single stage gear reduction

[Mouldy]

Re: single stage gear reduction

The overall diamater isnt important...the PCD and tooth count is what you need to know... half the PCD of each gear... then add them together that will give you your exact distance between centre's...if you dont have a milling machine or a precise way to drill it, you might find this difficult to make...Just add a tiny bit on top of the centre distances... its better to have them further apart then too close.

Look at this link to find out the PCD of you gears when you know the tooth count;
http://hpcgears.com/newpdf/spurgears_1.0mod.pdf

[Danjr1]

Re: single stage gear reduction

the design uses gears from technobots so getting the PCD is easy. Thanks for the help. Just trying to confirm that i can get the 6mm ali plate for the mounts, and that it will be able to bend to 90 degrees and what radius that would be.

[Danjr1]

Re: single stage gear reduction

The overall diamater isnt important...the PCD and tooth count is what you need to know... half the PCD of each gear... then add them together that will give you your exact distance between centre's...if you dont have a milling machine or a precise way to drill it, you might find this difficult to make...Just add a tiny bit on top of the centre distances... its better to have them further apart then too close.

Look at this link to find out the PCD of you gears when you know the tooth count;
http://hpcgears.com/newpdf/spurgears_1.0mod.pdf

Thanks for the help. The distance is 49.5mm so in the design, should i factor in 0.1mm or more do you reckon? I'm probably going to be asking Kenny to machine these parts for me as i cant trust myself with measurements this exact! i do remember from having RC cars that the gears should not be super tight together or is this factored into the design of larger gears?

[Danjr1]

Re: single stage gear reduction

Projects dead, was going to be overweight! Thanks for all the help anyway.

[Danjr1]

Re: single stage gear reduction

What would be more powerful?

Four Argos gearboxes with 18v motors, overvolted to 22.2v. Running on 75mm wheels

Or

2 speed 900 replicas, reduced down by 7.25 to 1, ran at 22.2v. Running on 130mm wheels

Both set-ups use electronize escs (if two speed 900 motors was used, could you have two speedos per motor?)

Cheers

Dan

[maddox10]

Re: single stage gear reduction

In this way, the speedo and batteries will limit the total available power.

The Speed 900's will demand a Sidewinder or stronger to give their potential. And then the 130mm wheels will prove an advantage.

[Danjr1]

Re: single stage gear reduction

I'm using 30a electronizes so am i right in thinking if i use two per motor, ill get 60a possibly from each motor? I'm using lipo so easily can deliver that sort of power

[maddox10]

Re: single stage gear reduction

The only result you'll have with 2 speedo's feeding 1 motor is 2 dead speedo's.

To make it simple. A speedo works because it cuts up the electricity in parts, and these parts can be shortened or lengthened.

You could sy, 1 minute is 1000 parts (the whole thing will buzz @1KHz) and each part can be run from 0 to 100%

0 is no power, 100 is full trottle. Now the cutting up is done with mosfets in most speedo's. For explanation function, these mosfets are tiny electricaly switched switches.

Now, try to switch 1 lightbulb with 2 switches. Each switch is in a different room, and you will have to switch exactly at the same time, otherwise you'll have a short.

[Danjr1]

Re: single stage gear reduction

Get it now. Thanks! The sidewinder has been discontinued now so I'll scrap the whole project for now me thinks

[maddox10]

Re: single stage gear reduction

No need too, you can use that 130mm 7.5-1 gearratio speed 900 setup at a much lower voltage and still get respectable power.


Let us say, 10S NiMH=12V

Speed 900@12V=6600 rpm

6600/7.5=880rpm

130mm*pi*880=359216mm/min= 359216/1000000*60=21.5km/h

Even dropping back to 3S Lipo gives you 19.9km/h
Or 3S LiFePo = 17.7km/h

[Danjr1]

Re: single stage gear reduction

So what your saying is if I run a speed 900 on a 30a electronize at 22.2v, it will probably blow the esc?

[maddox10]

Re: single stage gear reduction

The ESC will be a limiting factor.

On the other hand, if 666W per side ain't enough, you're in the wrong weightclass.

But, the Speed 900 setup as you propose runs a tad fast, doesn't it.
42km/h is a tadoverkill.

So, why the persistent use of the 22.2V? It's not if a 2450mAh 3S Lipo is that expensive.

[Danjr1]

Re: single stage gear reduction

Have a 6s lipo so makes sense to use what I've got. Thank you for your help by the way.

[maddox10]

Re: single stage gear reduction

Strange reasoning. ‚20 to have a battery that is lighter, smaller and more useable for the idea, of trowing a complete idea in the garbage can?

Also, if you want to use the 6S to drive a spinner, even then a seperate drive-battery ain't the worst idea you can implement.

[Danjr1]

Re: single stage gear reduction

What do people think of these pinions?
http://www.fxaeromodels.com/product_inf ... ts_id=4671

From brushless rc helicopters, just a bit worried about durability