Must cut 40mm hole in 1/4" aluminum bar

I tried a hole saw in my cheap drill press. Works perfectly for hardwood, but doesn't work for 6061 aluminum. I might try removing some teeth from a hole saw, see if it cuts a little better without the chatter. I am familiar with inwards and outwards leaning teeth.

Will I have better luck with a 40mm carbide cutter that has fewer teeth and maybe better chip removal? The hole diameter must be near perfect, so I might end up buying more than one (different versions) of those if it cuts through the material.

Is there a small machine made for cutting shallow holes in metal? I suppose a good drill press would work, but only if necessary.

I recently purchased DeWalt's small cordless metal cutting bandsaw and think it's great for cutting most small/narrow aluminum.

I really want to cut that hole.

Thanks.

This will do the job.

Best regards Tom.

BWAAAHAHAHAHAAA!!! Looks like that type has a special shank. I will try using ordinary carbide cutters and maybe a more robust looking hole saw, possibly after cutting a few teeth off.

You might try drilling a hole or two so the chips can fall out of the way and use a little oil to make it cut easier.

Dan

The machine tool one short step up from a drill press is a "mill/drill". In my limited experience with substandard import machine tools the floor-stand ones have decent power and rigidity to cut steel but may lack the accuracy to work to 0.001". The RF-31 mill drill from MSC that I used was good to no better than 0.005". It looks like the $1200 Harbor Freight 33686 and might have been adequate for fixing farm equipment, or a hobbyist with the time to fiddle with shims and adjustments. The old original US-made "Buffalo" mill-drill was precise enough to rebore small engine cylinders.

?category=1387807683 I can't suggest which to buy since I lucked onto a >60 year old US-made original this: I've used the 1990's Enco 100-5100 version of it after cleaning up some small castings that were factory "finished" to wood stove tolerance and considered it the minimum I'd accept for making small machinery with moving parts; shafts and bearings etc. Like my Clausing it can be disassembled into pieces small and light enough to carry up/down stairs.

Unfortunately the good old home shop sized US-made machine tools are now worn, hard to find and priced like new imports.

They have a 3/4" Weldon shank and you can get Morse taper arbors to take them if your drill press has a MT spindle, maybe other 3/4" Weldon shank adaptors are available I haven't looked. I use them frequently in my BP mill and just hold them in a 3/4" collet, they cut easily and produce accurate holes, much better than hole saws IMO. The carbide one linked to would be over the top for cutting aluminium.

  I gotta disagree with your opinion of the new machines ... well , some of them . My (Wholesale Tools ZX45) RF45 clone is rigid and accurate enough to machine anything I'm capable of doing . It wasn't cheap at over 1800 bucks , but after the addition of a 3 axis DRO and X axis power feed I think it's every bit as capable as a Bridgeport . Geared head and a dovetail column are the 2 reasons it won out over an RF31 type mill-drill .

....

As I mentioned, my experience with import mills is limited to a couple of low-end ones I used at work, at electronics companies that barely needed them. The places that employed mechanical engineers had Bridgeports. The Buffalo was in a small engine repair shop and I've only passed on what the owner told me.

Does anyone have a good or bad opinion of the smaller & cheaper ones like the Sieg?

While I grabbed time on the CNC mill whenever I could, a DRO or power feed aren't essential if you are shocked by the high cost of just the bare machine. My 1950's Clausing has neither and I haven't been tempted to install the DRO scales I bought for it, which on inspection would require some freehand butchering. A 6" ruler graduated in tenths of an inch easily confirms the dial turns count.

  Most of the reason I mounted the DRO is because the X and Y move .125/revolution while the Z moves .100/rev . The power feed is because I'm lazy and it is much more consistent . I get some really smooth finishes now even using a single-point fly-cutter ...

_I forgot to add. Adjust the table height so the drill is almost cutting when the drill is high. And set the drill rpm at the lowest speed.

Dan

Ugh! I learned to live with an 8TPI leadscrew but not to like it. To move to 0.6875" (11/16") takes 5 turns to the 0 mark at 0.625", then advance +0.050 to 0.675", +0.010 to 0.685", and +0.0025 to 0.6875". It's like reading a micrometer in steps of 0.025".

It's the per-tooth load that's your problem; the drill press probably doesn't have a low enough speed for proper high torque on the hole saw, so the per-tooth cut can't get deep enough. I'd suspect you're getting fine waste crumbs instead of proper chips. Lube is important for aluminum in this kind of thing, too.

The 'remove a few teeth' might help, or resharpening the saw (to make a slightly less agressive cut) might do some good.

Looks to me like you got it nailed . I'm still trying to decide whether to move all my daily use stuff over to the Win7 OS or leave it here on the XP boot .

Snag

---------------------- My only remaining "snag" was posting to Usenet, since the Outlook Express in XP was discontinued. Thunderbird didn't configure itself properly to send but Live Mail seems OK. The Firefox bookmarks were easy to export from XP and import into 7. Look under "Show all Bookmarks".

My fleamarket Win10 Thinkpad T530 gathers dust between update sessions.

Yes. I saw that tip on YouTube. Definitely will try it. I can afford a hole or two even if it's in the center of the cut.

Yep, it goes nowhere.

My Dewalt DCD991 (0-450 RPM no-load) might do a better job if I could get a perfect right angle on it, like in a makeshift drill press.

Planning to buy a DCD130 "mud mixer" (0-600 RPM). That might work well as most low-end drill presses, if put in a decent press (a thingy to move it through the work).

I use a clamped-down Portalign-type fixture to drill straight into structural steel too large to fit in the mill or drill press. Your hole saw may grab, overstress and break it, though.

If you remove teeth from the hole saw, vary the spacing between the remaining ones. A regular repeating pattern promotes chattering.

This is the right tool to cut large, smooth, accurate holes of any size within its range:

are slow and require the rigidity of a milling machine.

Kinda hard to migrate when both OS's are in the same comp ... I just replaced the failing motherboard in this desktop with a newer one that will run 7 , and installed it in an otherwise empty 500 Gb drive . So far that's the only "snag" I've found with this setup . Oh , and I run Tbird on all these comps , makes it much simpler to move to another comp , like using the laptop when we travel . Snag =================================== So I replied to you instead of to the group.

About 12 years ago I switched to cheap second-hand business laptops for less demanding, non-gaming applications like programming, CAD drafting and internet access. At first I did it to economize on UPS and battery costs because they draw around 1/10th the power, 30W vs 2~300W and have their own battery backup. An external USB keyboard on a roll-out shelf makes them as easy to type on as a desktop.

Then I realized I could use Win7 laptops as compact portable AC/12V/battery-powered televisions with recording and playback ability, as long as they had at least a 2GHz Core2 Duo CPU. I set up my computer bench with two large monitors, one an HDTV, on the upper shelf and whichever laptop(s) I'm using, or none, on the desktop static mat. A ham radio fleamarket provided a nice Altec speaker set with a subwoofer for watching PBS music programs. The monitor, keyboard and speakers remove all of a laptop's annoyances. Right now the upper HDTV is showing the local news and the laptop has recorded the weather.

Since these thicker laptops accept plug-in second hard drives in the DVD bay they can selectively boot one of two operating systems, and transfer files such as exported bookmarks or lists of settings between them. A large second drive can have a small bootable OS partition for emergencies and the rest a storage partition for videos etc.

There are several free programs that can back up the operating system partition to the second (faster) or an external USB (slower) drive so you are free to experiment and can restore the backup if your HDD goes bad or you mess up or are contaminated by malware. I've searched the backups to find one before the corrupted Java installation.

This ~10 year old Dell D630 laptop cost me $15. It has the base Intel graphics which is more reliable than the NVidia upgrade and adequate to display VGA video on a larger external monitor. Several other brands shared the overheating NVidia problem. AFAIK it's about the oldest that's still acceptable, my slightly older D820s have wonky 1st-gen SATA controllers though they do boot from SSDs.

I have newer and faster laptops costing from free, won't boot (CMOS battery) to the $100 Win10 Thinkpad. They stay stacked, available for more demanding apps like running an SDR radio receiver while the old guys do the grunt work.

This is a test to confirm that I can finally retire my XP laptop and post from this Win7 one.

  Looks to me like you got it nailed . I'm still trying to decide whether to move all my daily use stuff over to the Win7 OS or leave it here on the XP boot .