Pin Table

[Michael Kowalczyk]

Ok, pin tables are expensive,.

Hey Paul,
We got so busy with the design side that we missed the 1st part. What do you, or others, consider to be expensive? Let's use a 12" x 24" base, as you mentioned in your OP, as the standard to use for pricing a unit.

I know Epilog makes a 12"x12" and you can get 2 to make a 12"x24" but last time I checked they were like 395.00 each plus shipping. So that would bring it to at least $800.00+USD. Universal just came out with one that is 12"x12" with 16 pins and 4 guide pins for 325.00 each. So that's around 700.00 +- with shipping.

I bought a pin table, from Europe, for around 400.00 but it was 17"x29" and came with 80pins but I requested more. They have a 12"x25" with 50 pins for a little over 300.00. But the pins are very loose/wobbly and too short, aluminum base is not truly anodized and the business owner is very difficult to deal with and could not get refund without paying 750.00 in international shipping charges and customs. So I am stuck with an incorrectly machined block of aluminum and several 100 pins that all wobble. Maybe my expectations are high but a machine shop that supposedly does this all the time should be able to make them fit without wobbling and be taller and do it in less than 5 months.

Sorry for the nano-rant but just wanted to show that I have tried several methods and have tried a few that are currently on the market but none of them can do, what I want it to do or will be able to do, what the one I am working on will be able to do, for a reasonable price.

[Ross Moshinsky]

I'm not sure why this is complicated for everyone.

McMaster sells pins for next to nothing. We use .125"x1.5" pins PN: 98381A478. They are definitely accurate enough for a pin table. Then just take a piece of material and drill a bunch of holes. We used a thick piece of acrylic but something like Corian would work as well. It's not complicated. If you're concerned about marking your base material, just use taller pins.

[Robert Walters]

Question...

What kind of spacing between rows and columns of pins are you looking at?

Is it a H/V grid?

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Offset grid every other row?

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+   +   +   +
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How close to the edges of the base?

If you want the pins to be "snug", how snug?
Usually inserting/removing them over time would open the holes I'd think.

[Ross Moshinsky]

We did H/V with .25" spacing but honestly I don't think it will matter one way or another. Just save the file when you're done and use it as a template for laying out your parts. That way you can figure out exactly where you need the pins.

As for snug, we marked the holes on our big rotary engraver and then drilled the holes with a drill press. They are snug as the pins from McMaster are pretty darn accurate in their sizing. Will they get looser over time? Sure, but for them to get loose enough where it becomes unusable would take a good bit of time. I'm guessing years but if you use it all the time, even if it needs to be replaced annually, you're looking at an investment of a half a day at most and an annual investment of less than $20. Not really a big deal.

[Paul Brinkmeyer]

I got some brads from the local hardware store, and found a 0.065" dif in length. Just a little too much. Plus I would not know how reliable it would be if I needed more, and got some from a different batch or vender.

As far as cost.....lets just say the purchase of a pre-built fails in two ways.
1. Price is just too high for what I have found so far. I really do not have a target cost, but it should be somewhat less than the prices I have seen to date. If I could use say the steel balls, my total cost for parts would have been under $15.00. As it is for my own use and I have the time, drilling the holes might take some time, but will not stop me from selling anything.
2. I am trying to make something easy to clean or replace.

And I was hoping to use all local supplies. I might have to breakdown and order off of the internet.
Plus I do not have much shop equipment, so if my "spacer or pin" does not gauge off of the top of the plate, I will need to drill all the way through and stop off of the bottom by adding another layer of something under the corian for the pin to sit on. In other words, I can not stop my drill press at a certain depth repeatedly.

some great ideas out here.
And I am still trying different things. Today I hope to work on what height pin I want.

[Glen Monaghan]

I got some brads from the local hardware store, and found a 0.065" dif in length. Just a little too much. Plus I would not know how reliable it would be if I needed more, and got some from a different batch or vender.

Sounds like you bought loose, individual brads??? You need the flat, headless brads that are glued together in strips for nail guns. I just checked the ones I have and generally was seeing no more than 0.001-0.002" variance in length, with a maximum that I found of 0.004". I bought a couple of packages of 1000 each for something like $3 or $4 each, so probably a lifetime supply for my pin table.

-Glen

[Mike Mackenzie]

Here's another suggestion that is easy and in-expensive. This really only works for larger cutting ie pieces over one inch.For the larger parts what I do is use my cutting table and some 1/4 lag bolts. The 1/4 is the same diameter as the honeycomb cells and you just put them where you want them. It is a little bit of a hassle to get them in the area that you want but they work well and are easy and cheap. Once you set it up then you can run what you need.

I also remove the original adhesive and if necessary re-mask with the lo tack application paper.

Like I said this works well with larger cut outs will not work very well with small cuts this also will work as a location fixture when you get odd shapes that you need to do use the lag bolts in the cutting table to reference from as seen in picture 3.




Table2.jpgTable1.jpgfixture1.jpg

[Paul Brinkmeyer]

Glen, yes I bought loose brads.
To get brads for a nail gun it I will have to drive to the BigBox store. This is not longer local for me.
I do not go there very much, but next time I get close to one I will look.
Thanks

Mike, I have done similar things, and will continue to.
But I am still will look into building a pin table.
Thanks

[Bruce Larson]

Here is a totally different way to solve these problems. I cut and form bent aluminum thin sheet metal channels in many different lengths and widths, but the ones I use most of the time have about 3/4" high legs and are 1.5" wide and 12" long. Then I just place them with the legs facing upwards randomly under whatever I am cutting to have enough support for the parts. Small pieces just fall thru and have not been a problem. Occasionally, some medium small parts will tip up after cutting, but pushing stop and removing, then resumeing usually gets most everything. If I need to have an exact edge distance on the sheet, I use double sticky tape on two 1x1x3 wood blocks stuck to the top and edge rulers to set zero. Some small parts will fall thru and get re-cut or damaged, but if they are that small it is easier to just cut extras as you can't be worried about spending that much, and will save far more in labor. Oh, we tried the honeycomb, pins, small blocks, etc. but have been using this method for 5 years or so and it has been very effective. Simple and cheap.

[Michael Kowalczyk]

Hey Bruce,
Beautiful area you are in. It's been a few years since I was over there, Schlitterbahn and some resort hotel for a Thermwood training, and hopefully can get back again soon.

You know the old saying..." A picture is worth a 1000 words". save your fingers and send us 3-4000 worth of pics of what you explained above.

Thanks and ...

[Bruce Larson]

OK, here are two photos to illustrate. These particular channels have been in use for over two years, and you can see that a couple have had some HOT events, but nothing catastrophic. Ihad previuos prblems with honeycomb table getting flashback on acrylic at many of the comb joints. Here the only time the laser passes over a joint, it is only for a very small time and leaves no marks.003.jpg004.jpg

[Michael Kowalczyk]

Hey Bruce,
Thanks for the pics. That may work for large parts but might be an issue with the variety of small parts we do and they may hang up when they fall down or get in the laser path and get scortched. The way you have them currently positioned , IMHO, would inhibit much of the airflow from freely circulationing under the material. There is more than one way to tie a shoe and it sounds like this way works for you. Thanks for sharing.

How many watts is your laser? What kind of material are you cutting and how thick is it?

[Bruce Larson]

60 watt epilog, 1/8" to 1/2" acrylic.

[Rich Harman]

Here is my answer to the pin table. This was only a test piece, a first iteration of something fancier. It works well enough that for now, I can't justify spending more time on it.

The 3-1/2" 16 penny finish nails are pressed into the holes one by one, the holes are sized so that the nail fits very snugly but not so tight that it has to be hammered. Once all of them are most of the way inserted I place it on the concrete floor and use a length of PVC pipe to press the 6mm MDF all the way down.

The heads of the finish nails are spaced so that they fit into the honeycomb, it does't slide around. The nails are long enough that the laser leaves no marks on the MDF.

PinTable-001-L.jpgPinTable-002-L.jpg

[lee chitwood]

pintable1.jpgpintable2.jpgpintable3.jpg
Actually, I made a pin table using 3 laminated layers of 1/4" baltic birch ply with 3m PSA sheet on 2. Laid them out on CD, 1" o.c., 1/2" from left stagggerede. For the pins I used 3 inch Ram-set nails w/head cut off with a 4" grinder w/cut-off wheel. I bundled with an appropriate size hose clamp to hold them all at once while I ground them the same size on the former head end using a belt sander. All pins same length...very important. I miked the nails for the hole size for CD layout. I then cut all holes....alot (276)x3 layers. I keep a layout file colored with something the laser won't recognize, semi-transparent and paste over the pieces i want to cut in CD to locate the pins as required.