Drill press slipping

[old_picker]

I have a total tools floor drill press that I was using to cut a 2" hole into some 3mm aluminium with a bimetal hole cutter.

It kept stalling. I mean the chuck and everything would stop as soon as I put any pressure on it. The pulleys at the top of the machine were still spinning. The chuck was obviously spinning in the sleeve.
I eventually got the hole through but it was very slow going.
It was running at around 500rpm.

Any tips on how to stop it stalling like this?

[joe greiner]

This combination has a surface speed of about 265fpm, which should be OK. Try using a cutting fluid. For aluminium, Machinery's Handbook recommends mineral oil, or mineral oil plus kerosene. Also, pull the chuck and clean the tapers to get better purchase.

Joe

[Harry72]

Was the chuck spinning on the taper?
If so remove the chuck and give the taper a clean up with some W&D paper.

[soundman]

Yeh my drill press doesn't like big hole saws either.
It's unlikely the arbour is slipping in the press it will either be the belts or the arboiur slippin in the chuck.

Any large hole saw is a big ask for a drill press, there is a lot of leverage at a 25mm radius and in a press all the teeth engage at once, bet you had your fair share of chatter too.
Aluminium is soft and tends to grab prety well too.

I can stall the motor on my press with a 50mm hole saw and aluminium thickness irrelivent. come to it I can satll the motor with a 25mm saw.

With any hole saw on any material particularly metals or plastics you have to go slow in a press.

think more of advancing the blade thru the job rather than pressing the tool into the work like you sort of have to with a drill.

I've cut a lot of holes in ally with a hole saw on the press and slow & easy does it.

Diferent ally compounds will cut differently, some diecast boxes cut very freely others clog the blade and are a pain.

best lubricant for hole saws in aluminium on the press is the lenox detergent based lube in conjunction with metho. neither work as well on their own.

the detergent lube prevents adhesion and the metho gives cooling

I add the lube to the blade edge and to the cut, by droper bottle and the metho by squirt bottle as heat become aparant.
on big or deep holes you will need to stop and add more lube to the cut.

clogging the blade is a real problem, stop and clear as soon as there is any indication of a clog and clear it, if you don't it will just get worse and harder to clear and cutting will almost stop.

these days if i'm cutting a few holes and there is room I use a fly cutter, a lot more care but less grief.

cheers

[joe greiner]

Yeah. Fly cutter yards ahead. For thin material, elecrician's punch & die (e.g. Greenlee) is handy. Quite dear, though, so scout garage sales.

Joe

[old_picker]

Godammit!!
i spent $50.00 buyin a set of 4 bimetal hole cutters and arbor etc......
Wish I hadda bought the fly cutter instead.

Stupid :( as I had seen em around but never even thought of one of those.

So slow and easy is the go with these lil suckers right?
I will pull the arbor out and give it a bit of a clean up with some wetndry.
i guess after yesterday the arbor will be glazed up a little.

One more question.

How hard do you need to belt the arbor in??

I used a light engineers hammer travelling about 10" with medium force. Not enough to drive a 4" nail into a piece of OB.

[joe greiner]

Best not to hammer the arbor in. Hurts the bearings more than it helps the contact. Press in while twisting by hand - called "wringing." Should provide adequate purchase.

Joe

[soundman]

I press my arbour home with a blok of wood on the press table and lean on the handle. That should be enough to do it.

I've had a set of draw punches for years, cant remember if dick smith or jaycar still have them, They are damn good for thin metal bashing but the biggest is 25mm.

for cutting aluminium in the smaller sizes I have solid HSS hole saws that I only use on ally, the starett ones are the best. but a 50mm starett will be a big hit in the wallet, my 25mm costme something like $35 and that was 15 years ago.

The HSS ones cut much better and chatter a lot less.

The common bimetal hole saws are..... OK but they are always much better after they have been to a saw doctor for a sharpen.

don't get me wrong, there is no way I would be without my bimetal hole saw set.

But then agian I have more reasons to make large round holes in stuff.

For even bigger holes the router does a good job with a template. even in ally up to 5mm. but don't even think about a bit smaller than 1/2".

cheers

[Ashore]

Most proberly the morse taper slipping , there have been a couple of threads on how to overhaul a morse taper.
Another thing to check is that the top pully isn't slipping on its shaft unlikely but would give you the same problem

Rgds

[Krazee]

Hi,

I also have a TT drill press and experienced the same problem when cutting a 50mm hole in 6mm aluminium for a router table insert. Many times the chuck fell off. The arbor was highly polished at the top so guess it was slipping there. Tried all the suggestions above to get the chuck tight but no permanent solution. I think part of the problem was also that the chuck was not running true and the saw blade would catch/bind in the cut. This was especially noticeable when using the carbide tipped blade (only small number of teeth). Finally got there by taking it verrrry slowly, backing off the pressure to allow metal to clear from the cut and cutting from both sides as problem seemed to get worse the deeper the cut became. Unfortunately got another plate to do for a different router and not really looking forward to it. Might have to tune up the drill first.

Geoff

[mugwoody]

Hi all,

I have used a similar setup when cutting holes for a dash panel and found as always that the candlewax as per the stuff used at alcan and other retailers works best. It coats the teeth with the wax lubricating the swarf as it is produced and stops the ally from welding itself to the teeth. It is also very useful when bandsawing the ally. Apply the wax directly to the warmed up blade frequently as soon as you feel the cutter grabbing.

Peter

[joe greiner]

Geoff:

Probably belongs on another forum, but more direct here. I used a stout plastic chair mat for router insert. Stays nice and slippery. Thick food cutting mats also work as substitute for aluminium.

Joe

[Krazee]

Joe,

I started with a polycarbonate (6mm) insert as it was easier to work with but did not think it was rigid enough. Aluminium seems OK although even it will flex. I haven't used the router table a lot yet and so far not had a problem with materila not sliding on the aluminium.

Geoff