From: Doug <dj2210@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Mon, November 8, 2010 10:01:12 PM
Subject: Re: [Electric Boats] Catalina Conversion First Try
Thanks Jim for the kind words. I actually was pursuing both paths, the gearbox and a belt drive unit. I have all the parts except for the timed belt and supports so I might make one up to try.
After taking the video this afternoon I did play with the drive by loosening the reducer fasteners just as you suggested while spinning at a slow speed. Didn't really accomplish anything and I didn't loosen the coupling. The noise I can live with but not the alignment issue as I would be concerned about future reliability and integrity.
Another concern which I will ask Kelly is the AC current. While operating the drive with a dc current of 25amps the ac current was measuring 40 amps on each ac motor lead. I don't know if this is significance but doesn't seem correct.
--- In electricboats@yahoogroups.com, "luv2bsailin" <luv2bsailin@...> wrote:
>
> Hi Doug,
>
> I checked out your videos and photos. Nice looking installation. It's hard to tell the relative noise level from the video, but from the character of it I'm guessing it's mostly from the gearbox. That thin-skinned engine room on the C-27 acts like a resonant chamber and amplifies the noise too. My first conversion was on a C-27 using a chain drive and it was very loud, resonating through the whole hull. Changing to a belt drive helped a lot, but you could still hear the motor in the cockpit and more so down below, though not enough to inhibit normal conversion. I don't think you can ever make it dead-quiet, but adding insulation should knock it down to an acceptable level. The good news is that high-frequency noise is much easier to absorb than the low frequency rumble of a combustion engine. I'm not sure, but maybe a different gear oil could help a little too if that is indeed where most of the sound is coming from.
>
> I also could see a slight wobble in the motor at low speed. Is that the vibration you were talking about? I'm probably stating the obvious, but that wobble most likely indicates shaft mis-alignment. One trick I like to use is to loosen the mount bolts and run it slowly. It may then align itself or you can move things around a by prying and/or shimming, looking for a "sweet spot" where the wobble is at a minimum. Then gradually tighten things up while it's still turning. It may take quite a few tries to find that sweet spot since it moves as you tighten it. Another thing you could try is to re-clock the shaft coupling. If you have a shaft key installed you would have to leave it out of course, but you really don't need one with those clamp type couplers anyway. If it just won't track no matter what, you may have a bent prop shaft. Even so, It didn't look that extreme to me. I've seen a lot shakier setups giving good service.
> Anyhow, good luck with your new system!
> Jim McMillan
>
> --- In electricboats@yahoogroups.com, "Doug" <dj2210@> wrote:
> >
> > Ok so I took two videos, one showing the basic installation and the other operating at the slip. Here's the links
> > http://www.youtube.com/watch?v=RVztPV0Yxzk
> > http://www.youtube.com/watch?v=JIpHpoCZjjk
> > You might see the vibration I was talking about. I think I'll have to take things apart and use a dial indicator on the prop shaft.
> > Let me know if they work. I also took some stills which i'll put in the photo section under "Doug's C27 Conversion"
> > Doug
> >
> > --- In electricboats@yahoogroups.com, "tartan27hull157" <tartan27hull157@> wrote:
> > >
> > > Hi Doug,
> > >
> > > Yes, very interested in that video if you do get a chance. I am not much of a physicist, more of a linguist, but we do a fair amount of sound stuff, at least in the vocal tract. I am curious whether the pitch of the whine varied with rpm, or was it constant?
> > >
> > > And, since you're talking about taking video, you mean you can actually see the vibration?
> > >
> > > Does the Cycle Analyst not give you shaft rpm? I thought it had a programmable speed mode that converted motor rpm to bike speed, and I assumed you could tell it your number was 2:1 (or whatever is in your gearbox) and get shaft rpm.
> > >
> > > Thanks again, Paul
> > >
> > > --- In electricboats@yahoogroups.com, "Doug" <dj2210@> wrote:
> > > >
> > > > Paul
> > > > I will take some video the next time i'm down at the boat and post it so you can hear the noise and see the vibration. I was using a 36lb thrust Minnkota trolling motor for a month while engine-less, hung off the stern. That was quiet! Boat didn't go fast either. I wish this inboard was as quiet. Definitely a high frequency whine on mine but definitely within hearing range.
> > > > I stuck the Cycle Analyst in a plastic enclosure and made it swing-able mounting inside the companion way. That way it can be out of the way when not needed and doesn't get hammered all the time from the sun. Eventually I'll mount the speed sensor down on the shaft coupling to get RPM.
> > > >
> > > > I bought the Mars motor from Mars and months later the Kelly.
> > > >
> > > >
> > > > --- In electricboats@yahoogroups.com, "tartan27hull157" <tartan27hull157@> wrote:
> > > > >
> > > > > Hi Doug, thanks for the notes. After I posted I noticed that the title of your photo is "gearbox installation" so I should have figured that out. As for the noise issue, that was what I was really interested in, you think it was the PMAC itself? Not the controller (I have heard that they generate a high-frequency whine, though it's supposed to be out of human hearing range?), or the gearbox?
> > > > >
> > > > > Silence is a strong motivation for me so I balk a little at any noise issue.
> > > > >
> > > > > I did like the Cycle Analyst, building an enclosure I this is a good trade-off since you can find the best place it with minimum new holes and such. I assume you like to see it from the helm?
> > > > >
> > > > > Did you get the Mars 3001/KBL48301 combo from Kelly?
> > > > >
> > > > > Thanks, Paul
> > > > >
> > > > > --- In electricboats@yahoogroups.com, "Doug" <dj2210@> wrote:
> > > > > >
> > > > > > Hey Paul
> > > > > > I do have a 2:1 gear reducer and it reverses rotation but that worked out great for the Mars PMAC. The mount is aluminum and made up of 2 pieces of angle and U channel bolted together.
> > > > > > I also was planning on doing a belt/pulley reducer and still might just to see the difference. The advantage of the that is easier to change reduction ratio and the (for my install) placing the motor closer to the aft of the boat allowing for more space in my engine compartment. I can just fit 2 group 31 batteries between motor and compartment door. The other 2 batteries go where the fuel tank was.
> > > > > > Yup i did my conversion in the water but the bottom needs redoing so maybe I'll change the prop when that happens next year.
> > > > > > Every thing takes more time than anticipated. I thought I would have had this done last month.
> > > > > > P.S. I really like the large Cycle Analyst although you do have to provide your owe enclosure.
> > > > > > P.P.S. Did I mention that the Mars PMAC is noisy?
> > > > > > Doug
> > > > > >
> > > > > > --- In electricboats@yahoogroups.com, "tartan27hull157" <tartan27hull157@> wrote:
> > > > > > >
> > > > > > > Doug -- thanks much! This is very similar to what I am thinking of putting in my T27, the pictures are a great help!
> > > > > > >
> > > > > > > I can't quite see, is there reduction? From the angle of the motor it looks like it is bolted directly to what looks like a sort of bellhousing integrated with the pillow block...so, is it direct-drive? Or perhaps there are gears or a belt I can't see.
> > > > > > >
> > > > > > > I have a longer shaft alley, so my plan was to put the motor aft of the forward end of the prop shaft (above the prop shaft). The prop shaft and drive shaft would penetrate a plate which supports both the thrust bearing (below) and the motor (above), with a toothed belt running about 2:1 between them. Like you, I was going to mount this whole "sled" on rubber engine mounts, though I wasn't sure how much need there would be for dampening. My A4 didn't seem to vibrate much, and I have the shaft out to get it checked by a prop shop...I may replace it, as well as the prop (obviously, I am out of the water...if memory serves, you did your conversion in the water?).
> > > > > > >
> > > > > > > Anyway, thanks again for the detailed info and appreciate any thoughts you have on the design of the mounts. I looked into "drop-in" replacements and even helped another guy in the yard "drop in" his SolidNav Explorer...it didn't exactly "drop in," so I am still pretty interested in fabricating a solution specific to the space available.
> > > > > > >
> > > > > > > Take care and happy sailing, Paul
> > > > > > >
> > > > > > > --- In electricboats@yahoogroups.com, "Doug" <dj2210@> wrote:
> > > > > > > >
> > > > > > > > Thanks and yes I have 4 rubber mounts which you should be able to see under my photos. I didn't spend too much time in the alignment stages just made it connect to the coupler. My atomic four also had a vibration (although not as bad) so I'm wondering if the prop shaft is bent or not balanced.
> > > > > > > >
> > > > > > > > --- In electricboats@yahoogroups.com, tartan27hull157@ wrote:
> > > > > > > > >
> > > > > > > > > Doug-congrats on your first e-sail! Curious about your vibration issue. Do you have any dampening installed? I am looking at the same motor/controller combo and am trying to figure out best way to mount it.
> > > > > > > > > Sent via BlackBerry from T-Mobile
> > > > > > > > >
> > > > > > > > > -----Original Message-----
> > > > > > > > > From: "Doug" <dj2210@>
> > > > > > > > > Sender: electricboats@yahoogroups.com
> > > > > > > > > Date: Sun, 07 Nov 2010 02:17:24
> > > > > > > > > To: <electricboats@yahoogroups.com>
> > > > > > > > > Reply-To: electricboats@yahoogroups.com
> > > > > > > > > Subject: [Electric Boats] Catalina Conversion First Try
> > > > > > > > >
> > > > > > > > > Installed the Cycle Analyst this afternoon and since the wind was up decided I needed to sail. This is the first time that I've had a chance to try out what I spent time and money on. This is what I observed with my iPhone gps 5.4mph(4.6knts) @70amps. 50amps produced 4.5 mph. Battery consumption for the time the motor was on used 22ah.
> > > > > > > > > The controller (Kelly) temperature was slightly warm and the motor (Mars PMAC) was very warm. I didn't have a temp gauge but I could put my hand on the motor for a few seconds until I needed to let go.
> > > > > > > > > I do have some issues with vibration which I'll have to correct and it is louder than I expected producing a loud whine.
> > > > > > > > > Whats nice is just flipping a switch to run it- no water, fuel or smell.
> > > > > > > > > Doug
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > ------------------------------------
> > > > > > > > >
> > > > > > > > > Yahoo! Groups Links
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>
No comments:
Post a Comment