Graupner motors

[Max]

Re: Graupner motors

Why do you need an actuator for a rammer?
If you want a good one buy a gimson one

[Laser]

Re: Graupner motors

Yeah brushless motors can reverse but you need a special kind of controller to do that (which is why I said 'generally') which is why you pay so much for the RC cars with that function.

A drill motor crusher, as its been said, wouldn't be very effective as a crusher (might bend some plastic) but would be fine just to pin robots down so you can push them down the pit and such.

And he's right Ben, he hasnt mentioned using 900's for a few posts now .

ahh sorry, when he was talking about satanix I thought he was talking about speed 900's. my bad...

[archie2000]

Re: Graupner motors

no probs
we've all made mistakes
especially me

[archie2000]

Re: Graupner motors

ok, so i am seriously considering gimsons with 2 gears for extra rpm so it will feel powerful even if its not.
looking at the specs on the website they do 93.7 watts i think
apparently Argos drills do more watts than that.
is all that true?
should i just get drills?

[maddox10]

Re: Graupner motors

The GR01's are drill-motors/gearing in a convenient package.
The Argos things ain't more powerfull nor better in any respect, the marketing just overstates the power. Of course, there is a difference for nominal power and peak power.

With nominal power such a motor can run untill the brushes or bearings/bushings run out.

With peak power these will melt down in a few seconds.

Adding gearing/increase wheelsize to it will just make a change in top speed. More power will be used to reach top speed.
If that top speeds consume a certain amount of power, the motors will run hot, or even melt.

Let us take the GR01's as an example.

Most useable, cheap brushed , permanent magnet motors have an max efficiency of 70-75%
Now, you accept the 92.7W as a given.
Of that 92.7W, 25% or 23W is not used to give power to the drive, but to make heat. That's the power of a normal soldering iron
That heat is removed by the fan running at 15K rpm.

In stall no power is used for movement, and the fan ain't running. That means all power is converted into heat. 979.2W pure heat. That's a nice bathroom fan-heater.
And all that heat is concentrated in the tiny carbon brushes and thin barely insulated copper wires of the rotor.

I hope you get the picture.

[archie2000]

Re: Graupner motors

The picture is gimsons are quality, right

[maddox10]

Re: Graupner motors

The picture is gimsons are quality, right

You didn't get the picture.

Stall any suitable featherweight motor, and you get cooked rotors, burned brushes and even smoldering speedo's and swelling batteries.
Unless a safetyfeature like speedo-current limiting or fuses kick in.

For the price, those GR01's are the best buy you can do at the moment if you don't have lathe/mill machining capacity

Don't get me wrong. The Speed 900 MSR 12-XX drives we use in Hannibalito 3 and Kashei. And dave W uses in Satanix 1.666 are WAY stronger in all respects, albeit with a higher own weight.

But with the difference in pricetag... 2 Graupner Speed 900's =£90.
2 Z12 Mod 1 gears and 2 Z72 Mod 1 gears from Technobots=£54.94 .
£25 for the gearboxplates , 15mm steel axles and bolts.

Total = £169,94

2 Robotmarketplace PDX16 units will set you back an simular amount.

Compared to 2 GR01's... £49.8

After this, you still have to add a wheel to each unit.

[Ellis]

Re: Graupner motors

Here we are again with the Gimsons or drills being boring and weak. That simply is not true.

I insist, 4 12v drills running at 18v with 100mm wheels will give you a robot that feels powerful, because it is. And, power isn't everything. If you have a flat fronted robot, you could have rockets for drive and it would be beaten by a 35w Jaguar seat motor powered robot with a wedge built for a hundred quid. Plus, the suggested setup above gives you a speed of 10mph, which is faster than I (personally) can comfortably control a robot. Satanix drives so well because Dave is an amazing driver and I think the gyro setup he has helps things.

If you want to talk power, picture a robot with said 35w motor setup. Two of them drive a robot comfortably. A drill measured in the same way might well (theoretically) be more like 70w. So, twice the power of a single 35w motor in one drill. If you had 4 drills, on paper you would have 8 times the power of a 35w motor powered robot.

For a first machine, you will not be disappointed. Picturing bigger and (subjectively) better things is human and normal, and as I have said before I definitely don't want to kill your enthusiasm, but practicality and reality have to be in there somewhere.

Build something mate, and see for yourself. I'm dying to see what you end up building now.

[archie2000]

Re: Graupner motors

i will start with 2 drills maybe with grippy wheels
simple.
maybe with a lifter

[archie2000]

Re: Graupner motors

i just had a look in my cellar and dad found 4 motors.
a dewalt 9W07
a car fan motor x2
a windowscreen wiper motor
woo
bad news:
dewalts gearbox is in pieces.
good news :
inset day tomorrow so i will have a play with gears.

[typhoon_driver]

Re: Graupner motors

viewtopic.php?f=166&t=5226

This would potentially be a good start for a featherweight and you could fit a lifting actuator to it or look at using low pressure pneuamtics down the line.

[archie2000]

Re: Graupner motors

cheers Gary
the dewalt is a DW907
my memory is awful.
can i run 2 different motors like the dewalt and the car fan together on the same rpm?

[mattsdragons]

Re: Graupner motors

Just a note, sorry guys, ive got that

[archie2000]

Re: Graupner motors

good for you.
I'm starting from scratch.
then it will always be my robot
got a picture of the junk

[archie2000]

Re: Graupner motors

picking up from what Max said.
4 drills are more powerful than 2 speed900s.
this can't be true can it?
this may change my mind on the way i think of drills.
does anyone have any stats on any cheap drills?
thanks