HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 22, 2014, 07:05 AM
Registered User
Bernhard BB's Avatar
Denmark, Capital Region of Denmark, KBH
Joined May 2007
497 Posts
Discussion
cheddar oscillerende waterpump test

cheddar oscillerende waterpump test (2 min 3 sec)
Bernhard BB is offline Find More Posts by Bernhard BB
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 22, 2014, 11:38 PM
Damp and Dizzy member
Brooks's Avatar
Bozeman, Montana, United States
Joined Aug 2003
3,394 Posts
Bernhard, I wonder if you'd get more water flow if you slowed the pump. I would suspect that internal cavitation is killing efficiency. Your slow speed test seemed to put out almost as much water as your high speed test, but I may be wrong. If you are getting cavitation, that will accelerate wear on the pump.
Brooks is online now Find More Posts by Brooks
Reply With Quote
Old Feb 23, 2014, 04:47 AM
Registered User
Bradford West Yorkshire, UK
Joined Apr 2010
1,647 Posts
Although it's questionable to use an oscillator as a water pump apart from merely moving water, back pressure from a boiler is likely to push the cylinder off its seat, it was/is widely used as a lubrication pump in model Locos via a lever and ratchet and pawl mechanism. ie. very slow operation.

Regards Ian.
Circlip is offline Find More Posts by Circlip
Reply With Quote
Old Feb 23, 2014, 02:25 PM
Registered User
ooyah's Avatar
GLASGOW
Joined Feb 2011
306 Posts
Chedder water pump

Bernhard.
I think that Brooks has hit on the head.
As the pump is driven by the engine when it's running on the bench the engine nor the pump are doing any work, the pump is only moving water and at the high revs it's drawing air some where until it's under load.
Once the boat is in the water and the engine slows down under load the revs will be much lower.

I notice on the video that when you put your finger over the discharge end the pressure builds up and the pump works better.
I had one of these pumps fitted in a Clyde puffer some years ago and must admit that I was not impressed with the pump when it arrived.
However I powered it by an electric motor at 120 r.p.m. and it worked perfectly against a boiler pressure of 35 p.s.i. at the time of building I had no machinery so I used Meccano pulleys and a large "O" ring. .
With a full tank of gas I could sail all afternoon for about 4 hrs using pond water and had no problems at all.

Hope this helps.

George.
ooyah is offline Find More Posts by ooyah
Reply With Quote
Old Feb 24, 2014, 02:13 AM
Registered User
Bernhard BB's Avatar
Denmark, Capital Region of Denmark, KBH
Joined May 2007
497 Posts
Thank you
This was just a quick test
but after the pump This is fitted to the boiler, so it is very efficient operation from 0.30 to 35 psi no problem .. it provides almost .. too much water to be used as the bypass valve.
so it works ok ...
Bernhard BB is offline Find More Posts by Bernhard BB
Reply With Quote
Old Mar 07, 2014, 05:34 AM
Registered User
Bernhard BB's Avatar
Denmark, Capital Region of Denmark, KBH
Joined May 2007
497 Posts
hi
So the pump is now
in
For sale

Regards
Bernhard
Bernhard BB is offline Find More Posts by Bernhard BB
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log WATERPUMP upgrade pack for ROBBE U47 arkmodel Submarines 12 Apr 15, 2014 11:54 PM
Discussion steam boat with cheddar puffin,and one with tvr1a Bernhard BB Steam Boats 3 Jan 25, 2014 02:18 AM
Help! Need repair of broken/cracked crank Cheddar engine mendosherman Steam Boats 3 Jan 13, 2014 07:34 AM
Sold Maxwell Hemmens Marine steam engine with Cheddar boiler for sale mistairjoe Boats (FS/W) 2 Sep 30, 2013 08:29 AM
Discussion clutch and waterpump for nitro boat EJ1208 Racing Boats - Internal Combustion 17 Mar 30, 2012 09:20 PM