OPCODE 1-E Mono Cutterhead (Presto 1-D Clone)

[opcode66]

Not sure the suspension box will fit on a Presto Overhead. The box with my overhead will certainly fit a Presto. So, you'd be replacing the entire overhead from the Presto with my system.

[symatic]

I have a 14B, which has a fairly chunky overhead, kind of like a 8DG but fixed in place.



do you think that would fit? i can get proper measurements for you if you can't guess from the pic

[opcode66]

Yeah we can put my S66 on there.

[opcode66]

A little preview of PLS19 major functions in action! More in depth video to follow.

[opcode66]

After a lot of struggle, learning, and honest work I now have MIDI Input working on PLS19. Never implemented MIDI on a raspberry pi before, so that took some unfamiliar config and code. This is a screenshot of the Windows MIDI Control app. All the buttons you see are currently functional. Now, its time to integrate the iRIAA relay switching board and the digitally controlled heating board.

[opcode66]

Microscope has been sliced. Now, to make a joining piece and a swing arm and mount it on the lathe. That will form a very nice groove inspection scope.

Also, designed and machined an interface panel. Tons of buttons!!!!!

So, to review, you can control the lathe from individual function buttons, a menu system and LCD screen with directional buttons/enter/rotary encoder, full bluetooth remote control and programming, extensive MIDI remote control for sequencing control with audio.

I know, I know, you want proof. Video. Patience. It will be shot tonight or tomorrow!

[opcode66]

Scooty Turn Jr. - BLDC Platter Motor
The first test of V5 of my BLDC Platter Motor. Looking great! Need to adjust the off the shelf sensorless motor controller to get better performance at slow speeds. The controller I'm using is for making drones and wants to turn fast not slow. I'll now make my own motor control and add Hall Sensors.

[opcode66]

Overhead Motor Mount V3 with two motors: Pitch and Fast. And, now with a larger pulley reduction. And, the groove inspection scope mounted to a swiveling arm.

Tomorrow I test and troubleshoot the suspension controller circuit. If all checks out, that will be the last functional section to sort out. The rest is all logic to control cuts. That means I'm super close to test cutting on my lathe.

[opcode66]

Scooty Turn Jr. With Hall Sensors

[symatic]

looks great

how viable would that motor design be for a playback turntable?

there aren't many options these days since vestax stopped making decks and technics quadrupled in price.

The Hanpin decks are mostly rubbish for turntablists.... we need torq and stability.

[opcode66]

Yeah, I can put this into a standard turntable footprint.

[opcode66]

Scooty Turn Jr. - Nearly Finished!!

A sneak peak at what's cooking. I'll be working without stop until I get my custom speed control integrated. But, just wow!!!! So much work is now paying off!!

Refined hall sensor configuration, increased torque, can start from dead stop, maintains speed tightly, can run for hours with cool coils.

[opcode66]

Bipolar hall sensor array with pull-up circuit built, wired, and tested. PWM to DC Voltage circuit built, and tested. Next I program an Arduino and get wires connected. Then I can finally test my custom closed loop speed control. If all goes well, I'll have a more powerful and potentially more accurate motor than the Technics 1200. I've done this all independently within a 2 month timeline and concurrent with my lathe project. In-freaking-credible!!!!! Feeling very empowered right now.

[opcode66]

Arduino is connected. Everything seems to be a go here. Gonna program the board and start testing!

[opcode66]

Scooty Turn Jr with Custom Speed Control

I've added the Arduino and tweaked my code for this motor. The results speak for themselves. Real-time speed sensing and adjustment. This is really nice now and will only get better. This is nearly ready to cut records on!!! I'm going to start the CAD work to make a new base that I can mount onto my current lathe prototype plinth. Then, PLS19 will be Direct Drive platter that can counteract the drag exhibited by any cutterhead.

This is the last post here that is not explicitly related to the OPCODE 1-E Advanced Mono Cutterhead. I'm going to start two new threads for PLS19 and Scooty Turn Jr. New lengthy videos for each are forthcoming this week. Stay tuned. Also, please subscribe to my YouTube channel if you watch my videos. It will help to support my work. And, also, please hit the Like button on any videos that move you.

Take Care. See ya all real soon.

[dmills]

Daft thought for the platter drive motor, but I commend to your attention used washing machine parts, some of them these days are using high pole count BLDC drives to run the drum directly without any gearing.

I don't think the bearings are likely quiet enough but the rotor and stator might be a cheap way to get the annoying magnetic circuit components off the shelf?

Maybe something like a Maytag W10544980 and W10657810 (Samsung do an equivalent style thing with less poles but with sensors)?

For lower torque ripple I suppose you would really want to rewind for PMSM rather then BLDC operation.

Just a thought.

That is very nice work you are doing, gotten into the 3d printed components more then somewhat from the look of it!

[opcode66]

Hello, I'm Todd. Nice to meet you. I started reading the board in 2008. I've been a member of the Trolls since 2009. For some time I was very actively posting. Collectively my threads have somewhere in the area of 60K to 70K views. I've done a lot of interesting things and am about to start distributing much of my work.

I'll try to unpack your comment and reply as I can.

Daft thought for the platter drive motor, but I commend to your attention used washing machine parts, some of them these days are using high pole count BLDC drives to run the drum directly without any gearing.

For those unfamiliar with this word "daft", it is defined as silly, foolish, mad, or insane. That's a hefty insult. Cool. This tells me I'm definitely rattling cages. That's always a good thing.

I believe it was Flo who first floated the washing machine idea. So, let's give credit where it is due. That was about 10 years ago when I joined. Washing machine BLDC motors have a coil count starting at 18 and going up to 36 typically. The main consideration with the very high coil count is the overall diameter of the motor stator. Since I'm making a modern, feature packed, affordable, and portable lathe system that is the same footprint as an RCA portable lathe, size is a distinct concern. Starting with a high pole count washing machine stator (coil array) would force a particular design and overall dimensions that are not what I need. Additionally, since I'm going to be selling these units, I wouldn't want to use a part from some other manufacturer's product. What if they make a modification, what if I can't find enough used ones of that make and model when I need them, what if the manufacturer sues me for using their product in my product without licensing and permission???? Not a smart plan to go that route.

Besides these points, as usual, I would much rather do the tough R&D and really gain the overall understanding of the system. BLDC motors have to be designed in very particular ways or they will not work at all or will only work weakly and not smoothly. There are fundamental design principles which must be factored into any custom design. After 5 distinctly different approaches I not only nailed the dimensions, but also the torque and speeds I need while simultaneously acquiring a mountain of knowledge with respect to how this all works. From the coil construction/size/gauge/count/arrangement to the magnet count/size/arrangement to the ratio between coils and magnets to the hall sensors integration to the motor controller and finally to my own custom system to insure constant speed real-time via a digitally controlled closed loop. If I had the time, I could actually make a custom board that would have speed control and motor control together. But, for now, I use Arduino and a BLDC-8015A. I can program PIC chips in either ASM or XC32++ and can design and fab my own boards and do plan to combine both functions into a custom design. Next year likely.

To be 100% clear, this is a direct drive system. There is no pulley, no belt and no gears. The magnets are directly attached to the platter, same as in a Technics 1200. In fact, that's where the platter came from. I replaced the OEM magnet array with my own. My BLDC Direct Drive Platter motor called Scooty Turn Jr. has 18 poles, 3 phases, and 12 magnets which by far exceeds what is in a Technics 1200 turntable. My magnets are also stronger than those used in a 1200. Plenty of folks cut just fine with a 1200 and a Vinyl Recorder. So, to imply that this is anything but superior to that is simply not true. We don't need no stinking washing machines homie. I can very easily make a 54 coil version of this motor with no change in overall diameter and exactly the same size coils. Puzzle that one...

I don't think the bearings are likely quiet enough but the rotor and stator might be a cheap way to get the annoying magnetic circuit components off the shelf?

I've been fully rebuilding cutterheads for a number of years now. Over 250 full rebuilds. I've cloned all sorts of coils including the legendary Grampian with Feedback. So, making coils or coilforms is trivial at this point. There was a learning curve here because cutterhead coils are very different from motor coils. So, I did a fair amount of experimentation making various prototype coils and performing measurements with fixed voltage and my gaussmeter. There is a particular combination of materials, gauage of wire, shape, and ratio of dimensions required to make a good motor pole coil. I now understand all these factors. So, ultimately there is actually really very little difference between what I've done and the stator from a washing machine. They both have a plastic frame, coils made with the considerations I listed with iron cores and backings, and are geometrically arranged in a particular way and mounted into the plastic frame. Once I start selling some units, I can afford to have my stators cast and forged from iron. But, for now, what I have is phenomenal really.

On a separate note, with respect to bearings, my motor has a very similar configuration to most all turntables. A precision ground shaft or piston is attached to the platter via a taper fit at one end. The shaft is inserted into a precision fit metal cuff. Some like the Technics 1200 only cover part of the shaft. Others like what was in my RCA portable is a cuff that fully engulfs the shaft including the bottom. The bottom of the shaft is cupped and there is a a ball bearing which minimizes friction as the platter rotates at the point where nearly all the weight is distributed. In a Technics 1200 the bottom of the shaft is ground to a half sphere and rests in a cupped depression on a metal base plate beneath the shaft (acting very much like the ball bearing in the RCA). In my motor, I have a Mag Lift Bearing system. So, there is exponentially less friction at that crucial point that in either the Technics or the RCA. My motor is physically more efficient than both due to this design consideration alone.

Maybe something like a Maytag W10544980 and W10657810 (Samsung do an equivalent style thing with less poles but with sensors)?

The Maytag Man would thank you for the product placement. Not needed at all. And, even if I went that route, they would have sensors built in. You can't run a motor that slow and use "Back EMF" sensorless drivers. It doesn't work. And if you do achieve the slow speed it will be extremely jerky with almost no torque and you would likely have to start the motor by hand. See, my learning all this is a good thing because the community here now gets some cliff notes. By the way I plan to put all this into a video anyway. Pleases subscribe to my channel. https://www.youtube.com/user/opcode66 And, like my videos! Anyway, I know understand all the ins an outs of sensor placement so I can add them to any BLDC motor that is lacking them.

For lower torque ripple I suppose you would really want to rewind for PMSM rather then BLDC operation.

Just a thought.

Ok, here is a thought in return. The Technics SP-02 Platter Drive Motor made for the Neumann VMS lathes was BLDC. The platter drive in the Neumann VMS80 and VMS82, arguably the finest professional lathe ever made, was a Mag Lift BLDC motor (sound familiar???). The best commercial turntable for cutting is the Technics SP10 MKIII which has... can you guess... a BLDC motor. I think I'm cool man. But, thanks for the thought yo. Really brotherly of you, sir.

That is very nice work you are doing, gotten into the 3d printed components more then somewhat from the look of it!

One last attempt at a dig. Ok. Yes, in fact I prototype and R&D using as much printed plastic as possible. Where I can't use printed plastic I either lathe or cnc the part. But, printing is considerably faster and less oily (machining is messy work). Once I've finished a design, then I do the CAM and CNC work to make the parts which need to be metal in either Brass or Aluminum. I can lathe steel and do a lot with a bench grinder and vertical bandsaw as well with steel. My motor stator as previously stated has as much steel in it as your typical washing machine motor. The steel is embedded into a printed plastic frame. There is no functional difference between the two items.

Well, this has been fun. I hope everyone enjoys reading this. And, please do stay tuned for more huge accomplishments to be shown here soon. Take Care!!!! Subscribe, hit the like buttons and the bell on youtube!!!!

[dmills]

No digs intended man, daft was me saying I was just throwing something out there that hadn't been all that well considered or thought thru by me, I was describing MY thought not your work, which is awesome!

I get that your intended design is a compact machine and that that adds design constraints, and that you want to do a fully custom thing while figuring out all the detail which is a very cool approach.
I tend to lean more towards 'find stuff I can leverage' in my approach to design, being as I am generally not doing design with the objective of more then a very short series production run, but that is my choice.

I was actually saying I was impressed by how much use you were getting out of the 3D printing, I am way too old school and tend to favour cut metal, which makes my costs far higher, but I just have issues with precision that mostly I think come down to my inexperience with the technology.

Apologies if my post came off as having a dig, that was in no way intended!

[opcode66]

Shoot! I apologize for misreading. Written word is sometimes not as clear as real communication. Sorry.

When doing this sort of R&D work in a space that I have zero experience in, I can tweak individual parts 10 to 30 times. I also regroup and do total redesigns at least 1 or 2. To do the CAD to CAM to CNC for all those iterations would make doing this work take many, many, many times longer for me individually and with a very manual CNC machine. I was able to start from zero real knowledge and zero drawings to the working motor you see here in just under three months. My first drawing is dated July 6th. If doing only metal I'd be done maybe next year. But, who knows. Maybe longer.

One aspect of doing this sort of work is that you have more failures than successes. I pride myself on being a phoenix. I rise from the ashes stronger regardless of the nature of the negative situation. But, that takes a toll. It is actually really depressing. Battling that urge to give up, and raising your spirits from a place of disparity and depression is challenging. Not to mention actually doing the work itself.... But, this is a distinct component that adds to this sort of undertaking. Anyone who doesn't talk about this isn't really doing anything monumental and individually in my opinion. Being able to compress this stuff timeline-wise actually helps to get over failures, quickly bounce back, and finally reach your milestone Eureka moments.

Anyway, yeah, CAD to 3d print is like 1/10th the time ballpark vs. CAD to CAM to CNC to metal part. Once everything is sorted then for sure the necessary parts become metal. I never did any CAD, 3d Printing, CAM, CNC, Metal Lathing, or metal work in general for most of my life. I started 3d printing and CAD 2014. I started doing serious CAM and CNC work starting January of this year. I wish a wish beyond wishes to expand my tooling. Hoping to pick up a proper mill and an automated tool changing CNC sometime next year.

Take Care! More to come soon!

[dmills]

Written text on forums can be like that sometimes!

Most experiments fail to produce the hoped for outcome (Not quite the same thing as saying most experiments fail, you generally learn something), and yea, the 30th failure gets depressing. IIRC Edison said something about 'Now knowing 100 things that don't work', never a truer word spoken.

I tend to try very, very hard to design for cut sheet materials, (because lasers), and this means that prototypes for fit can be easily and quickly made in MDF or (for slightly more permanent things) acrylic sheet, you never quite get the flatness of tooling plate, but I can laser 10mm MDF or ply down at my local hackspace for 20c/minute of machine time, tooling plate needs to go to a real fabricator.

Regards, Dan.