[JustTheDad]

I have a 25 year old belt drive benchtop drill press with quite a bit of run-out, but it might work with one of these:
https://www.ohiopowertool.com/brands/cs ... ec-2-1-120

I could buy a 50 amp plasma cutter and make circle templates, but I'll be working in my basement and even though I have a cement board ceiling, welding blankets on 4 sides, and an exhaust fan, I'm not sure that's safe or a good option.

Or I could splurge and get a littlemachineshop 3990 mini mill. I have carbide end mills for my wood CNC, so some would be shareable, and even though I've never used a mill, it seems like it could replace my mini drill press. Of course, with a few end mills and bits, it is 30x the cost of the single annular cutter that might work for this one project.

Other than the cost differences, which I know are rather extreme, are there any downsides to these 3 options that would make them very unsafe or not actually functional? Like will the pseudo annular cutter not last for that many holes in a cheap drill press, will the plasma cutter make too much smoke or do a bad job, or can I not use a mini milling machine as a drill press?

Thanks
Todd

[tweake]

how accurate does it need to be?

plasma cutter is going to inaccurate and require cleanup, so its pointless on such small holes.
if the material can fit on your drill press i would use that. make sure you use good lube. may be a good idea to rig up some cooling air.
a cheaper way is to use 5/8" bimetal hole saw, which is what i would try first.

if you go the mill route i would get a substantially better mill.

[JustTheDad]

BiMetal hole saws that small can make 60-80 holes in 1/4" steel?

On the mill, I liked that mill as an option because it seemed like the best on available that I could fit easily. There was one in the UK that seemed nice, but it would be harder to ship and parts could be an issue.
Who makes a better mill that won't take up much more room than a drill press?

[tweake]

how long hole saws last is down to getting the right rpm, lube and cooling. plus they are cheaper so you can buy a few.
if you find you wear it out fast then get the carbide tipped ones.

for small mills these guys come recommended https://www.precisionmatthews.com/produ ... enchmills/

for small or home shops i think its better to get a mill rather than the cheaper mill drills. drill mills make poor mills but you can always drill on a mill.

[cj737]

An annular cutter is the way to go, pure and simple. You can possibly rent a Mag Drill and buy the cutter. Punching a 5/8” hole in 1/4” will take that setup about 15 seconds per hole. Use some cutting fluid or coolant, and you’ll be done before lunch.

I drilled 840 5/8” holes in my. 48x72x0.75top in about 10 hours. Took some time, but each hole is dead perfect and a single cutter lasted for all holes. There’s not a hole saw on planet earth that could take that much drilling…

[JustTheDad]

I had seen that website and read a little about them, Tweake. It's a big step up in price and I can't tell what the differences between a lot of their machines are, but maybe I'll give them a call.

CJ737, The hole saw I linked to is about as close to an annular cutter as a hole saw can come, but with a pilot hole bit since there's so much run out on a drill compared to a mag drill or mill. I found a similar one for $30 that I'll try with either a lot of cutting fluid, or I'll set up a mister with some dilute cutting fluid. That may buy me time before I decide on any more expensive options. Our local homedepot doesn't rent tools, and some of the holes will be in narrow pieces so I'm not sure a mag drill would work well even if I did find a place that rents them. Good idea though if I was drilling a flat top.

Thank you both.

[cj737]

You can rent those Mag drills at a Rental Works or such place that have construction tools. Runs about $30. The width of material doesn’t matter, as long as you place the drill itself on a piece of 3/8” thick or better (your drill press table could work too).

Hole saws can work, it depends upon the tolerance of the hole per your requirements. Hole saws are thinner-walled and don’t create terribly accurate holes. Annular cutters have thicker walls, a steeper tooth, and a pilot to punch the core out. It’s a machined quality hole, if you require it…

[tweake]

I had seen that website and read a little about them, Tweake. It's a big step up in price and I can't tell what the differences between a lot of their machines are, but maybe I'll give them a call.

a lot of the machines look the same but features and accuracy can be wildly different.
i just do not see the point of spending 50-75% of the price for a low accuracy machine. but it depends on the work you do.

[Metal Manipulator]

Before I would use a holesaw I would look into a hole cutter from Blair or a competitor. https://www.blairequipment.com/holcutters

[JustTheDad]

That's pretty much what I settled on.
https://www.amazon.com/dp/B01E4DPG2U?re ... tails&th=1
I'll let you know how it works out. Have a few other things to finish before I get to that part of my project.
Thanks

[stefuel]

I shortened a 33,000 gvw cab/chassis with air ride suspension. I had to drill about 60-70 holes in frame stock to do it. I never would have been able to get accurate holes without the use of a mag drill. Also way easier then fighting it with a hand drill