Endmill or something else for 1 inch hole

Drill with a 1" drill, then come back with a 1" 2-flute endmill that has had one flute ground back, making it into a 1" single-flute end mill.

Essentially boring the hole flat and true. You can leave the outside edge flute but take the corner and the end-cutting edge off of one side, the non-center-cutting side.

I`m not questioning your knowledge, I`m a complete newb but I`d like to ask your reasoning behind using the method you suggested. Since the hole depth is only 1/4" why not just use a 1" centering end mill. The point on a 1" drill is almost 1/4". Would`t it be tough to guess the proper depth to stop with the drill ? and why ground off one side of a 2 flute EM ? I think I know the answer you`ll give but I want to make sure I`m close..LOL
 
IMHO, your machine is not rigid enough for most the above suggestions. A large endmill is going to want to jump all over on you.

I'd suggest grinding an HSS cutter to go in a boring head after removing most the material with a drill. Use a really low speed and feed by hand with the quill, set quill stop to your depth.
 
Is this what you want to do?
1543428921492.png

I agree that your machine is not heavy enough to do this with one cutter. It could be done with a CNC machine, interpolating the circle with a 3/8 cutter or smaller. I didn't mean to have two images. My bad.1543428921492.png
 
Could you supply us with a little more info as to what your making ? There are lots of different ways to make anything . ;)
 
Could go with this type of tool, just by itself. Depending on the volume of parts or how costly the project is in different ways could pay to get a nice carbide tool if needed. Or maybe carbide wouldn't be best option. Need forum input on this...

I think your key to doing what you want will be correct feeds and speeds. Some people would chuck that up, turn on the speed to full and drive it in hard only to burn out the tool and mess up the work. But if the speed were set slow like it should (And I would ask questions here about the optimal speed for something that large diameter and in steel - if you have the exact type of steel would help) Also lubricant may or may not be helpful, not always needed for the type of material which is another good question. Get a cheap tachometer for exact speed, it will pay off.

The dedicated one use machine will help too because you can set up a V block and a stock stop to put the part in the right place each time.

And it would be great if these parameters are offered up in this thread to help out and enlighten us all! Best tool, feed, speed.
I do run at slow speeds when cutting steel. I have a home grown v block tie down system that seems to be working well. Basically I am using two brass straps holding the piece down using the t slots. I am going to throw some indicators on it to make sure it is not slipping. The piece itself sits in a v block that runs the length of the piece.

Unfortunately, I purchased the steel from a shop closing up. It machines like mild steel. Once I am through with what I have I will never buy “unknown” steel again.
 
What is the purpose of the drilling?

I am embarrassed to admit what I am building and coming from popular forum where I would get banned or shunned for mentioning the word. Yes, I am building cannons with very nice walnut carriages that I am also making. Not selling, these are to pass onto my children. I was recently forced to leave my profession and go on disability. ( I really regret not buying a mill when I had money -lol). I need to do the most I can without a lot of $$$. I have a Southbend 16 tool room lathe in my basement and this homemade mill.

The trunions have been my nemesis. I plan to mount them 1/4” deep and weld.

Sorry for the rant but I feel I need to justify canon building after being abused on another site. Not bashing the other site, they just don’t want to deal with beginners. :boxed in:
 
So far I think this is the plan, open for shooting holes in it.

Use a small endmill and remove most of the material. Finish with 1 inch endmill.
 
Use a small endmill and remove most of the material. Finish with 1 inch endmill.

Good idea, better, use a series of larger and larger endmills, finishing with 1". You're going to have problems with tool impact as it hits the top of the 4" piece, until it's cutting all the way around. This applies to every size you will use. You might want to use a small, maybe 3/8 4 flute end mill and hand drive it around the circle until you have a flat circle. Several passes, but easier than WHAP WHAP WHAP.
 
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