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Planobilly
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To me, this is more exciting than the actual amplifier. Just curious; you need a "CAM program" to translate you AutoCad output files? Your CNC machine doesn't accept .DXF files? Oh and I do understand how easy it would be to tear up your tools and your work without any "speed and feed" data.Planobilly said:As I use CNC more it is becoming evident that the amount of work required to produce only one part is rarely worth the effort unless there is no other way to do it.. Drawing a part in AutoCad or Solid Works and getting a CAM program to produce the code is a ton of work. That is why I am just writing the code for simple stuff. Once a reasonable code is produced the process of verifying that it actually works and adjusting speeds and feed rates also takes up considerable time and effort. Then there is the fixtures that must be built to hold the part. Lots of stuff for just one part.
Thanks for the education Billy. I had no idea that G Code is the standard. I probably deserve an infraction for not Googling.Planobilly said:The vast majority of CNC machines understand G Code. There are some other proprietary codes used by certain manufacturers of CNC machines. G Code is the standard.
You have a CNC, find the software to do lettering and use an end mill to engrave. Paint. Let completely dry. Paint contrasting color to fill engraving and wipe off excess while still wet. When done carefully, this leaves the contrasting color in the engraving and the background is the first applied color. It's easier to get a clean job if the two paints are different chemistries, for instance Lacquer or Epoxy for the base color and Enamel for the fill color.Planobilly said:I still have not figured out how to make a cover plate with the lettering.
Why not insert a small bridge rectifier etc. and use DC on the heaters? Then you can connect the negative polarity to ground (preferably through a resistor - I am somewhat paranoid about possible ground loops).Planobilly said:The transformer does not have a center tap for the 6.3 volt heater supply like the original did. Not a game stopper but I will have to run two 100 ohm resistors to ground in parallel to form a quasi center tap.
I have checked some suppliers, and come up with:Planobilly said:I am assuming a full wave bridge rectifier. I don't know how to get around the voltage drop issue across the diodes which I assume would be around 1.2V or a bit more. In general the heater voltage needs to be + or - 10% of the 6.3V I assume.
You should just use the 8 ohm winding and leave the 4 & 16 taps open.Planobilly said:The transformer I installed has 4,8,and 16 ohm taps. It is my intent to use a 8 ohm connection at least most of the time.
Question: why three jacks?Planobilly said:The three Cliff jacks on the back panel are isolated from the chassis. (see photo below)There is no impedance switch.
By using only the 8 ohm winding; no need for a switch. Switch contacts would be a good place to introduce a noisy output sound (poping, etc.), and should answer: "What effect, if any, would any of this have on the 820 ohm resistor?"Planobilly said:... do I need to install a switch that makes the connection on the tap ...