Bazmak-Making simple cheap milling cutters

[bazmak]

I am currently running a thread on making a model shaper
At the moment I am fabricating the table.Starting with a piece of 50x50x8 ms angle.The top of the table I wanted to use cast iron and to machine small
T slots,so decided to make a T slot cutter.My limited supply of silver steel
had nothing suitable,what I did have was a box old drills.So I turned down the shank of an 11mm drill made the cutter,hardened and ground it works better than a bought one and I can still use the drill

 

[mcostello]

A lot of times in this hobby the only limit is Your imigination.

 

[bazmak]

I agree but also its making a tool you cant buy or afford
I have used old drills before,the shank is soft enough to machine
and hardens well.When I have used the cutter for its main purpose I will try it on mild steel

 

[Wizard69]

I agree but also its making a tool you cant buy or afford

I have used old drills before,the shank is soft enough to machine

and hardens well.When I have used the cutter for its main purpose I will try it on mild steel

Nice work in on the cutter

I need to ask though, how do you keep from breaking small cutters like this? Are you using an axis with a feed motor, CNC Or something else? The reason I ask is that when manually using small cutters like end mills I'm in the habit of breaking such.

One problem here, that I learned, is that spindle speed is a critical. Even so I find working with small cutters to be problematic. I suspect a lot of that is due to zero feed back compared to using larger cutters manually. T-slot cutters just seem so fragile.

 

[goldstar31]

I'm having computer probs again. Damn and blast!!

Briefly, the probable answers to MY difficulties are THREEFOLD.

The first is wear/lack of rigidity. The thing that snaps carbides.
The second is wrong temper
The third is wrong speed.

My dear old Dad who could make rings around most 'experts' but could barely read or write did a lot of case hardening using the old fashioned piss and skin and horses hooves. A more modern friend- also long gone used silver steel/drill rod but diod something similar to Dad. He used Kasenit to case harden the outside of the clock making/watchmaking tools. In other words, the cutting edge was probably almost diamond hard whilst the core was still dead soft because he 'let down' to cool rather than have brittle tooling.

My dear old Dad would make his blacksmiths tools so that they did not shatter. I'm still using some that he made for me to dig out German incendiary bombs .

If you can follow the logic, This was roughly the way old wood plane irons were fashioned. They had wrought iron bodies- soft enough to be hammered but carbon steel cutting edges. Todays logic is little different , we have- or you have- carbide brazed to soft steel shanks.

Does this help?

Norman

 

[bazmak]

Small cutters in softer matls I never have any problems.High speed and slow speed,by hand,you tend to get feel for it after 50yrs.The problem comes
with trying to cut mild steel with high carbon steel cutters.Hence my comment
to try this cutter on mild steel AFTER I have finished my model shaper
I also reduce the speed with hc steel cutters or they blunt quickly

 

[Nick Hulme]

Todays logic is little different , we have- or you have- carbide brazed to soft steel shanks.

I've got a few of those somewhere at the back of the Tool Steel storage drawer, unless the big spider in the corner of the workshop has been in and nicked 'em for bench press weights ;-)
On a serious note, all tooling options have a niche, which may vary with your requirements, discounting any option out of hand will, under some circumstances, be incorrect,

- Nick