Looking For Local TW Acustic Raven Owner in Seattle.

I am looking for a local Seattle area owner of a TW Acustic Raven (any model) to help solve an issue I am having with mine. I would like to bring over a motor pod for a comparrison to help solve a problem. Any Raven owners willing to help another Raven owner.

Thanks.

Hi Andi,

Yes, I have been emailing Jeff. He has been both helpful and generous. But because of distance I think it will come down to me doing the detective work.

The Problem: Slight, but noticable, up/down cyclic motion of belt on pulley.
Tried: Re-level motor pod (many, many times). Reduced but not cured problem.

Recently I decided to try again and take a new approach. Now I noticed the pulley has some non-concentric motion, a wobble in multiple directions. It's hard to see but it's there. Using digital level, I leveled the motor mount within pod. Small improvements were seen re: the wobble and belt motion but still not cured.

While I had the pod cover off I slid the pulley farther down the shaft and noticed the wobble decreased to the point where either I could not detect it visually and the belt travel improved as well. I am waiting for a new belt to arrive to rule that out. Now, I suspect two things causing the wobble, the 4 rubber motor isolators are allowing a bit of excess motor motion or the pulley is not entirely concentric. My bet is on the motor isolators. I will probably try a couple things to see if that is the case. Or I could just order isolators/pulley and see what happens, but the boat from Germany is slow.

The intersting thing is that the belt motion is cyclic to 1 revolution of the belt more so than one revolution of the platter. It's somewhat minor issue but it shouldn't be an issue at all in my estimation. I have heard from some other Raven owners saying their belts are steady, no travel. So, that's my goal.

Hi Andi,

Yeah, I have discussed this before with both Jeff and Thomas via email cause I have had this issue from day 1. This is why I seek someone local to help sort the issue.

I'm guessing I have the shorter belt cause the pod is about 2-3cm from base of TT.

I did a bit of tinkering yesterday and found, this this time through, dropping the pulley down farther did nothing to alter the belt motion. I did one thing different, I put a bit more tension on the the motor suspension by moving the pod out a bit farther from the base. This seemed to reduce the motion a bit more. There is still some travel in the belt but better than before. Though I'd say that I do have it about 80% of the way to being steady.

I agree that that adusting the feet is mearly a way to put the belt in the center of the pulley and there shouldn't be some big deal regarding the levelness of the pulley.

I have flipped the belt, smooth side out, inverted top side down, and still had belt travel. If the platter/base wasn't already proven level I'd suspect it but it is (X10). I have also raised/lowered the motor position so the belt didn't ride atop the already smoothed belt patch area on the platter.
No change seen.

Thinking about it a bit I'd say that the pulley would be the last suspect. It spins too many revolutions to generate such a slow cyle of belt movment. And I think the same can be said about the motor isolators. I would think that any excess motion allowed by the isolators would make the belt up/down movement more rapid. So I am still suspecting the belt, and maybe it has a slight enough groove worn into it so it follows this motion. So that's my theory. I will try and talk to Jeff on Sat., to see when my new belt will arrive. Hopefully it's the correct length.

On a different note, what are you using to isolate your Raven? This is my next focus. I am thinking of trying some slate/cork combination. But since I use Naim Fraim units I want to keep the weight down since they are a light mass orienented approach. And I want to try and isolate the pod from the TT base buy using a separate cut out. Local dealers here are quite marginal for trying things before purchase. And my favorite local dealer hasn't beeen seen in almost 2 years, though his shop is still there. I feel like filing a missing person's report!

Well, I'd like to try and put a conclusion on this saga, at least for now. As it stands, my pulley was found to be defective. A different pulley improved belt motion considerably, though I can still see some faint "wobble" from the pulley any apparent motion from the belt, (which is faint) is probably due to the actual "cut" of the belt itself. It is considerably less than before. I am now convinced that the rubber isolation posts securing the motor are allowing some slight lateral motion of the motor itself. I was lucky enough to score a motor pod and I will put my theory to the test at some point.