Hello everyone. I have been working on my own DIY lathe now for a few months after years of thinking about building one or buying one (never had the money). It has been both a rewarding and frustrating experience. I think I have reached the point where I have gone as far as I can with the existing equipment.
I have been cutting at a slower speed for playback at 45 rpm and have been getting good results as far as frequency range. My main problem now is that I am cutting on a TTX turntable and at the slow speed, it will sometimes slow down or speed up. So I guess I need a new turntable or build a higher torque / slow speed one. Since I have been a troll to the lathe trolls for a while, I must thank everyone for all their posted advice and experience. I couldn't have done it without this place.
Most of the music I have been cutting has been my own. I mainly got into it to cut some records for a few friends and myself but would like to do more with it. Anyway, here is a picture of the cutterhead and a song cut on 7" lexan. You can hear the speed change in the intro. The cutterhead was originally designed for stereo but I had limited results with it (problems with phase and separation). Then one of the speakers blew which was a good because the mono cuts now sound much better. It is all pretty lo-fi. Some of the crackle in the recording I think is just static on the record because I didn't hear that on playback the first few times. Thanks again.
http://www.secretmessagemachine.com/cutterhead.jpg
http://www.secretmessagemachine.com/bipolardays7inch.mp3
My DIY Cutter
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
-
secretmessagemachine
- Posts: 10
- Joined: Sat Nov 19, 2011 12:28 pm
- Location: North Carolina
- Contact:
-
secretmessagemachine
- Posts: 10
- Joined: Sat Nov 19, 2011 12:28 pm
- Location: North Carolina
- Contact:
I am using standard sewing needles. I tried some gramophone needles that were sharpened but got way too much noise. They must have not been sharp enough or sharp at the right angle. And by cutting I mean embossing. It is usually easier to just say cutting. The sewing needles work fairly well since I put them in a shaft which came from an old inscriber.
-
secretmessagemachine
- Posts: 10
- Joined: Sat Nov 19, 2011 12:28 pm
- Location: North Carolina
- Contact:
Thanks everybody. The warble sound is from the song. Some of the guitar was put into a pitch effect which creates the warble. The main speed issue I have comes a few seconds into the song and doesn't really change after that.
You can stream the digital version of the song on the website if you want to compare it to the vinyl version.
http://secretmessagemachine.com/?p=176
If I can do some more shameless self promotion, you can buy it on itunes and through the website.
These are some possible solutions to the speed problem I have come up with so far:
1 Watch the speed like a hawk while cutting and adjust it as quickly and accurately in real time.
2 Build a turntable that has higher torque at very low speed
3 Buy a Presto cutterhead that will emboss a better sound at regular playback speed
You can stream the digital version of the song on the website if you want to compare it to the vinyl version.
http://secretmessagemachine.com/?p=176
If I can do some more shameless self promotion, you can buy it on itunes and through the website.
These are some possible solutions to the speed problem I have come up with so far:
1 Watch the speed like a hawk while cutting and adjust it as quickly and accurately in real time.
2 Build a turntable that has higher torque at very low speed
3 Buy a Presto cutterhead that will emboss a better sound at regular playback speed
Hi,
Nice job.
Some questions. How slow are you cutting for playback at 45? Have you tried 33 RPM? How are you doing you EQ?
What might be happening here is the step load of the cutterhead (as you drop it to start embossing) causes the servo to droop. It recovers after a few seconds. If this is the case, why not cut several seconds of silent lead-in to let the servo settle out?
Mark
Nice job.
Some questions. How slow are you cutting for playback at 45? Have you tried 33 RPM? How are you doing you EQ?
What might be happening here is the step load of the cutterhead (as you drop it to start embossing) causes the servo to droop. It recovers after a few seconds. If this is the case, why not cut several seconds of silent lead-in to let the servo settle out?
Mark
-
secretmessagemachine
- Posts: 10
- Joined: Sat Nov 19, 2011 12:28 pm
- Location: North Carolina
- Contact:
I'm cutting at 16.66 speed and I have tried cutting at 33 rpm for playback at 45 and lost a good amount of frequency with it. I might be able to make up for it with more eq but haven't really experimented enough to know. But considering the percent speed change from 45 to 16 is about 62 percent and the speed change from 45 to 33 is about 23 percent, it seems that the needle won't be able to move enough to get the frequencies I need.
I have been using audacity for eq and boosting the high end quite a bit. Then putting it through a low pass filter which seems to eliminate some of the distortion at the high end.
Other cuts I made were slipping in speed about a minute or more into the song, so I don't think it is the initial weight of the cutterhead. Maybe it has to do with the movement of the platter. If I push down on the outside edge, it will move down quite a bit. So maybe the torque of the turntable is fine, but it isn't stable enough. 12" cuts have much more fluctuation in speed on the outer edge. But also if I cut at 33rpm, the fluctuation is almost nonexistent.
I have been using audacity for eq and boosting the high end quite a bit. Then putting it through a low pass filter which seems to eliminate some of the distortion at the high end.
Other cuts I made were slipping in speed about a minute or more into the song, so I don't think it is the initial weight of the cutterhead. Maybe it has to do with the movement of the platter. If I push down on the outside edge, it will move down quite a bit. So maybe the torque of the turntable is fine, but it isn't stable enough. 12" cuts have much more fluctuation in speed on the outer edge. But also if I cut at 33rpm, the fluctuation is almost nonexistent.
Hi,
That all makes sense. Have you tried 1/2 speed 22.5 RPM? The TTX might have a bit more torque at 22.5 RPM.
How are you establishing the EQ curve? I looked at your file and see a rather large 10Khz response peak.
My trick is to use Har-Bal.
http://www.har-bal.com/
Its a mastering EQ, but it works great for creating custom EQ filters to pre-process your files such they cut flat. The way to use it is to cut your track with little or no EQ (maybe RIAA only) and then capture the playback and reference it to your original file. HarBal wil show you the sprectum of your source material and the captured playback. You can then use its FFT EQ to match the spectra of the cut material to the source. You can audition the results to get an idea of how it will sound with a better EQ in pace. Next, you save the created filter and use this to pre-process your audio before cutting. In effect, Har-Bal creates a calibration curve for your cutterhead. Since you use low speed mastering, you would preprocess at normal speed and then downsample to the desired cutting speed. The downsampling process should apply a lowpass, but it might be good to check. One limtiation of Har-Bal is that the amount of boost/cut is limited. You may need to apply the correction in two passes to get the desired effect.
Mark
That all makes sense. Have you tried 1/2 speed 22.5 RPM? The TTX might have a bit more torque at 22.5 RPM.
How are you establishing the EQ curve? I looked at your file and see a rather large 10Khz response peak.
My trick is to use Har-Bal.
http://www.har-bal.com/
Its a mastering EQ, but it works great for creating custom EQ filters to pre-process your files such they cut flat. The way to use it is to cut your track with little or no EQ (maybe RIAA only) and then capture the playback and reference it to your original file. HarBal wil show you the sprectum of your source material and the captured playback. You can then use its FFT EQ to match the spectra of the cut material to the source. You can audition the results to get an idea of how it will sound with a better EQ in pace. Next, you save the created filter and use this to pre-process your audio before cutting. In effect, Har-Bal creates a calibration curve for your cutterhead. Since you use low speed mastering, you would preprocess at normal speed and then downsample to the desired cutting speed. The downsampling process should apply a lowpass, but it might be good to check. One limtiation of Har-Bal is that the amount of boost/cut is limited. You may need to apply the correction in two passes to get the desired effect.
Mark
-
secretmessagemachine
- Posts: 10
- Joined: Sat Nov 19, 2011 12:28 pm
- Location: North Carolina
- Contact:
Thanks for the tip Mark.
I don't think I have tried 22.5 speed and I don't know why that hadn't crossed my mind. I have had O.K. results cutting a 33 record at 16.66. There was some loss of high end, but cutting at higher speed (33) does help solve the speed issue.
Har-Bar looks like a useful program, but alas, I am using a mac and don't really have that extra money at the moment. I might try and find a cheaper solution. Perhaps just a program that will show the difference in in frequency between basic cut and original file. Some of that 10k response peak might have come from the receiver I put the playback through. I moved the eq to the settings I enjoy for listening to records.
Also, I wonder if some of the extra high end could be resonant feedback. I am having a hard time getting either not enough high end or too much which causes lots of distortion. The low pass really helped which makes me think it is more than just the eq.
Thanks again for the suggestions.
I don't think I have tried 22.5 speed and I don't know why that hadn't crossed my mind. I have had O.K. results cutting a 33 record at 16.66. There was some loss of high end, but cutting at higher speed (33) does help solve the speed issue.
Har-Bar looks like a useful program, but alas, I am using a mac and don't really have that extra money at the moment. I might try and find a cheaper solution. Perhaps just a program that will show the difference in in frequency between basic cut and original file. Some of that 10k response peak might have come from the receiver I put the playback through. I moved the eq to the settings I enjoy for listening to records.
Also, I wonder if some of the extra high end could be resonant feedback. I am having a hard time getting either not enough high end or too much which causes lots of distortion. The low pass really helped which makes me think it is more than just the eq.
Thanks again for the suggestions.
-
pentlandsound
- Posts: 72
- Joined: Mon May 16, 2011 11:25 am
- Location: Edinburgh, Scotland
Hi - well done with your lathe - you're getting a really good sound out of it!
I found your posts particularly interesting because I've been following a similar path to yours, embossing on polycarbonate with a home-built lathe, and have run into problems because of insufficient torque in my recording turntable.
I started by recording at 45rpm for 78rpm playback, but found that I got just as good sound by recording at 26rpm for 45rpm playback. (I chose 26 because 26/45 is the same ratio as 45/78, so I can use the same prepared source for either!) The turntable I have is a Leak Delta (= Lenco L75) idler-drive, which isn't ideal, and I'm interested in getting a more powerful direct-drive one. I'd heard good things about the Technics SL1210 (now out of production), the SP10 (utterly unobtainable anywhere) and most recently the Stanton ST150/STR8150. Do any Lathe Trolls have experience of using the Stanton for embossing on polycarbonate, or can anyone recommend any other turntables?
Thanks.
David
I found your posts particularly interesting because I've been following a similar path to yours, embossing on polycarbonate with a home-built lathe, and have run into problems because of insufficient torque in my recording turntable.
I started by recording at 45rpm for 78rpm playback, but found that I got just as good sound by recording at 26rpm for 45rpm playback. (I chose 26 because 26/45 is the same ratio as 45/78, so I can use the same prepared source for either!) The turntable I have is a Leak Delta (= Lenco L75) idler-drive, which isn't ideal, and I'm interested in getting a more powerful direct-drive one. I'd heard good things about the Technics SL1210 (now out of production), the SP10 (utterly unobtainable anywhere) and most recently the Stanton ST150/STR8150. Do any Lathe Trolls have experience of using the Stanton for embossing on polycarbonate, or can anyone recommend any other turntables?
Thanks.
David
-
secretmessagemachine
- Posts: 10
- Joined: Sat Nov 19, 2011 12:28 pm
- Location: North Carolina
- Contact:
Well after cutting at 22.5 for playback at 45 I think I have found the solution. I haven't tried anything larger than 7" record so I don't know if the speed will stay consistent across an entire 12" or 10" record, but for now the ttx will stay steady through a 7" cut. If I want to cut a 33rpm record, I think I will have more difficulty. I would also be interested to know if there are other available options for high torque turntables able to emboss poly at low speeds.
-
aussie cutter
- Posts: 67
- Joined: Thu Sep 18, 2008 9:51 pm
I built my lathe using a Stanton STR8-150 turntable
It has 5kg torque - more than enough to drive the lathe
The one thing that you need to be mindful of is
"You will need to speed up your turntable a little bit so that when you engage the cutterhead you accomidate for the weight of the lathe, the cutterhead and the drag created buy the cutterhead when in operation so your stroboscope tells you that your cutting at 33, 45 or 78 - how much you have to speed up your turntable will depend on the weight of your lathe"
It has 5kg torque - more than enough to drive the lathe
The one thing that you need to be mindful of is
"You will need to speed up your turntable a little bit so that when you engage the cutterhead you accomidate for the weight of the lathe, the cutterhead and the drag created buy the cutterhead when in operation so your stroboscope tells you that your cutting at 33, 45 or 78 - how much you have to speed up your turntable will depend on the weight of your lathe"