Topic: cheddar plover (Read 9252 times)

pipercub1772 · « **on:** August 29, 2009, 10:26:17 pm »

cheddar plover ,anyone know much about them bore/stroke double acting etc are they same size of puffin or smaller any help appreciated thanks allan

gondolier88 · « **Reply #1 on:** August 29, 2009, 10:41:15 pm »

Hi Piperclub,

Single acting, 11mm stroke x 8mm bore if I remember correctly- proteus will put me right if i'm wrong.

Have you acquired one or thinking about it- I notice there is one on ebay atm- you can buy the 'puffin' still- it's marketed as the 'clyde oscillator' if your looking for something a little more sophisticated?

Greg

Bunkerbarge · « **Reply #2 on:** August 29, 2009, 11:08:05 pm »

The Plover was a double acting twin cylinder so self starting and reversing, therefore suitable for RC on a single channel.

Proteus · « **Reply #3 on:** August 29, 2009, 11:59:00 pm »

Plover 8mm X 1mm

Proteus,

pipercub1772 · « **Reply #4 on:** August 30, 2009, 12:54:11 pm »

thanks for the info guys just one point this clyde engine ive seen advertized up and down is it a copy of the puffin engine now done by stuart ,if so who is manufacturing it ,also my 3/8-3/8 twin oscillator is not 100%reliable at reversing this is the first and only engine i have is it to be expected thanks allan

Bunkerbarge · « **Reply #5 on:** August 31, 2009, 08:34:15 am »

Could you give us a little bit more information about your engine that is unreliable at reversing. These twin oscillators are very simple in thier operation and symetrical in construction so if they go one way they should just as easily go the other.

Is it unreliable starting in either direction? Is it smooth in operation when running? What pressure are you operating at? How old is the engine and when was it last taken apart for cleaning? What lubrication system are you using and what oil?

Give us a s much information as you can about the engine and we may be able to come up with some suggestions.

Proteus · « **Reply #6 on:** August 31, 2009, 11:14:22 am »

are you the chap that posted om Model Boats Forum?

Proteus

pipercub1772 · « **Reply #7 on:** August 31, 2009, 05:16:00 pm »

proteus/not me on model boats forum,bunkerbarge it runs well in forward it runners well in revers its smooth running in both directions it runs from 10psi i try and keep it about25/30 psi it ticks over slowly both forward and revers it is the change from forward to reverse that is the problem unless it is running quite fast it sometimes stops at what seems to be approx deed center making it necessary to flick the flywheel the engine is new got it from ebay about 12 months ago there is plenty of steam oil going threw from the lubricator , ran the engine up on air couple of times then on steam about 6 times on test rig then in the boat i am ready to try on the water but i would be very reluctant to put in revers it appears the crankshaft has cut outs for the crankweb so don't See much chance of altering the timing although there could be a small amount of adjustment to be gained couple of picks here thanks allan , (pipercub)

Proteus · « **Reply #8 on:** August 31, 2009, 06:06:07 pm »

Thats not a cheddar plover nothing like one , seems to be a scratch built one,
this is the paddle plover the only changes are the end plates to lie it down and the double ended crank. the regulator and base is completely different on yours

Proteus

pipercub1772 · « **Reply #9 on:** August 31, 2009, 07:43:07 pm »

yes i know its not a plover i was merely asking about one because i saw one on ebay as gondolier said ,i know mine is scratch built i am just indicating the problems i am having with it,i have a 1994/95cheddar broshure but it dose not list the plover engine i thought it may be same size as puffin or larger aparently its not

Bunkerbarge · « **Reply #10 on:** August 31, 2009, 08:00:49 pm »

OK, possibly a home made engine which runs well in forward and reverse but is unreliable when changing over. First of all stop looking for means of adjusting the timing, an oscillator cannot be adjusted as the inlet port becomes the exhaust port when running the other way so the whole thing has to be symetrical. This is why they are a bit heavy on steam as the timing is far from ideal.

My first thoughts would be a sticky engine due to a possible misalignement or lubrication. If we are assuming the oil is going in we must be sure it is the right stuff, always use correct steam oil. I would remove the engine from the boat, turn the steam control valve to either ahead or astern and slowly rotate the engine by hand. If you feel any form of slight resistance then this could be giving you the problem. Try the engine in both directions. If you have a sticky spot then you are going to have to identify what is causing it and the most likely causes, as I've said, would be a misalignement, possibly old piston rings or piston rod packing or maybe the wrong lubrication.

Take it out and have a feel then let us know before we get any deeper.

pipercub1772 · « **Reply #11 on:** August 31, 2009, 09:22:43 pm »

took it out turns over nice and smooth forward and revers no tite spots just a slight feel of compression as each cylinder comes through tdc ,i am using(v460 compound steam oil medium)

Proteus · « **Reply #12 on:** August 31, 2009, 09:44:54 pm »

Quote from: Bunkerbarge on August 31, 2009, 08:00:49 pm

OK, possibly a home made engine which runs well in forward and reverse but is unreliable when changing over. First of all stop looking for means of adjusting the timing, an oscillator cannot be adjusted as the inlet port becomes the exhaust port when running the other way so the whole thing has to be symetrical. This is why they are a bit heavy on steam as the timing is far from ideal.

.

yes but you can adjust on that engine the crank timing between the two cylinders .

Proteus

AlexC · « **Reply #13 on:** August 31, 2009, 11:01:57 pm »

I agree with Proteus.

If you look carefully at the second picture you can clearly see that the cranks are at 180 deg to each other, or pretty close to it.

In that condition self starting will be at best unreliable and the engine could actually start in either direction, regardless of the steam control valve position.

PC... you should reset the cranks so that they are at 90 deg to each other..... this will give you reliable self starting and consistant direction control.
Ideally the grub screws holding the crank discs to the main crankshaft should locate on to small flats on the shaft... have a look and see if one of the discs has moved, due to a grubscrew coming loose.

The 460 grade steam oil is perfect for that engine.

Hope this is of some help.

Best regards
AlexC

Bunkerbarge · « **Reply #14 on:** August 31, 2009, 11:05:32 pm »

To me timing refers to the points in the cycle at which steam is supplied and exhausted in the cylinder, which is obviously fixed in an oscillator.

If it is possible with this engine for the cylinders to have become displaced with each other as a result of the method of construction then obviously that could lead to the problems being experienced. As I am not as familiar with the construction as you perhaps you are better qualified to assist pipercub in getting it back to the correct relationship but it is looking like, as you say, the grub screws have loosened.

pipercub1772 · « **Reply #15 on:** August 31, 2009, 11:58:06 pm »

thanks for all your help i have chqt the grub screws they do sit on flats i have adjusted one to make it i think more central !but to be honest it was not far out, it now appears that when 1cyl is at tdc the other is only a few degrees different, less than in the picture you discribed , i will run it up tomorrow and see just did not quite understand about the cranks at 180 alex ,sorry my enginering is a bit limited if i get no joy i will put a better picture up thanks for all your time and help allan.

AlexC · « **Reply #16 on:** September 01, 2009, 11:12:19 am »

Hi Guy’s,

First let me correct an omission in a previous statement in my last post.

Quote: - In that condition self starting will be at best unreliable and the engine could actually start in either direction, regardless of the steam control valve position. End quote.

What this should have said was: -

In that condition self starting will be at best unreliable and the engine could actually NOT start in either direction, regardless of the steam control valve position.

I tried to edit the post to insert the missing word but cannot get access to do so.

Ok, PiperCub: -

As far as I can tell, from the pictures and your descriptions, it would appear that with your current set-up you have the situation that when one piston is at the top of it’s stroke then the other piston, in the other cylinder, is at the bottom of it’s stroke….. in other words the 2 cranks (crankpins) are at 180 degrees to each other.

What you need to achieve is that when one piston is at the top (TDC) or bottom (BDC) of it’s stroke then the other piston is at approx 1/2 stroke…. I.e. in the middle of its cylinder…. This will place the 2 cranks (crankpins) at 90 degrees to each other.

It may be that the original builder of the engine has not fully understood this requirement and made the common mistake of setting them at 180 degrees.

You may find that you need to make an extra small flat for the grub screw (with a small flat file), on one end of the centre section of the crankshaft, in the correct location to achieve the required 90 deg angle.

I hope this helps you a bit more.

Best regards

AlexC

Bunkerbarge · « **Reply #17 on:** September 01, 2009, 01:04:19 pm »

Also is the crankshaft split or all in one piece? If it's split what is the connecting arrangement and is there any possibility of that becoming displaced and offsetting the cylinders?

pipercub1772 · « **Reply #18 on:** September 01, 2009, 08:32:28 pm »

hi one happy sailor here,just ran it up on air forward and revers about 50/70 times never missed once no matter What psi it ran at it must have just needed that slight adjustment i finally got your drift Alex about the 90% bit it worked a treat ,got time tomorrow to put back in launch and test in steam but after tonight i don't see any problems much appreciated every ones help i will update tomorrow on the steam run thanks again allan

pipercub1772 · « **Reply #19 on:** September 02, 2009, 09:02:31 pm »

update, ran it up on steam still not 100% changing over but better, noticed that when engine gets hot its not as free to turn over by hand , runs on air like a sowing/machine easier to turn over by hand change/over never fails no matter wot psi there is plenty of steam oil running through so dont think its that i am introducing steam oil even when on air as well by upending the lubricator now and then even the regulator is not as free moving when hot, i have moved the timing minutely on what i consider to be a slightly large flat on the crank giving a minute adjustment this seams to make it run better going from stop to forward or opposite and faster one way or the other or set to give even running deepending where its set to any ideas. pipercub

Bunkerbarge · « **Reply #20 on:** September 03, 2009, 12:16:54 am »

If it runs OK on air but develops a tight spot when hot then it could be that it hasn't been run in properly. You should run engines in on air for about three to four hours, lubricating it frequently, before running it on steam for at least another hour or two to get it all bedded in nicely and running hopefully smoothly.

This could be an issue if the engine has not run much in the past and hasn't undergone a careful running in procedure.

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Author Topic: cheddar plover (Read 9252 times)

pipercub1772

Bunkerbarge

Proteus

pipercub1772

Bunkerbarge

Proteus

pipercub1772

Proteus

pipercub1772

Bunkerbarge

pipercub1772

Proteus

Bunkerbarge

pipercub1772

Bunkerbarge

pipercub1772

pipercub1772

Bunkerbarge