36:1 - 24:1 Drill gearbox Conversion

[Ellis]

Re: 36:1 - 24:1 Drill gearbox Conversion

I don't think it's going to be an issue. Our robot is in no way struggling to move around, it's virtually the same as it was before in terms of grunt, which leads me to believe the motors can happily handle it.

Two-speed cordless drills with 550 motors go to at least 24:1 as they often have a 900rpm option, and they're commercially designed to take the stresses of years of drilling. Plus many people use the 16:1 Banebots gearboxes without issue, which is even more extreme.

I'm open to it being a problem but I don't think it will be.

[RogueTwoRobots]

Re: 36:1 - 24:1 Drill gearbox Conversion

Only just remembered that the old Kaizer Mk.3 version ran 24:1 gearboxes onto 100mm wheels at Rebel Robots and the UK champs in 2009. It flew all over the place, and would powerslide nicely in the larger Rebel Robots arena. Shame it wasn't the easiest to control. The motors were 16.8V ones running on 24V and we never had a problem.

http://www.youtube.com/watch?v=y1HuBxWVCoI
http://www.youtube.com/watch?v=28_rBS3jy0o
http://www.youtube.com/watch?v=_vbu4v22xrA

[Liftoff]

Re: 36:1 - 24:1 Drill gearbox Conversion

Had a go at the makita motors I have on Liftoff and took the gearbox apart - it does not look anything like the GR02 gearbox though!

Its got 3 stages instead of 2, and the ratio is 48:1! No wonder why its so slow... :| Apart from that compared to the GR02 both motor and gearbox are enormous and weigh a tonne!!

[daveimi]

Re: 36:1 - 24:1 Drill gearbox Conversion

I was reading through this and it struck me...rather than mess about with stripping down old stuff would it just be easier to spend thirty quid on some fresh Gimson's?

[Bodge Job]

Re: 36:1 - 24:1 Drill gearbox Conversion

yes, but it would be expensive. £120 gimpsons, or £40 for the parts to change 4 motors. easy choice for me?

[Liftoff]

Re: 36:1 - 24:1 Drill gearbox Conversion

Why £120, wouldn't two motors be enough?

[PJ-27]

Re: 36:1 - 24:1 Drill gearbox Conversion

Plus some people have built their robots around existing drill motor gearboxes, the Gimson's, although with better mounting options, are quite different.

[daveimi]

Re: 36:1 - 24:1 Drill gearbox Conversion

Yeah never thought about people with 4 or 6 motors! lol

And yeah see what you mean about people with existing setups just after replacing their internals.

[Liftoff]

Re: 36:1 - 24:1 Drill gearbox Conversion

I don't understand the reasoning behind putting too much motors in the machine...in the end I think its useless having more power than you can transmit to the wheels.

The real issue would be the grip/friction at the wheels and motors powerful enough not to stall. But I stand to be corrected :wink:

[daveimi]

Re: 36:1 - 24:1 Drill gearbox Conversion

I admit that there have been times I've seen 6wd robot designs and thought I wonder if it would just wheel spin all the time?.

[Revsmin]

Re: 36:1 - 24:1 Drill gearbox Conversion

Nope
Ricochet drives nicely, fast, powerful and no wheel spin at all, and it has 6 motors.

[PJ-27]

Re: 36:1 - 24:1 Drill gearbox Conversion

Some robots have awesome drive with just 2 550 motors, it's all about how you put the power down and how you get it to the motors.
Having 4 motors and gearboxes is just an easy and cheap way of getting 4WD since setting up pulleys, belts and passive axles can be an expensive and time consuming process.
As for 6 motors though I can see it just being a hindrance since it'll create additional unwanted friction when turning.