Can gears be cast ......tooth and all it is a 4p gear Wich gives a depth of 1/2 inch .width of apaxamently 5/16 at the pitch line Width of the gear is 1 1/2 in 11 in diameter ....see rough scratch... Thanks Todd
My 1920's drillpress has some cast iron gears. You can see that the teeth were cast and not machined. Pretty rough surface finish though. So it was done in the past but i wont expect a lot of precision. The cast gears on my drillpress are at the height adjustment of the table so no high precision application. I think it could be difficult to pull the pattern without ripping off some theeth from the sand mould. Tim
yes what you are asking is possible Chapter 4 of the USN Pattern maker 1&C gives detailed instructions on making the patterns https://books.google.com/books/about/Patternmaker_1_C.html?id=yc64O50UGbsC keep in mind it is very common for gears to be cast, and then get a surface cut on the gear surfaces, and the hole to be reamed and a key way cut V/r HT1
Thank you Alot of math but it works ....the hard board was on the ends to stop spintering It comes out of the sand see how it pours when we get warmer then 8 below lol They do go round on shafts bolted on the mill at the right centers ........see what the shrinkage does Todd
Here is a link to a thread from a couple years back. Several people attempting several ways of printing a smaller diam 5DP gear. You will need a day and a half to get through the thread. http://forums.thehomefoundry.org/index.php?threads/casting-a-windmill-gear-in-grey-iron.533/ Most successful was to split the pattern and include both draft and machine allowance on the teeth. Then I clean up the tooth profile on the mill. That being said, here is a pic of a 5dp gear that was cast from an original loose piece casting. I bought this from someone that had a few poured. I think he has his parts poured at Tomahawk Foundry in Rice lake. Wi. Excuse the clutter, its cold in the shop so I just took a quick pic. I also have a smaller 16 tooth gear laying around someplace.
Sooooo now where to put the runs Between the spokes and in to the hub .... Or pour threw the feet with a ring
A little late on this. The gear I posted a pic of had a riser right up the center ... I believe they poured directly in the riser. I do not remember noticing any other gating that had been cut off.
older gears and siniliar items where often horn gated, so metal came in from the bottom then had a riser off the top, it's a good technique if done well, but it is tricky to do V/r HT1 P.S. I did something with a horn and posted a build over on AA ages ago might stll be there and ok???
3 stupids ? 1 was a short pour Calculated 24 Lb melted 27 ....not enough machinist hand book pattern weight X16 not this time Weighted it down with plywood ...could not vent through sand ? And no vents at all forgot to put top of horn in..now would the plywood coving 2/3 of the box cause the lack of fill in the theeth when the foot / higher than the gear filled? Causing a cold shunt from air lock? The bad spot is on either side off the foot 180 degrees from the sprue Let me know if I'm on the right track or way off Next time I'll use a bigger crusible Thanks Todd
Getting frustrated lol For some unseen reason I cannot pull the bottom of clean anymore put more angle on it tonight hope that helps Funny thing is I thought that would be the easy split ...not the rest of it comes out nice and clean do have to flip the middle box and top together or it collapses but can lift the top off fine when the bottom and middle are back together ..... Cheak box I think is the term I put dowels through the bottom box tonight Try tomorrow see what happens
Have the box fixed . ..twisting a bit Now as I hope you can see ...the feet have blow holes under them .or it was feeding from them The spokes in 2 places are thin And still sucked the sprue dry ....blow hole in the hub...... Put a feed in the top .....not so easy sand is thin now.....more of a rad at the feet ...... possible And totally do not get the missing teeth .... Any help would be appreciate Thanks Todd thin
Well the Pinion Gear works little shrink next pair I'll put a e feeder on the other side of the horn... HT1.....is that like the horn gate.
Messy but bit of grinding can make it work .....37 lb Put feeders in the top will move them for the rest Thanks for the help Todd
Thank you all for the help Turn nice ....a little noisy.but I'll grin d a bit more and that should fix that
