What is this fluid?

[TomB19]

Dumb question.

Can someone tell me what flavor of apple juice is in the side mounted syringe at 0:22, and why it might be necessary?

[YouTube2]https://www.youtube.com/watch?v=jrZuSqOOFHw[/YouTube2]

[SueDenim]

The whole unit is called a dash pot and is there to damp vertical oscillation of the cutting head.
The fluid is usually some kind of light oil... e.g. motor bike fork oil or something similar.

[TomB19]

Thanks! I appreciate your insight.

Take a jean jacket out of petty cash.

[emorritt]

Usually dashpots were filled with glycerine you can purchase at a drug store. Sometimes a light silicone liquid was used as well; glycerine ranges between 1000 and 2000 centistokes, so a matching silicone liquid could be used in that range as well.

[TomB19]

Is the cutting head pressed into the surface with a spring to allow for minute surface variations in the media or is the Z axis intended to be absolute?

[markrob]

Typically, the spring is used to reduce the down force of the head as a counter balance. The head floats as a spring/mass system and attempts to follow the surface of the media and establishes the cutting depth. With the addition of the dashpot, you have a damped resonant system. You want to tune the head suspension so that (frequency and damping) are able follow the surface and keep the cutting depth constant. If you set the frequency higher, it will follow faster changes, but at the expense of keeping the cutter from being able to cut vertical features (loss of low frequency response). It may also result in fluttering if it is exited by the cutter doing its thing.

There are other systems that use an advance ball. This is a low friction guide that is tied to the head and contacts the surface of the media. It is adjustable such that the head can be raised and/or lowered in relation to the disc surface. This establishes the cutting depth. This can reduce or even eliminate the need for a dashpot. You would still probably need a counter balance spring to adjust net down force.

Mark

[TomB19]

Thank you very kindly!

[juba bc]

this machine is mine, this is an improvised dashpot with a syringe and oil to minimize oscillations ... Mark has already given the correct explanations

[Discomo]

this machine is mine, this is an improvised dashpot with a syringe and oil to minimize oscillations ... Mark has already given the correct explanations

Lovely machine!
How did you make the up-down function of the stylus?

[juba bc]

I used a simple microwave dish motor

[Discomo]

I used a simple microwave dish motor

Amazing!
With arduino? Is it difficult to make this?
I'll love to add such a function to my VR but don't have a clue how. I must admit I don't have any knowledge of electronics and don't know where to start.
Can you give me some tips for an absolute beginner in electronics?

[juba bc]

I don’t use arduino, just old and reliable analog electronics, a microwave motor doesn’t need any electronics, it works directly on your home’s electrical network ... today I don’t use these motors anymore on my recording lathes, I only use them on manual mode even

[Discomo]

I don’t use arduino, just old and reliable analog electronics, a microwave motor doesn’t need any electronics, it works directly on your home’s electrical network ... today I don’t use these motors anymore on my recording lathes, I only use them on manual mode even

Well, a great build and sounds pretty good as far as I can hear on the vid.
Wonderful.