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

[ARC-170]

Thanks for the replies so far. You have confirmed what I thought: that floating it is just fine except when drilling larger holes with a big ol' DP.

I think the instructor is concerned about legal issues if some student gets hurt. At this point, I'm not able to say anything, even though the other machinists I've talked to say floating it is just fine, even in a production shop.

 

[ARC-170]

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.

I was taught it was about 1/2" or less, but use good judgement: make sure the vise is heavy enough, the RPM is lower, the part is a manageable size.

The part they are drilling is 6" x 2" x 1/4" thick aluminum.

Funny you mention gloves: many of the students are wearing them. As I've mentioned, I can't say too much as it's not my place in this particular class. I've watched them and they are keeping their hands away from the drill bit, so no issues yet.

 

[ARC-170]

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.

I wear the thin exam gloves all the time because I get sick of having my hands smell like cutting oil, plus it's just easier to get clean.

We are training these students to work as engineers and machinists in a production environment, but I've been told they can still float the vises by most of the people I've talked to. Let me know if that's not the case in your experience. As has been mentioned, I think this instructor is erring on the legal side. I hate lawyers.

 

[markba633csi]

In specific instances it makes sense to use a glove, for example holding a longish part where your hands are comfortably far from the
drill chuck

 

[ARC-170]

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.
View attachment 504564An 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.

I agree with everything you said! We really need to get some sort of quick-clamp hold-down; using a wrench to bolt/unbolt takes too long and the vise moves a tad as it's tightened down, causing more headaches. We are in a new facility and whoever ordered the equipment didn't really think about what was actually needed (but we have 60 adjustable wrenches!).

 

[Janderso]

Ever since that vise spun on me in 8th grade metal shop , I usually secure the work one way or the other.
John and Doc said 1/2" and down is probably ok. I am probably too careful.
Drill presses can bite.
Did your shop teachers have those ugly-bloody accident pictures that scared the bajesus out of you??

 

[SouthernChap]

I wear the thin exam gloves all the time because I get sick of having my hands smell like cutting oil, plus it's just easier to get clean.

We are training these students to work as engineers and machinists in a production environment, but I've been told they can still float the vises by most of the people I've talked to. Let me know if that's not the case in your experience. As has been mentioned, I think this instructor is erring on the legal side. I hate lawyers.

This is always the problem with instructing apprentices; experience provides the ability to contextualise safety rules and so follow an adjusted safety process that still satisfies the requirements for safety but allows for efficiency.

The apprentices may lack the experience but if they're made aware of why those safety rules exist, the smarter of those apprentices might be able to take the lesson on board...

But there's the problem. Some of the apprentices won't be smart enough and will require the lessons of experience (some won't ever learn). So that's why safety advise in teaching tends to be dogmatic. That and covering the ass of the teaching institution of course.

In my limited hobbyist experience, I would use my 'de-vice' (this: https://www.warco.co.uk/used-refurb-ex-display/303570-de-vice-work-holding-system.html ) to ensure the vice didn't rotate for most of my drilling until I got a cross slide vice.

Ultimately, the place where you're teaching will have its safety policies and you'll probably want to stick to those.

 

[Nutfarmer]

Had a neighbor when I was growing up drilling plumber tape with a hand drill loose two fingers. He was enlarged a hole when the drill bit caught thus spinning the metal plumbers tape. Hard to forget.

 

[Ulma Doctor]

Had a neighbor when I was growing up drilling plumber tape with a hand drill loose two fingers. He was enlarged a hole when the drill bit caught thus spinning the metal plumbers tape. Hard to forget.

I’m usually very careful with drilling thin materials , as they tend to get wrapped up in drill bits.
I have sinned and done stupid things, luckily loss to my pride and blood losses have been minimal .
From my experience, I find that sandwiching thin materials between 2 sacrificial pieces before drilling, takes the danger away .

 

[Flyinfool]

I almost always float the vice on the DP. But I always position it with the handle against the column so that it can not possibly spin, I do this out of habit almost regardless of the drill bit size.