Pin stops Dimmer style?

[scott m]

This is ridiculous logic because if you are not cutting shite out on the saw CORRECTLY whether you have a hand router, a CNC, an edge machine or a nuclear fission router your jobs will be incorrect off the bat. If your saw or saw guy cannot cutout 36 1/8 X 75 5/8 or whatever the sizes that are given to them then you have a bigger problem than pin stops or laser .

You yourself cannot cut this accurate, and I cannot either....Nobody can. You have to run a super z all the way around, no matter how you index your parts........This is not the case with a digitally cut part.

Anybody who runs 2mm overmaterial only on profiled edges and almost never misses raise their hand

I don't think you are getting it nick. Take this everyday situation....Take a 45 degree 16" high bar. The part is 4 feet long on the short side and 7 on the long side.(common situation)....cut it on your bridge saw with 2mm overmaterial. Put it on your pin stops....If your tools don't miss half the time, you are a better man then me. This is because, the angle involved magnifies any error in the cut. Most like you are going to place the long side against 2 pin stops and the end of the long side on the other. If the angle that was cut is not perfect and the width, you will wind up missing with this little amount of OM.

In fact, I have both laser and stops....If I were to set this up on stops I would have to use my laser to check the inherent error in placing the part against the stop.....Now the answer to this problem and I am sure most of you are doing is simply cut 1/8 or more oversize and run a super z.....And really unless you are digitally cutting, it is a necessity anyway, nobody can cut that accurate.....

The point I am trying to make is that your laser can be very accurate and you pretty much don't have to have pin stops, but it cant be unless it is mounted near the center of the table and you have and you have a precut piece to determine the error. It overcomes any error that the sawman would have made and you don't have to run so much OM.

Would someone please try this and post the results....Just put a scrap in the corner of your table on a couple of pods and leave it there all day.......

Chris.....re the thickness issue, it is true, but not too big a deal if your laser is on center. It takes a pretty big thickness difference to throw it off much. Not sure how your laser works, but on mine you can input the slab thickness. If you ask me the water on the part plays more havoc then the thickness, but I guess you don't have that problem anyway as you are not cutting on the machine(parts are dry from the saw)...

Try it man, you will not believe how accurate your laser will become.....Give me the benefit of the doubt.....You know me by now....

[Ken Lago]

Scott, are you saying one cannot cut accurate on a bridge saw?

[scott m]

Not accurate enough to run odd shaped parts with lots of angles and run 2mm overmaterial only on profiled edges using pin stops. If you are 1/16th off it turns into a big error on a 6 foot angled top.

[DavidL]

I can agree with Scott on the bartop cutting (angle) issue. I just always thought it was because my saw sucked. Now I know all saws suck (just kidding). I actually mark my VINYL (yes VINYL ladies) templates with the two edges that are my pin stop edges so my saw man knows. Everything else can be cut fat, makes for faster sawing for us. I do run a Z wheel on all profiled edges. What I don't run it on is unprofiled edges. In the case of using the laser for part placement, don't you have to run all sides? From a time standoint it may be faster to do that because it sounds like you have a faster table change than I do with the spindle locating all cups and pins for me. But tool wear and sizing has to come into play at some point I would think. Don't get me wrong, I would live to have a laser integrated to my machine, as I want all the tools available to me, but I have learned to work without it and would find it definitely to be a luxury item at this point in time.

[scott m]

There is also an inherent error in the pin stop placement. For example, if I have a 8 foot long retangle, getting it just perfect without the laser would be a PITA. I put it against the stops and then look at the laser and make sure it is parrallel.

One thing I have discovered with my laser, it is always out in the x or y or both and never twisted or skewed in any way.

[Ken Lago]

Scott, when you say 2mm overmaterial I'm a little baffled, I cut with 1/8" overmaterial anything less seems to invite trouble, I have many times had the blade glaze over and the cut not being 100% straight, the 1/8" overcut is always sufficient to compensate for that. I like a little wiggle room. The laser is great but so is the pin stops.

[GuyboR]

Scott, when you say 2mm overmaterial I'm a little baffled, I cut with 1/8" overmaterial anything less seems to invite trouble,

Ken,

FYI....
1/8" = 3mm +/-

[Ken Lago]

Scott, when you say 2mm overmaterial I'm a little baffled, I cut with 1/8" overmaterial anything less seems to invite trouble,

Ken,

FYI....
1/8" = 3mm +/-

I thought 1/8" was 4mm...+/-

[GuyboR]

3.175mm = 1/8" to be more precise.

1" = 25.4 mm

[Ken Lago]

3.175mm = 1/8" to be more precise.

1" = 25.4 mm

So we were both right...more or less

[GuyboR]

So we were both right...more or less

Yup.

[scott m]

Ken, if you do what I am saying you can get by with 2mm setting with the laser. You cannot do it however without this, pins stops or not on odd shaped parts.

[coolhandchris]

Ken, if you do what I am saying you can get by with 2mm setting with the laser. You cannot do it however without this, pins stops or not on odd shaped parts.

Yes, you can. Provided you are digitally cutting. Cue boyd on this, I had a talk with him about this last week. He does it everyday.

[scott m]

I would like to see it done with 3 pin stops......

I have like 25 pin stops that vacuum down to the table and can be placed in any position(that i have never used), I could set up 10 pin stops on a part and then yes I can guarantee it would be perfectly accurate. But with 3 stops and an odd shaped part, it is almost impossible to get it set just perfect. I know this because I do it all the time, but I have the laser to back me up.

[DavidL]

Scott I use three pin stops for each piece all day. If my saw man cuts to the template (1/8" over cut) this is not an issue at all. Even on Bat Wings. The only times I have had an issue were when the cut didn't match the template provided. I also do things for tops like circles or ovals, my saw man just makes straight cuts and they are shown as part of my "final" drawing. I true up on these straight cuts then mill out the shape via FB or z wheel.

[Jqualey4130]

In the last few months I have been getting braver and braver in what I can Digitally cut and machine. I have stopped running my super Z on most everything and I am only profiling edges that need a profile. I use pin stops and do not have a Laser. It makes your machine times shorter and lets you run more parts in a shift. But there are times (like Bat wings etc..) where it is not worth the risk of it mis-machining to run at least .1875 of over material and super Z it to make sure its is right the first time. Your air blow can move your part sometimes just a fraction enough to make life suck if you have very little over material on odd shaped stuff. (from the time you place the part against the stop to walking over and hit the button to vacuum it down it can move away from the pins a factional amount if you don't re check it.)

Its funny that most of the other trades we work with use tape measures and if its within a 32nd its amazing. We with all of our digital machines are getting screwed up parts due to a few thousandths of an inch.

[scott m]

That is my point david....You can get away with 1/8" or larger, but sometimes even with 1/8" you will have a runoff edge from time to time using pin stops or laser(no reference part).....That is .125......I am using .078.......and only on profiled edges. Non profiled edges get zip. And we rarely ever have a runooff edge....no pin stops.

Impossible to do without having a laser reference part as I described

That is my point.......I can run less overmaterial then with pin stops, no super z at all, making pin stops sorta a waste of time if you have a laser. It will only work with a reference part....Otherwise you have no idea where your laser is at any given time.

[Dan R.]

Scott, you have 25 pinstops and rarely use them? welcome to the hoarders club Hi am Dan, and I have a problem.

What is the big deal with saving the difference between .125 and .078 material? Is it that big of a waste factor? Super Z runs very fast (from my understanding) wouldn't it be better to be safer rather than 2 nminutes faster on a table of product? Is time that huge of a factor in a micro shop, like in a production shop?

I understand the possible runoff on the angled piece. I am confused about your laser being so reliable and yet always out on the x or the y but never skewed. This is confusing to me (even after 2 years of college engineering). How can one axis be out and not be skew the projection? As far as having the laser in the center, I have seen them set up at all types of goofy angles, can't they extrapolate the angles and come up with an accurate shot?

I am a bit confused on the part where your laser is super accurate and is always out on the x or y, but never skewed. Even after 2 years of college engineering, I can't make heads or tails about that statement. How can the projection not be skewed if one of the axis is out of alignment? I have seen lasers set up at several goofy angles for some reason or another. they seem to work okay.

Can't the angle of inclination and the coordinates be extrapolated via computer to compensate for any postioning (angles). I know this is done with long range shooting (the bullet being like the laser path) even figuring in gravity (bullet drop) and the Corealis Effect (rotation of the earth). Figuring a staionary target (granite) at a known distance and angle would seem easy to me. These ballistic calculators cost about $400 (I have a $200 wristwatch with the program), it seems that for north of $250,000 it should be a sovable problem.

[DavidL]

Scott-

If I were digitally cutting I could see only cutting +.078. I am manually cutting so my templates are all plus .125 on the machined edges. I would liek to know form those using lasers and not pins how tight are you ACTUALLY cutting your pieces in regards to overmaterial. Again - MANUALLY sawing, not CNC saws.

Dan - I have no idea what your talking about in relation to the shooting but my guess is that my pops does. We were never raised with guns in the house as kids, heck one of my friends dads had to show me how to shoot my first time. But in retirement that crazy old many has amassed quite the hobbyist collection and goes out to the range every Monday morning and sometimes on Wednesday. He even had my mom go out there for some "spouses" day!! Hell, whatever makes him happy .

[coolhandchris]

Also, without a hard stop in the way, such as a pinstop, you can always fudge the piece over the laser section a little bit. If you are cutting .078 OM and then eyballing a laser line, it seems like that would be within the margin of error for the human eye. Fudge it over a little more and bam, p1 works a little harder, but the boss doesn't bitch about edge runoff. On a raised bar batwing maybe they take the time to make it superperfect, but the rest of the time, it is fudgeable.

I am not knocking your method or a laser, I wish I had one for pod placement and fabcentering. But I think the lack of edge runoff can easily come from a piece placed too far over the laser and in reality, your .078 om becomes .125 and the p1 just eats it.

[scott m]

I cut 2mm overmaterial because I can...It is not about time, it is about tool wear and no super z, thus time.

I think my point is getting misconstrued. I am only stating that I can position more accurately with a laser then stops. This is only possible because of the reference part.

The laser is NEVER twisted. Either off in the x or the Y or both, but never more in the x or y from one side of the table to the other....Can't tell you why, only can tell you that is what I have witnessed for two years.

[Dan R.]

The definition of faith is believing something that you don't understand. I can not wrap my geometrical, mathematically inclined thought process around this theory at all. In this case, I have faith in your experiences and shall leave it at that.

[Lake Granite]

I overcut my parts by .092 (2.3368mm) I have never used my pinstops for setup. In fact the only thing I have ever used my pinstops for was to compensate for having complete idoits running our cnc. When they get so complacent with the laser that they dont check the pod setup before loading parts and end up setting a pod down and not lining it up. then I have used them for a known refrence to reset the parts after removing them and replacing or removing the mangled pod. I think I have done this 5 times in the last 2.5 years and has usually been with someone that was still learning the cnc process( trainee's). We never have a problem with parts not getting machined or runout of edges. I think the laser has paid for itself in setup times and luckily have not had any problems with either carter we have.