Where to get (Oil) Dashpot?

[12bitcuts]

Any suggestions where to find or how to make a small oil dashpot?

I have embarked on the lathe building & retrofitting journey.
I will be both building my own lathe from scratch and retrofitting an existing disc cutting system with some custom mods.

One area I am looking at is a dashpot or damper of some type to protect the cutting stylus as it lands on the blank.
For the life of me I can't seem to source where to get a small oil dashpot like those used on cutting lathes.
Something like this:



The closest thing I can find is an Airpot which seems like it might work as well but not sure if these have been tried and tested on a lathe.
https://www.airpot.com/product-category/product-lines/dashpots-shock-absorbers/

I also thought about experimenting with RC car shock absorbers but they seem too stiff.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=shock+absorber+damper+for+rc&_sacat=0&LH_TitleDesc=0&_odkw=shock+absorber+damper+for+1%2F10+rc&_osacat=0

[Soulbear]

Any suggestions where to find or how to make a small oil dashpot?

Hi There,
A starting point could be a Glass "Guitar Slide" something like this:-

Guitar Slide.jpg

Or, perhaps another cheap and viable alternative (if you know any Electricians/Engineers/Electrical Service Technicians) is to ask if they have any "Redundant" Older type Motor Control Gear. Oftentimes this type of Motor Contactor/Motor Control Gear, would have "Oil filled Dashpots" for Motor Overload Protection. Something like this :-

Motor Overload Dashpot.jpg

Now by and large superseded by Solid State/Electronic Overloads, these are "Old Style" Overload Dashpots so they look like a very promising , cheap ((Probably free if you know the right people to ask)) and available proposition to be "Hacked" into what you are looking to do. Have a little ask around
Just a thought
Best Regards
Soulbear

[ilovedrums247]

i'm using a "Stash Jar 1.3 Inches" that can be found with a google search. Filled with silicone RC shock oil.....Vroom vrroom : )

[ilovedrums247]

I used old speaker transducer parts and drilled holes to allow more flow. Essentially just trying to make a Neumann clone.

[grooveguy]

If you're using the dashpot simply to lower the cutterhead, an airpot ought to work just fine. The action of an air dashpot vs. an oil one is sort-of 180-degrees. An oil dashpot is effective against small, rapid up/down motion, an airpot sort of neglects that and is better at controlling large amplitude variations. Back in the days of 78s and wide-groove 16" transcriptions, an oil dashpot helped reduce tendency toward vertical oscillation of the cutterhead induced by compliance friction of the stylus having to cut away a lot of lacquer really fast. (See Oliver Read's explanation of this in The Recording and Reproduction of Sound.) Once CBS's Goldmark (and his unsung crew!) developed microgroove, that wasn't much of a problem anymore. A well-engineered cam to lower the cutterhead has always been the first line of defense against slamming sapphire into aluminum.

[CutR]

There is one from 6N on https://www.ebay.co.uk/itm/324343695901?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338468473&toolid=10001&customid=4aac5208-bf37-11ed-99eb-396263653663

[grooveguy]

Holy moly! Three hundred bucks for that? Back in the '60s, the university I attended had a Presto 8DG that, by that time even, was never used in the 4 years I was there. At the time I was cutting commercials and station IDs at home onto 16" discs for a local TV station that hadn't yet migrated to cart machines for that kind of thing. I was getting vertical oscillations at the outside of the disc, so I 'liberated' the Presto dashpot and adapted it to my RCA lathe. The school never missed it, but when I was later doing microgroove exclusively, I took it off and put it back on the Presto. Of course now I wish I'd 'appropriated' the entire 8DG, it was immaculate.

That 8DG Presto dashpot was similar to the one for the 6N on eBay, except that the top was completely open. I suppose the cap on the 6D one is to prevent oil from sloshing out when you lift the overhead off the TT spindle; the 8DG didn't pivot that way. I really think that for next to no investment one could make a dashpot like the Presto ones. Maybe one of those amber prescription pill bottles for the well, and a 6-32 threaded rod with a couple of washers, held with nuts, spaced maybe a quarter-inch apart to dip down into the oil. That's essentially what the Presto was. Kinda like this:

Snap1.jpg

I remember that I had to grind the washers into an elliptical shape, because as the head was lifted the washers would describe an arc inside the well and would clip the side at the maximum travel.