Buildlog.net Open Source Laser

Post your build logs here

Re: Buildlog.net Open Source Laser

Postby rEd86 » Mon Aug 16, 2010 3:54 pm

I think it makes more sense to keep them all NEMA17 to keep the costs down, as well as making sourcing the parts easier. I wasn't sure if because of all the threaded rods in the Z-Axis, you needed more power. Given it's not having to move quickly or often, I figured it was based on parts you had lying around.

---Ed
rEd86
 
Posts: 0
Joined: Mon May 03, 2010 6:11 pm

Z Axis Changes

Postby bdring » Sun Aug 22, 2010 7:27 pm

In preparation for the 3D printer head I am adding, I upgraded the Z Axis to improve it's smoothness. Previously the table ran up and down on leads screws only. This worked fine for adjusting the height. But the table would shimmy a little due to some lead screws not being perfectly straight. This is not an issue for laser cutting, but it will show up as vertical imperfections when printing.

I added some Misumi 20x80 vertical extrusions with v track and v groove bearings.

I also decided to switch to a NEMA17 motor and MXL belts. This will make all of the motors, belts and pulleys common. I decided to do a 2:1 ratio for more strength by making the motor pulley 18 tooth and the lead screw pulleys 36 tooth. The 36 tooth bigger lead screw pulley probably removed the requirement for folding back the belt on the pulley, so I removed all those extra bearings.

I had my digital camera ride the table up to show it's smoothness. The clicking is a non straight lead screw, but it does not affect the smoothness.
.
z_axis_nema_17.jpg
NEMA 17 Motor

z_axis_mxl_belts.jpg
MXL Belts and Pulleys

Bart
"If you didn't build it, you will never own it."
bdring
Site Admin
 
Posts: 2966
Joined: Sun Nov 22, 2009 7:33 pm
Location: Chicago, IL, USA

Re: Buildlog.net Open Source Laser

Postby macona » Sun Aug 22, 2010 8:58 pm

You know, good acme threaded rod is not that expensive. You can buy it and the nuts from McMaster and other places. Cheapest is 1/2-10 at $31.20 for 6'. It will solve a lot of wobble issues.
macona
 
Posts: 363
Joined: Tue Aug 17, 2010 10:30 pm

Re: Buildlog.net Open Source Laser

Postby bdring » Sun Aug 22, 2010 9:08 pm

I don't have any issues anymore. Even ACME thread would still need a track to meet the stability I have now.
Bart
"If you didn't build it, you will never own it."
bdring
Site Admin
 
Posts: 2966
Joined: Sun Nov 22, 2009 7:33 pm
Location: Chicago, IL, USA

Re: Buildlog.net Open Source Laser

Postby rEd86 » Sun Aug 22, 2010 11:37 pm

That is an excellent solution. Yes, an acme rod would be an improvement over the old threaded rods, but this is a rock-solid solution that should give even better results. How easy was it to level the build platform the first time? Some closeups of the new mounting brackets for the build platform would be enlightening.

--Ed
rEd86
 
Posts: 0
Joined: Mon May 03, 2010 6:11 pm

Re: Buildlog.net Open Source Laser

Postby bdring » Mon Aug 23, 2010 1:28 am

The other buildlog has more details. I need to figure out what goes on what buildlog :)

Adjusting is very easy. It is done before attaching the z slides. I used the gantry as a reference point. I raised the platform close to the top. I then measured down from the gantry from the highest corner with my caliper. I then raised each corner up to that point by rotating the t nuts up. You lift the corner so the t-nut is free to rotate. This will get you to with 0.013" worst case. (1 / 18 tpi / 4 t-nut points). If you want to tweak out the last few thou you can loosen a pulley from the rod and spin it a little. I got it to within about .004" and left it at that for now. That is pretty good over 2 feet of width. You might need to repeat the process a few times. If you measure the height as close to the rods as possible it is less likely to change. Then attach the z slides. They just prevent XY motion.
Bart
"If you didn't build it, you will never own it."
bdring
Site Admin
 
Posts: 2966
Joined: Sun Nov 22, 2009 7:33 pm
Location: Chicago, IL, USA

Building Instructions

Postby bdring » Thu Aug 26, 2010 3:44 pm

I get asked all the time if there are detailed build instructions. Right now the answer is basically, no. Some assembly drawings have some build information. Other than the buildlog itself and the forum, that is it. I have about 20 things on my project todo list and time for about 4 of them. Some people have offered to help, but no organized effort has started. I can help, but not do the whole thing.

I was thinking about starting a wiki for this. This way anyone could contribute and it would stay more organized than a build log. Does anyone have any recommendations for good wiki software. I would like it to be free, open source, self hosted and popular enough that it won't go anywhere soon. MediaWiki comes to mind...is that a good choice or overkill?

The wiki could also have some general info sections.
Bart
"If you didn't build it, you will never own it."
bdring
Site Admin
 
Posts: 2966
Joined: Sun Nov 22, 2009 7:33 pm
Location: Chicago, IL, USA

G540

Postby bdring » Sun Aug 29, 2010 5:34 pm

I installed a Gecko G540 in my laser. See my blog post for a review of the product and install. I wanted a four axis for some experiments with atangentail knife cutter and I wanted a smoother driver.

The interface on the G540 is not ideal for controlling the laser enable quickly, so I made a breakout cable. I will be adding to the cable, but this will do for testing. Below is a photo and schematic. click the schematic for a bigger view. the scaling the forum adds makes some lines disappear.
.
g540_cable.JPG

g540_schm.JPG
Bart
"If you didn't build it, you will never own it."
bdring
Site Admin
 
Posts: 2966
Joined: Sun Nov 22, 2009 7:33 pm
Location: Chicago, IL, USA

What is the real cost?

Postby bdring » Thu Sep 09, 2010 6:22 pm

I get asked via email about build cost often, so I am adding a post about the topic.

When I started this project I set a goal to be able to build a laser cutter for less than $1000. Was I able to do it? I definately had less than $1000 invested by the time I was able to cut a shape with the laser under CNC control. I was not starting with an empty shelf though. I already had a lot of the cheap stuff like nuts, bolts, wire, terminal blocks. I also cut all my own parts on my router, some of it from scrap material. I used cheap surplus things like stepper motors, etc.

Since that time a lot of feature creap has raised the price. Non essencial things like a gas spring assisted cover, assist air pumps and high end stepper drivers raised the price a lot.

I have the BOM on line with realistic, if not weighted high, prices. It does not contain prices for the electronics or the tube. Each person is going to start with a different amount of parts and a want a different amount of optional items added. If you only have $1000 to spend and don't have some material and cannot make you own parts, I would not start the project. I would suggest $1200 is probably closer. Do the math yourself, before you start the project.

Note: Remember this is open source. Feel free to make things yourself from the drawings. I do not make any real money from selling my kits. Don't feel any obligation to buy from me. If you want to help the project, just donate to it.
Bart
"If you didn't build it, you will never own it."
bdring
Site Admin
 
Posts: 2966
Joined: Sun Nov 22, 2009 7:33 pm
Location: Chicago, IL, USA

Re: Buildlog.net Open Source Laser

Postby jarkman » Fri Sep 10, 2010 1:27 pm

I'm sure this is an oft-asked question, but I haven't found it yet - where did you get your tube & the electronics for it, and how much was it ?

Thanks,

Richard
jarkman
 
Posts: 0
Joined: Fri Sep 10, 2010 1:16 pm

PreviousNext

Return to Build Logs

Who is online

Users browsing this forum: No registered users and 4 guests