exxos's Atari, Amiga & retro forum

HigashiJun wrote: 25 Mar 2023 12:28 Is there a denser resin that would make a mouse ball having a weight close to a real mouse ball ?

I'm looking for options.

stephen_usher wrote: 25 Mar 2023 13:56

stephen_usher wrote: 25 Mar 2023 13:34 Resins are just plastics, they're not heavy. You have to have them contain something very dense inside. Some sort of self-curing latex may work, but I have no idea what, if anything, is available.

P.S. Have you tried cheap boucey balls and sanded off the moulding ridge? They are reasonably dense, very grippy and dead cheap.

I have some coming, we'll see how they do. The original ball was 100% some sort of resin or other dense plastic. If I can get the right density it could be fine.

Well, the original of that type of mouse ball never worked very well anyway. A bouncy ball would be far more grippy and probably better. ;-)

stephen_usher wrote: 25 Mar 2023 14:30 Well, the original of that type of mouse ball never worked very well anyway. A bouncy ball would be far more grippy and probably better. ;-)

I'll get back to you when it finally arrives from China...

You can get 20 delivered by Amazon next day for less than £20. (20mm bouncy balls.)

stephen_usher wrote: 25 Mar 2023 14:47 You can get 20 delivered by Amazon next day for less than £20. (20mm bouncy balls.)

GRRR. I followed a link earlier in thread and forgot to look on Amazon...

So, by way of experimentation, I made a ball from Milliput, an epoxy putty, to see what the weight difference was between that, Delrin, epoxy resin and the steel ball.


It's not round enough to use, but size-wise it does give an idea of weight, and it is twice that of the Delrin ball, so it may be suitable if I can mould it well enough.

However the steel ball is really the thing that has the weight of a real mouse ball, so I am still thinking whatever I end up making should really have a ball bearing inside it for weight.

Hopefully the mould I ordered will be here soon so I can do some more experimentation. I've also ordered a 15mm ball bearing for my experiments of putting balls inside other balls!

rubber_jonnie wrote: 28 Mar 2023 15:59 Hopefully the mould I ordered will be here soon so I can do some more experimentation. I've also ordered a 15mm ball bearing for my experiments of putting balls inside other balls!

You do talk an awful lot of balls, you know? ;)

Good luck with the suspending-ball-bearings, though. How are you thinking to do that?

BW

Badwolf wrote: 29 Mar 2023 10:00

rubber_jonnie wrote: 28 Mar 2023 15:59 Hopefully the mould I ordered will be here soon so I can do some more experimentation. I've also ordered a 15mm ball bearing for my experiments of putting balls inside other balls!

You do talk an awful lot of balls, you know? ;)

Good luck with the suspending-ball-bearings, though. How are you thinking to do that?

BW

:lol:

That is going to be the hard part...

First off I will try it once my plastic mould arrives, but I'm thinking I need to make some small standoffs, one at the bottom and 4 around the circumference that hold the ball in position and allow me to pour in something like the RTV silicone I used to make the original mould.

I have some ideas but will need to get my hands on the 15mm ball bearing first.

In addition to that, I'm I think I'm going to need to make a new hard mould for best results (I can use epoxy resin for that), as the soft one isn't going to cut it for this, and though the hard mould I have coming should be fine for some testing, I doubt the quality will be good enough for the final item.

Should be fun!

I bet there is more than 2mm of rubber coating on a 22mm mouse ball. If you could find some sort of automated mechanical sander that could take off 2mm of rubber that might be the best solution?