[LeeWay]

Now that I might even come in on. I have a round column type mill that takes up space. Light rust everywhere due to a fire. Otherwise brand new Chinese machine. Clarification. It was not the heat of the fire that cause the rust. It was mainly the fire ext. I used and then had a bit of water added by the FD.

[engnerdan]

Dan,
If you're serious about this, please let me know, I'm very interested! Also, we might consider a new column casting or polymer concrete filled steel column. I can't believe how much flex there is in the column. I'm getting .002" in either Z+ or Z- directions just with hand pressure. I've checked torque on all the column bolts, and everything is tight.

Cheers,
Josh

My professor was out sick tonight so I had a little time while "watching" the video the sub put on. I started over on the new head casting. It may not look like much but its a very solid start, 3 vertical and 3 horizontal ribs and plenty of cast iron to allow the end user to build to the way they want. I will keep plugging away at a complete design with the intent of being used just for the BT30 spindle cartridge. It will require a new top plate and the end user to design their own draw bar release method.

-Dan

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[hayes]

I dig it! I do have a question though as I just don't know the answer - what would be better from a manufacturing, cost and rigidity perspective - a steel weldment or aged and hardened cast iron casting?

[engnerdan]

I dig it! I do have a question though as I just don't know the answer - what would be better from a manufacturing, cost and rigidity perspective - a steel weldment or aged and hardened cast iron casting?

Well aside from the cost of making the pattern for sand casting, a casting should be much cheaper than a fabrication like this. But making a pattern basically takes as much effort as a fabrication except in wood. I am hoping to I might be able to use the lost foam method and fabricate a copy of the headstock with the foam that is then packed with sand and when the iron is poured in the foam vaporizes.

A weldment will not absorb and suppress vibrations like a casting will. Plus a weldment will need a thorough stress reliving before machining. Additionally to make a mill headstock like this will take a fair amount of time and some expensive pieces of steel. I took a quick look for the steel stock (all higher grade than A36) and I came up with $400-500 in raw stock before cutting, fabricating, welding, heat treat. Stepping down to A36 cuts the cost down to $250-400.



Sometime in the next couple weeks I am going to stop a local foundry that does small odds and ends parts too see what they think of the design I have come up with and see if they can give me a ball park price. At that point I will take a serious look at what path I want to go down.

-Dan