Let the DP vise "float" or lock it down?

[ARC-170]

This is a question for those of you that have worked in a machine shop environment: when drilling holes in a part, do you lock down the vise, or do you let it float? I learned to let it float, but another instructor makes the students lock it down for each hole. We had a lesson where the students needed to drill 8 holes (1/4" to 1/2" diameter in 1/4" thick aluminum) and they had to relocate the vise for each hole (we have nuts and threaded studs). It took them about 90 minutes. They center-punched each hole, then had to locate the center bit over the punch and drill. For the larger holes, they had to center drill, 1/4" drill, 3/8" drill, 1/2" drill, then go to the next hole. It was very frustrating for most of them.

I think the instructor was concerned about safety, but I've never had a vise with a part in it spin in a drill press. RPM was about 800.

For larger diameter holes or holes where the location matters, I use a mill with the X-Y table, but the students are not there yet. I can see locking the vise down for production work where you are drilling the same hole in the same part in the same location many, many times. For this part, I would have punched the holes, center-drilled them (letting the vise find the center), used the 1/4" bit on all of them, used the 3/8" bit then the 1/2" bit on the larger holes.

I'd like your thoughts and comments, thanks!

 

[markba633csi]

Good question! And it begs the additional question: at what drill diameters is it safe to hand-hold the part being drilled vs. held in a vise?
I know that I have often held parts to be drilled provided the drill was around 1/4" or less. At some point I switch to vise, and at some other point I lock the vise down. Depends on material, part dimensions, and drilling speed as well as drill size. I do often wear gloves when hand holding, but not always.
I'm sure you will get a variety of answers.

 

[benmychree]

I think it depends on the diameter of the holes mainly, larger diameters mean more torque and chance of the drill catching and trying to rotate the vise and causing an accident, it depends also on the machine, on smaller machines it is liable to just slip the belt or stall the motor, on larger and gear driven machines the vise should be secured to the table. A device to absorb the torque so as not allow the vise to rotate is a good thing to prevent drill press accidents.
I do not agree with stepping the drill sizes up in small increments, it is recommended to start with a small pilot drill, and follow with a drill about the same diameter as the web thickness of the pilot drill, again it depends on the machine as to what is possible, but increasing the drill diameters by small increments is not so good, as it can cause problems with the drills wanting to "hog in" causing possible breakage and premature dulling of the drills from overfeeding.
Requiring the vise to be secured and re positioned for every hole can waste a lot of time, especially for small holes.

 

[benmychree]

Good question! And it begs the additional question: at what drill diameters is it safe to hand-hold the part being drilled vs. held in a vise?
I know that I have often held parts to be drilled provided the drill was around 1/4" or less. At some point I switch to vise, and at some other point I lock the vise down. Depends on material and drilling speed as well as drill size. I do often wear gloves when hand holding, but not always.
I'm sure you will get a variety of answers.

A best practice answer is that gloves should NEVER be worn around most machines, except possibly some types of grinders.

 

[Ulma Doctor]

Under 1/2” holes, I let it float

 

[benmychree]

Under 1/2” holes, I let it float

That would be reasonable in most cases.

 

[rwm]

I made this arm so stuff could float but not rotate. I like it. I only really use it with large drills or especially hole saws.


There are drill press clamps with arms that do the same thing and have been shown here also.

 

[SouthernChap]

A best practice answer is that gloves should NEVER be worn around most machines, except possibly some types of grinders.

What kind of gloves?

Nitrile examination gloves are between 2 and 5 thou thick. They're really rather fragile and they'll split and tear well before the skin does; the chance of such a glove catching and dragging a hand in is vanishingly small.

To be fair the point I'm making is not really about gloves, but the dogmatic insistence of broad application of a rule without considering the meaning or purpose of the rule.

Sure, in a production environment, strict dogmatic rules may be appropriate to guard against liability for accidents and possibly even to ensure even the most 'unthinking' of the staff are protected from themselves.

But eh, we're hobbyists here and I reckon it's worth not just repeating the 'mantra' but the underlying thought behind the mantra.

 

[SouthernChap]

A device to absorb the torque so as not allow the vise to rotate is a good thing to prevent drill press accidents.

That's the most sensible answer, I reckon. I used have a fitment that clamped around the column with a longish square bar with M8 threaded holes. I'd use it to ensure the vice didn't spin but it was quick to unclamp from the column and rotate it to a different position and use different holes.

 

[RJSakowski]

Locking down the vise before drilling requires the additional time to locate the hole to sufficient accuracy and invites inaccurate drilling such as drill wander. I rarely lock a part in the vise when drilling with the drill press. It is a good safety practice to provide some king of anti rotation mechanism, To that end, I will mount the vise securely but leave the part some free play so that the center punch mark on the part can center under the drill. There is a possibility that the part can climb up the drill as it breaks through. This can be prevented by using a hold down of some sort for the part. I have a modified Vise Grip type clamp that has a threaded stud which can be inserted through the slot on the table. It can quickly be locked or unlocked but provides a secure hold down.
An exception would be where I have to drill multiple identical parts. I would take the time to accurately locate the hole position on the first part while clamped securely in the vise and then provide a stop so that subsequent parts can be clamped in the same position. With this method, it then isn;t necessary to lay out the hole position on every subsequent part. For most cases, you can just mount a new part and drill. If you are concerned about drill wander, you can spot the holes on each part with a center drill and then remount the parts and drill the holes.