I guess this is where I should put these pictures as I was going to put em in the my molding bench but I lost all that I had typed so heres the pictures of the fan blade that I casted today same blade as before just a better casting, not perfect just better.
Two things I know one the back side wasn't rammed up like it should of been, two the melt was on the cold side, or I was using too thick of a flask, I need to cut me off a could pieces of that 8 inch pipe and square it up in on the lathe and weld on some handles and pins for something like this insead of using one thats four inches deep, thats a lot of sand to ram up, and I don't have an air compressor big enough too use a air hammer with a large tamper foot.
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
I moved this over here at Harry's suggestion so that it would be easier for people to locate.
I plan on continuing to cast this blade actually I will probably take the one off the milling machine that I received from a guy in texas that he said he didn't need anymore since he had put a 3 Phase motor and VFD on his milling machine.
For those that haven't cought the first part of my attempts to cast this fan blade, let me bring you up to speed on it. Its the plastic cooling fan off of the 2HP motor on my milling machine, it cracked and started rattling around and I took it off and tossed it on the bench and sorta put it out of mind till one of the guys on the Dovetail Column Mill Group on Yahoo that I belong to said his did the same thing, and wanted to know where he could get one.
Well in my infinite wisdom I mouthed and said that it would make a good casting project. Well I will say that I learned to not mouth off till after I try to cast something next time. My first couple of attempts are posted around somewhere the first was a dismall failure, the second not much better. The first was molded with greensand that had been mixed by hand, the second was mixed with greensand that had been run through my muller after I got it to the point that I could smash and mash sand in it this was before I was able to install the wheel to blend oil bonded sand with.
This last attemp was moulded with oil bonded sand, one of the major problems was that I didn't ram the backside of the mold hard enough it was full of holes in the sand. and I think that I should of used a wire to vent all of the blades even thou I had almost 100% fill on them in this pour.
I will try to cast this again maybe in the morning but by the weekend for sure. Hopefully I will get some of the stickyness out of the clay that is in the sand that I mixed night before last due to the flask pattern that I have been working on trying to get the last two parts casted was using up all the sand that I had mixed and with my spillage rate I was aware of the possiblity of not having enough to fill the flask.
Anyway in the next day or two I should hopefully try this casting again, please feel free to offer comments or suggestions on how to cast this part.
DAvid
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
Could you fill the back of the fan with bondo (after putting some oil on it so you can get it out again) it make a hard backing for it so it can be rammed up a little harder? I think making a small hole to vent the fins would be a good idea.
I like to build "Stuff" using Stuff that costs Stuff All!
yes that would help cause if you look real good at it you can see where it has been crasked all the way into the center hole. and that first pictures shows where it didn't ram up very good on that side.
My thinking on the vent wire is that two of the blades didn't fill completely.
But I also only used a 3/8 Sprue hole I wanted it to stay full. I didn't notice any shrink tears in it any where. But I do need to make a stub fit the shaft area so it will cast a shaft onto the blade when I pour it, for someplace to chuck up on if I get a good pour.
I am looking at maybe using one off of a 40HP motor for a pattern to make a burner blower with so this is a teaching experiance, the housing is no problem in a couple of the books I have it explains how to lay out the scrolls for the housing, But making a fan pattern from Scratch is a little beyound my carpenter skills, and why do that when we have prefectly good patterns in the plastic ones already available to use on the back end of motors.
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
Nudge wrote:Could you fill the back of the fan with bondo (after putting some oil on it so you can get it out again) it make a hard backing for it so it can be rammed up a little harder? I think making a small hole to vent the fins would be a good idea.
That would be a follower, its also a great idea for something like this for both holding a fragile object in shape while ramming the first side but also for making it much easier to ram the second half of the flask because you just remove the follower and if you have made it right the coping down is done.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun... Muller
yes I need to try and do the bondo thing as the one reason for using the plastic blade is so I don't have to build a pattern, and the amount of shrinkage will be minor on the thickness of the fan blades. but it will take a bit of bondo to fill the back side with, Plaster o Paris is a more likely canditate.
Bondo isn't cheap any more to many mexican body shops around driving the price of body working supplies up.
I hope to redo the pour on the blade before the weekend is over with, I was able to get a good and final pour on the eighth side plate for the flask, so work will continue on that little project now, I have finally decided to instead of using Angle to make a pattern and pour the parts for the alignment pin holders.
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
I know what you mean
cut a block of wood to take up most of the room, put the filler or plaster in the back of the fan then push the wood into it.
Well I got the fan blade to fill completely this morning, I rammed the blade up last night after retaping the crack that was in it where it had split, the casting is rough from I guess the sand, I screened the sand thru a 3/16 inch screen that I had from way back when I made a cooling tray for my coffee roasting gig.
after pulling the blade I vented thru the blade to the top of the mold, the sand helt up very well I did this last night and let the mold sit all night as I got too dark to mess with hot molten metal.
Please feel free to tell me that I did a not so good of a job but that I am getting closer.
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
looks muuuch better ...a few small spots at the very end of a couple blades didnt fill quite right it looks like, perhaps a little more head pressure. Otherwise, I think your ready to machine that bad boy and put it to work in a blower...
"Simplicity is the ultimate sophistication"
-Leonardo Di Vinci
"The future's uncertain and the end is always near...."
-Jim Morrison
...a few small spots at the very end of a couple blades didnt fill quite right it looks like, perhaps a little more head pressure. Otherwise, I think your ready to machine that bad boy and put it to work in a blower...
