Ok so i am trying to machine a piece of 1/2" round stock (6061-T6) and i need to figure out the best/least expensive way to make a cut. Basically i need to make an 1 1/4" dia notch in the center of a 50mm long rod of the 1/2" stock. This will be so that the 1/2" piece can sit on a piece of tube that is roughly 1 1/4" in dia, and not want to rotate so much. Currently i dont have easy access to a mill, but i do have access to a drill press with a cross slide vise. I have thought about using a hole saw, but i think that it would be less than ideal and leave a fairly poor finish. I have thought about just getting an endmill, but that poses some problems with the equipment i have access to. Is their some better way that i just am not thinking about? I have been racking my brain for a while on this one. I have thought about making my own HSS bit with a 5/8" radius on the tip, but that would still allow the part to rotate. I would just look for some sort of grinder bit for the drill press, but since its alu it would probably clog up pretty quick.
Need some machining ideas/help
- Thread starter sortafast
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gadget_lover
Flashaholic
The hole saw in the drill press will be the least expensive way. You are only making a shallow cut, so the stress will not be too great. The finish can be cleaned up with either sandpaper or a "flap wheel" sanding disk.
Go slow and use lube, and the finish should be OK.
A third way to cut an arc is to attach the bar to a table and rotate the table. You'd use the side flutes of a smaller mill (whatever fits the drill) to do the cutting. NOTE: This can cause the drill press chuck or arbor to come lose at speed, and is not recommended.
Daniel
Go slow and use lube, and the finish should be OK.
A third way to cut an arc is to attach the bar to a table and rotate the table. You'd use the side flutes of a smaller mill (whatever fits the drill) to do the cutting. NOTE: This can cause the drill press chuck or arbor to come lose at speed, and is not recommended.
Daniel
scott.cr
Flashlight Enthusiast
If I'm understanding you correctly, you want to cut an arc into the side of a piece of round rod to nestle a larger diameter tube into it?
With a drill press you could easily do this with a boring head set to cut a radius of 0.3125". Something tells me you don't have ready access to machinist's tools though... and boring heads aren't a good buy for a single job ($$$$).
I have a feeling that clamping the work piece in a vise and using a hole saw will be a very iffy job at best. You will need tremendous clamping pressure on the work piece for that type of cut. The good thing about a boring bar is that it's easier on the clamping pressure requirement than a hole saw.
I think your best bet would either be to have someone here help you with the machining job or modify the 1-1/4" tube instead. You can plunge a 1/2" drill bit through the side of the larger tube to make a notch. In this case, a 1/2" two-flute end mill is what you want to use... a twist drill won't work to cut a notch because it won't be going in point-first.
Be aware that when using an end mill in a drill chuck that you can only PLUNGE it into the work piece... if you try to cut slots, the end mill will most certainly pull out of the chuck. Oh, and if you get tempted to buy a four flute mill instead, stick with the two flute. When plunging, a two flute will chatter less.
With a drill press you could easily do this with a boring head set to cut a radius of 0.3125". Something tells me you don't have ready access to machinist's tools though... and boring heads aren't a good buy for a single job ($$$$).
I have a feeling that clamping the work piece in a vise and using a hole saw will be a very iffy job at best. You will need tremendous clamping pressure on the work piece for that type of cut. The good thing about a boring bar is that it's easier on the clamping pressure requirement than a hole saw.
I think your best bet would either be to have someone here help you with the machining job or modify the 1-1/4" tube instead. You can plunge a 1/2" drill bit through the side of the larger tube to make a notch. In this case, a 1/2" two-flute end mill is what you want to use... a twist drill won't work to cut a notch because it won't be going in point-first.
Be aware that when using an end mill in a drill chuck that you can only PLUNGE it into the work piece... if you try to cut slots, the end mill will most certainly pull out of the chuck. Oh, and if you get tempted to buy a four flute mill instead, stick with the two flute. When plunging, a two flute will chatter less.
65535
Flashlight Enthusiast
I would say saw it rough and undersized then grind it out to the correct size.
Well, I just got done making my own semi-adjustable "boring" head (i use that term very loosely). Now I am off to go back to the drill press (across town) to see how she works. Hopefully no aluminum gets hurt in the process. If it works, I will post pics, if not I will go cry in the corner.
gadget_lover
Flashaholic
I hope that works OK. It seems a "boring" head would be more dangerous in a drill press. It would have an interrupted cut that would cause a lot of off axis impact on the spindle. I imagine it would fail fairly quick, depending on the tapers involved.
Let us know how it works, OK?
Daniel
Let us know how it works, OK?
Daniel
well, it worked marginally well. The drill press i used was pushing the antiqueish side of things so it really couldnt be helped. on my 2nd attempt i got fairly good results, and with the help of a good buffing wheel it came out OK. But nowhere near what i was after. I might try the hole saw idea, but with the press i have access to, i dont thing it will turn out any better. I think this means that i need to try to talk the wife into letting me get a mill so i can make this work :devil: . But yeah, i can totally see that steel bit failing rather quick, but on the plus side i am only out like a buck for the scrap bin steel bar i picked up. Oh well, Just 1 more reason to get a mill.
PhotonFanatic
Flashlight Enthusiast
Is this what you are trying to create?
That's a 1.25" diameter notch in a .5" diameter rod.
Absent a mill, I'd just buy a grinding wheel and rough it out with a grinder. Finish with sandpaper.
Of course, I'm assuming your not selling this to NASA.
That's a 1.25" diameter notch in a .5" diameter rod.
Absent a mill, I'd just buy a grinding wheel and rough it out with a grinder. Finish with sandpaper.
Of course, I'm assuming your not selling this to NASA.
Morelite
Flashlight Enthusiast
PhotonFanatic said:Is this what you are trying to create?
That's a 1.25" diameter notch in a .5" diameter rod.
Absent a mill, I'd just buy a grinding wheel and rough it out with a grinder. Finish with sandpaper.
Of course, I'm assuming your not selling this to NASA.
If that is what you want done, I can do that for you. I have a 1-1/4" ball mill that will leave a nice finish.
modamag
Flashlight Enthusiast
Morelite, how would a ball endmill be any different from a regular square endmill in this case.
Just want to learn
Just want to learn
ball end mills leave a rounded bottom where as a reg. end mill would be flat, or rather have 90deg corners and be flat on the bottom instead of the smooth half circle like in the illustration.
BTW thanks for the offer Morelite, but in all reality the cut isnt 100% necesary for what i am doing, it would just be one of those nice bonus things. I was just going to try and see how hard it was going to be to do with what i had available to me. Besides im using it to build a case to buy a mill so it aint all bad.
BTW thanks for the offer Morelite, but in all reality the cut isnt 100% necesary for what i am doing, it would just be one of those nice bonus things. I was just going to try and see how hard it was going to be to do with what i had available to me. Besides im using it to build a case to buy a mill so it aint all bad.
modamag
Flashlight Enthusiast
I guess I should be a little more clear.
If we were to use a ball endmill it would be plunge from the Z direction and cut at the leading tip of the ball cutters.
However if we cut with the square endmill (or boring bar) we're just cutting from the edge.
Picture of it cut half way.
So the question raised again & rephase
"How would a ball endmill be any different from a regular square endmill in this case. Would the ball em leave less machining mark and be smoother?"
If we were to use a ball endmill it would be plunge from the Z direction and cut at the leading tip of the ball cutters.
However if we cut with the square endmill (or boring bar) we're just cutting from the edge.
Picture of it cut half way.
So the question raised again & rephase
"How would a ball endmill be any different from a regular square endmill in this case. Would the ball em leave less machining mark and be smoother?"
Morelite
Flashlight Enthusiast
modamag said:Morelite, how would a ball endmill be any different from a regular square endmill in this case.
Just want to learn
I didn't mean to imply that a ball mill would be any different or better. The method of machining will differ between to two mills. My only reason for offering to use a ball mill was because I have one but I don't have a end mill in that size.
gadget_lover
Flashaholic
sortafast said:
The hole saw should work better than you think. Locksmiths use them in steel doors all the time. The hole saw will be cutting a relatively small area in contrast to a large end mill. The hole saw will also be plunging directly into the material, so it will not be side loaded. If you give the pilot bit something to bite into it might give a cleaner cut, as the saw will be supported top and bottom.
They make bi-metal hole saws that are cup shaped and quite sturdy.
Daniel
connortn
Newly Enlightened
I've found it almost always neccessary to give something for the rest of the hole saw to cut into when improvising for things like this. Lay a piece of flat stock beside the round stock and clamp them both in the vice, then use the drill press and hole saw to drill through both pieces at the same time. That way the hole saw won't try to push out to the outside of your cut.
65535
Flashlight Enthusiast
A 1.25" ball mill would just slice throw aluminum.
Anglepoise
Flashlight Enthusiast
65535 said:
Not in an old drill press it won't............I think that is all sortafast has.
I think member connortn has the simplest solution for a drill press that has no draw bar to keep the chuck in.
