Reducing the thickness by 2 mm proved a little too much as the rubber between the treads was almost non existent so the final tracks are 1 mm thinner.
Here are the tracks on the old Defiant chassis ready to go on my measuring rig the yellow box is to ensure the sloping front of the robot doesn't get under the spring balance which gives more download on the chassis effectively increasing the weight.
The chassis as is weighs just 107 gms and as can be seen in the video peaks at around 300 gms of push. https://youtu.be/BMYZaKrMKhI
Last edited by peterwaller on Sat Jul 22, 2017 7:45 pm, edited 1 time in total.
Having improved the tracks I decided that the chassis although virtually intact was looking a bit tired so I decided to give it a bit of a spruce up (It was made in 2012).
Having made the tracks purple I decided to invest in some matching ABS for a new chassis and track drive wheels.
Here is the finished robot sporting 1.5 mm polocarb armour weighing in at 112 gms so is still likely to be part of a cluster.
Although the sloping front on the old chassis looked more streamline, robots did have a tendency to drive straight over so hopefully this should help stop that.
Last edited by peterwaller on Sat Jul 22, 2017 7:47 pm, edited 1 time in total.
That's funny you should say that I have been trying to convince myself it looked good for a couple of days but rather failed.
So I have been experimenting with some better looking scoops and came up with these 3D ptrinted ones.
The white one is a sample of High Impact ABS I was given which has a breaking resistance of 37 Kj per sqm as opposed to 26 for normal ABS.
Unfortunately I only had enough for one scoop but it prints better than normal ABS but only comes in the one colour.
I also have some PLA 3D850 which has a value of 40, (normal PLA 20) comes only in clear and that is at the moment printing so that may be used depending on how it comes out.
Unfortunately you appear to have to order it from Spain here is the link: http://smartmaterials3d.com/en/9-tienda-smart
Last edited by peterwaller on Sat Jul 22, 2017 7:48 pm, edited 1 time in total.
Awesome Peter , did it increase the weight compared to your boxy polycarb scoops? i might get my scoops 3D printed out of ABS (curtsey of Shakeys 3D printing service) for Propellant, but it depends
Last edited by HugoIsOnFire on Fri Feb 19, 2016 8:12 pm, edited 2 times in total.
Each scoop went up from 7.5 gms to 11.5 gms but it wasn't as bad as I expected seeing that the side panels went from 1.5 mm to 3.5 mm thick.
Here it is sporting one in High Impact ABS and one in PLA 3D850 and a third scoop next to it in Plastink Bionylon which I haven't found the figures for yet.
Last edited by peterwaller on Sat Jul 22, 2017 7:49 pm, edited 1 time in total.
I have ordered some of the high impact ABS and PLA 3D850 from Smart Materials in Spain and they are very helpful.
I had a data sheet for their Nylstrong which wasn't on their site so I emailed them explaining our requirements for armour to withstand impacts.
The Nylstrong which is 110 Kj / Sq m is not yet available but they suggested Polypropylene which has a breaking resistance of 85.4 Kj / Sq m which is over twice that of the two materials I was trying.
I had tried printing with a sample of this material but had been unable to get it to stick to the table but fortunately they emailed me a leaflet on how to use it and you need to print onto Polypropylene tape.
A quick search on the internet showed this to be the brown parcel tape I already had so I tried that and it printed really well so I now have 5 scoops in 5 different materials.
Unfortunately they had already dispatched the first order but I have now also ordered a roll of the Polypropylene which has quite an ability to flex rather like Polycarbonate which probably explains its ability to withstand impacts.
As well as being stronger it is also lighter I have changed the scoop design slightly to get rid of the need for support structure and the new scoop which comes out at 10.7 gms in ABS is only 8.7 gms in Polypropylene.
There is a courier charge of 20 € or £16 per order but when you consider the bulk and weight that's not bad.
All the materials have arrived so I am doing some experimenting.
I have redone the lifting tynes on flippant in the high impact ABS and also made the top sections double the thickness.
I have done some mods to Anticyclone to give more space inside and allow wider wheels and reprinted in the H.I.ABS.
Have also printed total surround armour in Polypropylene to see how that fairs.
Won't know how good it will be until its tried in combat at the next AWS.
Last edited by peterwaller on Sat Jul 22, 2017 7:52 pm, edited 1 time in total.
Looking great Peter. I look forward to seeing how the new materials hold up in battle. All this talk about high-impact ABS wants to make me get round to installing a heated bed in my printer...
