Ben's 2.x Laser Build

Post your build logs here

Laser tube #1 bites the dust

Postby BenJackson » Wed Jun 01, 2011 5:31 am

I don't think this needs much explanation:
IMG_0599.JPG


The other end (rear) had a much fatter fitting that required much more force to get on and came out fine...
BenJackson
 
Posts: 494
Joined: Fri Apr 15, 2011 6:13 pm

Re: Ben's 2.x Laser Build

Postby LeonS » Wed Jun 01, 2011 11:48 am

Bummer.

You may be able to fix the break since the CO2 seal was not broken. If the break was clean, a good epoxy might do the trick.

Regards and sympathies,
Leon
LeonS
 
Posts: 145
Joined: Wed Nov 25, 2009 8:09 pm
Location: Herndon, VA

Re: Ben's 2.x Laser Build

Postby BenJackson » Thu Jun 02, 2011 2:37 am

My air pump http://www.amazon.com/Active-Air-Commer ... B002JPM91W arrived today. I really wasn't sure how "70LPM" was going to translate to real airflow. It seems to be about right. I tested it through my 10' of 3/16" Tygon threaded through both cable carriers. It's reasonably quiet for its size and has large, squishy rubber feet (with mounting holes) that isolate it very effectively. If you use the manifold (and let it touch any hard surface) it will make far more noise than the pump. You could use it unmodified with the stub of fat tubing plus the manifold to reduce to 3/16 (and the manifold includes a ball valve on each outlet), or buy a new brass fitting to go direct to 3/16".
BenJackson
 
Posts: 494
Joined: Fri Apr 15, 2011 6:13 pm

Re: Ben's 2.x Laser Build

Postby twehr » Thu Jun 02, 2011 11:24 am

[quote="BenJackson"]My air pump http://www.amazon.com/Active-Air-Commer ... B002JPM91W arrived today. I really wasn't sure how "70LPM" was going to translate to real airflow. It seems to be about right. I tested it through my 10' of 3/16" Tygon threaded through both cable carriers. It's reasonably quiet for its size and has large, squishy rubber feet (with mounting holes) that isolate it very effectively. If you use the manifold (and let it touch any hard surface) it will make far more noise than the pump. You could use it unmodified with the stub of fat tubing plus the manifold to reduce to 3/16 (and the manifold includes a ball valve on each outlet), or buy a new brass fitting to go direct to 3/16".[/quote]

That is the one I am using and it does extremely well. I tried using the manifold with a single outlet from it. But those outlets are too small. I went with a single line from a new brass fitting. Works great.
twehr
 
Posts: 439
Joined: Mon May 24, 2010 4:49 pm

Re: Ben's 2.x Laser Build

Postby BenJackson » Sun Jun 12, 2011 8:28 pm

I got bored waiting for my replacement tube to arrive. I 3D printed a patch to go over the broken water fitting and epoxied it on. When a pinhole leak developed through the patch I just sealed the whole thing on with more epoxy. It's not pretty, but it is water tight!
IMG_0605[1].JPG
Band-aid for broken water fitting


That also illustrates how surgical tubing (in that case 5/16" which Ace had) is extremely prone to kinking even in a fixed connection like that.

On the other end I had already successfully installed the Tygon, which produces a much tidier connection:
IMG_0606[1].JPG
Other end with Tygon tubing


When I attached the tubing to the pump I tried a few methods since I was no longer worried about babying the tube. What I found worked best was to stretch the tube with needle nose pliers (jam the jaws into the tube, then pull on the handles in the "opening" direction) twice (rotate 90 degrees and jam the jaws in farther). Then coat the glass and tube with dish soap. The stretching is especially important for the fittings which are much bigger than 1/4" (on mine, the ones at the rear of the tube). The tubing quickly relaxes. The soap that gets into the tubes washes out.

Here are some spots I made. The smaller ones were at the lowest power that would start the tube and for the quickest tap I could get on the "test" button on the PSU. The only thing I had connected to the control pins was the power pot.
IMG_0607[1].JPG
Zot!


The water pump http://www.amazon.com/EcoPlus-Submersib ... B0018X2XT4 is great. Good flow, very quiet. The fittings are far too big for 1/4" tube (in fact, the ID of the fitting accepts the OD of the tube, which is how I have it jammed together right now). I need to take the plastic fitting to the store and find something to replace it.
BenJackson
 
Posts: 494
Joined: Fri Apr 15, 2011 6:13 pm

Re: Ben's 2.x Laser Build

Postby naPS » Sun Jun 12, 2011 9:15 pm

The easiest way to get the tygon to push onto the tubes is to heat it up in some nearly boiling water for a few seconds. Once you do that, it slips right on. At least, it did for me. After it cools, it returns to it's original rigidity, which produced a water tight seal for me.
naPS
 
Posts: 202
Joined: Sat Apr 09, 2011 1:53 am

Re: Ben's 2.x Laser Build

Postby dirktheeng » Mon Jun 13, 2011 9:18 pm

that's pretty cool ben... I may have to build a 3d printer myself!
dirktheeng
 
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm

The Second Coming

Postby BenJackson » Tue Jun 14, 2011 6:49 am

Buildlog 2.x Laser with laser 2.x, now with more dogbone:
IMG_0608[1].JPG


Also visible in the lower left is the air pump named elsewhere in the thread. Bottom center is the dead-bug/Manhattan style protoboard with L298 drivers which I originally built for my CNC Etch-a-Sketch. That's what drove the steppers in the earlier video.
BenJackson
 
Posts: 494
Joined: Fri Apr 15, 2011 6:13 pm

Re: Ben's 2.x Laser Build

Postby BenJackson » Mon Jun 20, 2011 7:24 pm

dirktheeng wrote:I will be interested to find out how valuable the led pre-alighnment turns out.

To install my new tube I:
  • Loosened the bottom setscrews all the way
  • Removed the holders I made for the setup laser
  • Installed the tube by sliding it in from the right (as viewed from the front)
  • Held it against the upper setscrews and rocked it slightly while tightening the bottom screw to ensure I felt when it contacted
The tube is oriented so the electrodes are straight up. This puts the final water outlet up which seems to be necessary to clear bubbles from the system. This requires routing the outlet tube back and up to avoid the Z motor bracket, but everything clears.

The total of my adjustments after installing the real tube was to make a 1/16th turn of the first mirror to swing the beam out about 1.5mm at the far end of the Y travel. I made test spots everywhere but I didn't adjust anything else. After making a test spot through the final mirror I installed the lens and made a final test spot at the approximate focal length. I was shocked at how small it was after doing all the other test spots!

I haven't installed the air assist nozzle yet because I want to tap it much deeper and possibly get a different hose barb for it (or just cut the original one shorter). So I'm not sure my beam will go through the assist, but I was careful to make the unfocused beam perpendicular so I'm fairly confident.
BenJackson
 
Posts: 494
Joined: Fri Apr 15, 2011 6:13 pm

Re: Ben's 2.x Laser Build

Postby BenJackson » Tue Jun 21, 2011 12:38 am

Here's the first thing I cut that was more substantial than paper:
IMG_0609.JPG


I still don't have my control board so that was done by pasting gcode into a terminal window talking to an Atmel AVR dev board (similar to Arduino) driving hand built L298 half-stepping controllers. I edited the gcode to make two passes and I just hold down the "fire" button for one complete circuit in the middle.

Whatever that cheapo thin plywood is (I think I salvaged it from packing material) it leaks out a bunch of burned sap like crap when cut. I'm glad I'm cutting on a temporary flat steel sheet because I wouldn't want to have to clean that mess off the inside of my machine! I guess there's a lesson about selecting quality plywood for laser cutting!
BenJackson
 
Posts: 494
Joined: Fri Apr 15, 2011 6:13 pm

PreviousNext

Return to Build Logs

Who is online

Users browsing this forum: No registered users and 3 guests

cron