Peter Wallers Robot Ramblings

[peterwaller]

Cheers for that but we will have to wait and see if it is as good as polycarb.
Scot the PLA 3D850 is slightly higher impact resistance than the ABS H I and you don't need a heated bed for that.
Actually they sent me a sample of it along with my order so if you are interested in trying it PM me your postal address and I will send it to you.
I have rather overdone the armour on Anticyclone and it has come our 5gms over so I have shaved a bit off the blade and am molding lighter tyres in an attempt to get it legal.

[scottylad7]

What a beast!!! Can i ask, whats the speed controller and ESC are you using please. Thanks!

[peterwaller]

All my robots run on my own design speed controllers that I used to make but I have a few around that get recycled.
They are bigger than Rory's and were more expensive for about the same spec so his are the ones to use now.
The brushless controller is this one from Hobby King http://www.hobbyking.com/hobbyking/stor ... duct=28404
I got the weight down to 150.2 gms even with all the extra armour.


That's my first attempt at 3D printing the name on the lid and still needs a little work.

[Hogi]

new spinner blade as well? looks great!

[peterwaller]

Actually it is the same blade just cut down a bit to reduce the weight.

[peterwaller]

I thought while I was upgrading Flippant the body shell had some damage so I reprinted that in H.I. ABS and even redesigned the polycarbonate flipper armour so it could be printed.

[peterwaller]

Just been doing a mod to the arena lid support.
Although the plastic pipe support worked reasonable well it did make the handle less easy to use and also relied on putting the support in the center to stop the lid from sagging to one side or the other.
The new one has an M10 stud through the handle and is 30 cms wide so the whole thing is much more rigid.

[peterwaller]

One of the more difficult parts of 3D printing particularly in ABS is that certain structures tend to distort usually resulting in corners lifting.
To overcome this you need to ensure the model is well bonded to the build plate to hold it flat until it is cooled down.
I started using a glass plate and covering it in glue stick and it gave reasonable results.
Some chassis still gave problems so I bought some of the capton tape which was about as good as the glue stick but I found a combination of the two was better but still chassis like Flippant still had slight curvature at the rear which although it didn't really effect the operation was non the less annoying.

Recently I found a spray product called dimafix which looked very good on paper so I bought some. http://www.crusaderstore.co.uk/products ... 399-15939/
It seems to work really well and when I did a test print of Flippants chassis it stuck so well that the side sepperated slightly rather than lift of the buildplate but this was fixed by upping the nozzel temperature from 240 to 245 degrees C to give better inter layer adhesion.

Here is the final test print showing how flat it is.

The adhesion is a function of the build plate temperature so at room temperature it just lifts off without a struggle.
It can be used with PLA I am just running a test now but you do need to use a heated bed (80 degrees C) but is seems to be working well.
I had a quick try with nylon but that didn't bond at all well.

[UserFriendly]

Interesting Peter, I've been having trouble with lifting corners. I didn't know whether it was that the bed temp was too high, or too low. I may try some of that. Do you need to clean it off the spray with something when you finished the print?

[peterwaller]

I print ABS with a bed temp of 95 degrees C and you do get a layer of spray on the print but that washes off even in cold water.