Isn't there an argument that the tube should incline slightly uphill to provide some antiskating force? Though that would increase wear on the outer face of the groove, which is probably already doing most of the heavy lifting....
Maybe level is a good compromise?
Bill, is there any reason not to go with the old-fashioned weight-on-a-screw approach used in regular arms? Could be as simple as a nut on a bolt sticking forward or backwards from your counterweight. Pick your thread rate appropriately and you could have a scale on it!
Or a small weight that slides up one of your pen shafts. Although the mind might require one on both shafts to rest easy....
Terry
Maybe level is a good compromise?
Bill, is there any reason not to go with the old-fashioned weight-on-a-screw approach used in regular arms? Could be as simple as a nut on a bolt sticking forward or backwards from your counterweight. Pick your thread rate appropriately and you could have a scale on it!
Or a small weight that slides up one of your pen shafts. Although the mind might require one on both shafts to rest easy....
Terry
Terry, The problem comes in that the common little balance that comes with cartridges just doesn't work for setting VTF on the Cantus. The vertical motion of the arm is constrained by the bearings in the static (non playing) state to the degree that the balance doesn't respond. You place the stylus on the balance beam and adjust the cw to where the balance goes down, but because of the constrained vertical motion and the VERY small zone of relatively free motion provided by the radial play in the bearing you can't reliably detect any restoring force that tells you you're on the spot. You fiddle with it and adjust cw and fiddle some more and try to guess if the amount of downward deflection of the stylus cantilever is enough or too much but you are never sure what you have. If it seems to play OK you settle for that. Any or all of the CW adjusters you suggest will adjust VTF. My arms have nice easy to use counterweights. But that isn;t the problem. If you could put the stylus on the gauge and adjust it with the platter spinning---fat chance! In the static state you can by watching the bearing inner race detect when the bearing is riding vertically and centered in the radial play zone and with the CW set the stylus to ride just in contact with the surface of the record. Then when you put the measured weight on the head shell with the record spinning the stylus drops into the groove with the precisely measured VTF. Doug has experienced this problem and bought a digital scales which he has used successfully. At midnight I couldn't run off to Harbor Freight and buy one. Besides I'm way too much a cheapskate.
Your sliding weight on the arm tube is a good fine adjuster. Perhaps with care and my measured balance weights I could put calibration marks on the tube eliminating the weight bin.
You may want to read this discourse a few times to get the full import of it. Once you have it it is a simple easy to do adjustment. Sorry to have not explained it properly in the first place.
BillG (the long winded one)(and a flute player too)
Your sliding weight on the arm tube is a good fine adjuster. Perhaps with care and my measured balance weights I could put calibration marks on the tube eliminating the weight bin.
You may want to read this discourse a few times to get the full import of it. Once you have it it is a simple easy to do adjustment. Sorry to have not explained it properly in the first place.
BillG (the long winded one)(and a flute player too)
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Ah, yes, (I think) I see what you mean. In your approach, there is four-point contact between bearings and runway - the front and back edges of the left and right bearings. So the arm cannot freely hinge vertically.
Do I remember correctly that the original design shows bearings ground to a point at the front edge, reminiscent of rail-car wheels? Is this intended to allow the carriage to "teeter" on the two point contact, providing vertical hinging, as well as presumably reducing rolling friction?
A vertical hinge that didn't permit horizontal deflection could be as simple as the pin in your flute key....
Terry
Do I remember correctly that the original design shows bearings ground to a point at the front edge, reminiscent of rail-car wheels? Is this intended to allow the carriage to "teeter" on the two point contact, providing vertical hinging, as well as presumably reducing rolling friction?
A vertical hinge that didn't permit horizontal deflection could be as simple as the pin in your flute key....
Terry
You are getting it! Remember though that there is the small amount of radial play in the bearings that lets the arm follow warps freely. It is in this zone that the arm is free to respond to VTF adjustments. For major warps the bearings ride up the track. The original design has been discarded as being inferior ln performance. This has been documented in earlier posts.
BillG
BillG
Hmmm, I am wondering about giving it a go myself. Too bad my regular off-cut materials, African Blackwood and sterling silver, would be a bit on the heavy side. Could look striking though!
I guess the critical components are the bearings. What's the current thinking on a spec? I see things like 10mm OD, 3mm ID, 4mm thick, 5 ceramic balls and a non-metallic cage that doesn't require lubrication. Are we getting close?
Any recommended source? (I can try here in Australia, but the mark-up on specialist items here usually dwarfs the price of postage from the original source.) Postage on such a massive weight shouldn't be too frightening.
Terry
I guess the critical components are the bearings. What's the current thinking on a spec? I see things like 10mm OD, 3mm ID, 4mm thick, 5 ceramic balls and a non-metallic cage that doesn't require lubrication. Are we getting close?
Any recommended source? (I can try here in Australia, but the mark-up on specialist items here usually dwarfs the price of postage from the original source.) Postage on such a massive weight shouldn't be too frightening.
Terry
Terry,
Great! I'm sure you will be a valued contributor. You will get a great arm in the process. Yes you are on the right track. Go to Ball Bearings | Ceramic Ball Bearings | RC Bearings | Tungsten Carbide | Powerpole Connectors | Silicon Nitride by Acer Racing and find their ceramic ball bearings page. Look up the 4x10mm (MR104) part for USD 7.99. There are similar parts all at the same price with slightly different sizes. With the 10mm bearing you will have to relieve the mounting shaft to provide clearance for the top of the track. See my pics. You will have to flush them clean in acetone or other solvent and blow them dry. All trace of lube must go. Make sure the corners of the outer races are flawless and clean. I assume you are able to cut some glass or can get some cut for you. I love the african blackwood. Drill some holes to reduce weight if needed. These are hybrid ceramic ball/steel races bearings. Full ceramic are far more dear. Keep us informed plz.
Good Luck
BillG
QUOTE=Terry McGee;3114420]Hmmm, I am wondering about giving it a go myself. Too bad my regular off-cut materials, African Blackwood and sterling silver, would be a bit on the heavy side. Could look striking though!
I guess the critical components are the bearings. What's the current thinking on a spec? I see things like 10mm OD, 3mm ID, 4mm thick, 5 ceramic balls and a non-metallic cage that doesn't require lubrication. Are we getting close?
Any recommended source? (I can try here in Australia, but the mark-up on specialist items here usually dwarfs the price of postage from the original source.) Postage on such a massive weight shouldn't be too frightening.
Terry[/QUOTE]
Great! I'm sure you will be a valued contributor. You will get a great arm in the process. Yes you are on the right track. Go to Ball Bearings | Ceramic Ball Bearings | RC Bearings | Tungsten Carbide | Powerpole Connectors | Silicon Nitride by Acer Racing and find their ceramic ball bearings page. Look up the 4x10mm (MR104) part for USD 7.99. There are similar parts all at the same price with slightly different sizes. With the 10mm bearing you will have to relieve the mounting shaft to provide clearance for the top of the track. See my pics. You will have to flush them clean in acetone or other solvent and blow them dry. All trace of lube must go. Make sure the corners of the outer races are flawless and clean. I assume you are able to cut some glass or can get some cut for you. I love the african blackwood. Drill some holes to reduce weight if needed. These are hybrid ceramic ball/steel races bearings. Full ceramic are far more dear. Keep us informed plz.
Good Luck
BillG
QUOTE=Terry McGee;3114420]Hmmm, I am wondering about giving it a go myself. Too bad my regular off-cut materials, African Blackwood and sterling silver, would be a bit on the heavy side. Could look striking though!
I guess the critical components are the bearings. What's the current thinking on a spec? I see things like 10mm OD, 3mm ID, 4mm thick, 5 ceramic balls and a non-metallic cage that doesn't require lubrication. Are we getting close?
Any recommended source? (I can try here in Australia, but the mark-up on specialist items here usually dwarfs the price of postage from the original source.) Postage on such a massive weight shouldn't be too frightening.
Terry[/QUOTE]
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I'd be tempted to go with a metal tube at first, as I can easily mill the slot. Any recommendations on internal diameter?
2 x $7.99 for the bearings shouldn't break the bank - the postage will probably be as much again! Thanks for that.
Any suggested source for the little connectors that go over the pins on the back of the cartridge. It would be wise to have an ample supply of these. Anything else I need to order up front?
Now, I guess once you make an arm, you need a test disc to evaluate it? Any recommendations for a suitable test disc? (Even if I could find my old one, it hard a hard life back in the days of AM radio. Then again, there might be uncharted territory at the bottom of the groove!)
On the playing weight front, how about mounting the cartridge on an ordinary arm, setting the nominal weight and measuring the clearance under the front edge of the cartridge, then loading up the linear arm (with regard to free-play zone as you had talked about) to give the same clearance?
A wedge style thickness gauge might work well here. You cut a right-angle triangle 10mm high and 100mm long on the hypotenuse, and mark a scale on the hypotenuse. (In this crazy new world, you can probably buy one readymade for less than the materials - anyone aware of such a thing?)
Actually, all we really need is a thin wedge of wood. Mark it with a pencil where it just touches the cartridge bottom on the pivoted arm and aim for that mark on the linear tracker.
Hmmm, my excuses seem to be running out....
Terry
2 x $7.99 for the bearings shouldn't break the bank - the postage will probably be as much again! Thanks for that.
Any suggested source for the little connectors that go over the pins on the back of the cartridge. It would be wise to have an ample supply of these. Anything else I need to order up front?
Now, I guess once you make an arm, you need a test disc to evaluate it? Any recommendations for a suitable test disc? (Even if I could find my old one, it hard a hard life back in the days of AM radio. Then again, there might be uncharted territory at the bottom of the groove!)
On the playing weight front, how about mounting the cartridge on an ordinary arm, setting the nominal weight and measuring the clearance under the front edge of the cartridge, then loading up the linear arm (with regard to free-play zone as you had talked about) to give the same clearance?
A wedge style thickness gauge might work well here. You cut a right-angle triangle 10mm high and 100mm long on the hypotenuse, and mark a scale on the hypotenuse. (In this crazy new world, you can probably buy one readymade for less than the materials - anyone aware of such a thing?)
Actually, all we really need is a thin wedge of wood. Mark it with a pencil where it just touches the cartridge bottom on the pivoted arm and aim for that mark on the linear tracker.
Hmmm, my excuses seem to be running out....
Terry
Thanks Fran - I'm sure I have one of those around here somewhere!
The HiFi disc seems more suited to the non-technical user. I also see one called The Ultimate Analogue Test LP which seems more suited to the technically equipped user. I'm more in the second class.
Ultimate
Comments anyone?
Terry
The HiFi disc seems more suited to the non-technical user. I also see one called The Ultimate Analogue Test LP which seems more suited to the technically equipped user. I'm more in the second class.
Ultimate
Comments anyone?
Terry
Terry,
Check back for earlier postings by dtut (Doug Tuthill). He did his early work with metal tube. 3/4" hard drawn copper plumbing tube should give a well made inner surface. Doug has gone to glass and finds it superior. You can load up an aluminium right angle with a couple of glass slips more easily than milling a copper tube. That stuff is very hard to machine. Aluminium is much easier to machine. The copper does well with abrasive disk cutting. I believe Fran has also used the glass V trough design.
Good idea with the wedge thickness gauge. Looks like we have a couple ways to skin the cat now. Can't think of anything else to order up front. Shop scrap should complete a working model. Were you thinking of 2 thin tubes for the arm or going with a more conventional wood or metal arm wand? For my very first carriage I used 1/4" dia aluminum tube. Had to do quite a bit of damping on that one. I like the looks of a nice hardwood arm wand better than the tubes, but the tubes seem to act better. Can't say how or why yet. Keep us informed please?
Rgds,
BillG
Check back for earlier postings by dtut (Doug Tuthill). He did his early work with metal tube. 3/4" hard drawn copper plumbing tube should give a well made inner surface. Doug has gone to glass and finds it superior. You can load up an aluminium right angle with a couple of glass slips more easily than milling a copper tube. That stuff is very hard to machine. Aluminium is much easier to machine. The copper does well with abrasive disk cutting. I believe Fran has also used the glass V trough design.
Good idea with the wedge thickness gauge. Looks like we have a couple ways to skin the cat now. Can't think of anything else to order up front. Shop scrap should complete a working model. Were you thinking of 2 thin tubes for the arm or going with a more conventional wood or metal arm wand? For my very first carriage I used 1/4" dia aluminum tube. Had to do quite a bit of damping on that one. I like the looks of a nice hardwood arm wand better than the tubes, but the tubes seem to act better. Can't say how or why yet. Keep us informed please?
Rgds,
BillG
Hmmm, maybe I should just bite the bullet and start with glass. Any suggestions on a source, or ideal dimensions? I have some test tubes 18mm OD, 15.65 ID and 150mm long. Might be a bit light on?
Haven't made any decisions on the arm materials yet. I like the triangulation concept for max horizontal stiffness, and I am attracted to metal so it can be earthed, notwithstanding your callous disregard of traditional shielding practice! What length of arm from pivot to stylus are we talking?
Terry
Haven't made any decisions on the arm materials yet. I like the triangulation concept for max horizontal stiffness, and I am attracted to metal so it can be earthed, notwithstanding your callous disregard of traditional shielding practice! What length of arm from pivot to stylus are we talking?
Terry
Hi Terry, I'll have to do a bit of measuring but I think your 150mm test tube might just do the job. Do a quick layout of the 10mm bearing inside a 15.6mm circle to see if it will fit well. Cutting the slot could be difficult but there is a post just a while back dealing with this. I have been touting flat glass strips set in a V. dtut, Fran and myself are all using the V trough configuration. Check my pics again. I cut ordinary window glass (float glass) into strips, 8-9 inches long and 1/4" wide, cheap, readily available, smooth and hard. As to my callous disregard, by the time you get through shielding the wires the drag may stop the carriage cold in its tracks. I'm absolutely amazed that we can get away with twisted wires. We need extremely flexible low drag wires.
Just did a quick measure. 150mm (5.9")won't do the job unless you can make some extenders that slip into the tube say 1/4"and are bonded with epoxy. The arm length on my pen tube taken from stylus to the center line of the bearings is 3 250". I think my last wooden arm was a bit longer. This isn't a critical dimension.
Rgds,
BillG
Just did a quick measure. 150mm (5.9")won't do the job unless you can make some extenders that slip into the tube say 1/4"and are bonded with epoxy. The arm length on my pen tube taken from stylus to the center line of the bearings is 3 250". I think my last wooden arm was a bit longer. This isn't a critical dimension.
Rgds,
BillG
OK, that's sounds pretty easy (at least by comparison to cutting a slot in a tube!) I guess the picture framing shop in the village would be able to do that for me. Less glass would die.
Yeah, I'm a bit amazed too! Hmmm, we have twice the mains volts around here, I guess that means twice the field. Anyway, in the worst case, a balanced front end could deal with any hum I can't avoid. Tempting to use Litz wire. Better HF performance too (cough, cough!).
Good to have a guide though. That's pretty short, isn't it, so whatever method I choose, we aren't talking a lot of materials, or massive stresses!
Probably the next issue I need to face is what cartridge to run with it. I'm currently running a Stanton 681EEE left over from radio days, but it's pretty uninspiring. (Probably good to experiment with first, as it's pretty indestructible!)
Are there any special characteristics demanded by linear tracking arrangements that I need to consider in choosing a replacement? Or, put another way, does any particular cartridge jump out and scream "choose me!"?
(I'm in the renaissance/baroque/trad folk field, so it doesn't have to deal with anything too difficult. I'm in the market for clarity more than anything else.)
Terry
Terry wrote:
"Are there any special characteristics demanded by linear tracking arrangements that I need to consider in choosing a replacement? Or, put another way, does any particular cartridge jump out and scream "choose me!"?"
Terry,
The subject of cartridges has come up several times. The general consensus seems to be that most anything will do the job. I'm wrestling with this very topic now. Some of my favourite records are well worn with lots of clicks and skips. The most annoying are the ones I have to get up and push the arm over a tic. Sometimes this can't be avoided, but the same records will play right through with my pivoted arm and even with the same cartridge. On the Cantus clone I get the feeling that very hi-compliance cartridges appear to be the most troublesome. My worst offender is the Signet (AudioTeknica). I recently resurrected an Empire 2000-eIII which was highly regarded when it came out. Had to straighten a bent cantilever and my trouble has diminished almost completely. Am about to buy a new stylus for it. I like the sound and the new stylus is not dear. Also have a couple of ADC XLM-2 carts sans stylus. These came from the same yard sale the Empire came from. XLM = eXtra-lo-mass. These carts get very high marks on the web. So I'm trying to decide if I want to pop for a stylus for the ADC. I don't have pots of cash to throw around on stylii or new carts especially if one of the ones I have will make me happy. I'm not a golden ears type. Also needing
a new stylus are an Ortofon OM40 body that will take a much cheaper OM10/20 stylus and the Signet (pretty hi compliance). Until I can get some real feedback so that I can get a new cartridge with impunity, buying a new cart is out. IIRC there was something about elliptical vs conical tips. I wonder if conical would have any advantage over elliptical with a linear tracker. So, no, nothing jumps out and says "buy ME" . Until we get some better information I would recommend finding something on ebay that looks interesting and you can find some supporting reviews. THE ADC XLM 2 can be had cheap enough as can the EMPIRE-2000E3. Kevin suggests NAGAOKA 100(?) as being a modern low cost cartridge. They can be had for around the $100 mark. Again I don't have that kind of money to play with. Any Cantus users please chime in on this subject please.
BillG
"Are there any special characteristics demanded by linear tracking arrangements that I need to consider in choosing a replacement? Or, put another way, does any particular cartridge jump out and scream "choose me!"?"
Terry,
The subject of cartridges has come up several times. The general consensus seems to be that most anything will do the job. I'm wrestling with this very topic now. Some of my favourite records are well worn with lots of clicks and skips. The most annoying are the ones I have to get up and push the arm over a tic. Sometimes this can't be avoided, but the same records will play right through with my pivoted arm and even with the same cartridge. On the Cantus clone I get the feeling that very hi-compliance cartridges appear to be the most troublesome. My worst offender is the Signet (AudioTeknica). I recently resurrected an Empire 2000-eIII which was highly regarded when it came out. Had to straighten a bent cantilever and my trouble has diminished almost completely. Am about to buy a new stylus for it. I like the sound and the new stylus is not dear. Also have a couple of ADC XLM-2 carts sans stylus. These came from the same yard sale the Empire came from. XLM = eXtra-lo-mass. These carts get very high marks on the web. So I'm trying to decide if I want to pop for a stylus for the ADC. I don't have pots of cash to throw around on stylii or new carts especially if one of the ones I have will make me happy. I'm not a golden ears type. Also needing
a new stylus are an Ortofon OM40 body that will take a much cheaper OM10/20 stylus and the Signet (pretty hi compliance). Until I can get some real feedback so that I can get a new cartridge with impunity, buying a new cart is out. IIRC there was something about elliptical vs conical tips. I wonder if conical would have any advantage over elliptical with a linear tracker. So, no, nothing jumps out and says "buy ME" . Until we get some better information I would recommend finding something on ebay that looks interesting and you can find some supporting reviews. THE ADC XLM 2 can be had cheap enough as can the EMPIRE-2000E3. Kevin suggests NAGAOKA 100(?) as being a modern low cost cartridge. They can be had for around the $100 mark. Again I don't have that kind of money to play with. Any Cantus users please chime in on this subject please.
BillG
While waiting for Curiosity to drop, I'll jump in here with a bit about carts. I did all my early experiments with a beater Shure M91. I found out later it's a pretty good cart and works well with LTs. There are good, cheap replacement stylii and not-so-cheap up grade or two available. I've mounted an AT95 and 120E, too. Both worked, but I liked the 95 better and it's cheaper. Right now, I'm running a Shure M97xE and I like it, but I'd better explain a little about that. Part of my recent silence has been because I've been building TTs - or at last new plinths for a couple of them. One is a Rek-O-Kut and the other is an Empire. The Empire replinth is the second one I've done. The first one didn't work well with the LT and neither did the Rek-O-Kut. I suspected the first Empire iteration was too resonant and the Rek-O-Kut had an ever-so-slightly out of round idler wheel that seemed to bother the LT. I figured the belt drive Empire platter, bearing, and motor mounted in a solid plinth might be the solution and so far that seems to be true, which brings me back around to the M97xE. I've had the cart for a while and couldn't seem to like it, but in the LT on the solid plinth Empire, it sings beautifully. Before I mounted the LT on the ROK, I was using the original ROK S-120 arm with a Shure SC35C conical stylus DJ cart - beautiful combination. I bought a N35 stylus yesterday which fits the SC35C, but can be run at 1-3 gr. instead of 4-5 gr. like the stock stylus. I will put that combination in the LT and I have high hopes for it. I'll post after I've spent some time with it.
I think LTs, TTs, and carts are another case of horses for courses. High compliance, low VTF looks like a good place to start in a general sort of way, but I suspect the specifics of each set up, and subjective taste, will be the eventual determinants. How's that for a polysyllabic cop out instead of saying "uh, gee, I just don't know."
Regardless, think about how fun we'll have buying and testing carts and stylii - just like the big kids who have pivot arms.
I think LTs, TTs, and carts are another case of horses for courses. High compliance, low VTF looks like a good place to start in a general sort of way, but I suspect the specifics of each set up, and subjective taste, will be the eventual determinants. How's that for a polysyllabic cop out instead of saying "uh, gee, I just don't know."
Regardless, think about how fun we'll have buying and testing carts and stylii - just like the big kids who have pivot arms.
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carts, horses
And then the pre-amp loading discussion might resume, especially with Shure bits other than the V. Lots of argument over on VE. I just was given a Pioneer integrated amp with switchable phono input, but it skips from 47k to 100k. I may have to try a Denon mc someday. Right now I'm painting my house for the last frakkin time.Got drudgery?
And then the pre-amp loading discussion might resume, especially with Shure bits other than the V. Lots of argument over on VE. I just was given a Pioneer integrated amp with switchable phono input, but it skips from 47k to 100k. I may have to try a Denon mc someday. Right now I'm painting my house for the last frakkin time.Got drudgery?
Terry,
Last night I settled in for a listening session with the Empire 2000. Sounded fine but something was lacking. Poor sound stage and overall dullness. Not what I was accustomed to hearing so after a while I remounted the Ortofon OM that I thought needed a new stylus and everything came alive. Sound stage was huge with great detail. Beautiful balance and fullness. This is what I was hoping for with the Empire. So will the Empire beat the 681? I think maybe yes, but if you are buying one, the cost of the more modern, lighter, way better performing, OM10 is only a small amount more. There are lots of vendors on the web that have new OM10s at around the $75 mark. And you can upgrade the OM body by buying only the appropriate stylus. For me, this is one that jumps out and screams BUY ME.
I will be getting a new OM10 stylus soon and should find it tracking at low VTF. The old one is doing great at a bit less than 2 grams. Not having any problem with skips yet. Drags the lightweight carriage with no trouble. So will need to check that with further use.
Rgds,
BillG
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