Hobby-Fab R7 Manual
Last updated: 08/13/20108 Rev. 9
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R7 Build Instructions
1. INTRODUCTION
The R7 is so named as this was the revision the SMW3D/ Hobby-Fab team released; this DIY CNC router
kit. The kit is fully open source. In addition, the kit was released in beta and all feedback taken to
improve build and functionality. Thank you for joining us on this journey. We truly hope this build will
help makers to achieve the satisfaction of creating a machine that will provide years of creativity with
their own two hands.
2. SET-UP
We would love for you to rip open this package like it’s Christmas morning and you are eight years old
again. We must warn though, we have individually bagged the steps and they will match the below
inventory as well as the videos on YouTube on the SMW3D/Hobby-Fab page. The videos are labeled
R7v1, this means R7 video one, etc. Please DO NOT open every bag and dump the build on the table.
This will severely impact your build time and locating the proper parts for the steps. The build videos are
very outdated, they should only be used for reference.
We also advise finding a large, clean, flat surface to build your kit. The first few steps can certainly be
performed on a smaller surface however, as the build grows, you will need a four foot by four-foot area
flat surface. It is also advised that you lay out each step individually with all parts for the respective step.
Lastly, before starting the build, please note the BOM (Bill of Materials) is described below and two
columns are present after the item description. Please open each bag prior to build and count each item
Performing this task now will prevent having to put off your build in the event we missed something.
Finally, please have fun and take your time. The build process will control all your cuts after, build it
once and build it right. The machine will provide years of great service.
Tools Required: (all should be locally available) Additional Items Required
Metric allen wrench set Bucket for water
Soldering iron and solder Table
Metric tap set Computer
8mm combination wrench USB A to B cable
10mm combination wrench Square and level
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Hand file
3. Build and BOM
The steps shown here will correspond with the SMW3D build videos. It should be noted these videos are
quickly getting outdated due to amazing feedback from users.
NOTE: as of November 2017, the mini wheels running inside the beam may be changed to Delrin.
NOTE: as of November 2017, mechanical limits are included in all R7 kits. The limits get installed as such:
Y gantry plate –limit faces rear of machine
X gantry plate –limit faces the right-hand side of the build looking at the machine
Z gantry plate –limit faces down
All wired NO
Step One:
In the first step, you will be assembling the Y gantry plates. These plates will run on the side of the R7 as
you are facing the machine. One notable change from the videos is the .2mm shims are no longer
needed. At the end of this step you will have two assembled Y gantry plates, each with eight mini wheels
and three large wheels (all on M5 x25 bolts), the ACME block will also be installed (M5 x 20 bolts). Take
your time on the wheels. If all wheels touch the C-Beam, you are in a great spot. We state in the video a
tension is required. We have found this is not true. Each plate can take up to an hour and a half to
completely assemble. So, sit back, relax, and let's build.
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STEP 1
Qty.
Smw3D
Builder
Y Gantry Plate LH
1
Y Gantry Plate RH
1
Large Xtreme Wheels
6
Mini Delrin Wheels
16
Adjustable Tension Anti-Backlash Nut
2
6mm Spacers
8
6mm Mini Eccentric Spacers
14
3mm Spacers
4
M5x20 Bolt
4
M5x25 Bolt
22
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Note, the large wheels get a shim from the wheel bag between the bearings but not between the
eccentric spacer and bearing. The mini wheels get a shim from the wheel kit, between the bearings in
the wheel and between the bearing and eccentric spacer. All bolts are M5x25mm bolts. Note, you will
most likely need to remove the limit switch to install the one wheel bolt that resides behind it.
Begin by installing the standard spacers on the smaller holes (bottom row), these will be a reference for
the rest of the wheels. Tighten these with a small amount of torque, do not tighten so much that the
wheel drags or locks. Next, install the next row up eccentric spacers and mini-wheels. Before tightening,
turn the eccentrics until the wheel on this bolt is as close to the reference wheel below it. Install and
correctly tension the inner mini-wheels on the inside of the C-Beam (250 length), before installing the
outer larger wheels. Install the large wheels on the eccentrics and adjust to the beam in the same
fashion.
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The ACME block is installed by using two M5 x 20mm bolts, 3mm spacers, and two M5 nuts. Do not
over-tighten these M5 x 20 bolts, it is possible to collapse the block. Simply snug up and use lock-tight.
You can adjust the tension on the ACME block at this time if you so choose. Insert one of the ACME
threaded rods into the block and adjust the set screw until there is slight resistance while trying to turn
the ACME rod through the block. Do not overdo it. You can always adjust this after the build is complete.
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Limit switch and barrier block shown installed.
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Step 2:
Step two has us assembling the front X/Z gantry plate. While looking at the completed machine, this will
be the front plate that holds the Z gantry and moves side to side in the X direction. Recall front to back is
Y and up and down is Z.
Note a change from the video, the Z is now driven by a single adjustable tension acme nut. Set the
tension on the ACME as we did in step one. Insert the acme rod and turn in on the set screw until there
is a slight resistance to turning the rod by hand. Do not lock the ACME in place by adjusting too far.
STEP 2
Qty.
Smw3D
Builder
Front XZ Gantry Plate (Machined)
1
Large Xtreme Wheels
8
Mini Delrin Wheels
8
Adjustable Tension Anti-Backlash Nut
1
1/4" Spacers
4
1/4" Mini Eccentric spacers
12
3mm Spacers
2
M5x20
2
M5x25
16
Note that all wheels are installed with ¼” eccentric spacers in this step to allow adequate room for the Z
gantry.
To begin assembly, note that one side of the plate has recesses. We will be installing bolts from this side
and the eccentric and regular spacers on the other side. Also, you will note one side of the inner gantry
wheel holes is smaller in diameter, we call these the reference holes. Install these and tighten down the
wheels, then use the eccentrics to add tension to the opposite wheels. All wheels on the reference holes
should touch the beam, this ensures a true Z. Install and correctly tension the inner mini-wheels on the
inside of the C-Beam (250 length), before installing the outer larger wheels. Install the eccentrics so that
the wheels are as close as possible to the reference wheels. Install the beam and turn the eccentric until
the wheel touches. Start in the center and work toward the top and bottom wheels.
Last updated: 08/13/20108 Rev. 9
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Install the outer wheels and turn the eccentrics until the outer wheels touch the C-beam.
The ACME block is installed in the same fashion as the first step.
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Note limit switch on bottom of plate, these wires will remain loose till install.
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Step 3:
Step three will be the assembly of the rear X gantry plate. The same principles apply here. Use the
reference wheels as a base and adjust the eccentrics to touch the inside of the sample beam (250mm
length Z). Continue by installing the ACME block with the supplied 3mm spacers and M5 x 20mm bolts.
Again, it is a good idea to adjust the tension on the ACME block at this time.
Note this plate is completely remodeled but the assembly remains the same.
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Notch in plate faces down. Limit switch on the left-hand side looking at the plate.
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STEP 3
Qty.
Smw3D
Builder
Rear XZ Gantry Plate
1
Adjustable Tension Anti-Backlash Nut
1
Mini Delrin Wheels
8
3mm spacers
2
m5x20
2
m5x25
8
6mm Spacers
4
6mm mini eccentric spacers
4
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Step 4:
Step four will be the joining of the front to the rear X gantry plates. When you have all the large wheels
in place, apply a light amount of tension on the M5 nuts to hold everything together. Then, adjust the
eccentrics so that the wheels are as far away from the center of the X axis as possible.
Once the wheels are installed and eccentrics have them spaced out, slide your 250mm length C-beam in
and adjust the tension evenly. Turn ⅛ of a revolution on the two eccentrics on one axle at a time. Start
with the far-left top corner then go to the top right corner, then the right bottom, then the left bottom.
If all are touching, you’re done. If not, repeat by turning each axle eccentrics ⅛ of a rev again. Once the
outside wheels all touch, move to the inner wheels.
There are no shims used here except for those between the bearings on the wheel kit. The assembly is
plate, eccentric, wheel, 9mm spacer, wheel, eccentric, plate.
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STEP 4
Qty.
Smw3d
Builder
Large Xtreme Wheels
16
9mm Spacers
8
6mm Mini Eccentric Spacers
16
M5x60
8
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Step 5:
Step five we will mount the spindle to the Z gantry. The Z gantry will be the up and down axis of the
machine. Note, the spindle clamp has been modified from the video. These spindle clamps are very
fragile in the un-mounted state. Be cautious with these. Do not try to bend them or force them open
with excessive force. Simply slide the clamp on the end of the C-Beam, install with a T-nut and M5 x 8
screw on both sides, and tighten. The clamp will be tight when installing the spindle. You can gently
spread the clamp by hand and slide in the spindle. The clamps should be on the stainless caps of the
spindle.
STEP 5
Qty.
Smw3d
Builder
800w Spindle
1
Spindle Clamps
2
M5 T-Nuts
4
M5x8
4
M5x35
2
250mm C-Beam
1
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Note, you can see both limit switches from the back view.
The Z-limit wires can now be moved directly up (in relation to the picture) and through the notch in the
rear plate and inserted into the Z-Axis screw terminals.
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Step 6:
Step six we will build the X gantry. Note, on the X gantry there will be a piece of 1000mm length C-Beam
and a 1000mm length 20x20 V-Slot. The V-slot will be the exact same length as one piece of C-Beam.
The ends of the beam will be colored to indicate the matching C-Beam and 20x20 aluminum V-slot.
Please lay all out and find the piece of C-Beam that matches the 20 x20 x1000mm perfectly.
We will be mounting these two beams between the left and right Y gantry plates. We will also be
mounting the first stepper motor to drive the X axis. The motor can be mounted on the left or right Y
gantry plate. One should think about the final installation of the machine at this time and debate if there
will be an advantage to the motor being mounted on one side or the other for space reasons. The
M5x15mm bolts will hold the beams to the Y gantry plates. The bearings will fit into the recesses in the
outside of the Y gantry plates. The ACME will thread through the anti-backlash nut on the X gantry we
built in a previous step.
Prior to installation, it is advised to lightly sand down the ends of the ACME to allow the 608ZZ bearings
to slide over the ends of the ACME. Only about .2mm need be removed from the OD of the final 40mm
of both ends of the ACME. The bearings and ACME will be held in place by the 8mm lock collar on the
end opposite of the motor, and the coupling on the motor side.
Install the X gantry on the C-Beam, thread the ACME through block on the X gantry, then install the two
side plates with the provided M5x15mm bolts.
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STEP 6
Qty.
Smw3d
Builder
M5x15
10
M5x55
2
1.5in spacers
2
608ZZ Bearing
2
8mm lock collar
1
6.35x8 Coupler
1
1000mm Acme
1
1000mm 20x20
1
1000mm C Beam
1
NEMA 23 2.8A
1
Shim: 12.5x8x1.5
2
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Above, the motor installation is shown. Use the two longer bolts and spacers to attach the motor. Install
the bearing, washer, and coupler as shown. Tighten all set screws on the coupler once the ACME is fully
engaged.
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