From RepRapWiki

Description

Isaac is a derivative of Mendel with the primary goal of making it easier to produce on 2.5D CNC machines. Isaac is a RepRap/RepStrap hybrid with parts that can be either printed on a Mendel sized 3D printer or a budget sized CNC machine. We have spent a significant amount of time on this design and we hope that our variation will allow cheaper machines to be produced as more and more people offer this kit.

Contents 1 Description 2 What's Different 3 What's the Same 4 Current Status 5 Build Documentation 6 Sources

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What's Different

We took great care to minimize overall costs of construction while maintaining the Mendel footprint. We significantly changed a lot of RP parts to make them machinable and still printable. We combined lots of parts where applicable, and tried to design things in such a way to make assembly and dis-assembly easier than the original.

• Vitamins: We have reduced the number of nuts/bolts/washers/bearings used to minimize costs where possible
  • Rods: Uses less smooth and threaded rod than the original
• Components: We have reduced the number of machined/printed pieces from 95 to just 45 (19 unique parts)
• Pulley Size: We could not find pulleys in the diameter of the original, so ours comes with 10 groove pulleys instead of 8
  • Slightly less X-Y resolution at 0.005 inches per half/step

• All machined parts designed to be (subtractive) cut out of plastic on a 2.5D CNC Router ... although they will (hopefully, untested) work just as well when (additive) printed out in extruded plastic on a Mendel or some other Isaac.

What's the Same

• Build platform
  • Want to buy that cool Mendel heater bed? It'll fit on Isaac!
  • (untested) the standard Mendel extruder should fit
  • the MakerBot's Plastruder MK4 fits on it (using an adapter plate)
• Smooth and Threaded Rod Spacing
  • Distances between Rods were left alone so that Updates/Upgrades to the original Mendel will apply to Isaac
• Belt pitch - Uses XL belts and pulley
• Metric based (SAE coming soon)
• Supports same motors as the original
• It is a RepRap, not merely a RepStrap -- an Isaac (or a Mendel) can print all the machined parts for a child Isaac (or a child Mendel) in extruded plastic.

Current Status

We have begun selling Isaac kits with a great initial response. The Alibre assembly files are complete and are now posted. The files are in STEP format and contain the entire assembly; every last part, nut, bolt, bearing, motor, etc. We are constantly updating the build documentation and have added a BOM.

Here is a video of one of our first Prototypes printing.

This video is shown with the Plastruder print head. We have since upgraded to a new print head and maintain print speeds about 50% faster than what the video showed.

Build Documentation

• Isaac/Y Motor
• Isaac/Y Idler
• Isaac/X Carriage

Sources

• The official Isaac webpage: http://www.flemingcnc.com/isaac.html describes 3 ways to get one:
  • $240 Buy a kit of all the plastic machined parts (currently HDPE) from the original designers: http://www.flemingcnc.com/sales.html
  • Print an Isaac on any RepRap or RepStrap (including some other Isaac) out of extruded plastic:

Isaac/Sources

• • Cut an Isaac on some 2.5D CNC router out of flat sheets of wood or plastic (The gray prototypes shown on this page were cut out of Trex wood-plastic composite): http://www.flemingcnc.com/isaac/docs.html

• The official Isaac blog: http://isaac-mendel.blogspot.com/