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Putting some grip (stippling) on an aluminium drive pulley.

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JimDobson

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Very interesting to witness this massive divide in practicality between countries, I posted this on the largest Aussie engineering & machining group there is and mentioned some of the comments and thoughts that have been espoused here......very very different reaction from fellow Aussies.
 

Steamchick

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Curious how when you read history, there is usually someone who thinks "it can never happen" - even after disasters occur. And so many disasters occur because someone who should have known better "didn't think it would matter"... e.g. Space shuttle explosions (because they flew when the book said "don't fly when the temperature is below ..."), Chernobyl ("Don't operate in this temperature range as it may run-away"...), Windscale, 3 -mile island, etc..... so it is not just in the home workshop that people ignore good advice from those with different experience.
Insurance companies gamble that disasters will happen, but the gamble is "when"...
On these Threads, we (the responsible? - including me) should endeavour to make things as safe as possible for the "uninitiated" (dare I say "innocent? - including me) readers who may not have the experience of how easy a "simple" job can become a disaster, and minimise "risky" advice. That is all anyone is really doing here...
Count your fingers before and after doing jobs with sharp knives. - Just in case....
K2
 

goldstar31

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But Ken( Steamchicken), the civilised world needs people who 'make mistakes' like 'Jim' and true to his type, he is showing other people to perpetuate his recommendations. Whether we like it or not we agree, they will continue- regardless of those 'good-doers'
So yesterday, I wss simply 'playing' in the workshop enjoying an uneventful assembling a motor and belt and whatever to makea tool and cutter run again. Frankly, I'm sorry to bore everybody. It was all to plan and that was that.
This morning the news broke that TWO pharmaceutical firms have future orders for supply the WORLD with vaccines. Great, I'm absolutely fed up with being deprived of enjoying what remains of my long life.
I'd wanted to 'have dinner in the best gentleman's club in Hong Kong' and with a bit more luck to go on a cruise and change out of my dirty, oily corduroys and perhaps 'cross the Tasmania' whatever that is.
I've worked bloody hard to be in such a position to do all of them but have looked after my family and its future and gained a lot of lovely friends.
So all that is left is to wait for 'Jim' to need medication for his inevitable 'self inflicted injuries' I'm am an old trooper- I've been there.

So all that I have to do is sit back and enjoy the dividends coming from one of those pharmaceuticals and also from yet another similar firm.

So thank you 'Jim' and the rest of you. I do appreciate just how valuable to society.

Your contribution has also greatly helped to fund research into things of which we have no control.

Oh yes, indeed! What would we do without the 'Jims' of this World?
 

Jules

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An interesting thread.
Many things in life have a degree of risk.
Jim lives in a country that had many dangerous snakes, spiders etc.
I know only to well how a simple operation with a powered tool can result in injury even when taking what you perceive to be enough care.
However I also enjoy watching many videos on the internet of people teaching skills Or demonstrating their skills.....Maybe doing stunts on a mountain bike.......or tricks flying a helicopter........
Some countries of the world still use massive heavy unguarded machines to produce many of the cheap items we like to buy.
My point is....In some countries we have evolved our use of machinery and place a high priority on safety.
I think we should be a little more tolerant of differing standards.
 

jack620

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Very interesting to witness this massive divide in practicality between countries, I posted this on the largest Aussie engineering & machining group there is and mentioned some of the comments and thoughts that have been espoused here......very very different reaction from fellow Aussies.
Which forum is that Jim? I’m only aware of Metal Work Forums where I’m a regular, and I haven’t seen you there.
 

jack620

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Regarding Jim’s video, it’s not how I would have done it, but I don’t care what other people do in their own workshop. I don’t care if they video it either. There are people fitting pulse jets to bicycles and posting videos of themselves riding it. That doesn’t mean I’m tempted to do it. Anyone familiar with YouTube knows you don’t take everything you see as gospel.

And to be honest, the pile-on I’ve just witnessed over the last few pages is nothing short of disgraceful. And how the hell did we get from a video of a man using his lathe in a questionable manner to Chernobyl? Ridiculous.
 

Steamchick

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Fair comment Jack. I was throwing that in to give this some perspective....
Both actions seemed OK to the operators with their experience.. but hindsight suggests the Chernobyl operator should have considered... "maybe not ". Being fair, we all do things we should not teach our children, but maybe we can all - or collectively - be self- censoring when we overstep the mark of sensible actions?
 

willray

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Very interesting to witness this massive divide in practicality between countries, I posted this on the largest Aussie engineering & machining group there is and mentioned some of the comments and thoughts that have been espoused here......very very different reaction from fellow Aussies.
I can see that. If I were to show one of my friends something equally dumb-but-not-life-threatening, I'm pretty sure that a good number of them would be saying "Yup, Go for it Will! Here, I'll hold your beer!"
 

Cogsy

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I'm sorry, but did you actually watch the video, or are you just arguing with the "safety nazis" just because you think they're safety nazis?
Nothing to be sorry about. I skimmed the video (it's a bad habit I have) but I have since gone back and viewed the relevant bits to make sure I didn't miss anything.

The cutter was being held in a pair of (modern-day irwin's version of) channel-lock pliers, which rely on grip strength to hold the part. The forces applied were out of the plane of the jaws, and in the weakest possible direction for channel-lock type pliers - a direction in which I've experienced plenty of things pivot, even when I thought I was being a gorilla on the handles.
I agree the force was being applied in the weakest direction of the tool, I don't agree on the name of the tool (because we call them 'multigrips' in this country).

His knuckle is within 1/2 inch of the rotating dremel saw, while the saw is being driven by the work.
I think 1/2 inch is understating it a bit, but his fingers were close.

It's blatantly obvious - because it happens in the video - that it's easy to slip off the end of the work, and because of the force "pushing into" the work to get the saw to act as a knurl, there's a lot of surprise excess motion when that slip happens. Plenty of motion to drive his finger into the saw, or the saw into the work at an unexpected angle, etc. The only reason this wasn't a video about a gashed knuckle, is because of luck.
If the tool slips off but stays secure in the multigrips which he is holding, there's no way for the blade to get to his fingers, and if it slips off it is no longer driven so won't have enough momentum to cause much of an injury. If the blade pivots in the multigrips, as we both suspect is possible, the blade could still be driven and may come in to contact with his finger. However, it will also come into contact with the side of the multigrips and this will a) stop it going deeper into his finger and b) stop the blade quickly as he lets go of the whole thing. There'd possibly be an injury but it's likely to be slight. Honestly, I end up with a 'gash' that needs patching at least every couple of weeks, either from bumping a milling cutter, sliding my finger along something I shouldn't or just bashing into something hard. If I don't have to stop working for more than a few minutes then I don't consider it a bad enough injury to worry about.

At the same time his fingers are within 1/2 inch of the driven saw blade, they're less than an inch from the chuck jaws.
Isn't this incredibly common, even routine? Mine get far closer when I'm sanding or sometimes filing a workpiece.

Using the dremel saw blade as a knurl is a clever expedient, exactly the kind of thing for which this site exists.

Defending the way that it was used, and pretending that it's acceptable to promote that approach as a reasonable and safe way to use the tool, is patently insane.
I believe there was some risk of injury during this process, but I don't believe it was as heinous as some are suggesting. I also would not recommend a beginner attempt anything like this - just as I wouldn't recommend a beginner do any filing under power, graving, metal spinning or even aluminium casting.

I also don't recommend anyone follow some of the things we commonly see and hear about on the forum from (sometimes) very experienced builders/machinists. For example, we see plenty of photos and videos with visible jewelry, people using and advocating emery cloth for sanding a rotating part and even people defending their use of compressed air to clear chips because "I've been doing it for years".
 

willray

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...
Many things in life have a degree of risk.
...
However I also enjoy watching many videos on the internet of people teaching skills Or demonstrating their skills.....Maybe doing stunts on a mountain bike.......or tricks flying a helicopter........
I seriously hope that no-one here is engaging in the "sport" of machining for the adrenaline-rush of leaving the shop at the end of the day with all of their fingers still attached!

If you are, I'm gonna suggest that you might be doing it wrong...
 

terryd

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Nothing to be sorry about. I skimmed the video (it's a bad habit I have) but I have since gone back and viewed the relevant bits to make sure I didn't miss anything.



I agree the force was being applied in the weakest direction of the tool, I don't agree on the name of the tool (because we call them 'multigrips' in this country).


I think 1/2 inch is understating it a bit, but his fingers were close.


If the tool slips off but stays secure in the multigrips which he is holding, there's no way for the blade to get to his fingers, and if it slips off it is no longer driven so won't have enough momentum to cause much of an injury. If the blade pivots in the multigrips, as we both suspect is possible, the blade could still be driven and may come in to contact with his finger. However, it will also come into contact with the side of the multigrips and this will a) stop it going deeper into his finger and b) stop the blade quickly as he lets go of the whole thing. There'd possibly be an injury but it's likely to be slight. Honestly, I end up with a 'gash' that needs patching at least every couple of weeks, either from bumping a milling cutter, sliding my finger along something I shouldn't or just bashing into something hard. If I don't have to stop working for more than a few minutes then I don't consider it a bad enough injury to worry about.


Isn't this incredibly common, even routine? Mine get far closer when I'm sanding or sometimes filing a workpiece.


I believe there was some risk of injury during this process, but I don't believe it was as heinous as some are suggesting. I also would not recommend a beginner attempt anything like this - just as I wouldn't recommend a beginner do any filing under power, graving, metal spinning or even aluminium casting.

I also don't recommend anyone follow some of the things we commonly see and hear about on the forum from (sometimes) very experienced builders/machinists. For example, we see plenty of photos and videos with visible jewelry, people using and advocating emery cloth for sanding a rotating part and even people defending their use of compressed air to clear chips because "I've been doing it for years".
Your comment about not recommending the process to a beginner is exactly the point that most of us were trying to emphasise. If people are carrying out such fringe and dangerous techniques and publishing them for all to see there should be some qualifying message such as "don't try this at home, I have years of experience and understand the dangers." Keith Appleby for one repeats such warnings frequently in his excellent videos as do many others.

In reply to another of your points, Jim uses a second finger to increase the pressure on the blade partway through the process and that finger is very close to the rotating saw, one slip while applying that force and the rotating blade is trapped between work and finger, damage is done in a fraction of a second in such a situation before one has the realisation that something is happening.
TD
 

Jules

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Anyone ever heard of Mount Everest ?
Bloody dangerous mountain.
People try to climb it and some even die trying.

Please be careful getting off you high horses guys.
We wouldn’t want an accident !!!
 

Bentwings

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I guess I missed the video.
But I’ve run aluminum veerepulleys on cars to where they broke s flange off. Usually breaking the belt too.if the belt is slipping it’s usually caused b6 not enough wrap around the pulley. As I recall the rule was less than 90 deg included angle. The most I ever did was lightly sand the groove with medium grit sand paper .pulley off and just hand sand a little. There used to be belt dressing in the shop but it just gummed things up. I also used the notched type belts as they bend easier. I don’t touch anything rotating .
no loose clothing rings watch bands. One of my former employers was a master machinist. He had his watch in a button hole in his shirts. I didn’t think think even that was safe but he was the boss. A single comment about it could get you an hour lecture on shop safety.
I value m6 body parts and don’t like theER trips. Either for me or taking someone there.
 
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