Eminent Technology ET-2 Tonearm Owners

Apologies for making this statement without reading all I've missed. (My father passed away and I had been his primary caregiver for several years, this has severely dampened my ability to give my (all) here for quite some time).
Just wanted to add... I've been using aftermarket 80W silicon fluid available at hobby stores with no sonic degredation,( paddle barely skimming the fluid)( I use an oral syringe to add/subtract fluid as needed, it's so much easier than fiddling with the paddle!), also using DuPont NLGI #2 w/ Teflon white lithium grease in my VPI bearing (ceramic ball bearing) to excellent effect.

Ct0517: an excellent description of the goings on with the leaf spring and how it works. I only wish Bruce would have mentioned the effects and the availability of the differing leaf springs years ago. A neccessity at this moment in time and should be included in future owner's manuals.

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 :-)

Richardkrebs: That is quite an unique design, so unique that it becomes very different from the standard ET design we are all using. In this respect there may be little use for any comparison. Therefore, I understand Ct0517's remark above. One thing I've been thinking about for some time for my upcoming tt project is machining tolerances. Checking my pricy platforms (Symposium, BDR) and even the acrylic top on my VPI plinth @ platter with a accurate level, there are enough variations in the degree of trueness that leaves me extremely conscious of the importance of the ability to machine as true as possible. This is one reason why I like the added flexability the stock ET design offers.

Slaw.
"Variations in the degree of trueness"
Totally agree. Since I had the luxury of building the arm and TT, almost concurrently, I could deal with these topics in real time.
Getting accurate alignment when two components are brought together from different manufacturers, without the ability to adjust, would be pure luck.