Laser Subcommittee Meeting 2018-12-17
Attendees:
- BlakeS, NickB, KamilS, FletcherB, Lemming
- G.Weike LC1290/Big Red
- Head crash into bed? at 20181128 https://groups.google.com/d/msg/artifactory-core/Nvj96_MpFSk/2j03fuWcAwAJ
- RussellC testing 20181209:
- 3mm ply cutting well
- some vibration when engraving at 200mm/sec, bottom of X belt vibrates - tension?
- Hour meter
- The hour meter started from 1.6 hours, at 20171210 , 475 beam-active cutting hours recorded over 12 months
| Date | Hour count |
|---|---|
| 20171210 | 1.6 |
| 20171217 | 11.5 |
| 20171230 | 31.2 |
| 20180210 | 72.05 |
| 20180305 | 95.8 |
| 20180604 | 181.65 |
| 20180702 | 234.8 |
| 20180827 | 295.5 |
| 20180924 | 326 |
| 20181022 | 375.5 |
| 20181129 | 426.9 |
| 20181209 | 475 |
| 20181217 | 488.9 |
- G.Weike LG500/Little Red
- No Class 2 red aiming laser
- Keys dying on control pad - down arrow?
- Test cut nice and fast, 3mm MDF at over 15 mm/sec
- 22mA, configured Max-Power still at 67
- Whiteboard says 9mm/sec? possibly less reliable cuts over the whole honeycomb workspace
- 2018-12-17 Fletcher tests at 16mm/sec
- KH-7050/Kellogg
- Has PC next to it - installed?
- Software seems to work?
- Kamil: Laser tube ready to install in the next week?
- IainG's 25W Shiny Rabbit https://fslaser.com/ table top laser cutter visiting for Canning STEAM, Science show @20181208/Little blue
- Currently borrowing Kellogg's compressor
- LC1290/Big Red fault finding
- Laser is cutting very poorly, but displayed current is still OK
- If the tube is failing; it's our third (second arrived broken) Reci W6, installed 2016-12-28: so it has had about 1000 hours burn time?
- If the HV PSU is failing; it's our second MYJG-150 (150W), USD$410+shipping, installed 2015-01? A suitable spare will probably be cheaper and we're inclined to get one regardless.
- Blake: Diagnostics yesterday 2018-12-16
- Cleaned mirrors, lens
- Checked alignment - OK
- No improvement ~20mm/s for 3mm MDF
- Tried to clean tube end
- Stopped cutting at all - just marking wood
- Still drawing 26mA
- Fault finding today
- We think could hear electrical arcing while laser running - 26mA
- Tried taking end cover off and recording video
- Cannot find actual arcing, possibly OK?
- STILL TO CHECK: Laser is operational, but is the plasma stable at both ends?
- Look for arcing of power supply - find nothing
- Take out power supply: model MYJG-150 (150W)
- Look through insulation for signs of arcing
- Maybe arcing at crimp
- Test outside with dummy load. milli-Ammeter in series and 1000:1 HV probe with multi meter
- 102 kiloohm resistor (100W)
- When firing power supply (“Text” = “Test”) button: 44mA, 4400V (193.6W)
- When connecting two dummy loads in series: 206 kiloohm: 42mA, 8700V (365.4W)
- The dummy loads do not drive the HV PSU at full power - 29000V (~750W)
- 130W to 145W output for ~20% power efficiency
- HV PSU models:
- Kellogg: BH-80W
- LG500/Little Red: MYJG-60 (60W)
- LC1290/Big Red: MYJG-150 (150W)
- LC1290/Big Red spare parts
- 2018-12-13 Blake: ordered laser head: AUD $70 (inc. GST)
- ETA 2019-01-02
- 2018-12-14 Blake: ordered operations panel: USD $45.60 + shipping
- ETA 2019-01-22
- Spare HV PSU? USD$200–$450?
- Beam combiner+lens? USD$30?
- Laser safety goggles