Elegoo Mars Heater - fits JP twin rail upgrade

thingiverse

** updated to include backlash bearing mod. This is a customisation of the "Photonsters PTC Heater Unit" by X3msnake. The body and secure locating parts are all printable on the mars (two prints are required, one for the main body, one for everything else) I have included supported files in the download. (basically I modded the excellent support work originally done by X3msnake) I created this when I modded my mars to update the z axis using the Jackson Products twin rail system, prior to this I was using the original Photonsters Unit simply stuck to the base using velcro, which worked fine. There was no longer room inside the case when the twin rail system was introduced though unfortunately. I have found reliable heating to be the most important factor in predictable results from the mars. The customisation removes the magnet holders from the original Photonsters body, these are redundant on the mars and removal makes supporting the heater body easier when printing on the mars as well as allowing space for the twin rail z riser. Heater locating is replaced using push fittings for 15mm copper tube to the top and bottom of the heater unit body. I also introduced a cable tidy system which channels the cable through the top of the heater unit, down the unit, through the copper, and out through the support foot. The top cap fixing also serves to hold the temperature sensor cable, which simply hangs down from top cap allowing temperature to be measured near to the resin reservoir. This system uses the top cap with a push fit fixing as the top support fixing and stick on velcro in a recess in the foot as the bottom fixing. Push fit 15mm copper plumbing tube is used to connect all the parts. By adding a rubber sealer to the bottom of the Mars UV cover and cutting a bit of rubber away for the cables to exit, this system is entirely non destructive to the Mars. ### 15mm Copper Lengths These measurements allow for a couple of mm adjustment at each joint: Top cap >>> 90ºBend 27mm (6mm visible) 90ºBend >>> Heater body top 32mm (10mm visible) Heater body Bottom >>> dogleg 35mm (10mm visible, the top of the pipe requires drilling or filing to allow for the cable.) Dogleg to foot >>> 32mm (9mm visible) I suggest avoiding standard brittle resins for the body, abs like appears fine, but standard resin resulted in a cracked body when I pushed in the temperature control, although no actual functionality suffered as a result. This method can be also used on the standard mars to provide secure fitting and cable routing for the photonsters heater solution. The same electronic hardware is used so I suggest looking at the original item for hardware instructions. https://www.thingiverse.com/thing:3442165 ###Update 06 March 2020 - anti backlash bearing I added an alternative top mount to accommodate a backlash bearing remixed from https://www.thingiverse.com/thing:3918220 The design requires a 3200RS angular bearing (10x30x14.3) I recommend the bearing is fitted and removed a couple of times before curing as its a tight fit. The top plate fixing is by design relatively loose, it is up and down movement that is being resolved with this addition, so the loose fitting stops any unwanted stress in other directions. Printing on the mars use Elegoo ABS as a minimum strength Resin, I'd advise printing 3 or 4 end cap screws as you will probably break at least one finding out how tight you can go. Installation is pretty straight forward, Remove to top cap from the mars, screw the seat screw onto the Z axis thread, untill there's 20mm or so of the thread showing, drop the bearing in, tighten the cap crew down, slide the top mount over the bearing, slide the top cap into the mount then screw it on. Finally tighten the Seat screw. I found that I could set the g-Code z axis to 155 which left around 1mm of free space. As my original g-code was set at 150mm, no print height is lost over the standard, basically this leaves a maximum print height of 150mm assuming a 5mm lift height.