DIY Laser/XY Gantry

Background

RussleH and 'RepRap' Matt (talk) took a look at the work is of the IMP Pick and Place at Ciseco
Pictures here
https://www.dropbox.com/sh/bhjxykpmvo0xxca/QPXxOIEow-/IMP

Locking a magnetic tape linear encoders, simlar to used on the PnP
This can give very high accuracy position feed back and at high speed

http://www.machine-dro.co.uk/digital-readout-systems/magnetic-tape-linear-encoders.html?p=1

Specifications

Size: Minimum 600mm x 900mm

Speed:

• 1000m/s for scan (X axis)
• 500mm/s for Y axis

Type of Gantry

Possible driver systems

• Fixed motor and looped belt to carriage
• Carriage mounted motor and fixed belt
• fixed motor driving a leadscrew
• fixed motor driving a ballscrew

Most lower cost laser cutters use belt drives.

Most larger machines use ball screws. Here are notes on the two ideas:

Belt Drive

Advantages

• Low cost

Belt Drive costs

• XY gantry for DIY laser is available here for $950. The cutting size is 900mm x 600mm

Ball Screws

More information on ball screws can be found here:

• http://www.cnczone.com/forums/linear_rotary_motion/8813-ballscrew_basics.html

• http://www.nskamericas.com/cps/rde/xbcr/na_en/Ball_Screw_Tutorial.pdf

Advantages

• High precision
• Used in commercial designs
• Unusual and interesting - not been done for table top lasers before.

Disadvantages

• Need to build this with high precision
• No DIY design available

Ball Screw costs

These prices have come from Zapp Automation (

Parts required include:

Ball screw 25mm diameter, 25mm Pitch: 2 x 600mm @£6/100mm = £72 1 x 900mm @£6/100mm = £54

End mounts: 3 x floating 25mm diameter @£30 = £90 3 x fixed 25mm diameter @£60

Type of Motor

Motors for each of the above could be one of the following

• DC motor
• stepper motor
• brushless servo motor