Hanoi Amator Project (HAP)

[Hanoi]

Trying to make Cutting Head without CNC, 3D printer

[jjwharris]

Hey that's looking great! Are you cutting or embossing? Bryan made some interesting posts about the vta/angle of cutting when designing your cutting head which could be if interest to you.

The posts are on this page https://www.lathetrolls.com/viewtopic.php?f=15&t=5371&start=560

[Hanoi]

Hey that's looking great! Are you cutting or embossing? Bryan made some interesting posts about the vta/angle of cutting when designing your cutting head which could be if interest to you.

The posts are on this page https://www.lathetrolls.com/viewtopic.php?f=15&t=5371&start=560

Thank you Jjwharris, I need to learn more and more!

[Hanoi]

Some more photos of my Cutting Head



After testing, one side is much vibration, one side less. I think because of the voice coil I made realy not good, I need to make new voice coil to replace them.

[Hanoi]

Some more pictures, not mounted yet!


Some more things I cant make clear:
- About Dashpot: I saw some one has, someone not so whats the function is ti? Can any one tell me or show me how and what it's structure, can be DIY?
- Count weight: How many grams stylus force on the blank disc should be as normal or if I use this stylus ( I bought 2 this already)? http://www.ebay.com/itm/Vinyl-record-lathe-cutter-head-presto-record-stylus-needle-styli-recorder/122737597253?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D1%26asc%3D41376%26meid%3Dc7a4e0951e2c49cbbc6dd7d385c0a13f%26pid%3D100011%26rk%3D1%26rkt%3D4%26sd%3D122691142804&_trksid=p2047675.c100011.m1850
Had anybody used this kind of stylus, pls give me some comments, I really appreciates for that, thank you!

[jjwharris]

Hey Hanoi,

From what I understand, the dashpot is to cushion the head, it stops it from dropping heavily on the record it may also provide a cushioning action when on the record.

Those stylus are standard groove stylus, so they won't play well on a microgroove record player, you will get a lot of background noise. You can however emboss with them by turning them around 180 degrees.

In terms of weight, i have had success embossing at 100g, but I know peter king embosses at 150g.

When i was trying to cut, with those same stylus, I had the weight set at 40-60g

[Hanoi]

You can however emboss with them by turning them around 180 degrees...

Thank you jjwharris, I dont understand why should turn around 180 degrees

[markrob]

Hi,

Nice looking head. It will be interesting to see how it performs. Looks like your moving mass id getting up there in size. Try to get it in the 1-2 gram range if you can.

The dashpot is used to add damping to the head suspension. Since it just a spring/mass system, it will tend to oscillate at its natural resonant frequency. Undamped, it becomes possible to excite this resonance due to platter runnout and slight warps in the blank. Damping is added via the dashpot to achieve critical damping (that is no overshoot or ringing). That leaves you with a second order low pass mechanical filter with no response peak at cutoff. Too much damping is not a good thing as it will slow down the response of the head suspension. Picking the right resonance is also important so that you track disturbances.

You can use a dashpot in the mode described in the other post. That would be in addition to the floating head suspension.

Mark

[Hanoi]

Hi,

Nice looking head. It will be interesting to see how it performs. Looks like your moving mass id getting up there in size. Try to get it in the 1-2 gram range if you can.

The dashpot is used to add damping to the head suspension. Since it just a spring/mass system, it will tend to oscillate at its natural resonant frequency. Undamped, it becomes possible to excite this resonance due to platter runnout and slight warps in the blank. Damping is added via the dashpot to achieve critical damping (that is no overshoot or ringing). That leaves you with a second order low pass mechanical filter with no response peak at cutoff. Too much damping is not a good thing as it will slow down the response of the head suspension. Picking the right resonance is also important so that you track disturbances.

You can use a dashpot in the mode described in the other post. That would be in addition to the floating head suspension.

Mark

Thank you Mark, however its hard for me to find a dashpot in my local, may use a simple spring instead!

[markrob]

Hi,

You can make one pretty easily. Just imagine a washer attached to a rod that is immersed in a small can containing a viscous fluid (e.g. mineral oil)

See the pictures below of a Presto damper

Damper2.JPG

Damper1.JPG

[jjwharris]

Hey Mark,

Is a dashpot likely to introduce problems with pitch on a slightly unbalanced platter? (eg. The Stanton 150)

[Hanoi]

Hi,

You can make one pretty easily. Just imagine a washer attached to a rod that is immersed in a small can containing a viscous fluid (e.g. mineral oil)

See the pictures below of a Presto damper

Damper2.JPG

Damper1.JPG

Yeah, Mark, I will try to make simple one, hope it help for next test

[Hanoi]

First ever test done, terrible noise ... bub bub bub...
Blank CD disc, it seams too hard for sapphire needle, without heating nor wax and without Dashpot (just a small spring as you can see at pic)
I'll try with Polycarbonate or Acrylic blank, need to find. There's not Lexan Sheet at my local, so I think find the same kind, can anyone tell me what the Lexan sheet it is? plz plz..

Cheers!
Hanoi

[Hanoi]

Another test with Polycarbonate sheet blank, heat light, however the turntable runs slow down, still crazy background noise. I may confusing about angle of needle, so what should the angle be, back or forwards angle? I really need someones help!? Thank you!
https://flic.kr/p/Yr2uRS
https://flic.kr/p/Z7SVgC

[jjwharris]

Are you embossing or cutting?

This is a good thread to read about embossing.

https://www.lathetrolls.com/viewtopic.php?f=15&t=2945&start=20

[Hanoi]

Are you embossing or cutting?

This is a good thread to read about embossing.

https://www.lathetrolls.com/viewtopic.php?f=15&t=2945&start=20

Hi jjwhrris,
I dont really know what this kind is, bad English
I tested on Polycarbonate blank (hope same as Lexan sheet, as photos below) and very noise from background even cant hear the music!
Iam confusing about the Angle of needle, as the picture I draw, I set as the 1st option, is it ok or can you correct me pls!

[Gridlock]

Haha that looks great. From your diagram I would use angle 1 or 3. How is the playback? You should post a sample of that. It almost looks like you're cutting on ACRYLIC and not PVC? I doubt you will get enough power from that turntable motor but to experiment

[Hanoi]

Haha that looks great. From your diagram I would use angle 1 or 3. How is the playback? You should post a sample of that. It almost looks like you're cutting on ACRYLIC and not PVC? I doubt you will get enough power from that turntable motor but to experiment

Thanks Gridlock,
well, playback sound is so bad, noisy, even cant hear the music. Blank I'm using is said "PC Grade A Polycarbonate sheet" seems too hard for cutting with sapphire stylus, I'll try to emboss on it, turning stylus around 180 degrees (as the 4th or 6th) as John's advice (very nice guy), add heat light, turtle wax (on the shipping way) and I will show later.

[Gridlock]

No dude don't flip the stylus around like that unless your cutting head is REALLY HEAVY. you want to glide over the plastic sheet with your sword blazing audio fidelity thing ripping the surface of the disc. Perhaps wipe some of the extra static bits and washing with warm water before playback. But hey, what do I know?

[Hanoi]

I did a test by turning needle around, grooves too shallow to playback, then I volume up, smoke came out from one driver. I got mistake trying to add more force onto the blank by turning up the sound. Could it be better to add more weight to Head?
Now I need to replace the voice coil and try again. (lucky its not the transducer Im ordering.)