User:Mstovenour

Michael Stovenour

Laser Rotary Engraver

Leadshine iST57

Dip switch settings

Thunder laser connector pin-out

Thunder Laser Rotary Engraver Cable Pin-out

5 pin / 9mm Round Female

Pin	V1 Color	V2 Color	Name
1	Red	Brown	+vDC
2	Black	Black	GND
3	Yellow Black	Yellow	PUL+ DIR+
4	Green	Purple	PUL-
5	Red	Grey	DIR-

Etching on Glass

How do I etch this onto glass? RDWorks insists on etching the background which is transparent in this PNG.

Source GIF:

eLab

60V 10A Adjustable Voltage Regulator

This is a complicated design because of both higher voltage than normal and a current above that of most integrated regulators. The approach I think would be most effective for this design is to leverage the best attributes of an integrated regulator (accuracy, stability, temperature compensation, short circuit protection, and thermal protection) and extend those with a pass transistor. There are a number of application notes that describe how to use a pass transistor, but I found one that extends both the short circuit protection and thermal protection to the pass transistor. The key here is to pick both an integrated regulator and a pass transistor that can handle the 60V range.

High Input Voltage

Most common integrated regulators only allow a voltage drop of ~35V max. The project requires 60V input. A 35V-40V regulator could be used so long a the output is never shorted to ground; if a short were to occur the internal pass transistor on the regulator would be destroyed. A way to overcome this limitation is to use the LM317HV and 2N4399 PNP pass transistor which have a 60V max input to output / VCE voltage rating.

Design

The design I recommend is from Section 4 of AN-103. This AN is for the LM340 but the application examples should apply to the LM317 as well. Using the LM317HV will allow the design to be variable voltage output.

This thread is a good description of how this system works: http://electronics.stackexchange.com/questions/218083/what-does-pnp-bjt-with-shorted-c-e-do/219157

The design shown here will allow the LM317HV to load share with the pass transistor. In this design the pass transistor will conduct a fraction of the current that goes through the LM317HV. The key here is that the LM317HV will directly react to the output conditions. If the LM317HV enters a short circuit, current limit, or thermal overload mode the pass transistor will also reduce its output current to match. One of the keys to this is to thermally couple the input diode, LM317HV, and the pass transistor. As all three heat, the LM317HV will react to protect the system.

It may be necessary to include more than one pass transistor depending on the power dissipation requirements. The ratio of the input resistor value can be adjusted to balance the current over all the pass elements. A singe 2N4399 will easily handle the peak current of 10A but it might not handle the power dissipation. For instance at 10A, if the input voltage is 55V and the output is 35V, this will require (55-35)*10A = 200W. The 2N4399 is rated as Tc=200W. So assuming we have a significant (possibly infinite) heatsink the transistor will still be right at the point of failure (or thermal shutdown of the LM31HV). We need to define some parameters around the minimum output voltage and maximum current output to define the expected worst case power dissipation.

IMO, the down side of this design is the need for very large power sharing resistors ahead of the LM317 and pass transistor(s). In addition to being bulky and expensive, these will be require careful PCB layout to manage the heat absorbed by the PCB.

Parts

LM317HV: The TO-3 case would be nice for power dissipation but the price goes from ~$2 for the TO-220 case to ~$40+ for the TO-3 case.

2N4399 (60V) transistor

2N5885G ON Semiconductor datasheet

1N4719: really most any diode that can sustain 3A with 0.4-0.6 Vf / 50V Vr. The reverse breakdown voltage is not all that critical. We just need a forward voltage drop that approximates the voltage drop on the pass transistor.

MIG Welding

Tutorial

Teach Yourself MIG Welding: the series

Teach Yourself MIG Welding (Part 1 of 4) Basics and Machine Setup

Teach Yourself MIG Welding (Part 2 of 4) Flat Horizontal Welding

Teach Yourself MIG Welding (part 3 of 4) Uphill & Downhill Techniques

Teach Yourself MIG Welding (Part 4 of 4) Overhead GMAW

Operational Check List

Gear

• Helmet
• Safety Glasses
• Gloves
• Brush
• Welding Leathers
• Side cutters for wire

Mig Gun

1. Handle

   -Check for cracks

2. Cone / Nozzle

   -Check inside for spatter

   -Remove, pull straight off or screw off

3. Contact Tip

   -Make sure hole in center is round and not blocked

   -Match contact tip ID to feed wire

4. Ground Clamp

   -Check that it is not damaged

   -Securely connect to work piece

Mig Wire Installation

1. Check size, e.g. 35 thou

   -Steel wire with copper cover

2. Install spool
3. Install nut / might be left hand threaded
4. Take tension off
5. Cutoff wire to get straight
6. Feed wire through drive wheel into the liner
7. Put tension back on feed wheel
8. Remove nozzle and contact tip
9. Turn on welder
10. Set feed speed all the way up or so
11. Hold lead as straight as possible
12. Hit trigger until wire comes out of Mig Gun
13. Re-install contact tip and nozzle

Shielding Gas

Gas Types

75/25 Argon/CO2

80/20 Argon/CO2

100% CO2

1. Thread flow meter into cylinder (Do not over tighten)
2. Take tension off feed wheel (so not to waste wire)
3. Turn on welder
4. Slowly open cylinder initially, then open all the way to seal
5. Pull trigger
6. Set flow rate to 15/20 CF/H (cubic feet / hour)
7. Return tension to feed wheel

Work Piece Setup

1. Work needs to be clean because there is no flux to clean
2. Use panel chart to pick volts / feed

   -steel-solid wire-75/25 : Wire size (e.g. 23thou) : Wire thickness

   -E.g. 24thou:11GA => 5/80 amp / feed settings

3. Set volts / feed rate

Machining Tutorials

Berkeley Student Machine Shop Phase 4 Walk-through

Plasma CNC

Operational Check List

Check Consumables

1. Power off Powermax1000
2. Manually pull gantry to front middle
3. Remove torch (7/16" wrench)
4. Remove shield, retaining cup, nozzle, electrode, and swirl ring
5. Reinstall in reverse order

Power UP Torch

1. Turn on exhaust fan
2. Power on Powermax1000
3. Connect Air
4. Air pressure (5 Bar)
5. Switch middle
6. Turn on plasma cam controller
7. Check that cutting is disabled (auto light out)

Set Machine Settings

1. Set Amps on Powermax1000

   -See manual for recommended amps setting

2. Machine / Settings (Tab)

   -3/16" steel 35 ipm

   -1/8" steel 80 ipm

   -16ga mild steel 60A 300ipm Kerf 0.06 pierce point lead-in 0.10

   -20/22ga mild steel fine cut 40A 325ipm Kerf 0.03

   -Or use Configurations tab

3. Machine / Initialize

Prepare the File

Zoom Keys

-Zoom Box (F1)

-Zoom Previous (F2)

-Zoom Table (F5)

1. File / Import (ins)
2. Select all

   -lines should be green

3. Edit / Link (K)

   -lines should be purple

4. Select One Path

   -lines should be green

5. Machine / Convert to cut path (P)

   -lines should be blue

   -Repeat previous step for all paths

6. Machine / Reorder Paths / Pick Order

   -lines should be red

Place the Material

1. Machine / Initialize
2. Load material on the bed
3. Attach ground clamp
4. Machine / Move to (V)

   -position the torch on material

   -yellow cross hairs

5. Select all

   -lines should be green

6. Edit / Move (M)

   -Click and drag

   -Move off the supports

7. Set Z-Axis on controller (z-axis up/down and shuttle)

   -1/16" - 1/8" (thickness of penny)

Test Cut Path

1. Select parts to cut

   -lines should be green

2. Disable cutting (auto light out)
3. Machine / Cut
4. Adjust work piece and image location if needed (V/M)

Cut Path

1. Select parts to cut

   -lines should be green

2. Enable cutting (auto light green)
3. Machine / Cut

Turn Down Equipment

1. Turn off plasma cam controller
2. Turn off torch power
3. Turn off exhaust fan
4. Remove air hose
5. Remove work piece

Solid Works

Tutorials

Solidworks Tutorial 1 Creating Sketches

Solidworks Tutorial 2 Modifying Sketches

Solidworks Tutorial 3 Part Videos