Indeed I have. A few years ago I roughly calculated what the bearing offset should ideally be for a 9" arm to minimise azimuth variation based on typical levels of warp and varying record thickness.
I reckon the bearings should actually be offset the other way by about 15-20°.
Not offsetting the bearing is definitely better than being perpendicular to the offset angle.
With my style of linear arm the off set and the bearings are perpendicular which is a very minor drawback.
Of course the use of an effective warp flattening measures elleviates this problem. With a flattened record the azimuth variation is so small it is probably inaudible.
I reckon the bearings should actually be offset the other way by about 15-20°.
Not offsetting the bearing is definitely better than being perpendicular to the offset angle.
With my style of linear arm the off set and the bearings are perpendicular which is a very minor drawback.
Of course the use of an effective warp flattening measures elleviates this problem. With a flattened record the azimuth variation is so small it is probably inaudible.
this is a great thread. The idea developed and refined for almost 10 years.
from time to time I came across this thread an was always fascinated by the sinplicity and the results.
so recently I decided to build one lt arm on my own. My skills in woodworking are good but not fine enough to build so fragile structures which have to be so accurate.
I decided to do this in 3d printing.
I plyed a while with tinkercad while waiting for my anycubic vyper.
when it arrived my moddeling was more or less finished.
I did not know anything about 3d printing and had several attempts to print exactly fitting parts. boreholes had to be made some 1/100mm bigger caused by material expansion when printing.
I bought some cheap bearings in 3x9x4mm and a set of borsilicate glas drinking straws of 10mm, 250mm long.
everything worked out fine, so here are my results.
from time to time I came across this thread an was always fascinated by the sinplicity and the results.
so recently I decided to build one lt arm on my own. My skills in woodworking are good but not fine enough to build so fragile structures which have to be so accurate.
I decided to do this in 3d printing.
I plyed a while with tinkercad while waiting for my anycubic vyper.
when it arrived my moddeling was more or less finished.
I did not know anything about 3d printing and had several attempts to print exactly fitting parts. boreholes had to be made some 1/100mm bigger caused by material expansion when printing.
I bought some cheap bearings in 3x9x4mm and a set of borsilicate glas drinking straws of 10mm, 250mm long.
everything worked out fine, so here are my results.
the arm can be turned away by 90degree to change a record.
At first I played around with a cheap AT-F2. It never sounded so good before. Very dynamic and vivid. After no hickups for about 20 Sides I changed to my Benz Micro ACE. tracking force as given by the manufacturer. It did never skip. It is working so well.
best of all: 3d printing is so cheap that overall costs are less than 10€
At first I played around with a cheap AT-F2. It never sounded so good before. Very dynamic and vivid. After no hickups for about 20 Sides I changed to my Benz Micro ACE. tracking force as given by the manufacturer. It did never skip. It is working so well.
best of all: 3d printing is so cheap that overall costs are less than 10€
the armwand is of carbon fiber.
6mm outer and 4mm inner diameter.
the arm is 62mm bearing center to needle. so there is only a very short piece of carbon just to connect the headshell to the arm carriage. the weight of the printed parts are:
Headshell = 2 grms
carriage = 3.5 grms
Counterweight = 3 grms ( plus two inlets of steel each 1grm)
the bearings are about 1.2 grms
carbon wand about 4 grms.
in total the arm is 17 gramms
6mm outer and 4mm inner diameter.
the arm is 62mm bearing center to needle. so there is only a very short piece of carbon just to connect the headshell to the arm carriage. the weight of the printed parts are:
Headshell = 2 grms
carriage = 3.5 grms
Counterweight = 3 grms ( plus two inlets of steel each 1grm)
the bearings are about 1.2 grms
carbon wand about 4 grms.
in total the arm is 17 gramms
Great to see your developments as well, as Ray says it would be interesting to see how the stylus is reacting as well.
Thanx for your video, but the camera angle doesn't show what the stylus/cantilever is doing so it isn't any help for evaluating bearing sticktion. If you could re-run the test with the camera from this viewpoint:
...and with an eccentricity of just 1 or 2mm, that would be revealing. Also, a run time of more than 3 seconds please.
Ray K
...and with an eccentricity of just 1 or 2mm, that would be revealing. Also, a run time of more than 3 seconds please.
Ray K
this are the specs of the Benz
- Type: Moving Coil
- Output Voltage: mV
- Freq Response: 20Hz - 20kHz
- Tracking Force: 1.8 - 2.2 g
- Mass: 8.8 g
- Channel Separation: 35 dB
- Channel Balance: 0.5 dB
- Load Impedance: 200-47k Ω
- Output Impedance: 12 Ω
- Stylus:
- Stylus Tip: 6 x 40um VdH
- Cantilever: 0.28mm Solid Boron
- Dynamic Compliance: x 10-6cm/Dyne