I am currently working on updating for the latest configuration, E,
generated circa 2/2014.
These drawings will be in smaller groups, more convenient for
cutting with human oversight at your own laser cutter.
These drawings can be grouped into larger drawings for use
with services like Ponoko in Inkscape.
File names have the file size, in MM, at the end of the file name. When importing SVG into Inkscape for conversion to DXF, resize the drawings to the indicated size.
|e20_30_116x174.pl||3.0mm||Forks with 3/16" diameter holes for standoffs and main axles.
Also has motor gear, and motor mounts.
All of these should be 3.0mm
|Should split so that motor gear and mounts are separate drawings.
It is critical that wide forks be very close to 3.0mm,
but the width is less critical for ither parts.
The motor gear must be a good bit less than the 4.5mm used for
the main drive gear, so that it will fit within the side plates.
4.5mm seems a bit thicker than necessary for the motor mounts,
but it is not critical that they be all that close to 3mm.
The e20 should be removed from this file name, since these parts are not specific to the e20 configuration. So far, these parts are usable on all LC models.
|crank links||e20crankLinks178x109.pl||1.5-2.3mm||links from spindle to legs||We need to fit two links within a 3/16" space. I am trying these in acetyl (Delrin), where 1.5mm may be adequate.|
|hips||e20hip45_180x132.pl||4.5mm||Linkage hip pieces, and a few space spacers, crank arm.||There is extra room on this drawing for small things.|
|e20bhef135x252.pl||1.5-3mm||BH and EF links||Thickness not too critical for these|
|Main brace||e20mainBar45_144x191.pl||4.2-4.5mm||Main bar
|Main bar links, and braces. Also motor hub and some spacers.
Thickness not all that critical for these parts. The braces might be a little more critical, as long as they are wide enough for main drive gear and some washers.
|payload T/B/F/B||e20payload30_171x285.pl||3mm||Payload bay top, bottom, front and back||These are not very configuration dependant. We should remove the e20 from the file name, since they can be re-used over small changes in configuration|
|payload sides||e20payloadSides45_186x219.pl||4.2-4.5mm||Sides of payload bay||The only part of this which is really configuration dependant is the spacing of the axle holes|
|gear side plates||gearPlates103x113.svg||1.5-2.5mm||side plates for main drive gear||There are 7 in this drawing, although each robot only needs 4.
I have found that even when thin, like 1.5mm, these do the job just fine.
Note that I like to bevel the edge on the inside of these plates to help keep the motor gear centered on the drive gear, that these plates surround.
I think it is a good idea to cement these plates to the drive gear.
|D-forks||hipForks73x97.pl||1.5-3mm||Forks for top (D) node on hips||These hold the axle for connecting to the top cranklinks. Thickness is not critical|
|catch bar||catchBar107x53.pl||1.5-1.8mm||Bars to secure payload top||Must be cut from a more flexible material, like acetyl. These bars can be flexed in place, and do not need to be secured with screws.|
|catch tab||catchTab63x61.pl||1.5-2.2mm||Tabs to secure payload top||These tabs are screwed into payload lid to secur it.|
|shims||stackers61x61.pl||Various||standard spacers for wide forks||I often need these in 0.5-1mm PETG for enough space around the hip
at D to have the forks hold a 3/16" long spacer.
Unfortunately, my "4.5mm" stock is rarely wide enough for a 3/16" spacer. I usually make the wide-fork spacers using a 2.8mm spacer (common for "3mm" or 1/8 inch stock) and a 2.2mm spacer (common from 0.100 or 1.098 inch stock)
|gear side plate||gearSidePlate38x38.pl||1.5-3mm||Single gear side plate||Convenient for cutting one side plate at a time from scrap
Not necessary if you cut gearPlates103x113
|motor mount||motorMount49x40.pl||3mm||Single motor mount pieces||Convenient for cutting one motor mount at a time from scrap
Not necessary if you cut e20_30_116x174
|2||3/16" OD hard steel rod, 12" in length|
|8||1/2" long, 3/16" OD #4-40 round female-female standoffs|
|2||1/2" long, #4-40 threaded rods.
May be constructed by cutting the head off of a #4-40 screw, and cleaning the threads.
|4||#4-40 flat-head screws, 3/8" long|
|6||#4ish self-piloting plastic screws, 1/4" long|
|32||#4-40 screws, 1/2" long.||4 spindles|
4 motor driver mount
|12||#4-40 screws, 7/8" long.||4 motor mounts|
|4||#4-40 screws, 1 1/8" long. (main bar)|
|4||#4-40 screws, 1/4" long. (spindles)|
Can use these while cementing parts
|Main bar and motor mounts|
|36||#4-40 nyloc nuts||4*8 hinges|
4 motor driver mount
|16||#4 internal tooth lockwashers||4 motor mounts|
4 main bar
8 spindles (both sides)
|14||larger diameter #4 washers||2 motor gears|
4*2 on spindles
4 under crank-arm
|90||#4 washers||2*4*8 hinges|
4 on spindles
8 motor mount
8 main bar
6 lid tabs
|12||1/4" long, 3/16" ID nylon spacers||on B-axle|
to space out legs
|8||1/2" long, 3/16" OD #4 nylon spacers||hinges|
|36||3/16" long, 3/16" OD #4 nylon spacers||3*8 hinges|
8 hip-B fillers
4 motor driver mount
|72||3/16" ID nylon washers (#10), around 1mm thick||~3*8 spindles|
Main assembly parts:
For Uno-based Bluetooth remote control electronics:
Welding is unnecessary for most of this project, simply an asthetic decision. However, welding the main drive gear to it's guidance plates should make the gear teeth a little stronger, which might be a good idea.
It may not be necessary to epoxy the motor gear to the shaft, but it should certainly make that connection stronger, and perhaps longer-lived.
These are still being re-written from the previous build configuration. This text should be augmented with illustrated, detailed step instruction pages as they become available
Note that there will be 4 left-handed, and 4 right-handed hip and foot pieces.
When the forks are installed "on top" of the foot/hip piece, half should face one direction, and the other half should face the other direction.
After the wide forks have been installed, install the narrow hip forks in a similar fashion. The hip-D attachment will have two forks tynes, instead of one fork tyne on top of stackers. If your 4.5mm stock is actually thinner than 4.4mm, you may want to cement a thin PETG shim under one of the fork tynes. I recommend installing the shim UNDER each left-hand hip, and ON TOP of each right-hand hip. (Which one is "left" and "right" is not critical, just that you maintain symetry)
We are now using a screw with a nylon spacer, 2 flat washers, and a nylock for each hinge
instead of a standoff, two screws, two flat washers and two lock washers.
I am no longer recommending the additional braces on EF or BH. (Unnecessary weight and complexity)
Nylon spacer hinges should have snug, but not tight nyloc nuts. I usually tighten them until I feel some resistance, then back off 1/4 turn.
Install 3 braces on each side of the main bar with 1 1/8" screws with
a flat washer below the head.
Then install the main gear axle onto the motor-mount side of the main bar, on the same side as these braces (opposite side of motor clip).
Install the other side of the main bar onto these screws, and secure loosely with a washer, lockwasher, and nut.
Slide the motor and gear assembly into place from the bottom.
Place the crescent motor brace and back clip around the motor holding it into place.
Rotate the motor gear until the hole is over the un-secured side of the motor fork. Install the other screw and washer by passing them through this hole. Plase 2 more spacers behind the crescent motor brace, then secure the back side of the motor clip onto the screw with a washer, lockwasher, and nut.
A screwdriver may be used to brace this screw as the nut is tightened.
Move the hole to lay over the other screw, brace it, and tighten the other nut.
Make sure the brace holes are alighed to cover the axle hole, and tighten these screws.
Roughen the crank-arm inside the counter sink, and near the hole on the other side. Apply some epoxy (JB-Weld) and screw this crank-arm to the main gear axle snugly.
Repeat for the other side, making sure that the crank arms are exactly opposing each other (180 degrees apart), and allow to set.
|XD||Xerocraft layout, linkage configuration D|
|20||scaled for 20mm crank arms|
|Layout for 2.2, 3.0, 4.5mm acrylic respectively|
|XXXxYYY||Scale of rectangle containing drawing, in mm|
This scale in the filename is for a rectangle containing the outside tips of the corner fiducials.
This should make it easier to import the drawings, just set the scale of the imported object
to the size referenced in the file name.
The spacing from center to center of the fiducials is actually 1mm less than the numbers in the file name.
Last modified: 140518