Re: Re: mounting cartridges, and adjustments...
here's a few 'specs" of my locale:
3048 ft elevation
avg yearly temp: 12.35℃ ( 54.23℉ )
avg yearly rainfall: 271mm (10.7")
avg yearly snowfall 130.6mm ( 5.14")
so you see rain is pretty rare here. And due to the Chinooks we get evaporation is very significant.
take care and have a great one
stew
Ok, so if the relation between the top of the plinth and the top of the platter stays the same, then a measurement of that will be all that's needed. I've decided to complete the arms as much as possible , with whatever I have on hand for internal wire . You may have to put some of it together yourself (minimal amount thought)TerryO said:
What midif? If your speakers are indications of what you might consider "midfi" , then we should all be so lucky
Cool. I think the mouse cords offer very good and otherwise worthless wire that performs (I think) well in this application.
Viceroy is among the best, 6 oz, NHL regulation weight and composition for about a single loon...
Well I live only a few hundred miles East of Vancouver (800 or so) and I live in a desert. I "hear" you get some relatively serious rain. But I'm willing to bet we get more wind (often tops 60 mph), and snow (that's our major source of moisture in Southern Alberta).
here's a few 'specs" of my locale:
3048 ft elevation
avg yearly temp: 12.35℃ ( 54.23℉ )
avg yearly rainfall: 271mm (10.7")
avg yearly snowfall 130.6mm ( 5.14")
so you see rain is pretty rare here. And due to the Chinooks we get evaporation is very significant.
take care and have a great one
stew
Just adding some food for thought. While I like the idea of an unside down air bearing, I don't like the knife bearing or jewel bearings I've seen. You already have the perfect bearing-air. Why not design an air bearing like the ET-2? Air bearing for both vertical and horizontal movement. You can still keep the arm length short.
Anyway this is the DIY path I'm going to attempt. I'll keep you all informed.
Anyway this is the DIY path I'm going to attempt. I'll keep you all informed.
Whenever I've showed anyone the design for the Ladegaard arm this is invariably the first comment I receive, but I believe it would be difficult to machine the two cylinders needed with enough precision at a reasonable cost. This is one of the problems the Ladegaard is trying to solve. I do hope you find a good way to accomplish this, and further, I hope you share it here if you do!
cygnus x1 said:
It could be many people have tried this before and failed? Which then lead to the current design. I just liked the sound of the ET2. I can find telescoping Alumining tubing with a .009 clearance, is that to much of an air leak? Maybe I'm just chasing my tail?
Yeah, getting the tube fit can be hard. Another thing is that most builders of the angle type drill the holes oversize and then fit a layer of mylar etc to the inside of the angle. They then use a hot fine wire to end up with a very fine tiny hole. Such a hole would be hard to drill but not impossible. I guess that is something that might be harder to do in a tube, but it must be possible as the ET people do it. Maybe a bigger airflow will solve it.
Fran
Fran
.009" clearance...and to TerryO, vinylkid, etc...
well I just had a bearing redone with .00025" clearance. Not sure what the need for tubing would be , but to me the air pressure could easily be adjusted for .009". I'd certainly give it a try if the tubing is available at a reasonable cost. To me this seems like a more appropriate way to go. However the Ladegaard has been a proven design that could (and can be) be improved upon.
I have a knife edge bearing'd tonearm from some POS turntable. The counter-weight and knife edge bearing are all that I'd salvage, and adapt from there. (The knife edge carrier looks "nice"), for a semi-standard Ladegaard arm.
still working on the "prototypes". I decided to turf all of them and start from scratch--using new tubing instead of salvaged, "new" bearings, a different counter-weight arrangement-----all more conducive to "standardizing" the build so that results are less prone to variations.
cygnus x1 said:
well I just had a bearing redone with .00025" clearance. Not sure what the need for tubing would be , but to me the air pressure could easily be adjusted for .009". I'd certainly give it a try if the tubing is available at a reasonable cost. To me this seems like a more appropriate way to go. However the Ladegaard has been a proven design that could (and can be) be improved upon.
I have a knife edge bearing'd tonearm from some POS turntable. The counter-weight and knife edge bearing are all that I'd salvage, and adapt from there. (The knife edge carrier looks "nice"), for a semi-standard Ladegaard arm.
still working on the "prototypes". I decided to turf all of them and start from scratch--using new tubing instead of salvaged, "new" bearings, a different counter-weight arrangement-----all more conducive to "standardizing" the build so that results are less prone to variations.
cygnus x1 said:
If you read the Ladegaard stuff, there is a part that talks about making two angles fit together perfectly. This is done basically with paper and epoxy, and sandwiching two pieces of angle together, and then taking them apart when the expoxy cures. I think This could be done to match two tubes together as well. Something to think about.
As far as the holes go, it would not be impossible to get mylar, or tape inside the tube. But tricky for sure 🙂 My current incomplete arm uses a "square" tube, and I was able to put mylar in there. Round surfaces are harder, I'm sure. I am also trying to skip the tape, and drill directly through the metal instead. I picked up a set of resharpened #83 drill bits from drillbitcity.com for USD 11.99, or so. they several US$$ less then the .30mm holes that are prescribed by Poul Ladegaard. With a drill press, I was able to drill 1-2 holes through aluminum per bit before they break. When they broke, they worked really well to punch holes in mylar when I gave up on it. I'm sure I was doing it wrong though and I've not been beaten yet on this front! The train station I commute from has several metal fabricators near it. I should stop in and see what someone would charge to drill the holes for me?
staggerlee said:
Did you use any machine oil while drilling? If you didn't try that and using less pressure while drilling. That should help bit life.
drilling in tube...
consider using a Dremel or similar rotary tool, held in a "drill press" intended for one. Also use a vise to hold the tube, I think you can get a little "V" to hold the tube and clamp the tube into it. Use very high speed, very little pressure and machine oil. That should allow you to do it....
consider using a Dremel or similar rotary tool, held in a "drill press" intended for one. Also use a vise to hold the tube, I think you can get a little "V" to hold the tube and clamp the tube into it. Use very high speed, very little pressure and machine oil. That should allow you to do it....
I'm not sure about such small holes, but I think for drilling aluminium methylated spirit is the recommended lubricant. Not sure what this is called in North America.
Thanks,
Googling it came up with some commercial products, so it is good to know what I can use that is already on my shelf. In the states methylated spirits is called denatured alcohol. I was using mineral oil, because I had it next to me at the time. Needless to say it didn't work very well.
Googling it came up with some commercial products, so it is good to know what I can use that is already on my shelf. In the states methylated spirits is called denatured alcohol. I was using mineral oil, because I had it next to me at the time. Needless to say it didn't work very well.
Stuey said:
I was planning on drilling the larger of the two tubes (from outside-in), using the idea of a pilot hole and then the tape and pin hole. I would then clean up the ID. Mount this in a square aluminum box section to make the manifold and seal the ends to complete. Just theory, but should work and resemble stock linear air bearings that I've seen.
A point to consider..a small hole through the material won't have the same geometry as the "tape on aluminum" approach. I believe (as in I don't know for sure) the larger opening after the air metering hole allows the air to "spread" providing a better coupling to the sled, and reduces noise as the volume increase causes a velocity decrease. Personally, I would use a starter bit to "funnel" the exit.
Casey
Casey
Stuey said:
Used to use paraffin for machining aluminium when I was an apprentice toolmaker many years ago.
Regards,
Mick.
I have a question in reguards to Nanook's unipivot design, I've tried searching but haven't really found what I need. What is the mounting distance from the center spindle to the pivot point? Thanks for any help, Nick
Trower...
the mounting distance is moot, as the base is movable....
Please see post #24 of this thread for a sketchup with the dimensions...
In the case of my original (and subsequent) tonearms(s), the distance is approximately 305mm (approximately 12") + an inch or so. I use no anti-skate, and the headshell offset is something like 20 degrees. Again, I don't actually know, because I use a "straight" headshell that allows for the cartridge to be rotated. I then use an alignment protractor and adjust the cartridge until I get good alignment with a grid at 57.5 mm from the spindle centre--not really "standard" alignment, but it works. Use whatever protractor alignment distance you prefer. The Oracle setup procedure suggests a spindle to alignment point of 65.5 mm.
I know this seems a little contrived, but I really don't know the complete specifications, as I got good alignment almost immediately (again because the complete base can be moved around the plinth). Obviously if you have a suspended deck, then the arm will not move with the suspension unless some kind of rotating arm board is made and attached to the suspension sub-chassis at the stock location.
Hope that helps.
stew
the mounting distance is moot, as the base is movable....
Please see post #24 of this thread for a sketchup with the dimensions...
In the case of my original (and subsequent) tonearms(s), the distance is approximately 305mm (approximately 12") + an inch or so. I use no anti-skate, and the headshell offset is something like 20 degrees. Again, I don't actually know, because I use a "straight" headshell that allows for the cartridge to be rotated. I then use an alignment protractor and adjust the cartridge until I get good alignment with a grid at 57.5 mm from the spindle centre--not really "standard" alignment, but it works. Use whatever protractor alignment distance you prefer. The Oracle setup procedure suggests a spindle to alignment point of 65.5 mm.
I know this seems a little contrived, but I really don't know the complete specifications, as I got good alignment almost immediately (again because the complete base can be moved around the plinth). Obviously if you have a suspended deck, then the arm will not move with the suspension unless some kind of rotating arm board is made and attached to the suspension sub-chassis at the stock location.
Hope that helps.
stew
The tiny holes for the ladegaard arm are easy to drill in aluminium.
Mark out where the holes are going. Then drill most of the way through with either a 2mm or 3mm bit, dont go through!
Now, get a 0.3mm drill bit, you'll probably need a few, i get about 7 holes from each bit. These drills are tiny, i believe they are the smallest drill bits available, but may be wrong.
if you put these in a power drill they will just break. You need an archemedies (sp) drill.
Drill a 0.3mm hole in the middle of the big hole you just made.
Ill go get some pics to explain.
Mark out where the holes are going. Then drill most of the way through with either a 2mm or 3mm bit, dont go through!
Now, get a 0.3mm drill bit, you'll probably need a few, i get about 7 holes from each bit. These drills are tiny, i believe they are the smallest drill bits available, but may be wrong.
if you put these in a power drill they will just break. You need an archemedies (sp) drill.
Drill a 0.3mm hole in the middle of the big hole you just made.
Ill go get some pics to explain.
here we go.
As i say, you need to drill a bigger hole first. A 0.3mm hole right through doesnt work as well as a 0.3mm hole feeding a bigger hole.
http://aolsearch.aol.co.uk/aol/image?invocationType=topsearchbox.image&query=archemedies+drill
As i say, you need to drill a bigger hole first. A 0.3mm hole right through doesnt work as well as a 0.3mm hole feeding a bigger hole.
http://aolsearch.aol.co.uk/aol/image?invocationType=topsearchbox.image&query=archemedies+drill
For those contemplating a DIY tube arm....the whole tube is not necessary.
This guy made his arm out of the same piece of tube, split a piece of the tube for the slider & just opened it out.
Airbearing Tonearm
Personally, I think the Ladegaard approach is more efficient. Certainly the latest inverted design uses air flow of less than 200lph to float as opposed to other cylindrical designs which need 900.
Users of the cylinder type airbearing often complain about audible hiss. The inverted Ladegaard....AKA Terminator is effectively silent.
Ladegaard also chose to split the vertical & horizontal components to conduct experiments in their respective inertias. He concluded the best combination was a high lateral inertia & low vertical. The link has already been posted elsewhere in this thread.
The original posting of the inverted bearing Ladegaard can be found here:
Terminator Prototype
Finally, I wouldnt dismiss the simplicity & effectiveness of the blade bearing without hearing it in this context.
This guy made his arm out of the same piece of tube, split a piece of the tube for the slider & just opened it out.
Airbearing Tonearm
Personally, I think the Ladegaard approach is more efficient. Certainly the latest inverted design uses air flow of less than 200lph to float as opposed to other cylindrical designs which need 900.
Users of the cylinder type airbearing often complain about audible hiss. The inverted Ladegaard....AKA Terminator is effectively silent.
Ladegaard also chose to split the vertical & horizontal components to conduct experiments in their respective inertias. He concluded the best combination was a high lateral inertia & low vertical. The link has already been posted elsewhere in this thread.
The original posting of the inverted bearing Ladegaard can be found here:
Terminator Prototype
Finally, I wouldnt dismiss the simplicity & effectiveness of the blade bearing without hearing it in this context.
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