CNC Adhesive Application ??

[eric_halpern]

I'm considering buying a Shopbot for adhesive application. My plan is to replace the router with a battery powered caulking gun and buy empty caulk tubes to fill them with the adhesive of my choice.

I need a Shopbot owner in the Philadelphia area to help me with this. I would fabricate and adapter that would mount my caulk gun in the same brackets that mount a Porter Cable 7518. Then run a simple drawing that draws long "X" back and forth lines of latex caulk on paper or 1/8" masonite.

The slowest speed of the caulk gun lays out a continuous 3/16" diameter string for 12 to 15 minutes. I need to learn what IPS or IPM setting jives with 10 ounces of caulk.

I want to make sure I can draw reliable patterns before I plunk down money for a machine of my own.

Anybody in the Philly area willing to run this experiment with me? I'm willing to pay for your time!

Thanks,
Eric
cell 610-710-9099

[Gary Campbell]

Eric..
This should be a fairly easy process to accomplish. You can draw out your caulk patterns using PartsWorks or any CAD program for that matter, and toolpath the machine movements from them.

Once the partsfile has been generated you can add lines to it to switch your caulking gun on and off. Personally, I would try to use multiple air operated guns that can be switched by the control software from the modified parts file.

You will have to experiment to find the speeds that work best, as there are many variables that can't be calculated ahead of time.
Gary

[eric_halpern]

I'm not sure how controllable the air powered caulk guns are?? I know the electric type are easy and smooth. IN the final version I'd run a power supply in place of the battery and install a limit swith on the z-axis to turn on the caulk when the z lowers to the work area and off again when it rises.

I still need to have some limited experiance with this before I can justify a machine purchase (used or new).

Thanks,
Eric

[Gary Campbell]

Eric..
The electric may be easier as you say. Another option is to switch the gun(s) using an output from the control software. This will insure that the gun is on or off when needed independently of Z position.
Gary

[coolhammerman]

Eric:
It is incredibly easy to control the caulking gun from the software. The same relay that turns the router on and off with a command line in a Shop Bot program, will effortlessly dispense caulk when and where you want it. First lock the caulking gun in the ON position. Then plug it into the power source (such as an extension cord) coming from the control box in your Bot. When the program is in position, the software will allow the caulking gun to dispense and when it needs to stop, the software will interrupt the power effectively turning the gun off.

The command is:

SO,1,1 'Turn Caulk Gun On

(Add movement commands here)

SO,1,0 'Turn Caulk Gun Off

Repeat this sequence as often as you wish.

Easy as pie. Good Luck,
Ron

[eric_halpern]

Guys, I appreciate the details.

What I need to know is how smooth the procedure will run?

Will the caulk "paint" evenly, or will it be blochy or thicker at the start of a run and thinner at the end?

Will the delivery to the wood (or paper for testing) hang corners without breaking the bead?

It would tell me a lot to run someone else's pattern on their machine with my caulking gun and Cable Porter adapter.

Anybody within an hour of Philly want to play? I'll gladly pay for your time.

[Gary Campbell]

Eric...
I am sure that you can get your process working. There are many more complicated processes than yours working fine out there. The speeds (move, corner, ramping)are all able to be set to meet your needs. I think you are more likely to be limited by the quantity held and uniformity of bead of the gun than the ability of the ShopBot to move the tool.
Gary

[jseiler]

This may sound silly but...

You can find out some things by pretending to be a cnc machine. Lay out some scrap, approach the work from the top and push the trigger like you imagine a shopbot would. Just be robotically consistant. If you can do it by hand simulating a shopbot, you'll do even better with a bot. If it takes intelligence to do the job right, the shopbot could still probably do it well, but you'll have to program your toolpaths more carefully.

I think some of the big questions are...does the caulk act the same way all the time? Does temperature affect it, air flow, rapidity of movement, humidity? Does it always break bead when you lift to a certain height?

As far as breaking the bead at the end, you can always end your glue early and pull really far away from the work to insure it breaks.

One of my friends used to work for a company that made glue dispensing guns for high speed corrigated box lines. The used high speed solinoids to make dashes, dots, thin the bead, etc. Those lines move fast too.
You may end up with a higher tech gun at some point to get really good consistancy.

John

[ed_lang]

ShopBot makes a relay board that will give you 5 controlled relays to control your glue gun. You will not be presented with the push the start button when you issue a SO,1,1 (Switch Output #1 to on). This may not make sense to you now, but it will to other ShopBot owners now and you too will know all about it soon.

My suggestion would be to call ShopBot and talk to them about this application. I expect I could have this working real quick if I was closer to you. I am in Central Virginia, more than a short ride from you.

Let us all know what you decide to do.

[khaos]

Also, remember the basics that adhesive/chalk "behaves" better at a warmer temp. My experience with my air powered chalker has been the cooler the tube the less consistant the output is.

Just my 2 cents,

[oddcoach]

Hi Eric
I am about 45 min north of philadelphia and would be happy to experiment
John Haggerty