Nimble Gimbal - Gimbaling Extruder Motor Mount for Zesty Nimble by slonold

Last crawled date: 3 years ago

Single axis gimbaling mount for mounting the extruder motor for a Zesty Nimble
Lowers amount of force that drive cable can exert on Nimble body and printer motion system. https://youtu.be/qfjgy3MI5Gg
12 June 2018 - Design (123D), stl and stp files for Style B version all included in Nimble_Gimbal_Style_B.zip file. Design, stl and stp files for original version are in Nimble_Uni_Gimbal_Motor_Mount_42mm_Threaded.zip
6 April 2018 - Updated with Style B captive nut version, anti-vibration washers and strain relief. Style B is easier to assemble as axle is a free bolt installed from the external face of the arm which allows assembly/disassembly with the arms attached to panel. Also, no tapping required.
Very much work in progress - Style A (original) for 40mm length Nema 17 motor. Design and step files included in zip. Style B for any motor size.
Parts - Style A:
M3 x 12mm Button/Socket Head Cap Screw - for bearing axles (Qty 2)
M3 Lock Nut (Qty 2)
M3 Washer OD < 5.75mm, ideally 1mm thick - these Nylon "DIN125/ISO7089" ones work well - for bearing standoffs (Qty 4)683 Bearing - 3mm x 7mm x 3mm (Qty 2)
M5 x 12mm (+/-) Button/Socket Head Cap Screw - for mounting Zesty motor bracket (Qty 4)
M5 x length to suit your mounting surface - for fixing arms (Qty 6)
Parts - Style B:
M3 x 10mm Button/Socket Head Cap Screw - for bearing axles (Qty 2)
M3 x 2mm longer (typically 8mm) than your current (typically 6mm) motor mount bolts if using strain relief (Qty 2)
M3 Lock Nut (Qty 2)
M5 Lock Nut (Qty 10)
M3 Washer OD < 5.75mm, ideally 1mm thick - these Nylon "DIN125/ISO7089" ones work well - for bearing standoffs (Qty 2)683 Bearing - 3mm x 7mm x 3mm (Qty 2)
M5 x 12mm to 14mm (+/-) Button/Socket Head Cap Screw - for mounting Zesty motor bracket (Qty 4)
M5 x length (isolation washers take up 2mm for each face and need 8-9mm insertion into arm) to suit your mounting surface - for fixing arms (Qty 6)
Tools
M3 Tap (Style A only)
2.4mm drill (Style A only)
M5 Tap (Style A only)
4.2mm drill (Style A only)
3mm drill (Style B only)
5mm drill
10mm(13/32") drill (Isolation Washers only)
Small File
Bearing press of some sort, i.e. a socket with an outer diameter just under 7mm and an inner diameter > 4.5mm
Instructions - Style A
Size bearing housing to 6.9mm ("0.272") ~ remember the rueful expression that goes something like "... i bored it twice and it is still too big..."
Carefully press bearings into arms.
Assemble arms onto gimbal, ensure good alignment so that gimbal pivots freely.
Then locate holes for arms on mounting surface.
Then mount motor - fit is snug around Zesty motor mount bracket so may have to relieve radius where arms join body.
Instructions - Style B
See exploded diagram.
Size bearing housing to 6.9mm ("0.272") ~ remember the rueful expression that goes something like "... i bored it twice and it is still too big..."
Carefully press bearings into arms.
Size 3mm and 5mm holes if required.
Insert nuts.
Assemble arms onto gimbal, ensure good alignment so that gimbal pivots freely. Note that a single washer goes between the bearing and the motor mount on each side.
Then locate holes for arms on mounting surface.
Inner arm bolt holes are 68mm apart on centre and bolt holes are 20mm on centre within the arms.
Vibration Washers
Panel holes need to be a 10mm+ (13/32"). A little bigger is probably better than smaller.Note that in order to minimize vibration transmission, mounting bolts on arms are best just tightened enough to prevent things from flopping around.
Printing
Mount and Arms: PETG recommended for toughness and ability to absorb vibration due to its lower flexural modulus but PLA or anything else with good layer adhesion should be fine. Overall vertical shell thickness of ~1mm and 20% infill should be good. Did not use support. Dimensional accuracy important for captive nuts.
Isolation Washers: X60 recommended (you have a Nimble, you CAN print it no problem!!) TPU (i.e. NinjaFlex) or soft TPE should work but keep perimeter wall thickness low (<0.5mm??). With the X60 i went with a 0.3mm nozzle and 0.2mm extrusion width, 3 perimeters, 0.125 layer height and 5 top/bottom layers.