Thread: ouch!

Originally Posted by BobL

Guarding is a type of "engineering control" so its number 4 out of 6, and is the same as designing the danger out of the process,

For those that are not aware the hierarch is
1) elimination - get rid of the process altogether,
2) substitution - uses a different machine
3) Isolation - set up so the operator is completely physically isolated from process/machine
4) engineering control - guards
5) Training
6) PPE

7) Get some other sucker to do it for you.

Questions:

1) Is the musclechuck any good? I replaced my Triton collet with one, and it certainly seems alright, but I'm far from an expert.

2) Would a grrr-ripper (or however many r's there are meant to be) have helped?

Glad to see things are turning out pretty well post-surgery.

Thanks yum'
I can't comment on the musclechuck (although I may be soon looking for such a thing!) but a grrrr(?)-ripper probably wouldn't have helped in this case. I had a positive grip but that grip was too low AND there was nothing physically between my hand and the router bit. WHEN I get back onto the job I'm going to make a pair of plane tote like handles to fix to the pattern which will both lift my hands above danger and put something physical in front of them.
ive also been thinking about my spiral up-cut bit. The up-cut direction of the spiral meant that, as soon as the bit became loose, the cutting action would pull it up and out of the collet ...as it did. If I used a down-cut bit though, the cutting action would be trying to lift the workpiece off the table?
Fletty

Originally Posted by yumcimil

Questions:

1) Is the musclechuck any good? I replaced my Triton collet with one, and it certainly seems alright, but I'm far from an expert.

2) Would a grrr-ripper (or however many r's there are meant to be) have helped?

Glad to see things are turning out pretty well post-surgery.

Why not a normal trimming bit ??

I'd be expecting a bit such as the flute type which is almost like a drill to want to pull up or down depending on its use. I will admit if used with router on top that pressure would keep it out of harms way. This however would not stop the bit coming loose.

One thing I am finding is the internal shaft gap between the shank of the bit and wall allow to much movement and force being applied at the job on the jaw of the collet has to allow movement which it should not. I feel a shank spacer is required to make snug the none held part of the collet.

Up-cut bits are for doing plunge cuts like mortices etc. The up-cut action is to clear the waste which improves feed rate and reduces overheating of the bit. Down-cut bits are also usually for plunge cuts but the downward shearing action produces a cleaner edge with less tear-out than an up-cut bit. They don't clear the chips as easily and require a slower feed rate. Neither is really designed for edge cuts and I'm not sure what, if any, the benefits are of using one for that. I would use a straight cutter.

A spiral up-cut bit pulls itself into the cut, which is usually a good thing. If the bit is loose then it will probably pull it out of the collet, however that alone should not preclude using them because I don't think I'd want any bit flopping around at 20,000 RPM. The bit needs to be secure.

Incidentally these bits were originally designed for overhead routing (CNC), hence up-cut, which is actually down-cut when you have the router upside down in a table. I have a stack of them and they are very good bits. It's not uncommon for them to need a specific bushing though. For example I have a 3/8" bit which has a 3/8" shaft, so I needed a 3/8" to 1/2" bushing.

G'day Fletty, good to see that you are well on the road to recovery.

Just some thoughts re the bit coming loose especially as it appears to be the first time.

Did the bit bottom out when you tightened it? When I first started, back in the days of black and white, I had my bits marked with a fine Nikko so I wouldn't bottom them out, I quickly discovered that it was a tedious procedure and discovered the "O" ring trick. This holds the bit off the bottom and allows you to tighten the collet and the slightly compress the "O"ring. No stuck bits and always tight. The only problem I have ever found using this method is that on very rare occasions when the bit is removed the "O" ring may come out wth the bit or if the router is inverted for hand use the "O" ring could fall out. My first procedure is to always eyeball that the "O" ring is where it should be.

The other part of the procedure is to check the shaft of the bit, any gunk, rust or anything which could prevent positive clenching of the bit. Also check the collet itself to see that it is totally clean. Then and only then do I mount the bit.

Takes much longer to write than to do but it works for me.

Hope it helps you out.

Regards,
Bob

Hi Bob,
The incident itself is still a bit of a blur except for a few flashbacks and I haven't pulled the collet apart yet to check BUT one memory is that the router bit was a bit too long for the height of the workpiece and amount of router lifter travel, so I might have pushed it too far into the collet before nipping it up?
I'm looking at so many things while I'm grounded but I'm quite taken with the (I think) Whiteside router bits which have a reversing helical so that they are both upcut AND downcut in the same bit with a bearing on the top and bottom.
I'm starting to think that I did push the bit to the bottom of the collet, this meant that the collet couldn't nip it up over its full length, the upcut spiral meant that as soon as the bit came loose it rose, the cutting edge bit into the MDF pattern, the workpiece spun clockwise and dragged my left hand into the cutter.
Ive been back to the hospital today for another check of the graft and there are a few concerns but its giving me time to think.
Ive done some work on my new dust collector (poor factory assembly), started cataloguing my possessions and I've designed an Australian Colonial style dresser to use a marble slab bought off the forum and the blackwood I bought at the Boutique sale. I can't wait to get back into the shed!

fletty

Good to hear that you have a positive attitude and are looking for answers.

it is an experience you won't forget and hopefully we can all learn from it.

Regards,
Bob

Hope those concerns are not to serious Alan I thought you were being a bit quick on shed time for Saturday. Still seems you're achieving something worth while in the interim.

I feel lucky . Just yesterday I was dovetailing on a Leigh D4 doing the tails.

6mm shank in a Hitachi TR12 with a Hitachi 12 to 6mm adapter. As I was cutting the third
tail it started to feel different, it was a subtle feeling , not as smooth cutting. For those of you familiar with a Leigh
its difficult to see whats going on at the bit face if you keep your head above the jig and router.

Anyway as luck would have it, I turned the router off, and lifted it off the jig after it had stopped spinning
and low and behold the bit had started to come out of the collet so the shank was being asked to cut the
edge of the tail.

Normally I tighten my bits so that I am straining my neck muscles a bit bringing the spanners close together,
but yesterday morning having watched this video, I changed my tightening technique

http://www.youtube.com/watch?v=ggb8UgRwpA8

Never again, I will not follow his recommendations under any circumstances and will go back to tight as possible.

And Fletty's experience reinforces that all precautions not just fingers should be taken with a router.

I will not fire up my routers until I have good eye protection and leg protection ( for hand held ) . in other words
I am going to assume the worst: the bit is capable of flying off in any direction , spinning at 20000 rpm wreaking all sorts of havoc
on any tissue that it makes contact with. Thanks Fletty for alerting and reminding us of the risks.

It was going to be a busy day but my car breaking down made it even busier. I got to the hospital late for my weekly check up of the graft, the nurses were as beautiful and caring as if I was on time and the doctor was very positive about the recovery all of which put me at ease. However, scraping and removing excess bits from the graft was a different matter all together.....OUCH!
The second major event on todays agenda was to drive North to visit Daughter No1 but the broken car put paid to that. None the less, the car is now fixed and I leave tomorrow ... with possible diversions via Greg, Claw Hama, HNT and Scribbly Gum through the week ... but it just wouldn't be me to give them too much warning? In fact too much warning would give them time to be somewhere else!
I reckon I'll be back working in the shed within a couple of weeks. Any pressure on the finger sends me through the roof and that needs to go before I pick up something sharp or heavy.
It would all have been so much easier if I hadn't...........
fletty

Routing a t slot 1/4 inch stehle bit running through some tassie oak bit rose in the collet (can tell as remains were higher)broke apart push stick hit remains of shaft heard small bangs and tinkles as pieces hit walls and machinery me untouched thank imaginary friend for pushstick

Originally Posted by fletty

.......... I had a positive grip but that grip was too low AND there was nothing physically between my hand and the router bit. WHEN I get back onto the job I'm going to make a pair of plane tote like handles to fix to the pattern which will both lift my hands above danger and put something physical in front of them.

Fletty

I'm not the squeamish type, not a fan of the nanny state nor the self appointed Smart Australian Router Safety Expert (SmartARSE) but I have become cautious. I have been looking at articles and videos relating to the 'Mitre Maker' because it does what I am most fearful of and that is rout end grain and with a very low shear angle router bit. The videos show it working smoothly and without any 'snatching' at the workpiece, the workpiece appears to be held securely in the jig and, to me most importantly, it has a clear guard between the hands and router bits!
The designer seems to have thought of the 'what-ifs' but I can't help but think that a rising router built could cause an expensive although probably non-injurious incident?
i wish them very good luck with their venture but I will probably wait and watch someone else use it before I do?
fletty

Originally Posted by fletty

I have been looking at articles and videos relating to the 'Mitre Maker' yadda yadda

Do a search for same on here fletty - there was a thread on it, and I think the consensus was that such a thing could be made pretty easily for a very small cost (my recollection is that at least one member thought so.....but that may have been me.....)