The Secret Society of Lathe Trolls

It will fit pretty much any lathe with the appropriate mounting plate. I can either supply the dashpot assembly without the mounting plate and you can make this at your end or I can also supply the mounting plate as well.

Opcode66, apart from being involved in research and development projects pertaining to the bleeding edge of transducer design, I also have a day job doing work on any equipment a customer wishes me to work on, regardless of who made it or who did work on it in the past. Good to confirm that it was y...

I finally found some time to measure up the 75A and calculate what will be needed. The dashpot cylinder itself will cost GBP 85 and the mounting bracket will cost GBP 30. The cheapest option for a plunger is a non-adjustable type, with exchangeable pistons to achieve different amounts of damping. Th...

Thank you, boryo, more to come soon!

Symatic, to make an airpot work with oil, you would need to somehow "extend" the cylinder upwards of the valve (screw at the top) so there is oil both below and above it, moving between the two chambers. As it is, it is missing a chamber... This is because for air, the "second chamber" is the "big o...

Many thanks, everyone! Here's the fully assembled suspension system: 1.JPG 3.JPG 4.JPG 10.JPG 16.JPG Many more detailed pictures of the "making of" and description on the Agnew Analog Blog: https://agnewanalog.com/blog/2019/04/06/a-new-suspension-system-for-vintage-lathes/ . Teaser: 22.JPG We starte...

Mark, well, yes, you are right, the suspension unit itself is a mechanical low pass filter, but the effect it has upon the recorded modulation on disk is that of a high pass filter, since by "responding to disturbances" near and below the natural frequency, it essentially absorbs part of the energy ...

Symatic, you cannot really adjust damping properly just by ear, unless you have super accurate full range monitors and a high-end repro setup. I do, but even then it is tricky. A very rough/crude adjustment can be done by eye, just look for strange radial spokes (moire pattern) on the disk. For prop...

A few pictures of the Presto 171-A "inertia" damper I currently have in my lab: IMG_8553.JPG IMG_8554.JPG IMG_8555.JPG It works reasonably well on the 75A with a Presto 1C or 1D. I could try to make one, but it would be much cheaper to adapt an oil dashpot to fit the 75A. I can machine something sim...

Many thanks!
I have been super busy with some urgent repair work and a couple of restoration projects, but will present some progress on the new head in due course!

My mother an myself are known to supply vacuum platters, including Neumann-style 16" tops, a few different versions of 14" platters, a 12" platter and even a 7" platter, along with sub-platter assemblies with adjusters to eliminate runout, precision shafts, bearing assemblies, etc. Unless you are sp...

25.JPG A suspension unit "toolpost" for holding the cutter head, with integrated dashpot. 1.JPG This fully machined aluminum piece offers exceptional rigidity and positioning accuracy. It allows horizontal position adjustment to bring the stylus to the centerline, vertical adjustment for height, he...

The documentary film by Elina Verikiou "Magnetic Fidelity: A Love Story" will be aired on Greek national television tomorrow, March 11, 2019, 21:00 local Greek time. It shows some hot bands, some sexy analog tape machines, a Fairchild lathe in action, some super sweet bunnies, some touring musician ...

Variable pitch and automations on an ancient Presto MRC-16! Read here: https://agnewanalog.com/blog/2019/03/08/presto-mrc-16-variable-pitch-modification/ 21.JPG This started as a "can we just fix this broken piece" and escalated out of control, where the Flintstones enter the space age! This kind of...

Interesting, I may have found photographic evidence to support your claim which would throw an interesting monkey wrench in the general realm of knowledge on Presto transmission setups. The MRC16 would be an exception to the rule vs the standard. In order to test this, please provide the inner and ...

Rsimms3, I do agree with you that "idlers" might not be the appropriate term to use for this, since by definition, idlers are not meant to be part of the transmission ratio. The very popular term "idler drive turntable" is also not technically accurate, since an idler does not provide the drive. In ...

With directly driven lathes (Neumann) and gear driven lathes (Fairchild, Presto 8DG), your only realistic option is a good frequency converter. With idler driven lathes, you could also use a frequency converter, but it might actually be cheaper to use a properly designed step-down transformer and ex...

Many thanks, Sue Denim and jjwharris! Update coming soon.

Really exciting and interesting work! Look forward to hearing more Many Thanks! More soon! Congratulations for your work! I'm sure that if you posted it here then you already have very good results. If it fits on my lathe for sure I will buy one. Best, Bob Thanks, Bob! It will certainly fit on your...

opcode66 wrote:If you're doing moving magnet you then I already did that, fyi. Wouldn't be a first.

Nope, it isn't moving magnet either. I did briefly consider this concept, but dismissed it in favor of an entirely new approach which seems much more promising up to now.