The Secret Society of Lathe Trolls

what was the principle of the coil on the funnel and also what is the principle of the big iron square? The coil was for generating a feedback (error) signal to be subtracted from the source to compensate for incorrect frequency response. The block was for testing the magnet structure for the feedb...

I'm confused. Why is it that you want to change over to pulleys?
Isn't the 8dg direct drive? Mine is a rim drive 8D so I really don't know how the pulleys come into play with the direct shaft.
In your photos I don't see the direct drive shaft.

Bryan

Hey guys, thought you would get a kick out of what I found 2 weeks ago. I'm not going to tell you what I paid other than to say that when he told me the price I said "OK, that's reasonable"... First up: A Presto 75 cutter with a GE Bantom 501 tone arm (and Pickering V15 cartridge). It's in a portabl...

Jonas wrote:Bryan, can you show a side view of your head in working position above record.

This stylus is broken (the entire cutting tip) but you can still see there is clearance with the stub touching the disc.

And here is an adapter to make this work on my Presto 8D...

Bryan's right. [/b] Love it! I wonder if he is missing the mount on the back of the head. There would be one that sets the head for 15 degrees (most common) to match the angle of the bridge piece, and another one that is 20 degrees if a special bridge was installed - designed for 20 degrees if fitt...

Actually, when your stylus is perpendicular to the record surface as it should be your head will look like this and you have plenty of clearance like shown ...

Bryan

I see your issue.

It's possible you don't have the stylus protrusion set correctly. It should be 2.35mm from the surface of the bridge as shown below. If it's more or less than that it will also affect cross talk as shown in the table.

Bryan

Time for an interesting update via YouTube:

I do have a quick question on the buck converter. Will it do step up conversion as well? It seems as it would. No. That specific one is down only. You can buy one that is up, down or both. Each version has it's own application... I don't know what current you need for the other motor you mentioned....

Hi sameal, Here is a schematic and a list stuff to buy on E-bay. This will do what you want and be really inexpensive. IMG_6358.jpg I forgot to mark the diode. Be sure to add that. A 1N4004 will work fine. First thing you need is a 5v opto isolated relay module like this... It will connect to your a...

Would you have a schematic of the dual supply for the solenoid? I can work up a schematic for you with stuff you can buy cheap on E-bay. I did something like this to run a valve on my freeze dryer a year or two ago. I see from one of your photos that the solenoid has two wires, uses 12v and says it...

Here we go with the good stuff. As you saw, the U-shaped motor bracket has 4 big holes. Originally, 4 bolts and spacers went through there but did not touch the bracket. They were there to limit movement of the Bodine motor when transporting the suitcase (the lathe was originally mounted in one). So...

Hey guys, just about done! Tonight I'll share some more trials and tribulations before the final solution! When we left off, I was messing with the wire rope isolated platform. I tried a round belt and found there was enough tension needed that the top platform would rotate since the pulley was not ...

Thanks! I fell out, It was shipped so maybe it happened in transit! There is a troll thread here that you will want to look over: https://www.lathetrolls.com/viewtopic.php?t=5109 One picture of the cutting head clearly shows the stylus should be straight. Also, you will want to look closely at a pa...

So Flo,
Any info on your new head?
https://www.lathetrolls.com/viewtopic.php?f=1&t=7937&hilit=flo

B

The next step was to calibrate the meter in the "output" switch position. Again, I had a 500 ohm load on the 500 ohm taps. My load has a switch for selecting the impedance, a range selector and has a meter built in. Per the manual, Calibration of the meter is done with an input source of 1khz. The m...

I had to delete the video in the previous post because of the music. For those who got to hear it, that sounded damn nice even filmed with an iPhone. More stuff for tonight: I don't think I mentioned but there is a balance control for the 807 "A" pair, and 807 "B" pair. That pot was adjusted to make...

More details to come.
But here is a quick sound check video...
Audio is cut off several times so you can hear what the background 60hz is.
Also shown are the tube currents for all the tubes and how close they are in the 10 - 0 - 10 range as specified in the manual.
Enjoy!
B

Hey guys, Alan Graves has moved back to Eugene, OR and is going to drop by my place on Thursday Sept. 20th at around 10am. Anyone in the area is welcome to drop by and say hello. This will not be our usual "once a year" get together, since he is back in Eugene permanently now! I'm sure we can schedu...