| Author |
Message |
JR
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 30, 2006 - 10:10 pm: | |
Brian Brown, (and anyone else with genset vibration control knowledge) don't you have a Yamaha/Kubota genset? Wondering if you are satisfied with your generator install? Mine works great...just a little noisy outside...on both sides of the coach. Transmitting noise across from the engine mounts apparently. Are you using the original isolators? Looking for some isolators that will be softer yet fit the dimensions of the original isolators. These things are about 3" tall, with 10mm studs on both ends. Any ideas on where to find softer (this seems logical) isolators would be helpful.
I've got 1" of Rubbatex sound deadening material, have removed the muffler and isolated it from the coach, and nothing has changed the noise levels. It's not bad inside the coach, just outside near both front wheels. About as noisy on the opposite side from where the genset is mounted. Time to remedy this if possible. May not be possible. Using a 6.5 kw Yamaha diesel generator, EDS6500. Genset hadn't been started since last use in August, but started immediately. Works great, just like it a little quieter. The gen is mounted in the AC condenser compartment on an 87 MC9..and it's really tight. Thanks, JR |
Cliff (Floridacracker)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 31, 2006 - 4:57 am: | |
JR,
Ordered mine from Grainger online.
Good selection and unreal delivery speed.
Ordered at 16:00 on Monday and at my door by noon on Tuesday. They ship from regional warehouses.
Good Luck
Cliff |
Sojourner (Jjimage)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 31, 2006 - 11:00 am: | |
Air mount is best isolator for vibration…steel spring (coil spring) is second best. And so on.
Firestone Airmount/Isolation
http://www.firestoneindustrial.com/Industrial/index.htm
Check with factory support for proper selection to meet your need.
I believe 1M1A-0 is your Assembly with Blind nut, 1/8 NPT,
brass stud WO2-358-3001 or Blind nut, 1/8 NPT, brass
stud, stainless steel ring WO2-358-3005
Very good guideline for selection & mounting point for Airmount & Airstroke
http://www.firestoneindustrial.com/Industrial/Literature/Airstroke_Airmount/MASAM_203_e.pd f
On page 7, “Airmount Vibration Isolator Do’s and Don’ts”
Interesting guideline….” The distance between the narrowest mounting points should be at least twice the height of the center of gravity above the mounting points.”……..
Remember choose airmount version…not airstroke only version.
FWIW
Sojourn for Christ, Jerry |
Sojourner (Jjimage)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, January 31, 2006 - 11:15 am: | |
For exhaust connection, use SS flex braided coupling such as this;
http://www.dezod.com/pd_stainless.cfm
Many front wheel drive auto have them…so salvage yard is your source…they usually in great condition because stainless-steel.
FWIW
Sojourn for Christ, Jerry |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 01, 2006 - 3:02 am: | |
Hey JR, yup I have the same genny. The beast is LOUD, for sure. I put a big Onan muffler on it and discovered that it's not the exhaust note that's the major noise now... I think it's the intake and belt noise. 3000 rpm just makes a lot of racket.
The original quiet box it was in helped a bunch (gone now)... lots of heavy sheet metal and foam. Mine is exposed to the air because it's in the old condensor compartment, so I'm thinking of building a big air box "quieter" for it with large pieces of insulated sheet metal, making the air turn before getting into the compt. and quieten it substantially (me hopes).
Some pics of my install here: http://www.brownland.org/bus/genny/
I'm not experiencing vibration issues too much... I can feel it running, but it doesn't seem too bad. Mine sits on the factory isolators and in the factory pan (that I sawzalled the heck out of to squeeze it into the compt.). The suggestions given seem like it would help the vibration issues, though.
Someone on this board awhile back recommended that I redo the pulleys and governor (??)on the engine to get it down to 1800rpm, but it's probably beyond my skills presently.
HTH,
Brian Brown
PD4106-1775
Longmont, CO |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 01, 2006 - 9:40 am: | |
Brian, I am curious as to the construction of your genset. Is it two separate units, belt driven? The reason I ask is that 3000 rpm is unusual unless you are running at 50 hertz.
If the engine is rated to operate at 3000 or 3600 rpm then its hp at 1800 rpm would be significantly decreased. If the alternator is operating at 3000 rpm then it is producing 50 cycles (hertz) and you have some modifications to do. LOL
Richard |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 01, 2006 - 10:39 am: | |
Richard, yes the genny is a belt-drive unit. Here's the unit specs: http://www.yamaha-motor.com/outdoor/products/modelhome/452/0/home.aspx
Yeah, the lower-rpm sounds like a major project... if it's even doable at all. And there's plenty of other projects higher on my list for the old blue bus.
Thanks,
Brian |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 01, 2006 - 11:02 am: | |
Yes, I seriously doubt if it is doable. It would require a significantly larger pulley on the engine and I suspect the output hp would drop by about 50% decreasing the output capacity of the genset by about 50% and then there would be a possible governor problem trying to maintain 1800 rpm on the engine. Major, major project in my humble opinion.
Richard |
JR
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 01, 2006 - 9:29 pm: | |
Hi Brian,
I though you had one of these critters. Just wanted to know if you had worked thru (or experienced) the noise issue.
Re: Richard's question, .the engine already operates at two speeds...1800 low, and 3600 loaded...it makes 120VAC (per volt meter) at both speeds, but will accelerate whenever any load is placed on the unit. I don't begin to explain how the electrical part of the unit works.
The tiny Kubota diesel is too small to operate at 1800 continuosly. Probably heat up too.
My issue is not vibration that is felt..and it's not bad at all inside the coach...it's a "buzz" that is transmitted thru the body of the coach. We spend a good bit of time outdoors and it's just a little obnoxious. I believe Sojourner hit on one source of body noise (he covered everthing actually) with the air intake system. My filter cannister is securely bolted to the bus body.
That will be changed this weekend. And, the mounts are probably too firm. It isn't the muffler or exhaust system causing the noise. The exhaust has been removed and left to hang (for quick experiment only) and no difference at all.
The thing worked without complaint all last year. Runs ACs when driving in hot weather.
Remotes from the drivers seat.
New mounts will solve some of the problem, and the intake will have to be hung in a muffler hanger or some sort of isolating mount.
I bought this genset because I'm a Yamaha dealer, and the unit is very compact when removed from its "quiet box." The compact part has worked very well...the quiet is not as I'd like.
I just received the rear airbags from Luke today and plan to get them installed this weekend. Maybe get to look for some genset mount airbags or soft mounts later this week. Sojourner sent a good bit of info to digest.
Thanks much, JR |
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