BED LEVELING-
Leveling the bed is harder- on my machine the left and right leadscrews are driven by separate steppers, so of course they get out of sync occasionally. I initially would turn the machine off and raise one side by manually moving the belt on the low side. That gets old, so I installed a
relay to cut the power to one side and then motoring the other side up or down to level it. This is easier with a wireless remote which has two speed settings and can be changed very accurately. Measuring the difference from side to side and front to back... I have been thru a number of
different setups and finally have settled on this digital dial gauge which mounts to the rails with a switchable magnet and bracket.
. If you have not experienced a Magswitch, they are powerful magnets that you can turn off by rotating the knob on top. I love magnets.
The bed is made up of 36" blades, which sat in pockets machined out of a piece of aluminum- that was leveled with screws thru the pocketed alum bar. That was impossible [for me] to get level across the whole bed... so I fabricated a new bed from 80/20 extrusions which is supported by four
bolts which facilitate the leveling. I can now get a close enough level over the entire bed, which is not necessary very often but is needed when you have the entire bed covered with a sheet of material.
BLADE BED RECONSTRUCTION-
This has some relationship to the bed leveling so lets do that next.
. My bed as built consisted of square alum tubing on the Y axis to which the leadscrew blocks[nuts] attached- each side driven by a separate stepper and driver. This has been a burr under my saddle from day 2. The two motors get our of sync [see above]. Another problem was the black aluminum strip that was machined out to accept the ends of the blades- they had 4 or 5 vertical slots to adjust the blade all to the same plane[ at least that seems to be the theory- in practice it is... hard]. The Y tubes are rigid and are connected with steel angle [bent not forged] which leave a bit to be desired but I let them continue in my build. I used 80/20 10 series extrusions that are 1 x .5 inches as I have a lot on hand and like it, for new straight X axis members, using the original black alum strip for spacing- the blades rest on the extrusion so they are good. I made 4 leveling assemblies and positioned them close enough to the square tubes so that I was not concerned about the angle flexing that close to the
ends.
. I use my patented blade clamps® and have had the blades raise up from the pockets occasionally so I made wood tensioners to wedge between every other blade and alternate from front to back. If I rework them I will make them from impact modified acrylic which is an awesome product.
The loops in the top make them easy to remove if necessary [also patent pending
]. If I have not used enough words [not likely] or the correct words to explain this let me know. AIR FLOW EXPERIMENTS-
Some of the things I have done to [try] to improve exhaust air flow-
I cover the portion of the bed that I don't normally use, which is about half. I have used ACM sheeting, coroplast [plastic cardboard] and whatever comes to hand. This is also handy [but not a good thing] to pile debris on, partly cut plastic, tools, and all the detritus that seems to follow me around. I try to keep the pile below the level of the gantry...
Keep the piping outside the cabinet to the bare minimum possible, and use metal AC/Heat duct- not the flex tubing which is so much easier.
I installed panels inside the cabinet to cut down the volume and try to guide the air as much as possible.
. I have two 4" high flow muffin fans [ not computer cooling ] on the floor of the cabinet pointed at the exhaust port [that come on with the exhaust fan]- about half way back from the exhaust outlet. I also have aux fans on the front lip of the cabinet that can be used and directed however might help air flow.
I should mention that I never shut the lid of my machine unless it is the last resort to keep smoke in the machine. That will rub some people wrong but it is how I roll. I think that might be the airflow portion of our program.
OK- lets wrap this up- with a large cabinet the parts that fall thru the blade bed [ which I use mostly ] are hard to reach [mine are down 28" or so] and cleaning the inside is a pain. My solution was making a frame of 15x15mm extrusion one meter by one meter and attaching alum screen to it- most parts fall and bounce toward the front so I can open the main front door and retrieve them. It also catches most of the scrap pieces which can be swept out an opening in the front sized to a dustpan. I know most of this stuff is not necessary, but it keeps me amused. Gene
BTW- The backscratcher is a good reach tool- also I have my mom's reacher/ grabber tool for many uses.
. OK- one last though- I bought a laser from Automation Tech [ made by Senhui laser ] in Chicago and it had a strange bed configuration that I had not seen before, but it is actually a good idea. The blue piece is a drawer that slides out to empty the parts/detritus and the exhaust hose connects directly to the sunken portion of the bed. Result is good airflow with a lot less volume along with the easy to empty drawer.
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