we are going to be pouring these cases out of A356.1 and a T6 heat treat but we do pour almag from time to time, might cast a few and see how they hold up and compare the weight.
could be done, but the case would have to be flipped 90° from the one im making now and half would be in the drag(bottom) and half in the cope(top). Problem with running a clean casting in the cope is all the gas and impurities rise to the top so it might be hard to get polished castings from it.
I have always wanted to learn how to do sandcasting just never had the time. You do some grate work I can't wait to see it done....
this is a great thread, i just started my new blower motor project, i am hooked thanks for all the info and great pics.
I did foundry stuff back in high school and loved it. I still have trivets and stuff i made, thing about doing it was nobody would come around to mess with you while you were working 'cause everything was heavy and you could beat then withit it or molten aluminum and when i had the thing full of molten aluminum everybody disappeared. This is a great thread, it is reassuring to see American pride and profesionalism - the attention to detail, precision and how durable the mold must be. Just looking at it and you know that it must be right. Thanks for keeping us involved in this project.
No kidding! That's neet that you have access to the 3D printer and the CNC. I have to make all of my patterns by hand. I sure would like to hook-up with someone local who has access to a 3D printer and do a couple of projects...
You could probably find one somewhere, i know a lot of the retailers that sell the high end printers also offer services to print, there are also company's that offer services to 3D scan parts. To print you just need a model of what it is you want.
Day 14: Tuff filling the seam lines of the pattern ----------------------------------------------------------------------- precision drawn riser blueprint ------------------------------------------------------------------------ to scale riser layout ------------------------------------------------------------------------ Riser pads cut and drafted 7°, out of mahogany -------------------------------------------------------------------- Grinding the risers -------------------------------------------------------------------- risers line up ---------------------------------------------------------------------- Risers layed out on the pattern, these will be squeezed in the mold then lifted from the top before the pattern is taken out of the mold. ------------------------------------------------------------------------- The pads will be mounted onto the pattern with positive draft, the risers are drafted to pull from the top of the mold.
I have a low-tech 6-71 blower manifold for SBC. You can probably use the same idea with the 4-71, is to take an aluminum carb manifold, and weld a blower base plate to it. Would be fine for street use. I saw a 3-71 blower setup for a dodge baby hemi at Bakersfield a few years ago. It used a hot-heads manifold and the center was machined out and a mounting bracket welded on. Just an idea.
Day 15: Spot gluing the pads to the risers so they will all be drilled equally, you can also see the center lines and drill lines marked with a thumb gauge and razor. ----------------------------------------------------------------------- Drilling 1/4" holes through the pads and risers, all 1/2" from the outsides so that ever riser will fit every other pad when molded. --------------------------------------------------------------------- you can see the center-line and drill line marked on the pads with a thumb gauge and razor. ----------------------------------------------------------------------- all done, now just break the pads off the risers ------------------------------------------------------------------------- Cut and ground 1/4"-2" dow pins to locate the pads to the plate and for the risers to fit. ------------------------------------------------------------------------ The risers are re drilled with a 5/16" drill allowing a 0.0625(1/8") tolerance of the diameter, or 0.03125(1/16") radius tolerance from the pins, allowing each riser to be interchangeable to any pad. ------------------------------------------------------------------------- Pads glued down and ready to drill the plate to fix the pins.(just stuck them in the pads to take the picture for now) ------------------------------------------------------------------------- You can see that the riser is allowed to rock a little bit from the tolerance drilled out earlier.
well hopefully by the end of what i talk about in this video, you will be able to. <iframe width="560" height="315" src="http://www.youtube.com/embed/cJ20Yoq5LNY" frameborder="0" allowfullscreen></iframe>
lol most the stuff i use you can build, smaller scale, but it still works. ill be building and videoing it all, CNC router, mold squeezer, 3D scanners, anything needed.
so if you were going to cast an intake it would be designed to pour upside down, you would do that so you have a way of supporting the cores, i'm thinking of a 3X2 for my low deck Desoto, dual plane and a water crossover.
Wow! You've put an amazing amount of time and energy into the videos... and I really did your bubble venn diagram! I do have a question about the blower design... mainly about the outer look of it. The two big ribs at either end look clunky... not really shapely or pleasing to the eye. Is there a reason for this? Did you simulate the blower running, and was there a need for that extra material for support of the ends of the rotors? Also, how is this thing going to bolt on to a manifold? It seems the lip is a little small to use the traditional style bolting method... but then again, I'm no expert, I'm just going by what I've seen on traditional blowers. (and please forgive me if you've already mentioned these things...) Sam
We actually cast in the drag(bottom) not so much for ease, but aluminum is always better quality when you cast in the drag, all of the oxides and impurities will float to the top of the casting and it is always better to have a high quality casting in the drag. Also makes it less likely to have porosity, which means we will have more castings that are able to be polished. Im actually making a video right now about cores and quality, its about 5min long right now and i talk about the design of the blower core, im waiting till i video making the molds and casting the blower before i post it online tho.
the extra material is actually all machine stock, we made it this way so that we only have to make a pattern and corebox for one casting, but we can take that casting and machine it to full round, half round, or what ever type of plate we want for it. The lips are a bit small, just how it turned out by my design, i tried to make them as wide as i could, we aren't to worried about it, when we spot face the bolt holes it might cut into the sides a bit but that is caused more by the nature of casting green sand and its tolerance more than the design. Green sand castings have a tolerance of around ±0.03, which means that when we fixture the casting on our CNC it 'can' be out by 0.03, 'if we locate off a cast surface', but we usually like to machine top and side faces perfectly 90° in one operation, then refixture the casting on a machined face, then located off of the other 90° faces for any precision machining (like boring ) which results in a perfectly accurate machining of multiple faces but the casting can be off a bit from the machining.(well accurate to 0.0001-0.001 depending on how accurate we want it) shrink also comes it to play with that and is extremely hard to calculate accurately without some expensive software. aluminum will shrink anywhere from 0.005-0.013 per inch, just depends on the mold, metal temperature and casting. 0.0013 doesn't sound like a lot but for a 16" blower casting, it can shrink up to 5/32
also, i was talking to my dad earlier in the week, my next pattern will be a half round front bearing plate for our 671 that will be extended an 1" so that you can bolt it onto any 671 and run 871 rotors, cheaper way to have an 871 if you already have a 671 case
day 18: Was told today that the flask should be in tomorrow, depending on if it comes in early in the day or late, ill have castings by tomorrow or wed. --------------------------------------------------------------------------- Here is the CNC we will be machined and boring the cases on, 92' mazak 6 pallet 4th axis ----------------------------------------------------------------------- Counter sinking screw holes ---------------------------------------------------------------------- hand tapping screw holes ---------------------------------------------------------------------- a precision blended Crisco and aluminum shaving tap and die lubricant ---------------------------------------------------------------------- drilling out the holes for the riser dow pins --------------------------------------------------------------------- pins are all pressed in, we actually put them on a lathe and filed them down a few thousands because they where pressing in a bit hard -------------------------------------------------------------------- Start of the gating system, ground down to the 3° on the core print ---------------------------------------------------------------------- Sides are drafted from 1.5° from bottom, bottom width is 2" ----------------------------------------------------------------------- Blocks lined up --------------------------------------------------------------------- Blocks cut and ground to fit ----------------------------------------------------------------------- top view of the draft --------------------------------------------------------------------- ground down to allow the metal to flow smoothly -------------------------------------------------------------------- runner bar and basin cut and shaped with 5° draft ---------------------------------------------------------------------- drilled out and screwed down
My father was a wood pattern maker at Chevrolet engine plant in Tonawanda for 20 years. They made the big blocks that carry the "Tonawanda" stickers on the valve covers. He had some work on the side and i would help him with mahogany patterns for punch tooling. Reading your posts bring back memories of working with him. Thanks!
Day 19: Flask and jackets came in today, completely done mounting the drag gating, all i have to do tomorrow is spot-fill some spots with tough fill tomorrow and paint, then taking it over to our foundry to cut the squeezer board, drill the flask pins and mount the down sprue pins. ------------------------------------------------------------------------ 20x30" jackets, will be slipped over the mold before pouring to keep the cope and drag together and also to prevent from the hydraulic pressure of the molten metal from bursting out the sides of the mold. ------------------------------------------------------------------------- 20x30" flask, this is what the pattern will be sat in, filled with sand then squeezed together to form and pack the mold. -------------------------------------------------------------------------- screwing down the rest of the gating ----------------------------------------------------------------------- Tough filling the holes ---------------------------------------------------------------------- tough filling the runner bar so that there is a wide fillet so the metal will flow smoother, you never want sharp edges in any section of your gating or part, also increases strength of the mold and casting. ---------------------------------------------------------------------- 1/8" leather fillet strip, glued down to give a radius on the parting line when molded. ---------------------------------------------------------------------- Laying down fillet ------------------------------------------------------------------------ filleting up and around the gating ------------------------------------------------------------------------ screwed up and misread the drawing for the drag basin, chiseled out the tough fill, reground to 1 1/2" ------------------------------------------------------------------------ 1/16" aluminum plate, the filter will be set right here. ----------------------------------------------------------------------- little trick of the trade, put some paper towel or clay in before you tough fill, makes it easier to cut out if needed. ------------------------------------------------------------------------ retoughed filled and sanding ----------------------------------------------------------------------- 1/16" plates are even filleted for draft clearance when molded. ------------------------------------------------------------------------ spot super glued the fillets that connect together to help hold them down and to fill in some gaps, will be touched up tomorrow with tough fill. ------------------------------------------------------------------------ Needs one more sanding and a few touch ups then painted
Day 20: Took the pattern over to the foundry today, setting up the cope(top) side of the pattern and getting the flask pin holes drilled out, should be ready to mold and cast tomorrow. Ill have more photos up of today later on. --------------------------------------------------------------------- haulin' flask ----------------------------------------------------------------------- Tough filling the corners of the leather fillets before painting --------------------------------------------------------------------- Drag(bottom) side of the pattern Painted and ready to go ---------------------------------------------------------------------- Taking the pattern over to the foundry ---------------------------------------------------------------------- Bringing some wood along too ------------------------------------------------------------------------- Place where we prep all of our patterns, this is the same place where i build the corebox and pattern in my other video of the hammer. ----------------------------------------------------------------------- Leather filleting the cope(top) side of the pattern ---------------------------------------------------------------------- done ------------------------------------------------------------------------ Our 70 ton sand hopper for our green sand lines. ----------------------------------------------------------------------- Line 3 of our molding stations, this is where we will start out making the blower molds, the pattern will be hand drawn by 2 people for now. --------------------------------------------------------------------- If production increases on the blowers though the pattern will be ran on line 4, which will all be lifted and moved by a machine, allowing only one person to make the mold. ----------------------------------------------------------------------- four 2000 pound furnaces filled with 1400°F molten aluminum. we also have an overhead crane that lifts a 3000lb tilter to refill our furnaces for when we run extreme high production. ------------------------------------------------------------------------ Pouring deck, the molds are placed on pallets and pushed across the deck for the deck guys to pour the metal, temperatures can reach up to 120°F in the summer time here. ------------------------------------------------------------------------ These are our tilts that drop the molds and castings into the shakeout trough, the pallets slide underneath the deck and roll make to the molding stations(not a fun jobs to fix if you screw up and get one stuck under the deck ). The castings are pulled out of the sand and the sand runs down the trough and up a conveyor belt to the top of the 70 hopper, and the process repeats.
Day 20.2: end of the day photos for day 20. If everything works out correctly, I should have a casting in my hand tomorrow . ------------------------------------------------------------------------- Intake adapter plate sitting on top of the blower pattern(its sitting on the pins about 2" off the plate, that is why it looks off) -------------------------------------------------------------------------- Mounted the adapter plate to the pattern board. ------------------------------------------------------------------------- Red pattern paint for the Risers and pattern cope(top) ------------------------------------------------------------------------- Making more cores, hollowing them out with a die grinder, this makes it easier to break up the cores in knockout ---------------------------------------------------------------------- How not to hollow out a core ----------------------------------------------------------------------- Glued together and ready to be placed in the mold.
Day 21: well i was put on hold today for molding the blower, we have to run another job that needs to get done. Will be molding tomorrow, good news though that the intake adapter plate pattern will be ready to mold tomorrow too. -------------------------------------------------------------------------- Our pattern for our 100 series grenade shift knobs i saw sitting on a rack, figured id take a picture of it, you can check those out at http://www.diamondp.com/category_s/128.htm ------------------------------------------------------------------------- cope basin drilled and screwed down, pin for the down sprue through it. ------------------------------------------------------------------------- Outline of the flask, you can also see a hole punched and the bottom of the picture for the flask pin hole location ----------------------------------------------------------------------- punched location for the flask pin hole -------------------------------------------------------------------------- Laying out the mold buttons(used to locate and hold the mold in place -------------------------------------------------------------------- Setting the pattern up on the press --------------------------------------------------------------------- centering the cutter for the flask pin holes ----------------------------------------------------------------------- Flask pin holes cut out ------------------------------------------------------------------------ Pattern button, and the cutter used to make the opposite indention in the plate. ----------------------------------------------------------------------- Cutting the indention of the buttons, the buttons will be mounted on the other side of the pattern ------------------------------------------------------------------------- buttons mounted, flask pin holes cut, down sprue basins mounted, only a few more things to do ------------------------------------------------------------------------ Intake adapter mounted with gating ----------------------------------------------------------------------- Cope ----------------------------------------------------------------------- Leather Fillets all done ---------------------------------------------------------------------- Pattern sat down on the flask drag(bottom) ---------------------------------------------------------------------- Cope(top) sat down on the pattern --------------------------------------------------------------------- These are the flask pins i was talking about, they are the guides for pulling the cope and pattern off the drag, this prevents the molder from tilting the mold, there is still room for human error, but this greatly reduces it
WOW. Thanks for spending the time to write this up. very nice work. Youtube is full of Joe Dirt videos on casting, not that there is anything wrong with that, but its very cool to see how the contemporary seasoned pros do it. What is your glue for the sand cores?
The Jalopy Journal
