A RouterStrap is a RepRap made from a commercially made benchtop CNC router, with an extruder head fastened next to the Spindle.
There are lots and lots and lots of people making these things. Some are better than others. Do some comparative shopping. and help fill in this wiki page.
Many CNC routers designed to cut MDF are themselves built mostly of MDF, and therefore can be considered at least partly self-replicating (and therefore RepRap, not merely RepStrap).
- "The drawings used for producing our in-house MechMate CNC routers are published on this site, for free ... to build "once-off" machines which may not be sold for profit."
- one forum post claims that all the parts, motors, control electronics, etc. for a typical MechMate runs to around $6,000 (not including labor for assembly and calibration)
- ... tweaking MechMate design for lower cost: discussion
- Many MechMate CNC routers can hold and cut a full-size 9 foot x 6 foot sheet of material. That's bigger than even the biggest proposed RepRap, the BigRap.
- Yes, but does it have enough resolution to use it as a RouterStrap?
Seems to also duplicate MillStrap.
general design ideas
A router (subtractively) shapes solid materials using the sides of a rotating cutter. It is used to cut material that starts out as large flat slabs.
A router has a flat sole plate that presses against and slides over the face of the material.
A router both
- (a) pushes a toolhead in the X and Y directions through the raw material, enduring significant forces in the X and Y axis (often both simultaneously), and
- (b) requires precise positioning in the X and Y axis. (The Z axis is either "all the way up so nothing touches the raw material" or "all the way down with the sole plate against the material).
This is difficult, but not quite as difficult as a CNC Mill milling machine which requires strength in all three X, Y, and Z axis.
There are at least 2 ways that a router-based RepRap can help build its next generation:
- Using a router bit that protrudes from the sole plate much less than the full thickness of the raw copper-plated FR4 raw material, a router can cut copper trace patterns and isolating gaps between them as part of Automated Circuitry Making.
- Using a "straight" router bit that protrudes from the sole plate slightly more than the full thickness of the raw material, a router can be used to cut out FlatPack parts. (In this case, you need a sacrificial board under the raw material).
- Cartesio is a reprap printed CNC machine
- Eiffel is one of the CNC router projects. (Eiffel will also be a 3D printer.)
- BigRap aka MegaRap may be the name of a scaled up large, room-filling CNC Router able to handle raw materials that come in a "full-sized sheet" of 1.2 m × 2.4 m ( 4 feet × 8 feet, aka "four by eight") slab. It may be a PourStrap. See Development Pathway#MegaRap.
Other CNC Routers
These are generally non-self-replicating, non-GPL. (Boo, hiss!)
The ShapeOko is an opensource, hobby-level CNC machine using aluminum extrusions (MakerSlide for v1 and v2, a pair of custom extrusions for the nascent v3). ShapeOko by default uses Nema 17 motors (but one can upgrade to NEMA 23) and an Arduino based controller running open-source software in its stock configuration, like most RepRaps. (It runs Grbl on the Arduino, a Smoothieboard is an alternative controller option as defined on the B.O.M. page).
FireBall CNC Router
- Location: US
The FireBall CNC Router is a commercial, hobby class CNC router. It is made from MDF, rather than aluminum or steel. On the other hand, it is inexpensive, and this is very helpful, because we don't need a 150 lb unit to move a RepRap extruder around.
They're somewhat popular, and probably a decent buy.
If you are getting one to just use as a RepStrap, bargain hard with the salesperson for a 'naked' machine, without the stepper motors, electronics, and so on, and use the RepRap electronics and motor.
Without Motors, Electronics, Etc.
- Base Price ~600USD.
(pre-shipping from US, pre-tax, etc.)
With Motors, Electronics
- Price ~1000USD.
(pre-shipping from US, pre-tax, etc.)
See main article K2
Location: US http://www.k2cnc.com/shop/proddetail.asp?prod=KTM-0704&cat=26 K2 has good-looking machine, made from aluminum, and they're a mature brand (in internet years), so they may be quite reliable. They're rather expensive, as are their 'extras' but who knows, you may get great support with that. Also, they're probably turnkey systems that _just_work_, and this may justify the cost.
Nema-23 motors, steel rails, HDPE frame.
The entire machine is bolted together with Allen-head machine bolts so every part is replaceable. Zenbot has several CNC routers for under $ 1 500 (not including the spindle). Made in the US.
VLTIMA project: low cost CNC (open-source hardware and software)