flat belt pulley pattern - Printable Version

flat belt pulley pattern - Printable Version

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RE: flat belt pulley pattern - oldgoaly - 09-04-2013

DA,
do you have a junkyard nearby? about 15" wide conveyer sections, from the mold bench to the pour spot, takes a little rigging. I've tried this, I need a few more sections or move closer together, easier to wait til the boy is home. Sorry I would not be much help, I'll bet there are some old engine guys in you area that might help! WD had a buddy in OKC???? can't remember his name. Good luck just take it easy no need to make another trip to the doc.

RE: flat belt pulley pattern - dallen - 09-04-2013

(09-04-2013, 08:58 AM)Mayhem Wrote: I was wondering if it may have been an option given you don't have the capacity to pour that much cast iron in one pour.

I can melt that much and pour it, but I only have one crucible that will hold enough to do it in Cast Iron and I don't want to melt iron in it right now cause then it will only be good for iron.

RE: flat belt pulley pattern - dallen - 09-04-2013

(09-04-2013, 10:24 AM)oldgoaly Wrote: DA,
do you have a junkyard nearby? about 15" wide conveyer sections, from the mold bench to the pour spot, takes a little rigging. I've tried this, I need a few more sections or move closer together, easier to wait til the boy is home. Sorry I would not be much help, I'll bet there are some old engine guys in you area that might help! WD had a buddy in OKC???? can't remember his name. Good luck just take it easy no need to make another trip to the doc.

moving the thing about isn't the problem as most of my stuff is close so I can ram it up on the pouring bench and will just have to carry the sand in a bucket about 15 feet so the heavy part will always be on the bench.

as far as pouring it in iron once I know how to gate it so I can get a full pour and all that, then I know a guy that has a tilting furnace and for a bottle of propane I bet I can talk him into doing the melt for me. Plus I think he's got some stuff for resin bonding sand which means that I could get a mold that won't tear when removing the pattern

DA

RE: flat belt pulley pattern - oldgoaly - 09-04-2013

I would think the way to go is the spure in the center of the hub of your pattern. Tilt furnace has some advantages, I have a 30lb clay-graphite crucible to melt scrap into ingots and a tilt furnace was an plan, but the pot furnace kind of slowed that idea.

RE: flat belt pulley pattern - dallen - 09-04-2013

Goaly

either way I turn the pattern if I pour down the middle there will be a 4 inch free fall inside the mold because of the hub, and any way you look at doing it that way is wrong with this part.

I've given the thought of gating it in the middle with a horn gate and letting it fill from the bottom which will keep it from washing out any of the sand. I've also given thoughts turning the thing so that the outside is down and gating into the rim it three places. with some risers at the gates.

there's just so many damn ways to go at it, and not all of them are going to work. plus this thing is going to have to be poured cold in the 1200 degree range I would think.

I've been giving the up thru the bottom with a horn gate some really hard thoughts that way I only have one gate with one riser dead center over the part that will be doing the shrinking.

DA

RE: flat belt pulley pattern - oldgoaly - 09-04-2013

a bunch of ways of pouring it, but when your are close to the limit of the batch, the part as the gating is the most efficient use, center pour 6-8 small risers on the outer hub? would be nice to see how the oldtimer's did it. hmmm wonder if there isn't some sketches in some of the old foundry books??? If I wasn't playing with drill bits and derusting /priming /painting, ahhh the smells of molasses fermenting / chelating, oxalic acid, phosphoric acid. Not to mention purple cleaners and primer smells. all smell better than the dead mouse hiding somewhere in my welding area!

RE: flat belt pulley pattern - Rickabilly - 09-04-2013

Of course the big difference with gating Iron and Ally with reference to either gating into the hub from underneath or just pouring straight in through the top is that the sand floats very well in the Iron, which means the longer your runners the more chance you've got of picking up sand and of course the iron cooling on it's way in through the long path, while pouring in through a central riser sounds like it will break up the bottom of the mould this can be averted by fitting a solid ceramic/graphite plate at the bottom of the hub so that the sand doesn't erode in the initial part of the pour, keeping in mind that whether you pour into the centre or into a horn for an under feed the metal still has to drop a long way onto sand in the early part of the pour, when we did track wheels at the Steelworks foundry it was straight down the middle, with a well at the bottom and the ceramic plate to prevent breakup of the sand, we also used a crane to pour as we were talking about 100 Kg final component mass, so 150-200 Kg pours at least, so well out of hand pouring range.

I was looking at the last photos of the pattern and I realised that beyond the Alloy wheel comments from before, it looks a lot like a nut bowl that my Gran used to use at Christmas, where each section had a different type of nut or Sweet in it, so do try to keep it clean and you've got a very usable nut bowl for when we all come around

Regards
Rick

RE: flat belt pulley pattern - dallen - 09-04-2013

did a little research today and found out that my A20 crucible will hold enough metal to pour the pattern with, I may have to have a smaller crucible standing by to finish filling the riser but I will just have to wait till it happens to find out anyway whats in the bucket is twenty pounds of aluminum.

and just to scratch an itch that I had as to the age old question will it come out of the sand after molding so I rammed up the outside have in a cheek that I have for one of my wooden flask.
what you see tore up around what looks like a core print is where I forgot to remove a part from the pattern that I had been using to hold it with in the lathe.

one problem with the graphite plate is I don't have one

RE: flat belt pulley pattern - Rickabilly - 09-05-2013

It would need some experimentation but maybe a vermiculite tile? I'm ad libbing now and have no idea as to the strengths or weaknesses of vermiculite as a mould component, it looks a lot like the "Ceramic plates" we used to use, but might be a whole different material, I know it is used in "Gunnable" refractory linings in liquid steel transfer tun-dishes and ladles, but on it's own?... the good thing about vermiculite is that the tiles are cheap and easy to get for the lining of combustion stoves, I bought ten tiles 6" x 12" x 1" for about £10 on Evil Bay for my little LPG furnace, The big question would be moisture and thermal expansion , but it might be a good thing to find out, as no doubt, this issue will come up again.

Regards
Rick

RE: flat belt pulley pattern - dallen - 09-05-2013

todays slave labor in the heat of the shed first up is the one and only
Shop Monster my sidekick

Second is one half of the flask that this thing will be poured in. yep its full of sand

Third is where I rammed up the inner half of the pattern

I ended up with a couple of small tears but I don't know if thats because of me or the sand not being rammed up as hard as it should of been, its in one heck of a place to ram just have to keep trying till I figure out if its me or the foundry gods messing with me.

there were a couple of other spots but they were tiny and I can live with them.

DA