Team MedBots

[maddox10]

The main advantage of front drive wheels is that the weapon doesn't swing out when aiming. Disadvantage, it's a very nervous way of driving (kind of driving a car backwards). Razer solved that by using driven omniwheels on the back, making it a lot more stable.

[Max]

Sounds interesting, I imagine having a set undriven wheels at the back may help it go in a straight line and restrict over steer, something without too much grip so they can slide.
What do people think this: http://www.esska-tech.co.uk/esska_en...d_air_ms_.html as a pressure relief valve for a heavyweight, I think they were discussed before and found to be a bit low rated but ok?

[Max]

What do people think this: http://www.esska-tech.co.uk/esska_en...d_air_ms_.html as a pressure relief valve for a heavyweight, I think they were discussed before and found to be a bit low rated but ok?

Does anyone know if it is suitable as a full pressure relief valve, has anyone used it?
Thanks,
Max

[teamshock]

Seems to be the same as the one we have in Manta so should be fine

[psychostorm]

That looks exactly what I've got. Roughly the size of a thumb?

[Max]

Hi,
I was just wondering if anyone used some form of lubrication for their hw gearboxes? I was thinking of perhaps graphite or grease? If I did would I have to seal up the entire gearbox?

[mightymouse]

Max

Used to grease the gears but the mdf powder from the arena floor would stick to the grease and make lovely grinding paste.....I run them dry now.

Trev

[maddox10]

If the gearbox is open, don't use grease.

As Trevor says, grinding paste is grease with abrasive stuff in it.

[Max]

Right then no grease! I've found that by gripping the axel of my motor ,which pokes out the back of the motor, in a cordless drill chuck and running it works well to 'break in' the gearbox and remove some of the tight points without straining the motor at all!

[Max]

Good news! I have finally finished my heavyweight gearboxes! They are 10-1 for for use with 8 or 10 inch wheels. They run on Bosch 400s on 12v but I may upgrade to 18v. They use MOD 1.5 gears from technobots, most the gears were 30-40% off!
Here is a picture:

And a video:
http://youtu.be/YSGHnPsCXjo

Also I have nearly finished my FP pneumatic ram which I made all by myself at school- very chuffed! I just need to drill ports-


Next job is to make up a manifold to connect everything tomorrow them can pipe up all pneumatics and then make a body for the robot.

Any questions or comments welcome!
Max

[maddox10]

How heavy is the piston and rod?

[Max]

The whole ram ways 3.5kgs, the rod is 20mm stainless rod. It is 63mm bore, 145mm stroke. So it weighs more than it needs to but better to be safe than sorry! The walls are about 6mm aluminium and the end caps are 30mm thick aluminium, its held togther by 8M6 tie rods all 2mm away from the wall of the tube- should do the job.

I don't know the weight of just the rod and plunger but can weight it tomorrow for you, why do you ask?

[maddox10]

keeping the moving weight down is a good enginering practice.

[Max]

Ok I'll weigh it tomorrow, the end cap is pretty thick so should be alright- I'm going to attach some sort of spike to the end as the weapon (not very effective but quite fun) so that could also add some weight. I may add some rubber disks to the inside to act as dampers.
I guess for a spike weapon some inertia is a good thing!

[RogueTwoRobots]

Nice job on the gearboxes. What's the diameter of the output shaft?