Hi Folks
I've been working on a variant to Goopyplastic's excellent T-Slot Tantillus and I'd like to get some feedback before I start building it in earnest. I’m uncertain if this should be a new post or not as it leans heavily on Goopy’s work so I'll stick it here to start with and I'm sure I'll get told if it should go somewhere else.
The attached images show the WIP model. I'll post more if there's interest and/or as it progresses.
The principal change I've made is significant increase in size, the current design is ~450mm per side (external dimensions).
The increase in size has driven or facilitated a number of other changes:
• Thicker linear rods to support the print head/carriage; twice the span would increase the deflection for a given lateral force so this should be offset with thicker rails. In my case I’m using 12mm rods for the x-y rails supporting the print head and leaving the side rails as 8mm, mainly because this is what I have to hand and I don’t want to have to change the bearing mounts on the corner brackets to accommodate for a larger roller bearing.
• Moving the Nema’s driving the x-y motion back into the printer’s envelope; I’ve used a similar approach to Ultimaker in placing the Nema below the relevant drive/linear rail and linking the 2 with GT2 pullies and an appropriate closed loop belt (all off the shelf stuff from SDP-SI).
• Completely re-designed Z axis; including an 8mm Lead screw instead of spectra, using T-slot and 90 degree brackets to support the platform and using horizontal t-slot supports for the top and bottom mounts. This should facilitate easy Z scaling and allows for a variety of nut traps to be used to link the lead screw nut to the platform.
Further changes I’ve made:
• Using Sintered Bronze bushings instead of linear bearings – mainly because I’ve got spares and that’s what Ultimaker use. This has meant I’ve had to re-do the original x/y ends to take the bushings as well as accommodating for clamping the 12mm rods.
• Re-designed print head/carriage for Dual Bowden extruders. This is still very much a WIP but the idea is to have each hot end clamped in place with 2 pieces of machined aluminium (top and bottom sides of the printed mounting structure). This should allow for micro adjustment of the HE heights relative to each other with some sort of consistent thickness shim material. The top piece of Aluminium will also be tapped with an M5 thread to take a push fit pneumatic coupler. This is not properly represented on the attached renders btw.
Anyway, although I’ve heavily modified my mendelmax and I’m no stranger to 3D Design, I’d greatly appreciate any feedback, positive or negative. Also happy to share source files if anyone want’s to tinker with the design.
I've been working on a variant to Goopyplastic's excellent T-Slot Tantillus and I'd like to get some feedback before I start building it in earnest. I’m uncertain if this should be a new post or not as it leans heavily on Goopy’s work so I'll stick it here to start with and I'm sure I'll get told if it should go somewhere else.
The attached images show the WIP model. I'll post more if there's interest and/or as it progresses.
The principal change I've made is significant increase in size, the current design is ~450mm per side (external dimensions).
The increase in size has driven or facilitated a number of other changes:
• Thicker linear rods to support the print head/carriage; twice the span would increase the deflection for a given lateral force so this should be offset with thicker rails. In my case I’m using 12mm rods for the x-y rails supporting the print head and leaving the side rails as 8mm, mainly because this is what I have to hand and I don’t want to have to change the bearing mounts on the corner brackets to accommodate for a larger roller bearing.
• Moving the Nema’s driving the x-y motion back into the printer’s envelope; I’ve used a similar approach to Ultimaker in placing the Nema below the relevant drive/linear rail and linking the 2 with GT2 pullies and an appropriate closed loop belt (all off the shelf stuff from SDP-SI).
• Completely re-designed Z axis; including an 8mm Lead screw instead of spectra, using T-slot and 90 degree brackets to support the platform and using horizontal t-slot supports for the top and bottom mounts. This should facilitate easy Z scaling and allows for a variety of nut traps to be used to link the lead screw nut to the platform.
Further changes I’ve made:
• Using Sintered Bronze bushings instead of linear bearings – mainly because I’ve got spares and that’s what Ultimaker use. This has meant I’ve had to re-do the original x/y ends to take the bushings as well as accommodating for clamping the 12mm rods.
• Re-designed print head/carriage for Dual Bowden extruders. This is still very much a WIP but the idea is to have each hot end clamped in place with 2 pieces of machined aluminium (top and bottom sides of the printed mounting structure). This should allow for micro adjustment of the HE heights relative to each other with some sort of consistent thickness shim material. The top piece of Aluminium will also be tapped with an M5 thread to take a push fit pneumatic coupler. This is not properly represented on the attached renders btw.
Anyway, although I’ve heavily modified my mendelmax and I’m no stranger to 3D Design, I’d greatly appreciate any feedback, positive or negative. Also happy to share source files if anyone want’s to tinker with the design.