Need some turning done please......

[Beerbotboffin]

I'm currently building a Gingery metal lathe, and need a timber pattern turned for the pulleys.

Problem: I don't currently have a wood lathe.

Would anybody in the Brisbane area be able to help me out?

As far as payment goes, i can only offer fame and undying thanks.

Cheers for looking.

[bitingmidge]

Beerbot,

Don't misinterpret this as an offer :rolleyes: , but if you have no luck closer give me a hoy, and I'll see what (or even whether) I can do! I guess I have to do it someday, I'll haul out the book and have a look at what's required.

I've seen a few guys take cheap pressed metal versions as moulds, but haven't got that far in my thought process yet.

Actually I haven't got further than thinking it wouldn't be a bad idea.....

I assume you'll carefully document the process here somewhere eh?

Cheers,

P
:D

[bitingmidge]

Hmmmm.... I've checked.

One 6" pulley, One 3,4,5" stepped pulley, but no other detail.

Better scan the web for more info!

P
:D :D :D

[Schtoo]

If you get really stuck, rig up something that will spin some foam you can 'sand' into pulleys. Add sprue then coat with thinned plaster or even better, wall topping compound.

Jam the mess into a bucket full of loose sand, take an old tin can with a sprue sized hole in the bottom and stick it over the sprue as a head.

Pour.

Wait 30 minutes.

Pull it out of the sand, hose it off.

Cut off sprue, clean up pulley and it's done.


It might end up a little gassy, but provided you make a good foam pattern, it shouldn't need very much clean up and the casting should be sound.

Or get some wooden ones made up. At least one of the guys here has done it, and it will get the lathe running, letting you make better patterns later on.

(BTW, while you are still casting, you might want to look into a quick change tool post. One design is dead easy and could easily use some cast ally tool holders. Let me know if you need a link to that design.)

[bitingmidge]

(BTW, while you are still casting, you might want to look into a quick change tool post. One design is dead easy and could easily use some cast ally tool holders. Let me know if you need a link to that design.)

Yes!

Beerbot, here's another pulley pattern idead
http://www.backyardmetalcasting.com/castingpulleys1.html

Cheers,

P

[Schtoo]

Midge, here's (http://www.aardvark.co.nz/pjet/qctp.shtml) one version of it. Not the place I found the idea, but I didn't bookmark where I found it first.

No need to get so technical as this one, a steel post that threads onto a hefty stud would work quite well too I am sure.

[Beerbotboffin]

Thanks all for links & advice. Have pretty much committed to a 2 part wooden pattern, don't want to use lost foam (though I do have heaps of foam and my own foam cutter).

The problem is that I'm not using green sand, but "petrobond". Petrobond is an oil bonded sand, gives an EXCELENT surface finish (not as good as an investment casting, but next best). As a result, petrobond is no where near as easy to use with lost foam, ans I am a little concerned about porosity from the foam.

[bitingmidge]

Thanks for the link Schtoo! I had seen it before, and didn't quite understand what it was for, I think I do now, so either I've learned a bit or I'm hallucinating more than usual!

Beerbot, where did you get the petrobond in Bris?

Cheers,

P

[Beerbotboffin]

I got the ptrobond from Cast Metal Services in Brissy.

Their address is 275 Toombul Rd Northgate. (07) 3266 6266. I don;t think they have a web site.

They are over near the airport, and I spoke to Barrie, who was extremely helpful.

They sell either the constituant components (which are HORRENDOUSLY expensive), or in a 25L bucket, pre-mixed for about $80. I think (from memory) if you buy the powder alone, it's about $400, which while it makes about a tonne of sand, is pretty hefty.

To give you some idea, I used about half a bucket to do the lathe bed, so if you get the premixed version, you should be able to knock up some hefty castings with it.

Hope that helps.