John W’s tool grinder

[Johnwa]

I initially started casting aluminum about 25 years ago, but haven’t done much in the last 10 years. With a few different threads discussing metal casting, I caught the bug again.

I need projects that are useful when done. Otherwise I lose interest and end up with something half finished. I have plenty of those already. I think a cutter grinder would be both useful and a challenging project. There are lots of resources for the Quorn T&C grinder on the internet so that is what it is going to be.

Other than the original book there is one resource that needs mentioning. There are “modern” detailed drawings available on the Onshape page. Onshape is an online CAD program with both free and paid options. With the free option your drawings end up in a public area where they can be freely downloaded as “STEP” files. I found a number of drawings of the Quorn and have downloaded those by Toni Ionescu. These are “assemblies” so once loaded into Fusion 360 it is possible to view it part by part and see how they fit together.

I redrew some of the parts to make them more suitable to my casting and machining abilities.

John

 

[Johnwa]

The attached picture is the castings so far. Patterns for A&B were made the traditional way using wood and bondo for a filler. They took lots and lots of sanding. The other patterns were 3D printed and only required a bit of post processing.

 

[Johnwa]

This picture is a closeup of the rocking lever casting. I used a 3D printed pattern with no attempt at post processing. It didn’t pull cleanly from the sand but otherwise was fine.

 

[Johnwa]

Here’s a pic of a failed casting.

 

[Gennady]

You have whole lot of cleaning for those parts!

 

[PeterT]

Good progress John
What are you using for for aluminum stock to melt?
For the (I assume) direct 3DP burnout like part F, what is its thickest dimension like over the hub?

I'm doing similar 3DP filling & priming (for a different purpose). These are tiny parts so kind of a PITA. Its kind of like micro auto-body work. But I am actually quite impressed with how spot filler & primer adhere to the PLA. A lot faster than making shapes the classic way.

 

[Dan Dubeau]

Looking forward to seeing this come together John. I've long wanted to do a similar project.

What did you use for a core in that bottom failed casting?

I had similar results from 3d printed patterns straight from the printer bed. Pretty rough around the edges, but otherwise fine for quick one off parts not needing high finish or perfect results. Very quick from cad to casting with little work too. Of course, some smoothing and secondary finishing of the printed patterns can yield much better results where needed.

 

[Johnwa]

Peter
I have a large stash of aluminum. Most of it is is from Toyota transmission cases. Factory castings are the correct alloy and don’t require any additives like silicon or copper.
I used the prints like normal wood patterns so no burn out. The molds are rammed green sand. The thickest portion of part F is ½”. With the exception of the end piece the rest is ¼” thick.

John

 

[Johnwa]

Dan
I used thin wall aluminum tubing filled with sand for cores. The tubing will end up being bored out.

John

 

[Dan Dubeau]

Dan
I used thin wall aluminum tubing filled with sand for cores. The tubing will end up being bored out.

John

Thanks, That's what it looked like, but wasn't sure if it was steel or not.

 

[jorogi]

Dan
I used thin wall aluminum tubing filled with sand for cores. The tubing will end up being bored out.

John

Dang that's clever.

 

[Gennady]

John. How is that aluminum tubing did not melted while liquid aluminum was flowing in ?

 

[Susquatch]

With a few different threads discussing metal casting, I caught the bug again.

Holy Crap John! Now that's a PROJECT!

Can't wait to see the final product.

I'm very jealous of your talents!

 

[Mcgyver]

Good stuff John .... Deepest respect for a project that starts with you own castings!