Wildseyed Simple Hot End

From RepRap
Revision as of 20:27, 18 May 2011 by Wildseyed (talk | contribs)
Jump to: navigation, search
Crystal Clear action run.png
Wildseyed Simple Hot End v2

Release status: Working

WildseyedSimpleHotEndv2ProfileView.JPG
Description
Wildseyed Simple Hot End
License
GPL
Author
Contributors
Based-on
[[]]
Categories
CAD Models
External Link

Design Goals

When I began building my first RepRap, I found that many of you were experiencing problems with the hot ends, either because of design flaws, or the difficulty of manufacturing. I then convinced myself that there was plenty of room for improvement. I began with the following goals to guide me:

  • Simple construction with readily available tools and materials
  • Reliability
  • Easy Maintenance
  • Low Cost

Tools Required

  • Drill Press
  • Drill Bits
  • Hack Saw
  • Tap and Die Set
  • Large Pliers or Vice Grips
  • Flat File
  • Caliper
  • Scissors
  • Soldering Iron
  • Barrel Crimp Tool
  • Small Brush or Cotton Swab

Materials Required

  • Aluminum Block - 1" x 1/2" x 1/2" (LxWxH)
  • Brass Coupling - Air Hose Type Female 1/4"
  • Copper MIG Type Welder Tip - 0.025/0.6mm
  • Set Screws - M4x5mm(1), M4x10mm(4)
  • PTFE Rod - 1.5" x 1/2" (L x D)
  • Thermistor - 100k, Glass Bead
  • Power Resistor - Aluminum Encased, Dale 5 Ohm 1% 5 Watt
  • Kapton Tape
  • Emergency Tape
  • Heat Sink Compound
  • Crimp-on barrel connectors - Small
  • Small Alligator clips
  • Insulated Wire - Teflon preffered, but any will do
  • Plastic Ties

Assembly in Seven Easy Steps

  1. The Aluminum Block
  2. The Brass Coupling
  3. The MIG Welder Tip
  4. The PTFE Rod
  5. The Thermistor
  6. The Power Resistor
  7. The Wraps

Step One - The Aluminum Block

The Aluminum Block

Using a punch, and a 7/16" bit, drill a hole through all, from the top of the aluminum block. The hole should be equi-distant from the three nearest edges. For example, if the block's top dimensions are 1" x 1/2", the the hole should be centered at 1/4" x 1/4". Next, widen the top half of the 7/16" hole using a 1/4" bit. Finally, use a M3.5 bit to drill a hole for the set screw. Tap it with a M4 bit.

Note: When drilling the aluminum block on a drill press, holding the block using pliers will help eliminate troublesome vibrations.

Step Two - The Brass Coupling

The Brass Coupling

in progress...

Step Three - The MIG Welder Tip

The MIG Welder Tip

in progress...

Step Four - The PTFE Rod

File:ThePTFERod.JPG
The PTFE Rod

in progress...

Step Five - The Thermistor

The Thermistor

The thermistor is the most likely cause of failure in any hot end. It is very fragile, and subject to shorts if not installed properly. Careful installation will ensure reliable operation, and accurate temperature measurements.

For this step, you will need a 100k Thermistor, and several lengths of Kapton tape. The goal is to encase the thermistor in several layers of capton tape, to insure that the leeds are insulated and supported, while still exposing as much of the glass bead as possible to direct contact with the heated surface.

Step Six - The Power Resistor

The Power Resistor

in progress...

Step Seven - The Wrap

The Wrap

in progress...