www.Quarterscalelegends.com

Been thinking about a homemade diff for largescale applications, and today I got a couple of old grinders and started tinkering a bit.






As I don't have access to a lathe, cnc thingy or anything like that, I have to try to find things that work together, and this is where I'm up to so far.










OPTION A:




Grinder heads mounted on the chassis with large sprocket somehow mounted on some casing also holding the smaller gears.















































OPTION B:

I discovered that the holes in the pocketbike sprocket and the holes in the grinder plates line up perfectly.
With this setup, all that would be required is a bearing on the end of each axle, and a way to secure the bolt holding the small gears.
Basically, the whole setup will rotate.

Given the limitations of my workshop, I will most likely go with this setup.
If this works, I will have a large scale diff for about $15.

I found a piece of square tubing that will fit perfectly on this setup and cover the gears and the bolts.
The small gears can be attached to it somehow, I'm sure.

The tubing will cover the red area in the picture.

I reckon your onto a winner there mate.
You mention a tube covering the red area, could you use that to locate the bolt holding your small gears?

For sure.








I do believe I mentioned that in my previous post.....

Looking good!!!!



Ed

Dirty_Vinylpusher wrote:For sure.








I do believe I mentioned that in my previous post.....

Sorry mate, you said square tube i thought you were talking about crush tubes on the bolts.
The tube i was talking about was what i thought was a round tube large enough to encase the whole diff assembly.
I make silly mistakes sometimes, but thats life aint it

troppo wrote:
Sorry mate, you said square tube i thought you were talking about crush tubes on the bolts.
The tube i was talking about was what i thought was a round tube large enough to encase the whole diff assembly.
I make silly mistakes sometimes, but thats life aint it

Nah you're ok mate.
I see where you're coming from now.


So

The square tube I'm talking about will cover the whole assembly as highlighted red in the picture.
I can't use a round tube as it will get in the way of the bolts holding the two grinder halves together.
A square piece will allow the bolts to run all the way through, right in the corners of the tube.
It's a pretty tight setup with not much room to spare.


The small gears can then be mounted on/in this tube.

You could easily do a crush tube setup with a sheetmetal wrap around the body of the diff. If i understand what your saying the whole diff will rotate so a sheetmetal casing with the crush tubes will make it a bit tidier , and you could have the casing sealed but easily open-able for repairs.
Just thinking with my work brain (not easy at this time of night after a beer or several lol) .
I can see what your doing and its beautiful in its simplicity, but oh so bloody brilliant.
I dip me lid to ya

Ok here's some pictures to explain it a bit better.

Jesus, that could have been made for that, its a perfect fit. A bit of 75x75x2mm rhs, i woundnt have thought of it.
Great work, now you just need to sort mounts and axles and you have a complete dif assembly

Yeah it's a leftover piece of a colorbond fence post from a job I did a few years back.
Knew it would come in handy one day.

Starting to understand how this is all gonna work,
Main thing is to make it strong enough.

DVP: I'm really enjoying your project, keep up the good work.

Kevin

Thanks.
I enjoy tinkering.

If it works, it's a bonus!

awesome idea, I think it will do quite well.
Those grinders take a fair kick on startup too so I reckon it will hold up to almost anything.