A good damper for a tonearm lift

[InDaGroove]

For those of you building or modding a TT, here is a great device that you can incorporate into an arm lift for controlling the rate of descent. It is basically a precision air cylinder with a fine adjustment that controls the air escape. Go to www.airpot.com and click on "free sample". Select "dashpot". You will have to provide some info- company name, etc.

On my own DIY TT, I made my own lift device, but with an 11.5" arm, I couldn't damp it well enough with oil to result in a slow descent at the stylus. I added one of these, and it is perfect. Hopefully I can get a picture up soon.

Colby

 

[maxro]

Thanks for the tip

I just got one in the mail today. Pretty neat item, though a little bulky. How much would these cost if one were to buy them? I can't imagine them being all that cheap.

How did you implement yours? Got any pics yet?

Now, I've just got to design my dang tonearm...

-Max

 

[InDaGroove]

For the time being, I connected it to the horizontal bar that raises the tonearm. Since my platter is so high (3 1/2") I had plenty of room under there. When I can get to it, I'll be making a new lift, with the dashpot built in. The dashpot can be cut down shorter, as it only needs to travel a short distance. One thing you need to keep in mind- it does need to travel a short distance before the pressure inside builds up. My lift bar is 2" from the arm pivot point, and the arm is 11 1/2". The stylus freefalls about 1/4" before the damping starts.

Good luck with it!

 

[maxro]

My platter is only about an inch above the plinth, so I think I'll run mine knob end up with a teeter-totter underneath the plinth. This way the damping could be easily adjusted by the exposed knob.

Good to know about the delay in damping. Maybe I'll make the lever such that the rod inside the dashpot will have a longer stroke than the arm lift.

I won't try cutting the daspot down as it is made of glass. I'd rather have to work with its size than ruin it trying to make it fit in a neater way.

Thanks again for letting people (me included) know about this.

Has anyone else taken advantage of this offer?...Anyone?

Max