Cutting 3.25" Hole in Aluminum

[Rob F.]

Remove compound & replace with an angle plate, attach your part to it with some spacers behind. Slow carriage feed.
This guy did a nice job of attaching an angle plate to his unmentionable lathe here:
Easy Lathe Milling Attachment - YouTube

 

[Texasbowhunter]

Remove compound & replace with an angle plate, attach your part to it with some spacers behind. Slow carriage feed.
This guy did a nice job of attaching an angle plate to his unmentionable lathe here:
Easy Lathe Milling Attachment - YouTube

I like this...one day I would like to make one but for the time being I had visualized a angle plate which I happen to have and mounting to the cross slide...Then attach securely the triangular plate to the angle iron in the location I'm seeking...So were on the same page here

Now where I'm at a loss is what type of cutter are you suggesting for the 3.2 dia. hole that will be in the chuck of the lathe?
Thanks
Paul

 

[jermfab]

If it’s just the one hole the router trick or some of the other suggestions will be the most economical.

If this will be a recurring thing spend the money and get a Milwaukee Steel-Hawg annular cutter. Check eBay… I see lots of the bigger sized steel hawg cutters there. In aluminum the carbide tipped cutter is hardly consumable.

I know Milwaukee makes an MT3 arbor, I don’t have anything MT2, so I’ve never looked.

That’s the absolute best option for making a large diameter hole with an underpowered machine like a drill press.





Be safe.



Jeremy

 

[Just a Sparky]

I'm confused. You said it *will* fit on your lathe, now you're saying it won't?

Which assumption should we be working under here?

What's the swing over bed on your lathe?

 

[Texasbowhunter]

I'm confused. You said it *will* fit on your lathe, now you're saying it won't?

Which assumption should we be working under here?

What's the swing over bed on your lathe?

I was under the impression that the plate would swing chucked up in the chuck...
No It wont chuck and spin freely attached to the chuck...
However if I am able to attach it to a 4x4x1/4" angle iron and secure it to the angle attached to the cross feed Yes it will
I'm going to try and attach a pic of plate profiled for reference
Pic is worth a 1000 words I hear
So its 12.5" horizontally and 11.5" Vertically
My lathe has only a 12" swing

 

[Texasbowhunter]

Would this work for the type of fly cutter I would need? Will it cover the 3.2 bore I wish to cut...That's if I fab an angle atop the cross slide and attach the aluminum to it and chuck up a fly cutter in jaws...Price does not seem to unreasonable for various sizes offered

Precise 3 Piece Fly Cutter Set - 4002-0003 - Penn Tool Co., Inc

or this one

HHIP 4002-0018 R8 SHANK FLY CUTTER WITH 2-1/2" HEAD: Industrial Products: Amazon.com: Industrial & Scientific

 

[Rob F.]

TWO MILLING MACHINE MACHINIST FLY CUTTERS | eBay
For your hole that needs no accuracy something like one of these should work. A boring head like a criterion or? would let you easily dial in the exact size.
If you can get a morse taper tool you might be able to remove the chuck and run it right off your spindle's taper.
edit:
Just saw your post, the Penn tool set is better than my link. I would not get the R8 tool in amazon link, it would have to stick way out to grab it on the parallel shaft at the back.
second edit:
This type boring head is what I was thinking:
Vintage Boring Head Jig Boring Fly Cutter 3/4" Shank 3" Diameter Adjustable | eBay
This particular on might be priced a bit high, (IMHO should be $20, no holes on bottom/end) but he will take offers...

 

[mike44]

cutting hole in aluminum

mount a faceplate with an MDF piece on the faceplate. Find center bore or punch the work. Run TP with a center up to the work and hold the work with the TP. Clamp, bore etc what ever it takes to hold the work on center. Now you can trepan it or use a hole saw to get close and bore to dimension.
mike

 

[Texasbowhunter]

Well I have done some checking around today and discovered I have a 2 7/8" hole saw as I described earlier...one I would not feel comfortable using for the final application...
Thoughts at this time is to mount angle to the top of the cross slide and attach the plate to it with some hold down clamps I picked up for the use someday to be able to bolt down material to the table of a mill...
Once I get the plate secured where I desire the hole to be I would attach the hole saw 2 7/8" into the chuck and cut the initial hole...could be considered a relief hole so to speak but at least the bulk of material will be removed and then not to much more has to be removed
Then install a cutter perhaps something along the lines of a fly cutter or ???? chucked up in the chuck and make the final cuts ever so slowly to achieve the desired hole diameter...
In theory its seems it would work in my untrained mind...

Dilemma is and its not a big one is I have absolutely no experience with a fly cutter assuming this were the approach I would attack this on...I believe I would get the guideness from the members here to help with what to do and what not to do...
If I was to use this process and it was successful this could open up more avenues to pursue later if the occasion were to arise...

Or

Pay the $57 dollars to a machinist I talked with today to do this job for me
Going this route the job would be done absolute and should not have any worry's
Down side no opportunity to hone my possibility's to expand...
I believe I know what I want to do and use my $57 and invest in some more tools to expand on
I know I have the confidence to do the job now with my limited experience and your guideness...


Thoughts

 

[Rob F.]

Your plan sounds fine, If you can find a cheap boring head it will just be easier to adjust it for size each time you move the cutter.

Flycutter is better at flattening a surface, but it can work for boring. If you have to buy, look for the boring head first with plan B to use flycutter.

 

[CarbideBob]

Paying the $57 dollars is sort of cheating and you do not get to do it.
Here is weird and more than 57 dollars of time.
Layout the hole, drill all around inside a bit.
Slap the slug out. Fly cut / bore to size.
So many ways to skin a cat.
Bob

 

[johnoder]

Layout the hole, drill all around inside a bit.

Or whatever you need to do

 

[johnoder]

Have this contraption. Clark #4 does 2 1/2 to 4" and has 4MT shank. I think its more sheet metal intended

 

[Texasbowhunter]

Paying the $57 dollars is sort of cheating and you do not get to do it.
Here is weird and more than 57 dollars of time.
Layout the hole, drill all around inside a bit.
Slap the slug out. Fly cut / bore to size.
So many ways to skin a cat.
Bob

Agreed
$57 more dollars to be put towards tools and more then that the feeling that I did it and did not have to out source...
Plus as a bonus the work around knowledge will be priceless
Thanks to all for there guideness
Rob presently I'm looking at the boring bars kit offered on eBay...They are a bit more then I had hoped but not finished looking on the WWW...I do not have a fly cutter so one or the other will have to do...
I like the idea of the fly cutters utilizing the square bars vs the round 1/2" bars I found for the boring bars kits
Paul

 

[DDoug]

What is the accuracy requirements of said hole ?

 

[Rob F.]

What is the accuracy requirements of said hole ?

Flycutter accurate. From post #1:

The hole I'm shooting for needs to be clean without any ugly in the cut walls...accuracy doesn't have to be precise since the part that will go into the hole I can adjust for tight fit in my Lathe...I have several hole saws of various sizes but I fear that the quality of the hole would be sub standard as far as the wall finish...

 

[Texasbowhunter]

What is the accuracy requirements of said hole ?

I really don't require a said accuracy just as long as the hole is perpendicular and clean...
The sleeve that will insert into the hole I will fit to the hole provided in the plate...
Paul

 

[MilGunsmith]

Since you can rough out the hole in the plate with the hole saw, why not use a line boring type cutter in the lathe. A piece of round stock with a center hole drilled in one end, chuck up the other end. Somewhere in the middle, make a square hole to fit a lathe bit, either HSS or a carbide tip. The hole only needs to be .375" or .500" square depending on the bit. It could even be .250", just drill a hole and square it up with a file. Make another hole at right angles to the square hole that is tapped for a setscrew to hold the bit in place. Stick the bit thru and measure for your finished diameter and lock in place. The bar runs thru the roughed hole and the tailstock supports the center drilled end. Fixture the plate on the carriage with the angle and then run the carriage back and forth to make your cut.

 

[michiganbuck]

$57 Is about 2 1/2 hours and likely I could drill press drill, knock out and file that part on such time for a very nice looking part at .006 or less error.

 

[GregSY]

So you don't believe what I told you about fly cutters not working in a drill press.....How are you gonna create an accurate hole when the whole table is shaking .200" and that flimsy 2MT spindle comes loose 1/4 way through the job?


The fly cutter is sorta the darling of the home machine crowd. It's like the can of motor rebuild oil, or the spark plug that promises 2000MPG and an extra 150HP.