Wednesday, October 3, 2018

Rebuilding my CNC with T Slot aluminum and Fully Supported Linear Rails Part 2

I have been rebuilding my CNC with T Slot aluminum and Fully Supported Linear Rails.  Now I am testing it with a Laser to see its accuracy.  I built my own laser by buying the laser, the housing, the heat sink and the controller separately.  Its a 2 watt laser but the power is throttled back to just burn the material.

Here is the video on youtube:


The accuracy is greatly improved!  The X axis used to have some play in it but now it is right on the money.

The fan power pin on the laser controller is backwards from all of the other connectors.  You will need 5-9 volts on the analog connector to turn the laser on.  The blue trimmer sets the laser power.


Monday, September 17, 2018

2018 Lancaster NY Hamfest

The 2018 Lancaster NY Hamfest is over.  It might be the last one for me this year unless I go to the one in Elmira NY.

This is my display. I had already sold some stuff!
 This was a really neat home made 811 tube RF amplifier.
 This vendor had lots of antique radio's.
More of the same vendor stuff.
 How is this for a beautiful radio?  Its a "Scott Tuner" but not HH Scott!
 Here is a couple of beautiful Heathkit radio's.
  This is what the hamfest looked like from half way down one isle.
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Monday, September 10, 2018

Home Repairs/Upgrades

 I recently replaced the lattice in my carport with the heavy plastic.  The panels are called "26 in. x 8 ft. Polycarbonate Roofing Panel in Clear" I did it because one of my neighbors threw out the panels.  Then I replaced the slats that were on my deck with the lattice.

This picture is what the carport looked like half done.

This is what the carport looked like when it was almost done.

This is the old deck rail slats being removed. I had already started replacing the slats with lattice when I took the picture.

This is the new deck rail with lattice installed and painted.

Sunday, September 9, 2018

Chevy HHR Exhaust coupling repair

My HHR started sounding more like a tractor.  I could not see the problem but I could feel the heat coming from this joint.  As you can see it was rusted out.
I purchased two 2 inch pipe clamps at the local car parts store.  They are Ni Exhaust Solutions "Split Flange".  Each one comes with two bolts.  They have to be pried apart and worked back and forth until they open and close.  Then, open one side of both clamps and put a bolt through the closed sides.  Then rotate them into place so the first bolt is above the fitting.  Then close the flanges and install the lower bolt.  It took me over an hour to close the lower flanges.  If you can get them close to closed you can get a flat blade screwdriver in there and close them the rest of the way.  Then install the lower bolt.  That took a long time as well.  One of the issues is the metal gasket gets in the way.  I think I managed to damage the gasket as once it was together it still leaked.  But at least the pipes were not going to fall off the car!

Here is the clamp once installed.  It was hard to tighten the upper bolt as the socket set would not click in the short space.
Split Flange Clamps

It still leaked so I covered the whole thing with J-B Weld "Muffler Weld" Cement. 
J-B Weld Muffler Cement
That solved the problem for now.  I know that eventually I will need a new exhaust but for now the leak is fixed.


Friday, August 31, 2018

Comparing 2018 LED projector models

2017 Projector brightness ratings in Lux. (See previous post)

Epson EMP-S1     Rated: 1200 lumens     Tested: 460 Lux
Pyle PRJD907      Rated: 2000 lumens     Tested: 230 Lux
No Name CL312   Rated: 2000 lumens     Tested: 100 Lux (Note: damaged LCD)
Pyle PRJG65        Rated: 150 lumens       Tested: 30 Lux
Erisan                   Rated: 1200 Lumens    Tested: 40 Lux
Crenova XPE460 Rated: 1200 Lumens    Tested: 60 Lux

2018 Projector brightness in Lux.

Dell 1201 DLP           Res: 800x600       Rated: 2000 Lumens    Tested: 600-800 Lux
Fugetek FG-857        Res: 1280x800     Rated: 2300 Lumens    Tested: 80-200 Lux
Blusmart LED 9400   Res: 800x600       Rated: 1800 Lumens    Tested:  30-60 Lux

Comments: 
FG-857 is big and bright with a great native resolution too.
LED 9400 is bright for its small size.

Testing the FG-857:


Testing LED 9400:


Testing the Dell 1201 projector:




Monday, August 20, 2018

Rebuilding my CNC with T Slot aluminum and Fully Supported Linear Rails.

I am rebuilding my CNC with T slot aluminum extrusions, fully supported linear rails and a smaller Z axis.  My book "Inexpensive CNC Projects has been my best selling book for 2 years.  During that time I have added USB interface with an Arduino Uno and a Laser.  Now I am changing the frame to T slotted aluminum among other improvements.  I was able to get a great deal on six pieces of 18" 2020 aluminum extrusion.  Then I had them professionally cut to length.  Afterwards I discovered that the 16.5 length should have been a little shorter.  The length was based on 18" -(2 x 20mm).


Once I got the frame together this is what it looked like.  The red bearings were problematic as the outside diameter is 7/8" and I could not find anything that fit them.  That is about 22 mm diameter.  There are some 22 mm clamps that are used on Drones but they are wimpy as they were not designed for use on a CNC machine.
T Slot CNC Frame

The new Z axis is only four inches wide.  This next picture shows the new Z axis in front of the old six inch wide Z axis.
New Z Axis
These are some things I have learned about 2020 T slot aluminum:
1. A 10-32 screw fits the T slot nuts.
2. A 10-32 Truss head screw head fits the T slots.
3. A standard 10-32 nut, once filed slightly, fits the T slots.

Here is my current state of construction, the fully supported rails and matching bearings is a huge improvement well worth the $40.
T Slot CNC being assembled
Here is a close up on the experimental Z axis with 22mm Drone clamps holding the bearings.
Close up of Z axis
GRBL has changed since my book was written.  You now have to manually extract the zip file and copy the "GRBL" directory to the Arduino/Libraries/ directory.
Installing GRBL

Then to load GRBL select grblUpload and open it.
Loading GRBL
Then when you upload it you will get an error message.
GRBL Error
Then when you run G Code Sender select 115K for the communications speed.
Next set your steps per mm as in $100=320, $101=320.
Then check to see if a 10 mm move in X and Y move exactly 10 mm.
Then check to see if a 100 mm move is in fact 100 mm.
Next attach a marker and print something.
I found a file that prints a 5 inch ruler that is a nice test of the CNC.

Here are the drawings for the smaller Z axis.  Sorry the drawings are from Visio not Autocad.

Z Back:
Z Front:


Z Top (and Z bottom with no holes for stepper motor):


Z Back for Continuously Supported 12mm X axis (1" x 1.1" or 26 x 28 mm bearings):
Note that 10-32 screws will fit the 12 mm bearing blocks.





Wednesday, July 25, 2018

2018 Batavia NY Hamfest

I bought a "new to me" Canon SX160 camera at the Batavia Hamfest.  It has 16x optical zoom (64x with digital) and 16 Megapixels.  It also does great video.  Here are some pictures I took with it.


There was some space for more vendors as seen in this picture.  There were three isles of vendors.  I was just testing the camera so I did not catch anything interesting.

Now to get the pictures from my Sony camera that hopefully shows more vendors.  Here is my carload of stuff for sale.

Here is a look down one of the isles of stuff for sale.


Monday, June 18, 2018

Here is a comparison of some of the amplifiers found on eBay.

I have been comparing the specifications of some of the amplifiers that I have worked with:

L-10 Amplifier:
Size: 200x41.5x?? mm
8 Ohm 100 Watts
4 Ohm 200 Watts
2 Ohm 350 Watts +-55VDC
Gain: ?? 
Output Transistors - 3 EA: A1943 C5200

L-15 Amplifier
L-15 Amplifier:
Size: 150x40x?? mm
Size: 5.9x1.57x??"
8 Ohm 150 Watts
4 Ohm 300 Watts
2 Ohm 600 Watts +-55VDC
Gain: 36x
Output Transistors - 3 EA: IRFP240/IRFP9240

L-20 Amplifier
L-20/28 Amplifier:
Size: 110x65mm (L-20)
8 Ohm 200 Watts +-65V
4 Ohm 350 Watts +-60V
2 Ohm
Gain: 34x
Output Transistors - 4 ea D1047 B817
Note: L-20-SE has 2SA1943 2SC5200 transistors
Note: L-28 Includes capacitors and speaker protection

PR-800 Amplifier
PR-800 Amplifier:
Size: 245x65x30mm (or 195x90 with 4 Capacitors)
Size: 9.64x2.55x1.18"
8 Ohm 500 Watts +- 95VDC
4 Ohm 1000 Watts +-90VDC
2 Ohm 1000 Watts +-65VDC
Gain: 40x
Output Transistors - 4 ea TTA1943 TTC5200
Note: Includes Capacitors and Speaker protection
Note there are 2 sizes; one with 2 large filter capacitors and one with 4 large filter capacitors.

NJW0281/NJW0302 Amplifier
NJW0281/NJW0302 450W+450W HIF
Size: 259x73mm
8 Ohm
4 Ohm 450 Watts +-85VDC
2 Ohm
Gain: Very Low - needs preamplifier
Output Transistors - 4 ea NJW0281/NJW0302
Note: ATX power supply pins fit the connectors on the right side.

Wednesday, June 13, 2018

Rebuilding LAB Series LS800 Amplifier with a PR-800 Amplifier

I had rebuilt this LS800 amplifier with a L-15 amplifier but I decided to upgrade to PR-800 amplifiers for much more power.  This is a picture of the old amplifier dissembled.

This is a picture the old power amplifier section.  It was really cobbled.
This is how the PR-800 amplifier boards arrived.  Note that the power output transistors will have to be soldered on.
Pr-800 as it arrives
Here I have added the output power transistors.  I also moved the driver transistors to the top side of the board for mounting on the heat sinks that I have.  Their leads barely reach the tops of their holes.
PR-800 with power transistors
This is what it looks like mounted on the heat sink.  I went back and added washers under the heads of the 3/4 inch 4-40 screws.  Note that little plastic washers must be installed in the two To-220 transistors (Q12 and Q15).  Make sure to check for shorts to the heatsink with a voltmeter!
PR-800 Mounted on heatsink
WARNING!!  Something was really wrong, it tripped the circuit breaker and shorted the output transistors!!!  I eventually found the problem.  The 2SD669 (Center transistor Q13) has to be soldered UPSIDE DOWN on the top board!
Upside Down Transistor on PR800
Here is the schematic of the output section.  Note that the 2SC5200 (Q16, Q17, Q18, Q19) transistors are connected to the + power source and the 2SA1943's (Q20, Q21, Q22, Q23) are connected to the negative power source.  Also not that the two boards are the opposite of each other.  The 2SA1943's will always be next to the power filter capacitors.
The schematic was derived from this schematic found on the internet.  The protection circuits do not match what I received.

Here is a labeled picture

I have both channels working fine now, but only one at a time.
PR-800's mounted on heat sinks
As you can see I cut off one side of the heatsink.  I also switched to silicone insulators because they are less messy.  One channel is missing two power transistors because they were fried when I installed the 2SD669 right side up.
This project is finally done!  The cooling fan was mounted to the front cover to make working on the amps easier.  The heatsinks were mounted to the bottom of the cabinet.  The LM3915 LED VU meters have the bottom LED always on and the top two red ones are in parallel thus giving 12 LED's per channel.


Rebuilding some old speakers

I was given some speakers that I had built back in the 70's and that had been in use at a churhc for about 20 years or more.  They were made to look nice, but I will rebuild them to look tough.  I also want to upgrade them from 25 watts to about 150 watts or more.

This is what I bought at a Hamfest to rebuild the speakers with.
This picture compares an old speaker with one of the new ones.
 Initially this is what initially had to work with.  I only had one of these bass speakers.
 Here is one cabinet stripped down and the old speakers sitting on top of it.
I painted the front plywood black and started reassembling the speakers. I traded something for some tweeters.  They are rated at 75 watts.  I also added some grills to protect the woofers.