Constructing Janus, by Dirk

Post your build logs here

Made a lot of progress on the laser

Postby dirktheeng » Sun Aug 21, 2011 2:14 am

Well today I made a lot of progress on the laser today. I worked most of the day today and I think the only thing I have left to do is do an alignment and it's ready to go... also I have to put the table top on and level it. Here's a few pics of the progress I made:

The first thing I did was tear down the shelf... took the power supply off and disconnected the wiring and removed it from the rig. I cleaned up the burrs from drilling the holes, sanded, cleaned, primed and painted the pannel. I primed both sides, but only painted the top as that is the only thing that will show. It is not the best paint job I have ever done and is far from smooth, but it will serve the purpose of keeping the rust from forming. It was hot outside today and the paint didn't have enough time to self level.. plus I tried using one of those trigger handles for the spray paint and it kept getting in the way of the spray, building up and dripping. I had to sand out the drop marks. Anyhow, it worked out and looks decent. The paint is dry enoug to touch and work with, but is still soft... I will wait a day or so to let it set up before I install the power supply. I will also use adhesive wire hold downs to run the wiring.

Painted Shelf

I also got the front pannel installed. I had to cut the corner out of the corner bracket that i moved so I could get the switch farther tothe left. I also had to notch the plastic a bit. I got the wires connected to the 9 pin serial port.

Front Pannel Install

I ran the 9 pin serial cable up the santion and par way across the horizontal member using the slot covers to hold them in. It worked very well.

Front Pannel Wiring Rout

I also tied down all the wiring on the electrical panel.

Mounted wiring

The wire you see going off the side is the CAT 7 wire that goes to the laser from the pololu driver board. I have to add a selector switch to the front pannel to select between the pot and PWM, but that will come in time.

I will also add a relay that will be controlled by the arduino which measures the flow sensor. Right now I have a jumper wire shorting the switch to ground.
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm

Aligning the axes

Postby dirktheeng » Sun Aug 21, 2011 10:44 pm

Well, today I got the axes aligned. The first thing I did was to level the frame. I have a self leveling laser and I used that to get it fairly close. I was surprized at how flexible the frame is. This means that I will have to re-level the frame every time I move it to a new surface as the flex of the frame could move the gantry out of plane. The next thing I did was check the level o fthe gantry. not surprizingly it was pretty good. I used a spacer to lign up the table corners to the botom of the nozzle (I found that my table is somewhat racked (not planar), but it is very close (within about 1/64th). That should be good enough. The final thing was to square up the gantry to the side rails.

To do this, I put a carpenters square against the RHS rail because the RHS gantry bracket will let me get the square right up to the nozzle on the cart. I had to take a corner bracket off to get the square up to the rail... no big deal.

I raised the table up about as far as it would go and put a peice of plywood on top of the table and that let me set the square right up at the top of the rail. I could then run the gantry car back and forth and adjust one of the pulleys so that I could get it to run true. Eventually, I got the cart to be able to just kiss the suare all the way accross the length of it's travel. I'd say that is pretty good.

Here's a couple pics:

Squaring setup

Here's the cart at the right side:

Cart RHS

Cart on the LHS:

Cart LHS

This should be square enough to get an initial laser/mirror alignment done. After I get that done, I can cut some squares and check the diagonals.

I am getting so close to being able to make first cuts. I am excited!
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm

Should I wait for the makerslide?

Postby dirktheeng » Sat Aug 27, 2011 9:38 pm


I am at the point where I would be putting a decent amount of work into aligning and finishing the laser, but I am on the list to get makerslide. I understand that this stuff is supposed to be ready very soon. The question is: do I put all the work into aligning and getting everything working just to have to rip it apart and do it again in a week or two when the parts get here? I want to use the makerslide because I can get farther travel on the axis that I can now. What would you all do?
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm

Wait for MakerSlide

Postby bdring » Sat Aug 27, 2011 10:22 pm

It will be ready in a few weeks. I don't plan on putting it in mine until another reason for tear down. It only makes it cheaper and easier to build. You are past that. It uses all the same wheels, etc. A few brackets change to clear the v rail where it is not present on the current system.
"If you didn't build it, you will never own it."
Site Admin
Posts: 2966
Joined: Sun Nov 22, 2009 7:33 pm
Location: Chicago, IL, USA

What ducting to get?

Postby dirktheeng » Wed Aug 31, 2011 9:58 pm


I am trying to make sure I will end up getting the right size ducting. The flange measures about 4.25" on the OD. I want to be sure this fits a standard 4" flexible duct. Can anybody confirm this?
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm

Re: Constructing Janus, by Dirk

Postby BenJackson » Wed Aug 31, 2011 10:49 pm

It doesn't. I just had to butt standard 4" duct up and tape it. I asked somewhere what it was supposed to fit but I don't think there was an answer.
Posts: 522
Joined: Fri Apr 15, 2011 6:13 pm

Re: Constructing Janus, by Dirk

Postby twehr » Wed Aug 31, 2011 10:58 pm

BenJackson wrote:It doesn't. I just had to butt standard 4" duct up and tape it. I asked somewhere what it was supposed to fit but I don't think there was an answer.

I used flexible laundry (dryer) duct and it fits nicely INside the flange. No tape. No fuss. No mess. No hassle.
"The answer is usually easy and obvious once you know what it is." tw

DIYLaser Blog
Posts: 439
Joined: Mon May 24, 2010 4:49 pm

Re: Constructing Janus, by Dirk

Postby dirktheeng » Thu Sep 01, 2011 9:29 pm

Ben, Tim,

Thanks for the info. I figured it would be something like that, but I just wanted to check. I'll probably end up having to tape it (and would want to anyhow to make sure I was getting max flow).
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm

little laser and belts here now

Postby dirktheeng » Thu Sep 01, 2011 9:37 pm

Finally, the little laser arrived. I bought one that would fit into Ben's 3d printed alignment setup and it took almost 2.5 weeks to get here... but it only cost $2.50, so.... I didn't realize it when I baught it, but it shipped from china.

The belts I got from Bart also just arrived so now I can align the axis and the mirrors safely and not have to do it again. I decided to wait to install the maker slide until later when I tear it down for some reason... either that, or I will make something else out of the slide... probably a desktop router.

Anyhow, this weekend I will start on all that. I will hopefully be cutting something by Sunday or Monday. I am excited.
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm

New Belts installed and start of alignment

Postby dirktheeng » Sat Sep 03, 2011 8:31 pm


I had some time today to get the new belts put on so I have full travel in the y axis and I got it squared up.

I used the red laser and the 3d printed holder/aligner that Ben made for me to start to get everything aligned b/4 I start aligning the co2 laser. I got the red laser spot to stay absolutely still on masking tape that I put over the last miror on the gantry nomatter where i move the car, which is great. However the beam is not reflected strait up and down when it comes off the last mirror. I am not sure why at this point. However, I suspect that my entire gantry is out of level. That is, it is the top is rotated to the rear if the axis of rotation is colinear with the travel axis of the y axis. That is going to be a little bit hard to adjust as there isn't any adjustment in that direction. I am thinking about shimming the rear bearing on the cart up a little bit.

I haven't checked the other direction for square yet, but that should be easier to adjust.

Any suggestions?
Posts: 616
Joined: Thu Sep 09, 2010 4:49 pm


Return to Build Logs

Who is online

Users browsing this forum: No registered users and 4 guests