Hello.
There has been some private questions about the design of my modified ET2.
I have included here some more photos for those who may be interested.
The target design brief was to
- eliminate all unneccesary joints.
- minimise different material count
- eliminate any unneccessary components that could move
- make it as rigid as possible
- make it as inert as possible.
These took precidence over convienence of use.
http://cgim.audiogon.com/i/vs/i/f/1370870032.jpg
The main pillar and manifold are acrylic, since the decission to make the TT plinth out of acrylic was already made. This allowed me to fuse the arm pillar to the TT chassis eliminating one joint. No allowance is made for making the spindle parallel to the platter, after the fact, but I decided to machine the bottom of the pillar should this be required. Measurements showed that this was not needed.
Two cavities are milled into the pillar. In one is glued a lead billet, the other is filled with sand.
4 X M5 capscrews in machined slots pass thru to the manifold. These are loosened and the removable VTA screw is turned to raise or lower the manifold. One turn is approx 1/2 mm (20"). Tightening the cap screws creates a very strong joint. The manifold is indexed to the pillar with a lug each end to keep it level.
The pillar manifold interface is not curved. This because I did not have the machining capability at the time of build.
2 x M2 grub screws pass thru the manifold and contact the bearing sleeve pushing it slightly towards the pillar. At 120 degree increments there are 2 small pieces of shim metal inserted in the gap between sleeve and manifold. Tightening the grub screws presses the sleeve against these shims removing the compliant o'rings from the loop.
Arm lifting is done by hand and the wand rests on a piece of foam at the cartridge end, when off the record.
The goose neck is solid aluminium made from the same grade as the spindle. The oil trough paddle is attached to the goose neck.
This is a 15 year old design, if I did it today there would be a few changes, but the fundamental architecture would be the same.
As you can see my ET has had a little surgery :-)
There has been some private questions about the design of my modified ET2.
I have included here some more photos for those who may be interested.
The target design brief was to
- eliminate all unneccesary joints.
- minimise different material count
- eliminate any unneccessary components that could move
- make it as rigid as possible
- make it as inert as possible.
These took precidence over convienence of use.
http://cgim.audiogon.com/i/vs/i/f/1370870032.jpg
The main pillar and manifold are acrylic, since the decission to make the TT plinth out of acrylic was already made. This allowed me to fuse the arm pillar to the TT chassis eliminating one joint. No allowance is made for making the spindle parallel to the platter, after the fact, but I decided to machine the bottom of the pillar should this be required. Measurements showed that this was not needed.
Two cavities are milled into the pillar. In one is glued a lead billet, the other is filled with sand.
4 X M5 capscrews in machined slots pass thru to the manifold. These are loosened and the removable VTA screw is turned to raise or lower the manifold. One turn is approx 1/2 mm (20"). Tightening the cap screws creates a very strong joint. The manifold is indexed to the pillar with a lug each end to keep it level.
The pillar manifold interface is not curved. This because I did not have the machining capability at the time of build.
2 x M2 grub screws pass thru the manifold and contact the bearing sleeve pushing it slightly towards the pillar. At 120 degree increments there are 2 small pieces of shim metal inserted in the gap between sleeve and manifold. Tightening the grub screws presses the sleeve against these shims removing the compliant o'rings from the loop.
Arm lifting is done by hand and the wand rests on a piece of foam at the cartridge end, when off the record.
The goose neck is solid aluminium made from the same grade as the spindle. The oil trough paddle is attached to the goose neck.
This is a 15 year old design, if I did it today there would be a few changes, but the fundamental architecture would be the same.
As you can see my ET has had a little surgery :-)