way stronger.
A sheet of 200*200*3.2mm weights 1 kg. An avarage feather is 300*400mm, resulting in 3 kg baseplate.
Did some testing these last few days, by making this platform:
IMG_3432.jpgIMG_3433.jpg
the motor holders are made out of 3mm steel, if it turns out to be too heavy, I might make them out of HDPE.
The wheels are made using slices of go-kart tyres which I screwed them to the wheels:
IMG_3435.jpgIMG_3436.jpg
The go-kart rubber is very grippy! When I try to push the robot, the wheels don't slide but they turn the motors.
The problem is that leaving them this wide, the wheels aren't perfectly round, but they flex with the weight.
Also the scooter motor had arrived, and I will do some tests on that later.
Updates:
Started the build by getting the base and making the axe mechanism:
IMG_3460.JPGIMG_3459.JPGIMG_3462.JPGIMG_3468.JPG
Right now it weights 8,5kg including the axe, the gear ratio for it is 5:1, having on the handle 55 teeth and on the motor 11.
The base is 2,5mm steel and the dimentions are 315mm X 370mm not counting the slots for the wheels.
This is what (hopefully) it's going to look:
Cattura.PNG
I decided to make a lower body (kind of looks like K2 now), to save weight, and the scooter motor is closer to the center:
Cattura2.PNG
I will think of a cover for it later.
Thats a real nice drivetrain there. Will be interesting to see the robot finished.
So, some time ago I found a place to get the HDPE from italy, and 2 days ago I ordered some sheets.
I thought that the parcel would arrive next week, but after school I found them in the living room:
IMG_3469.JPG
Wow they look chunkier than I thought!!
They are two 20mm black sheets and two 10mm white (they only sell the 20mm sheets in black).
I only really need one of each but I wanted some more to use them when needed.
So hopefully I will make some progress these days.
One more thing, what insert do you use and how you "insert" them in the HDPE?
Edit:
Little bit of progress, I made the supports for the axe out of wood, after I made some modifications to the very cheap jigsaw:
IMG_3471.JPGIMG_3472.JPGIMG_3473.JPG
I also need to shorten the chain, like a lot! Which means some spares.
Also about the inserts, are these good?:
IMG_3474.jpg
Or I need ones without the lip?
Last edited by Tashic; 29th January 2015 at 13:19.
Nice progress mate. Look forward to seeing the finished robot. Might want a bigger shaft on the axe though? What size is the current one?
Thanks, the shaft is 1cm diameter.
Yeah you probably want a bit more on that. Maybe try for 20mm if you can manage it? I don't own an axe bot myself but I seem to recall Hatchet's shaft being 15-20mm...
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