Motorised sand sieve thoughts.....

[DAPPH]

I will think about making a pattern, shrinkage is not an issue , I will start with the original bit I have left and add some ply, body filler, paint, etc. maybe an outer magneto chain cover as well!
I have scrap alloy wheels and some other new BMW suspension uprights in what must be a good quality alloy.........................

View attachment 475175View attachment 475176View attachment 475177View attachment 475178

Warm the broken bits with a hot air gun spray with brake cleaner to fully degrease lightly wire brush the broken faces and degrease yet again . Super glue two bit at a time & set these glued up parts on plasticine supports to hold them in place as soon as you have super glued two parts accurately together let arts cure for 24 hrs. in a warm place then glue up these groups till you have the complete form to be cast again use plasticine to support things
slip it in a strong poly bag , then in a bigger back lightly packed with polystyrene beads Now slip it is a large glued 7 screwed wooden box on a bed of beads and back fill with loose beads to top of the box and screw the lid on well if you want to send it by carrier or post .
Rebuilding as above I have successfully cast glue repaired motor support brackets for an Acorn Major woodworking master machine ( circa 1953 ) Had to use a bit of " Plastic Padding " to fill in a missing bit and sand it down

 

[oldbikedavey]

Dave, I have successfully used a long handled fine plastic kitchen sieve bolted to a frame over a bucket with a small motor and an off center flange on the frame giving a lovely vibe & results so long as the casting sand is dry . I was able to drop a 10 kg bag of silver sand through it once I'd got it dry enough in about 40 minute when I made my initial casting medium.

Added ( Old food processor big chopping blade set 2 min per jug) wizzed up fullers earth cat litter to get a fine binding powder which was also sieved as above . I wetted the medium too much and it went sloppy had the ideas of then whizzing this & added a tablespoon of cheap talcum powder to a fine slightly damp slop which also got sieved .

Dropped it out onto a big tray and a couple of times a day rubbed it in my hands as it dried to get a very fine powder that set very nicely when the mould was dry . I didn't cast metal successfully as the wax forms I made died as they came out the latex moulds I'd made ..will be trying again in the new year . It's sat in two 3 gallon buckets out side undercover, has set very dry but crumbles to dust if rubbed hard /

The energy input required to process sand rises exponentially as it rapidly turns to a semi plastic state.
I'm sticking with the oil sand and 'fluffer' route , post mulling.
Greensand is not for me....

 

[oldbikedavey]

Warm the broken bits with a hot air gun spray with brake cleaner to fully degrease lightly wire brush the broken faces and degrease yet again . Super glue two bit at a time & set these glued up parts on plasticine supports to hold them in place as soon as you have super glued two parts accurately together let arts cure for 24 hrs. in a warm place then glue up these groups till you have the complete form to be cast again use plasticine to support things
slip it in a strong poly bag , then in a bigger back lightly packed with polystyrene beads Now slip it is a large glued 7 screwed wooden box on a bed of beads and back fill with loose beads to top of the box and screw the lid on well if you want to send it by carrier or post .
Rebuilding as above I have successfully cast glue repaired motor support brackets for an Acorn Major woodworking master machine ( circa 1953 ) Had to use a bit of " Plastic Padding " to fill in a missing bit and sand it down

He'll bring it over here by car, I'd reckon.....

 

[Matchless]

He'll bring it over here by car, I'd reckon.....

But not the 3 wheel one!

 

[Matchless]

Warm the broken bits with a hot air gun spray with brake cleaner to fully degrease lightly wire brush the broken faces and degrease yet again . Super glue two bit at a time & set these glued up parts on plasticine supports to hold them in place as soon as you have super glued two parts accurately together let arts cure for 24 hrs. in a warm place then glue up these groups till you have the complete form to be cast again use plasticine to support things
slip it in a strong poly bag , then in a bigger back lightly packed with polystyrene beads Now slip it is a large glued 7 screwed wooden box on a bed of beads and back fill with loose beads to top of the box and screw the lid on well if you want to send it by carrier or post .
Rebuilding as above I have successfully cast glue repaired motor support brackets for an Acorn Major woodworking master machine ( circa 1953 ) Had to use a bit of " Plastic Padding " to fill in a missing bit and sand it down

Main problem with that process is that the picture showed the only bit of the steering wheel that I have, would need a LOT of very super glue and a big bag of baking powder! the river kept the rest, and as it was pulled out 50 years ago I suspect I won't find it now.....

 

[gaz1]

Part of the situation is that the whole setup has to be extremely compact, and able to whizz through about 5 - 10 lbs of previously mulled and reconditioned oil sand in short order, and with excellent deployability.
The fluffer idea sounds very useful , and a variation upon a disintegrator arrangement....
It would work, but like all foundry stuff, it's a rare old learning curve...

if you want small

you will see theres more involved with it

 

[Erie Fred]

if you want small

you will see theres more involved with it

This is what I was suggesting using a Dewalt pad sander bolted firmly on top (or to one side)

The first 2 videos show a "Lab screener" we use one to grade shot blasting grit.

 

[oldbikedavey]

if you want small

you will see theres more involved with it

I'll be going down the 'fluffer-disintegrator ' route , I think.
There's a high energy requirement for disintegrating mildly friable plasticene....

 

[oldbikedavey]

Main problem with that process is that the picture showed the only bit of the steering wheel that I have, would need a LOT of very super glue and a big bag of baking powder! the river kept the rest, and as it was pulled out 50 years ago I suspect I won't find it now.....

View attachment 475539

That's going to be more fun than enough to make much sense of.
Then again , I do like a challenge....

 

[not done it yet]

Ask Noel Shelley on the model Engineering forum. He should/might be able to advise.