This morning I switched 2 stepper wires on each of the X and Y axis drivers and both axis limit switch wires and it homes as it should. The arrows on the controller are right now too. I'm waiting on a 24 volt pneumatic control valve to turn the incoming shop air on and off. That will be wired so the air is on when the machine is powered up. I have a 24 volt 5 way valve the will be made into a "air assist" valve. Got to go to the store for plywood for the bottom of the cart for the chiller to set on and a 5/16" barbed "T" and 1/4" reducer to hook up the water pressure safety valve. Also need to get to the metal store and get aluminum to skin the machine with.
Last night went to get a sheet of 3/4" plywood and had sticker shock. $62 for a sheet of 3/4" AC plywood is outrageous. I bought a sheet last spring and it was only around $35 if I remember right. Back in'98 when I built my house, I paid less than $9 a sheet for 3/4" plywood T&G for subflooring. What really caught my eye was OSB that I paid less than $4 a sheet for in '98, was almost $50 a sheet. That's over 1000% increase. How in the hell can a person afford to build a house today with these prices???? Anyway, I didn't buy any plywood and will use a piece that I have. It just won't be one solid piece like I wanted.
The 24 volt pneumatic valve I got leaks a small amount of air when the machine of off. Got it off Amazon, so it's going back. I might look at finding one locally of better quality. I got most of the aluminum for the skin yesterday. I reinstalled the tube this morning, hooked up all the cooling lines, and filled the chiller with distilled water with a little bleach. Working on the installing the drag chain on the X axis. Need to go get some 4" duct pieces and finish the exaust. Then fire it up and do a mirror check and try some cutting. Then install the skin.
Double check you have the inlet/outlet hooked up right, they have a flow direction, in reverse it can leak.
I double checked and I had it right. There was a couple of people left reviews that had the same problem. I was hoping I would get a good one.
After getting fume extraction ducting installed, I set the parameters on the CW-5000 chiller to hold a consistent 20 degrees C. I cut a 200mm square out of 1/8" acrylic at 30% power and 15mm/sec to check the calibration and to see how square it was. The square measured 206.13 on both sides and was about 1/2 a degree out of square according to my 10" machinist square. Calibrated it via the controller and moved one of the Y axis shaft a hair, and got it square and cutting the right dimensions. Then moved the head to the right front of the bed to try cutting a 100mm square out of the same acrylic. It didn't cut all the way through in a couple of spots. This was done without checking the aliment of the mirrors with the tube installed. Tomorrow, I will do a correct mirror aliment and try again. Then I'll get the skin installed.
Did a mirror alignment and it will cut the same on all 4 corners now. I'm going to cut out a N scale structure today and see how well it engraves and cuts. I'm still learning RDWorks. I need to figure out how to do all of one layer before it starts the next. I'll get the skin on today or tomorrow and make it a somewhat air tight cabinet and add a 2nd fan for extraction of the cabinet for engraving.
Since cutting the acrylic, the fume extraction didn't work all that well, and I haven't tried to use it at all since. The acrylic smell hung around in the house for about 12 hours. So I started on enclosing all of it and going to have a second exaust on it. Ran out of the stainless screws and will have more on Tuesday. On the front, I have almost a 1" gap on the door for incoming air to sweep across the top of the bed. The plan is to have a glass window on the canopy. Need some more aluminum sheet to finish the top and figure out how I'm going to do the window Here is the back With the tube door open. You can see the water pressure switch I installed on the right side at the tube water inlet. Need to pull the tube again so I flip it on it's back to enclose the bottom
I printed some tubing holders for tubing management. You can also see my visual water meter with temp probe in it. I ordered a 400 cfm, 8 speed inline fan from Amazon for the second extraction fan. https://www.amazon.com/dp/B07FPFVZTZ?psc=1&ref=ppx_yo2_dt_b_product_details
She's shiny! This is the fan I'll be going with. Inline fans can't overcome static pressure. If you have any plans to add any sort of filtration, it's worth thinking about.
Thanks for the heads up on the static pressure of the different fans. If the air exchange is too much this winter for the furnace, I will replace the fan and look for a filter system for it to duct the air back into the room. Just have to be careful of what I cut. Did you read all the reviews on that one??? A lot has reported bearing noise after awhile in use.
I did. Most people are using it non stop, vs our maybe a few hours a week at the most. If I got to the point of using it regularly, then it would be a justified consumable. Also people are far more likely to post negative reviews than positive, yet it's still 4.5/5 with 1000 reviews.
I never ever read the good reviews, only the 1 star and maybe the 2 star. Many of the 4 and 5 stars are paid reviews and even if they are not, I want to know what's wrong with the item and not what's oh so nice. But that's just me.
Acrylic window in place but not sealed yet. I had this piece and it fit, so I used it instead of glass This is about where the bed will be when cutting. I should get great air flow across the top of it once I have the duct installed.
The bottom is done and sealed up. I went looking for a 2"X24" HVAC floor vent for 6" vent pipe, but had no luck finding one off the shelf. Could of have one custom made, but the cost was way too much. I had this 4"X16" left over from when I built the house and it should work almost as well. I screwed up the 4" pipe I had on the bed, so I need to get some more to replace it. I stuck a straighten out elbow on it for now.
Yes, but I'll have directional flow plates inside the cabinet The incoming air will be coming in the gap you see here. Airflow should flow across the bed and into exaust ducting and on to the outside. The secondary 4" fan will be working in conjunction with the 6" fan but the bed will be covered to keep a vacuum. Once I start using it, I throw up some pictures of it in use to help understand the complete airflow/ extraction system. If I get too much splashback from the honeycomb, I'll make a knife bed to set on top of the honeycomb bed.
I'll be honest but to me it's kind of counter-intuitive. I would have thought that extracting from the top and having the air come in from the bottom would be the ideal way to go since the smoke tends to rise rather than to drop.
That could pick up / dislodge small cut pieces, causing crashes later. Downdrafts are fantastic in a laser, "pulls" the stock down - and also, pulls the smoke out the bottom of the cut preventing sooting of the top surface. You also always want to Extract air (maintain negative pressure in the cabinet) - never have a fan blowing into the cabinet. It pushes fumes and smoke out every little gap. Sucking it out, much more effective.
Negative pressure in the cabinet is the main key to keep smoke away from the mirrors and lens. They have to stay clean to keep the beam intensity at the cutting lens. If you get any smoke residue on the mirrors and or lens, it hard for the beam intensity to cut through it and thus have less power at the cutting lens. This is why lasers cutters/engravers are most generally built inside a cabinet. Secondly, it's a way to extract the fumes and smoke to the outside.
I must have written it poorly. I totally meant to have negative pressure in the cabinet. I meant to have the passive inlet in the bottom and the active, re fan, outlet at the top. The opposite of what is done in this build. I can see the merit in wanting to avoid the lens and mirrors getting covered with soot. If your way works then I guess that's the way to do it.
Finally got my bulkhead fittings for the water and air lines Friday. I also put some screen wire over the exaust opening to keep debris out of the fan blades. Hope to finish all the venting to the outside tomorrow.
Have all the exaust venting done, but it has been somewhat of a nightmare trying to find all the right fittings off the shelf. Originally, I was going run both the 6" and the 4" to the outside separately. While getting some supplies, I started piecing parts together and decided to try to get both into one vent to the outside. The 6" going up is the cabinet exaust and the 4" is the bed exaust. Just before the elbow on the 6", the vent pipe increases to 8" diameter. I used aluminum tape and taped every joint and seam, so no fumes escaped through any of them. Two steps forward and one step back again. Now with all the venting done, I went back to level the machine up and couldn't do it. When I installed all the skin, I didn't have it level and when I tighten all the skin down, it made it too rigid. So I tried just loosing all the screws and it wasn't enough. I had to take the rear panel and the big panel on the front off and oblong a few holes. I got it level and tighten everything all up and did a finial mirror adjustment. I cut some 1/8" acrylic and it did a great job of cutting. The exaust extraction worked super well. All the fumes were sucked out and had no smell left in the room. The cabinet blower is strong enough that if any loose paper is in it, it gets sucked to the bottom vent. Good thing I put the screen wire over it.
It's been a few months and I discovered a few problems when I first started using it. First was, it wasn't very square. Even though I took the time and did everything I thought to get it square while building it. To get it square, I took some posterboard and cut a 18" square and measured corner to corner. By loosing and adjusting the left Y axis driveshaft coupling, I was able to get it within a few thousandth of a inch of being square. While trying to use a compound lens, I found out the my bed wasn't very flat. A compound lens has a very narrow focal length (I'm guessing somewhere around .020" to .025"). I 3D printed dial indicator mount that I could mount the dial indicator on the lens tube. I took a sheet of .040" styrene and put it on the bed with the bed fan on so it would suck it flat to the bed. It had a hump in the center of the bed of over .080". After doing a lot of adjusting to the bed frame, honeycomb bed and Z axis leadscrews, I got the whole bed so that it was + or - .006". After all the bed adjustments had been made, I did another beam alignment and got all 3 corners to hit the beam in the same place on the head. But the upper right corner (dreaded 4th corner) was about 1/8" to 1/4" low. I couldn't raise that corner, so I went to the lower left corner and lowered it. Now I have the beam hitting all 4 corners in the same place on the head. Then I adjusted the head (so glad I made the adjustable head mount) so that I got the beam straight down the center on the lens tube. It took 2 full days to get all of this done, but now I have a very good machine. With the RECI W2 tube, I can cut 1/4" plywood easily.
One of the first projects was a sawmill for my model railroad. Here is the framework in CAD Parts cut Framework glued together
Nicely done! But you have hidden lots of that beautiful framing. I'm building a cotton mill for a model railway based in Yorkshire UK, and I have 3d printed lots of machinery for the inside, including facsimiles of the drive belts that would have been driven from an overhead shaft, but you can hardly see them through the windows Alex.
