Unnamed FW crusher build diary

[Andy]

Looking fantastic that mate. Would be great to test it against hardox to see if you can pierce it. Hope to see it in action soon!

[cjsowry]

nice.. keep away from my bot with that thing!!

[leorcc]

What is the weight now?

[Al_]

That's like a kick to me when I'm already down as I just can't find time to make progress hahahah ... that's really brilliant progress though mate..
Especially seen as we both started this at the same time and all I have is a 4wd rambot made out of ply and a weapon test platform..
I went the mechanical route rather than hydraulic and hitting no end of problems. Latest one is gears losing teeth like a 90 yr old bloke. Lol.
its been great to follow your build though, can't wait to see it in action and test against something tougher.
:-) :-)

I hear you on the time front, I thought I would be finished before now but there is never enough time to do it and I'm already missing events this year There was no way I was considering the mechanical route for the crusher, I don't have the tools or mechanical knowledge to do it, plus I had an antweight many years back that had the same problem you are having with the loosing teeth!

Looking fantastic that mate. Would be great to test it against hardox to see if you can pierce it. Hope to see it in action soon!

Me too, and if I had some hardox or other steel, I'd love it to try it out and see what I'm up against.

nice.. keep away from my bot with that thing!!

No chance! I've followed your progress on Luna-tic and it looks great.

What is the weight now?

With battery its pretty much 13kg. Armour for the rest of it is tight but there are a couple of places I can save around half a kilo if need be.

[Maxamuslead]

With battery its pretty much 13kg. Armour for the rest of it is tight but there are a couple of places I can save around half a kilo if need be.

go the razer route and get drilling some holes. Also did you say at the arm made out of Alu ?

looking impressive all the same

[calumco]

Wicked! Love it

[Al_]

go the razer route and get drilling some holes. Also did you say at the arm made out of Alu ?

looking impressive all the same

Yep, arm is mainly aluminium, so not a lot of weight to save there even if I did go crazy with the drill.

[Al_]

So after making some new motor mounts I was finally able to try and drive Pressure Point for the first time yesterday, and it went well.... for about 5 seconds I just moved the bot forwards, backwards, and was turning left and right on the spot when the left hand threaded screw that holds the wheel onto the drill motor sheared.

The motors are the standard 12V Argos value drill motor/gearboxes running on 5s and as far as I am aware, lots of people use this motor this way. Likewise the wheels are 100mm diameter Nylon with mountain bike tires screwed on.

Have I just got unlucky here with the screw shearing or am I doing something wrong and is there anything I can check for? I have scrounged another left hand thread screw and would like to check before I risk breaking another one.

[R9000]

Sounds like you just got extremely unlucky. There's no reason you should have sheared one of those screws... It's never happened to me.

[Maxamuslead]

It still a little weight which you could use else where.

Bad luck with the Gearbox, any chance when you where hacking it you did up the bolt too much?

[MattLampitt]

Can you put some pics on of what you have done? And how much thread is off.
How iv done mine in my prototype seems perfect. Can Rally it around full pelt even carrying adults back and forward and there is no hint of that happening, and I'm talking 10 mins at at time so it's no light work.

[Al_]

I don't think I have done anything out of the ordinary, just a 3/8 UNF insert melted into the wheel centre which screws up to the shoulder on the gearbox output shaft. This is then retained by the left hand threaded screw and a flat washer. I'll get a few pics up when I have chance. Hopefully I was just unlucky but the break in the screw was almost level with the end of the gearbox shaft hole, so could be tricky to remove.

[lowndsy]

Was the screw taking sideways pressure rather than just squeezing the nut to the wheel?

If it helps I found some hand screws on Amazon that are a bit longer than the standard Argos one - up to 30mm length, which might make it a bit stronger?

[Al_]

I don't think there should have been any sideways pressure on the screw, its all taken by the gearbox output shaft, so the screw should have been just squeezing the nut in the wheel on to the shaft. I'll double check its all square and true when I get to have a look at it it at the weekend. Is there any chance you could drop me a link for the longer LH screws please? I got this spare out of an old dead battery drill, but if I break this one too then I'm out of them.

[RogueTwoRobots]

Sounds like it must be a bad one. I used drill drives for years (still do occasionally) and I've never had a LH screw shear from normal use. Even after several matches, they're usually fine.