View Full Version : Safety !!

02-04-2002, 05:38 AM
How bout a thread on safety issues. Particuarly things you have learned from. For example, I learned while demonstating my shopbot to a prospective shopbotter that you can't always trust the dxf conversion to cut the inside of a part file first and then the outside - the thing caught on the router at 20K rpm and went flying! Wheew!
My latest concern is that the MDF dust I'm creating is both hazardous and possibly flamable. Dust explosion thing. I dunno. Has anybody had a problem with that. I'm not paranoid by the way, I just work for a very safety consious company (Intel) and like to take the attitide home with me. Any Ideas and experiences would be appreciated. I know at least half of us are brand new it seems and could use the advice of the oldtimers.

02-04-2002, 08:33 AM
If you look at safety regulations they are normally written 'after the fact'. 'Guard Rails' on scaffolding and safety lines attached with specifications occurred AFTER many were killed or maimed. This is simply evolution. An 'open' router bit spinning at 20-30K can create a lot of mischief. Do you have to be told to make sure it is tight? Do you need a sign that states 'do not use router to stir coffee in paper cup'. With your own machine, you are now boss, management and safety engineer. This means you are the one required to think.

Ron Brown - wdyasq@yahoo.com (mailto:wdyasq@yahoo.com)

If Stupidity got us into this mess,
then why can't it get us out? - Will Rogers

02-04-2002, 06:41 PM
Hey Ron - what a cool idea for the shopbot... coffee stirring! I take mine black though, so no stirring required.

Regarding safety and what I have learned from using the ShopBot:

Your machine will let you know if your material is not securely held down to the table top, even if you assume it IS. In two instances I had during the first few times using the machine, cut parts lifted and got wedged in between the table top and where the bit wanted to go next. The bit created enough friction on the parts to start them smouldering. Had I not been in the same room while cutting, I would never have noticed this and a fire could have resulted.

Part of the contributing factor to my parts lifting was the vacuum dust pick-up combined with the erroneous thought that a down-spiral bit would not allow the parts to lift. And the only method I had been using for material hold down at that time, was a shopvac set-up. I learned just how fast it lost holding power once parts were cut from a full size sheet of masonite.

From this I have adopted the following routines/practices...

I make sure my cut parts will not move, either by using screws or double sided carpet tape, or by screwing hold down brackets to the table top.

I always stay in the same room as the ShopBot while cutting, unless I am not cutting all the way through the material and there is no chance of parts lifting.

If I'm not cutting all the way through the material, I always stay within hearing range while cutting to make sure nothing weird is happening.

I wear hearing protectors when the router is on. I wear a cartridge type dust mask when cutting materials that spew dust even with the dust pick-up turned on. Yes, I have cut slate and a concrete/clay based house siding!

Never place your face parallel with the spinning router bit to watch it cutting. I know it sounds obvious, but who here hasn't been tempted to get that close up view? Can you say SHRAPNEL?

Never try and dislodge a spinning part that's still stuck on the router bit. Yeah it's another obvious thing but when you panic, sometimes you don't use common sense. No, I haven't actually done it.

Never manually hold down parts by placing your hand or arm in between the Y carriage and the X rails when the Y carriage is closing the gap your arm or hand is occupying. Another DUH! but again, if you're not thinking and you're watching the cutting instead of where the tool is moving, I imagine you can wind up quite sore. I've always managed to remove my arm before it's too late!

If you see the router bit glowing RED HOT, it's time to do something QUICK. I have used a squirt bottle/atomizer as a makeshift lubricating and cooling system.

I'm sure more will follow.

02-04-2002, 09:28 PM
I'm not a coffee drinker, so maybe you guys could help me out. What would the ideal feed and radius be for stirring coffee? Offhand I'd guess that the average radius of a styrofoam coffee cup would be about an inch and a quarter (I'll actually measure the first one I see), but the speed of stirring I have no clue about. (Note: I do not have an infinitely variable spindle, so the feed rate will have to accomplish the 'stirring'. Those of you with variac setups and/or other spindles capable of sub sonic speeds will have to just keep your suggestions to yourselves. Oh, never mind, I'm just ticked off that I don't have the equipment you have. Suggest away. Just try not to get all uppity about it.) Also, does a coffee with sugar and cream need more stirs (or even at a different speed?) than a coffee with only sugar? What about sweet-and-low? If the stirring is totally automated, would the coffee experience be compromised in any way? If so, would the market value of the coffee be affected?

I think it's time for some in-depth experimentation.

Science! Science! Sciencesciencescience!

Teresa Holtz
02-04-2002, 11:21 PM
Mr. Brown, why do you respond to people with the sarcasim? You turn this potential ShopBotter off. I don't know wether your joking or serious. I'm a teacher and I tell my kids the only dumb question is the one that is not asked. Every person should be responded with dignity. Safety is very important and should not be joked around with IMO.

02-05-2002, 12:36 AM
I don't even drink coffee.
I think this an important thread though and should have had it's own topic header a long time ago. Yep, I'm a safety nut. I preach it, I live it I think it's important. Thanks for the input and keep it coming. Mabey we should make sure we are not corrupting minds of youths as well? Never know who is reading and we don't want to give the wrong impression. Thanks for the input. Can we get a topic header under safety? I vote for it. Can I get a second ?..... who's in charge anyway?

02-05-2002, 12:59 AM
Ms. Holtz,

This is reality, no one is here to hold your hand and tell you everything is "OK". If one makes a mistake or 'forgets', the result can be more than serious. One is always responsible for their own safety. Safety rules are only a guide-line.

Sarcasm can be a far better tool than reality. If you would like, I can go there in the personal mode. I don't care to relive some of those experiences.

There are no dumb questions. Still, one needs to understand these are tools that can be instruments of death and destruction. To ignore this fact is to invite problems. There is no way to make tools completely safe. The more understanding one has of the power and destructive powers a tool may have, the safer one may be with the ability to control that tool.

It is a fact many of us work alone with our tools. We will not have the luxury of a supervisor or foreman to tell our family the news of our 'industrial problem', if we have one. We must think and react without government controls or any kind of supervision. The evolution I spoke of will probably not be reported in published ShopBot literature.

I hope you will tell your "students" they are responsible for their own destiny. They do not need to be a ward of nannies.

Ron Brown - wdyasq@yahoo.com (mailto:wdyasq@yahoo.com)

If Stupidity got us into this mess,
then why can't it get us out? - Will Rogers

02-05-2002, 07:46 AM
The number one biggest safety issue would have to be securely holding down whatever material is on the table to be cut (or stirred).

Now with this coffee project, I'll also have to be a bit concerned about the temperature of the coffee. If it spills, it could be a serious burn hazard.

02-05-2002, 09:14 AM
I don't know about you guys, but I think the ShopBot is the safest tool in my shop. I hurt myself pretty bad on a tablesaw one time. Coulda done it just as well on a bandsaw. I just about shudder everytime I think of what my jointer could do to one of my hands. How about injury possibilities on a planer, or even a stationary belt sander? I could go on and on.

One of the things I have come to really like about my ShopBot is that it IS safer than the Old Way I used to make a lot of my parts. For example, how am I going to get hurt when the SB is dilligently producing parts downstairs, and I am drinking coffe upstairs! Oh darn, it all keeps coming back to coffee. Most likely I was drinking too much coffee that day I got wrapped up in my tablesaw....

As I see it, all of you are correct. Sure, it is possible to hurt yourself on a machine like this (but I think you'd have to be Almost Stupid to do it). On the other hand, this type of product seems to attract people that are maybe a bit more renegade than most folks. You know, people that don't like to be told what to do. Even people like that want to go home at the end of the day with all of their fingers. That'll keep them safe enough, I figure.


02-05-2002, 09:25 AM
For mixing cake dough, a spiral down bit is best

Seriously though, I support Tom's proposal for a safety thread. However, there could be some legal issues if the "Official ShopBot Forum" gave out bad safety info under the ShopBot Company banner. Maybe the way to approach this is for SB'ers to tell of their experiences and how they personally are going to stop dangerous events from happening again. There should be a disclaimer saying that all advice given on the Forum is at your own risk, unless it is a ShopBot employee giving the advice.

Remember that most of the dangerous things like routers, clamps, dust extractors are not supplied by ShopBot and therefore the onus is on each individual for his/her own safety.

02-05-2002, 11:08 AM
Ladies and gentlemen, I worked in a shop a few years back and saw two very experienced, and respected cabinet workers meeting for the first time. Between them they had over 50 years of shop time, and had produced numerous beautiful products.But as impressed as I was in meeting them, the image that still sticks in my mind today is the fact that when they shook hands there were only 6 fingers ( total) involved...
To paraphrase an old marine saying.."eternal vigilance is the price of shop safety...".

02-05-2002, 11:24 AM
I was being really stupid once and got my hand pinched by one of the stepper motors. I almost got a bruise.

Well, to be grammatically correct I should say: One of the many times I was being really stupid I happened to get my hand pinched by a stepper motor.

But yeah, the REAL horror stories I know revolve around table saws and shapers. If you think about it, running the ShopBot is a very different kind of activity than running other power tools because, unless you happen to be running a production job that involves alot of repetitive loading/unloading, it's not essentially a hand-eye coordination activity. And even in those high production situations, it's simple enough to arrange the jigs and program the machine so that your hands and body don't ever get close to any cutting tools or moving parts.

I would be most concerned about safety issues with a ShopBot if it were running in a multi person shop or a school setting where someone other than the operator was in close proximity to the tool.

02-05-2002, 11:29 AM
The first thing that comes to mind when discussing safety and a router is when it comes to bits and knowing what their intended RPM limits are.

I read in Fine Woodworking where someone died trying to use a Rosette cutter intended for drill press use in a plunge router.

I also remember someone questioning the use of a Wagner safety planer in a router. That sounds like a shrapnel machine to me.

I've broken a few 1/4" diameter and down bits and it's no big deal, but I think bits over 1" in diameter need to be treated with a good deal of respect.

02-05-2002, 11:51 AM
I've had the same problem of a part coming loose and jambing causing the smoldering ash mentioned above. I guess a smoke alarm might be good if you could hear the thing. Then of course a simple fire extinguisher nearby is common sence.
If you wanted to get fancy you could wire up some sort of autofire extinguishing system, but who's got time for that?

As far as stirring coffee I think that at the high speeds of the router and with the right profile you could actually brew the stuff with frictional heat. It might be something worth pursueing for people warming up there fancy high frequency spindles. At least you wouldn't be waisting that warm up time. Hey you might as well grind the beans at the same time

02-05-2002, 12:38 PM
Hi to all...I've be reading the forum for quite a while now being jealous and dreaming of the day I can get my very own Shopbot. As an "outsider looking in" some of the best safety advice you have provided involved the things that someone new to the tool might not think about...grounding the dust collection system really well comes to mind. Things like this that you experts have encountered would be very helpful in keeping us hopefull owners out of trouble...thanks

02-05-2002, 12:51 PM
Anybody for a cup?


On the safety issue, where have everybody mounted their emergency stops and why?

I nearly got my arm "squeezed" by the y-car when I stuck it between the y-rails (through the gantry) and the car was approaching. So the stop switch is mounted on the front end of the y-gantry.

02-05-2002, 04:36 PM
Do you believe in Gaurdian angels? When I first got my ShopBot I was looking right at the cutter, like you shouldn't, then I reached out and tryed to adjust a homemade dust shield and my index finger hit the 1/4" 23,000 rpm blade. It was very painful, I jerked my hand back and looked at my finger in disbelief. It felt very numb, but not cut or bruised at all. Well I thanked mine and never did anything like that again.

02-05-2002, 10:59 PM
I don't like straight black coffee, but I bet the Bot would make a great cup of English Toffee Cappuccino. Possibly a 1/2" compression spiral?

As far as the emergency stop goes, right up front there, just the same yours Gerald. It's always right where the action is. One other purpose I made it serve is that I used one of the spare wires in it to mount a terminal out the side for my zero plate.

One thing that I would like to be able to do is to have the warning sound come through the computers speakers so I could turn the volume up enough to here it over other shop noises. I've tried a few things but it didn't work or it messed up something else like playing CDs , when the Bots not running of course. Maybe this could be implemented in the windows version.?

02-06-2002, 12:30 AM
Didn't expect the coffee graphic to end up so HUGE - it is only 3.6kB. Bet that Bob Neitzke is again regretting the day he taught me to post pictures here [img]http://www.talkshopbot.com/forum/clipart/crazy.gif">

Scott, interesting that you want a louder alarm. We turned ours right off. To each his own I suppose. . . . . .

David, that is a fine reason for not sharpening bits

Support (Admin)
02-06-2002, 11:57 AM
Just a reminder to stay on topic - which is safety, not coffee...

02-06-2002, 02:34 PM
Hi Support, noticed that Tom's beer opening post of 11:57am has been modified to cut out coffee

Has Shopbot Support now turned Tom's thread, in which he shared the coffee humor, into a serious "official" thread? If so, please delete my posts above. The coffee cup graphic is then completely out of place.

02-07-2002, 07:05 AM
Shop Safety,

I too have some concerns with safety.

We moved our Delta duel bag dust collector to the other side of the room. Also installed a micro fine bag insted on the regular bag. I bet there is a ton of suspended particles in the air after a day of routing. We still use masks.

The question of flamable of dust particles in the pick up tube doesn't seem to be an issue. That was the advice I recieved from my industrial equipment supplier. Aparently flexible tube no longer than 25' is too short to cause the electrical static problem.

Hold down porblem.
I suggest you create what RAMS calls a bridge. We use it on all small parts. While this is a option of RAMS, you can do it manually. We used to draw a teeensy rectangle and attach it to the sides of the part to be cut. The inside of letters stay put until finished. Make them small enough so as be able to lean down on a shart chisel, parting them free. This works for us on wood product. Plex will require perhaps only one very small bridge.

Router Bit Changing
I am amazed that we have such great computer equipment and tools to find ourselves leaning over the router, mucking about, fumbling over, the antiquated means of changing the router bits.Aside from the discomfort, think of the time lost. You would think there would be a way to change these out fast and comfortably.

When will some smart engineer put his mind to a easy tool change. Perhaps bits with a notch that feeds into the holder with no threading. No stinking collets. Doesn't the router turn in only way. A half lock system seem like a sinch.

Perhaps this is just my proble. Pardon the rant.


02-07-2002, 08:14 AM
Hi Joe, what others may call "bridges" are called "tabs" by ShopBot. If you are going to use only one tab, then this must be right at the end-point of the cut - similar to stopping just before you have cut all the way around the part.

02-07-2002, 03:31 PM

There are auto tool changing router heads/spindles. Unfortunately, they are VERY expensive and probably half of the cost goes to product liability!

Tool changing is fairly straight forward (most every Machining Center has one) but most machines that do have tool changers are "encased" or have shields or guards around them.

On the Shopbot (or any router) you have two things that make it more "difficult". First, most routers are open framed so if a tool collet/bit was to come out, the chance of it hitting someone is MUCH greater.

Second, because of the high RPMs of the router, seating, locking ect are much more of an issue. If a tool or collet was to come out at high speed, the tool or collet will contain a LOT more energy than if it came out of a VMC (which generally do spin their tools over 4Krpm).

Now, if you figure out a system that gets around these problems (and many have) but you can do it inexpensively, sign me up as your first customer!

Bruce Clark

02-09-2002, 12:47 AM
Ok, no more beverage comments from me either. I think some kind of auto change system would be great. Automation is the first step in an injury free workplace. So as was said before, the Shopbot gets you most of the way there. There are still possibilities for improvements. What would be the best size dust collector and flters to keep the dust hazzards down? I'm looking at the JET series. They have a 600 and 1200 cfm that look reasonable. Do I need 1200 cfm or would 600 do for just the shopbot? What micron size of fliter should I get for MDF dust?

02-09-2002, 09:12 AM
Tom, I use the Jet 1 h.p on one of my Bots, and it does a great job. I also use an old Reliant 1 h.p. on my other machine, and that works almost as well. I think it really comes down to the distance you will have between your Bot and the dust collector. I run about 10 feet of hose for the Jet, and 14 feet for the reliant with a grounding wire on both.I also have one of those "air filters" that collects a lot ( but certainly not all) of the very minute particles which remain suspended in the air long after you are finished cutting. It's amazing how much fine dust that can pick up in a short time, and the scary part is that if IT is not picking it up, my lungs would be...Go for the best dust collection your wallet can handle,since in the long run it may be the most important tool in the shop..As has been said a few times before " you BUY a dust collector, or you ARE the dust collector...."

02-11-2002, 01:37 PM
The Material Data Safety Sheet for MDF makes interesting reading (sort of). Here's a quote from it:


There is a copy in the incoming folder on the ftp site.

Dave D.

03-19-2002, 01:08 AM
Tom, well as always I'm late in reading the forum but if you haven't gotten your vac system check out the line that Grizzly has at grizzly.com I own the 2 hp unit and have for about 8 years it has never given me any trouble.also for fine dust use a 5 micron filter bag on the top bag and as far as Bill's coment on the distance he is right but you also have to take into consideration the elbows flexible tube etc. they also have a book on figuring out your vac requirements

Mike Schwartz
03-29-2002, 04:09 PM
You may also want to check out Oneida Air Systems dust collectors. They're top notch at a reasonable price. http://www.oneida-air.com/

04-04-2002, 09:21 AM
On the subject of safety,
I'd like to add one small thing I learnt decades ago, when I worked for ESSO Standard Oil Co.
ESSO was/is big on safety
(petroleum products: yuh THINK??)
and maintained a huge billboard in the yard,
which one couldn't miss each morning as one arrived to work!

Check this, and let it stick with you...

- They are CAUSED !!!

11-08-2003, 12:31 PM
I recently acquired a second Shopbot and have been facing a new safety challenge. While before, when I had one machine, I relied on hearing the router’s noise as a obvious means of telling myself “hands off”, I now find my hands having some “close encounters” with the router bit because I fail to identify the router as being switched on because of the noise of the second machine. This is accentuated by the use of hearing protection which makes the sound of a router spinning in the air fade in the background of another router which is in a cutting mode.

Most of the safety issues come back to the use of common sense procedures and constant vigilance. But I would like to hear of any suggestion of techniques which you may be using, which would help remind oneself of the current status of the router.
I would like to be able to access the wiring of the router (PC) after the on/off switch in order to power a warning light. Has anyone tried that?

Thank you


11-08-2003, 12:37 PM
Maybe connect a second on/off switch somewhere else in the cable to the router - more accessible for your hands, and to connect a light? ie. leave the built-in switch of the router permanently "on".

11-08-2003, 12:45 PM
ShopBot has relays available that you can use to power up and depower your router during the beginning and the end of a cut. I am fortunate to have some and they work very well. when you start the file the router starts and shuts don at the end of the cut.

If you wish you can build them yourself, ShopBot hase the schematics available in your owvers manual. With the relays you could also include a flashing strobe or something similar to indicate router movement.


11-09-2003, 03:28 AM
How about one of those yellow flashing lights? Not too bright or it would get tiresome. I'm sure grainger.com has a bunch of them. just an idea. A lot cheaper than doctor's and medical bills.

11-09-2003, 05:17 PM
The second on/off switch is an easy fix to your problem. Just wire it to control the outlet where your router is pluged into and wire the switch to a location away from the ShopBot. I installed a switch with a light for my wifes' soldering iron for her stained glass, but no flashing light though, just a low wattage red bulb. Since then her iron has not stayed on for any longer than needed. If you do decide to do a "remote switch" to control your router be sure is rated to handle the amps pulled by it. With a little extra to handle the flashing yellow light. As far as dust goes, I don't think you can totally stop it, unless you encase the entire shopbot in a dust cabinet. I have seen one done that way when I was looking to buy one, a PRT48, totally encased in plexi-glass with drop sides to allow access for material placement and part removal. Personally I have a home-made dust collection system that does a good job, except for the dust that settles on my wifes' glass that is.