Jointer guards: Pork chop vs. Euro style

[James Zhu]

Peter,
Because it folds down the scales are a little confusing at first glance. Here is the folded down position.

Attachment 336113

The long bar with scale on top is used for cutting widths from where the scale starts to the blade. Notice the block is positioned against the bottom stop that is close to the slider table. This calibrates the top scale and is adjustable for blade thickness etc.

Attachment 336114

For wider widths a short bar is inserted with a fixed stop on the end and you now read the bottom scale. You can also use the longer bar for this by putting the fix stop on it. If making repeat cuts where you might flip the unit up and down the bottom fixed stop can slide over and lock anywhere on the bottom bar to keep position.

Attachment 336115

brilliant design, does not get in the way when not in use, probably the best parallel fence on the market. It would be fantastic if it had a digital readout.

[mac campshure]

My old Porters have a porkchop guard that is pretty well designed but my favorite ( don't have a picture ) is a porkchop made from wooden boards segmented like a rolltop desk. The guard folds down when off the edge to stay out of the way. The old EMA Fortis, Unitronix polish jointers used it. Dave

Hi Dave ,
this is on my Polish 410 jointer.
mac,,,IMG_0849.jpgIMG_0848.jpgIMG00072-20110103-1431.jpg

[Joe Calhoon]

Thanks for those Joe. It appears that your outrigger/support is fabbed of aluminum, and a fairly nice job. I wonder if the current offering in steel is the same dimensionally, and would support direct mounting as you show. As you know, the unit i got for my T74 was poorly executed in my opinion. I am hesitant to explore that route again.

Peter,
Mine is steel about 4 or 5mm thick, heavier where it attaches. Not pretty but functions well. It adjusts for tightness and flatness with the table. I don't know what Martin is doing with these now.
support arm.jpg
close up of support.jpg

[Erik Loza]

Ouf of curiosity, I went to the parts portal for one of the Asian mfrs. who brings in their J/P's with the Euro-style guard, thinking that perhaps I could find a source that was more competitive in price. Surprisingly, it was about the same price as it is from any of the Euro machinery vendors. Maybe the Asians are buying the Italian-made guard for their machines. That would be funny.

Anyhow, I don' have anything to add except to say that I feel there is definitely a market for stuff like this here in the states. We just need an ambitious soul.

Erik

[Anthony Whitesell]

I just finished adding the power feeder to the Grizzly G0490. Now you can see why I'm interested in the spring-loaded suva-style guard.

[William Burnett]

Well -- I went to dredge this up and had an extremely long and well thought out (at least I thought so) response, but the server dumped it when I tried to post.

So in brief: I think this entire discussion is interesting but most (all?) of you got caught up in the "exposed cutter" during normal operation discussion and the personal preference debate. Accidents in that context are 100% operator error and can be avoided, no different than (not) sticking your finger in a light socket...

We can go back and forth all day regarding what is enough "idiot" protection and if it is the job of a guard to protect you from dragging your fingers through the cutter or laying your hand on it, etc. The two styles clearly have a difference in some of those aspects depending on the operation being performed, etc.

The real question (to me) is protection during violent kickback where the board disappears and the hand is drawn into the cutter. The bridge (if it is built well) offers infinitely more protection in this scenario. There is simply no reasonable spring tension on a pork chop to close the gap faster than then hand moves toward the cutter, push block or not. You will note that even a push block will not save you, as it is likely to be ejected from your hand right after the board is ejected, and before the pork chop closes.

Sure, on thick stock there is a chance that a hand could get drawn back in and under a bridge, but that can be somewhat easily engineered of the equation. A properly designed (they can be GREATLY improved upon) bridge would offer even more protection both in normal and kickback scenarios. I will save my design thoughts on this for another day, but here are a few hints:

Looking at the "suvamatic" guard: The travel motion for edge jointing should have an easily adjustable (spring loaded index pin?) limit stop to prevent violent kickback from further displacing the guard. Likewise, the vertical motion should have the same. Not as convenient, but far safer than the just the spring. That same feature set could be used to fully lock the guard to one range of motion, (again to prevent guard displacement during violent kickback)... plenty of ways to improve upon this style of guard with minimal cost or loss of ergonomics.

Those of you "a guard-less" jointer makes you "more aware" and "safer" proponents... you're whistling past the graveyard. There is NO WAY that you have the speed or strength to prevent injury during a violent kickback, regardless of your technique or experience. Your "safety" is in your own mind and the odds are overwhelmingly against you keeping your fingers, regardless of how long you have been LUCKY.

Be safe

[Brian Deakin]

please see

https://www.youtube.com/watch?v=PsjM-FcBVp4 regards Brian

[William Burnett]

Brian: I am not sure what relevance that has to the discussion, unless it is to point out the bridge style guard? I think in that context, the style of bridge is much less desirable than the suvamatic style due to its static nature, both in normal operations and during a kickback event.

Out of scope, but in context to the machine itself... To me it looks like a modern shopsmith, with many of the same pros and cons. One could argue that it takes up more space than its mobile base mounted individual machine counterparts. That is, given that footprint, lack of mobility and need for workspace around it. Does it do each task as well as or better than each machine, etc...

[Warren Lake]

never had a jointer kick back let alone a violent one and have lots of time on them. Rear table is a chip limiter its not like a big wing cutter hanging out 1 1/2" say on a shaper where material gets sucked in. I could see issues with a Knot but still have never had them.

[William Burnett]

Warren,

I would have honestly thought the same thing, that is until I did some research while refurbing a craigslist delta knock-off. From what I gather, there are a fair number of stupid injuries (running a trailing finger through the cutter as it overhangs the back of a board) but there are plenty of horror story injuries that result from violent kickback causing the board to be ejected whilst using gravity, momentum and force to guide the fingers into the cutter.


It appears that most of these terrible accidents happen during facing and not edge jointing. Even with a very thin pass, there is significant surface area in contact with the cutter. That combined with the high cutter speed can produce a lot of force.

I don't think any particular guard schema should be mandatory (esp for home use) but do feel that there are logical improvements that can be made to what is available now. Is there a market for it? I have no idea.

I used to be the "guards are stupid" guy. Over the years have become very fond of my appendages and am always looking for safer ways to operate dangerous equipment. I just picked up a used G1023 saw for a song, but am tempted to sell it and invest in a model with a true riving knife or... I cringe to say it, a SawStop. (I am appalled that they used lawsuits to attempt to get laws passed to mandate their technology be added to all new saws when the manufacturers opted not to license it due to cost and other concerns).

[jack forsberg]

never had a jointer kick back let alone a violent one and have lots of time on them. Rear table is a chip limiter its not like a big wing cutter hanging out 1 1/2" say on a shaper where material gets sucked in. I could see issues with a Knot but still have never had them.

I think for milling select and better grades common to furniture making it's mostly true for kick back Warren , But badly warped cupped pieces can kick back because of lack of support near the head. very cupped wood milled cupped down(the common training in NA) can and does dive into the cutter block and hit the lip of the rear table making the operator slip or lose hand position. . there are also the less common operations like tapering and rabbet cuts that take large (1/2" 3/4" deep) that exposes larger section of the cutter block that can and do kick for the untrained . Some people have no idea what knife projection to use in some cases and i have seen knifes way to far out of the head to be safe and are way more aggressive and less chip limiting than when set to the proper 1/16" projection of the block. Excessive project of knifes is a major cause of kick back. I will add that the bridge is the only guard that is left in place for a rabbit cut not true of the pork chop.




Often what the problem here in NA is they have on idea how to use the bridge guard safely or the other guards that are available for other operations.

look here for safe work practices

http://www.hse.gov.uk/pubns/wis17.pdf

[Warren Lake]

thanks get all that and it makes sense.

my knives are .050 out every time, in honing they drop down a bit. I did testing when I started on my machine and a few different projections. Too high was noise and almost feel the knives pounding not sure how to describe it but that number is right for my machines. I dont get kickbacks I joint convex side down, there is nothing to fall in to the cutter. I dont take huge passes and material thickness nowadays is a disappointment compared to when 4/4 was 1 3/16 or so thick. i like to joint and plane then let it sit on its side a few days then re machine, some percent always moves

William ive never been a guards are stupid thing, same time I know people missing fingers that had guards. I was in shops that didnt have guards a long time ago different time than now a days.

[William Burnett]

William ive never been a guards are stupid thing, same time I know people missing fingers that had guards. I was in shops that didnt have guards a long time ago different time than now a days.

I too know folks who have been injured with guards in place. I am sure in some cases it was still operator error that could have easily been avoided and in other cases a flaw or failure of the guard.

I was never a safety glasses guy, and still struggle to remember them when using power tools. About 20 year I was working in a coal mine that required them portal-to-portal with strict enforcement. I picked up a very heavy piece of MUDY expanded steel guarding with a 14" screwdriver in my left hand. As I pulled the guarding out of the mud to install it back on the machine, it slipped out of my hand. My arm shot upward and the screwdriver took a deep gouge out of the glasses, glanced off of them, cut my forehead and sent my hard hat flying backward. The glasses saved not only my eye, but I am guessing they prevent the screwdriver from entering my eye and then brain....

That story has no real relevance to this actual topic other than to illustrate that guards have a purpose, be they machinery guards or personal protective equipment. I suppose it also illustrates that we all make stupid mistakes, often times without ever fathoming what can go wrong. Clearly, one should not perform tasks while holding dangerous objects that are not needed for the task...

To that point (not fathoming what can actually go wrong), I more then ever in favor of well designed guards. At least they give you a better chance when the SHTF. Likewise, I find myself avoiding dangerous equipment unless I know that somebody else is home in case something bad were to happen.