Introduction

OverlapStrap is a 3D printer that I have designed to be made mostly from the same parts as are needed make a reprap mendel. The idea being that I can print the needed 3d parts, with the repstrap, then dismantle the repstrap and build Mendel, without having to have bought lots of extra parts and materials.

Assembly3D.png
Figure 1: Main Assembly (not finished meh!)

Build Instructions

Start by getting your MDF cut into strips of 136mm, 81mm, …

Drilling

Measure the location of the hole as accurately as you can, and mark it with an engineer’s scribe. Then use a punch to make a dent on the peice which will make a nice point on which the drill bit will stay on, and not slide round all over the place. Make sure you use sharp drill bits and if you are using a cordless power drill make sure it is full of juice so that the drill is running fast. You should also consider doing it in two stages. Start with a small pilot followed by a hole of the desired size, this is because smaller drill bits will be easier to keep within the centre punched dent.

Drawing Files

These are the files that I have created so far describing the parts of my OverlapStrap project

Materials

Overlap Materials

What Qty Mendel Qty Strap Overlap

8mm Stud

9m

9m

100%

8mm Bar

3m

3m

100%

M8 Nut

104

90

86.5%

Nema 17

4

5

80%

M4x16mm Cap

38

53

72%

M4x40mm Cap

115

11

9.5%

M3x20mm Cap

50

20

40%

624-Bearing

48

27

56%

Extra Materials

What Where Cost Qty Total

16mm dia PTFE rod 350mm

ebay: Ringwood Precision Engineering

£3.50

1

£3.50

1/2"×1/2"×1/8" ALU angle 1000mm

ebay: Ringwood Precision Engineering

£1.50

3

£4.50

3/4" Alu square bar 247mm

ebay: Ringwood Precision Engineering

£3.65

1

£3.65

Fixing Block (pack of 24)

B&Q

£2.98

3

£8.94

6mm×1220×2440 MDF sheet

B&Q

£9.14

1

£9.14

Total

£29.73

Tools

What Notes

Vernier Calipers

Engineers Scribe

Not essential, I used stanley blade as alternate

Set Square

Tap & Die Set

M4 and M8 required

Hacksaw

I used a mitre saw, which makes square cuts easy

Power Drill

HSS Drill Bits

3.3mm 4.0mm

Git Project

Alternatively the files are available in a git project which you can checkout using the following command

git clone http://www.gilesbathgate.com/OverlapStrap.git

Thingiverse

The design is not currently complete, but when it is I will probably upload it to thingiverse

Copying

Copyright © 2009-2010 Giles Bathgate. OverlapStrap is licensed under the terms of the GPLv3 See: COPYING