Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: 1 [2] 3   Go Down

Author Topic: Comtesse query  (Read 14089 times)

Sailmaker

  • Guest
Re: Comtesse query
« Reply #25 on: September 22, 2009, 09:42:22 AM »

I wish I had modified the pully as I am sure it's going to give trouble. The only other way is to do something obout the servo range, the Hitec has such a large arm throw and I wonder how other Comtesse builders have overcome this.

I had the same problem with the hull moulding, very poor design. I ended up using a large blob of Araldite adhesive and squashed the wood up and compressed it with the screw.

I wonder what will break or fall off on its maiden voyage.
Logged

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 19,090
  • Location: Peterborough, UK
    • Model Boat Mayhem
Re: Comtesse query
« Reply #26 on: September 22, 2009, 10:31:57 AM »


Can you drill holes lower (inwards) down the servo arm which will reduce the 'throw'?
Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

Sailmaker

  • Guest
Re: Comtesse query
« Reply #27 on: September 22, 2009, 03:02:08 PM »

I'm sorry if you are all gettin bored with this, why should I be the only one. Todays pre-sail checks continued the spate of disasters.

1, The transmitter died, this was your suggestion Martin, a broken battery box.
2, The main sail got stuck, the sheet had come off the pulley and jammed, good job it was at home.

It was as I said before the pulley is too high, with the servo mounted low down the rope angle was too great. It seemed there were 3 ways to sort the problem.

1, lower the pulley, impossible no access.
2, raise the servo, impossible no access and alter the center of gravity.
3, modify the servo arm, raise the rope by 45mm.

The picture shows the prototype effort. This as Martin suggested lowers the throw of the servo quite a bit.
I have re-tighened the sheets having moved the jib sheet as well and it seems to work well.

A note to Bugsy, do make sure the main sail runs true before sealing the cockpit as there is no access once you do.
Now a new transmitter box has to be made.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #28 on: September 22, 2009, 05:49:13 PM »

I set mine up by drawing up (on the plan) the angle of the rope entering and exiting the pully. I then set the pulley equidistant to those lines. As can be seen from my previous photo this involved lowering the pulley by about 8mm and angling it down slightly.

Another option SM, is to either cut out the existing pulley or, if not possible, obtain another. Mount it onto a spare piece of ply that will fit behind the bulkhead, pass it through and glue it in place. Difficult, yes, but if you're going to have the cockpit out to replace the servo mounts it would be worth doing, I think.

Good luck with it.
Logged

tigertiger

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,033
  • Location: Kunming, city of eternal springtime, SW China.
Re: Comtesse query
« Reply #29 on: September 23, 2009, 01:04:12 AM »

Another option would be a faillead with a tube that extends to the depth you need. 8mm no problem but 40+ would be a bit of an issue.

I like the idea of angling the servo, this way the pull tension is in the direction the servo was designed for, without any leverage effect.
Logged
The only stupid question is the one I didn't ask

Bugsy

  • Guest
Re: Comtesse query
« Reply #30 on: September 25, 2009, 07:58:16 AM »

A little mod I'm doing for the aerial wire using Macdonalds straws. Makes it easy to install and remove the receiver should you need to.

BTW The grey paint is overspray from the hull painting.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #31 on: September 26, 2009, 08:43:12 AM »

Sailmaker.

Just a thought regarding your sail servo problem, have you tried turning it round on the mounting. This moves the pivot-point further away from the pulley and makes the angles much better.

I know the plans show it the other way but it really does improve it.

Gary.
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #32 on: September 26, 2009, 08:56:03 PM »

Thanks Gary, I am unable to do anything with the radio gear now the cockpit has been glued down. The first sail is on Monday so I'll see how it goes.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #33 on: September 28, 2009, 07:19:50 AM »

Good luck with the first sail.

I've just done a trial rig of mine and am quite pleased with the result. I have decided not to fit any deck furniture but keep it simple. I just have to add some deck 'non-slip' patches, an deck edge line and a float to check the best location for the battery.

Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #34 on: September 28, 2009, 02:35:48 PM »

Very nice finish Gary, makes me jealous of your skill.
Anyway it was off to the lake today via a short Geocaching trip. It was generally light wind with moderate gusts.
The pictures show the Comtesse in all its glory.
There are a number of issues I am faced with;
1, Failure to sail in a straight line. The rudder trim was altered on one tack to improve the line only to find it wrong for the opposite tack, running nearly close       hauled.
2, Reasonable rudder control in constant wind but total failure to turn to Starboard when the wind increased or gusted. I ran aground twice because of this.
    The yacht seemed to decide what to do on its own and the only way out was to turn to port and carry on.
3, Both sails were not pulling equally probably just sheet adjustment.
4, Tricky to go about without sufficient forward motion, tendency to go into "Irons" then a  problem to move on.

The green flag is for the transmitter channel and to function as a tell tale.
All in all a succesfull first trial especially for a new sailor.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #35 on: September 28, 2009, 03:11:28 PM »

Nice one, and what a great bit of water.

Looking at the pictures I would advise the following:

Set the jib out more, from the pictures it looks to be in too much in relation to the main.
The jib also looks too tight for the wind conditions (but difficult to judge from a photo)

Rake the mast back a little from vertical say 5 mm and then try it.

Gary.
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #36 on: September 28, 2009, 04:25:12 PM »

Gary,
A question or two.

How far do your sails deploy at full stick and what is the rudder angle at full stick.

I have just noticed my sails do not go out more than a broad reach setting.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #37 on: September 28, 2009, 08:13:05 PM »

I can get the main to just touch the stays (full up + full trim) in that position the jib is also in full 'running' trim.

My rudder angle from straight is about 30 - 35 degrees, too much really.

I set my rig up (full down + full trim) with the main exactly in line with the centre of the boat and the jib able to move approx. 40 mm either side of centre. Mast vertical. Jib as low as I can get it.

I'll play with this setting when I get it finished and afloat  %)
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #38 on: September 30, 2009, 04:01:45 PM »

Thanks for the info Gary The problem I have, not enough sail travel since I shortened the servo arm. Looks like a re-fit job.
I took it out today in light winds and it became clear it does not compete well at all.
The clubs 1metre class were outsailing me in the light winds. The larger sail area helps them as well.
Still it's quite relaxing sitting on the bank.
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #39 on: October 01, 2009, 07:09:09 PM »

Because of the problems with the rigging I have dismantled everthing and removed the radio tray to re-posotion the servos and move the main pulley.
The pulley is now level with servo and with a smaller arm the travel is much better.

Can anyone tell me what sail cord to purchase to replace what Robbe supplied. I don't seem to be able to get the type Robbe supplied.
It's was 1mm cord that seemed to be plastic type.
Is it ok to use bottle screws on the mast stays because the Robbe design is difficult to adjust.
Thanks.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #40 on: October 01, 2009, 07:18:59 PM »

I put fishing swivels on the stays and that allows easy adjustment without the wire twisting.

Dacron fishing braid is what you need for running lines.

I've just made up a back stay as an experiment. Its adjustable and allows you to put bend in the mast as needed.

First trip out shortly, as soon as our visitors have gone  :-))
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #41 on: October 03, 2009, 03:23:02 PM »

I have re-arranged the servos and radio,  and moved the main pully to give more sail movement. So far it seems to be better.
In the light of all the problems I wish I had bought the Victoria instead.
Logged

tigertiger

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,033
  • Location: Kunming, city of eternal springtime, SW China.
Re: Comtesse query
« Reply #42 on: October 04, 2009, 01:46:44 AM »

Hi Sailmaker.

In answer to your questions.

The line for the sails sheets. 25kg Dacron from Sailsetc.com will do the job nicely.
http://sailsetc.com/fitrig.htm# product no D25. 20m spool for 2.25  :-))

How far should the sails be out. Well this is how I set up mine.
Stick full back and the trim also full back.
Main sail about 10-15 degrees off centre. If central she won't move anyway.
Jib about 5-10 degrees bigger than the main (i.e. 15-25 degrees). It needs to be offset further than the main (your picture looks the opposite),this creates a 'slot' for the wind to accelerate over the curved side of the mainsail increasing power.
Stick full forward and trim full forward should have you touching the shrouds.

Don't worry about the sail arm, you can make them out of a piece of ply or plastic. I think Martin used a plastic ruler on his sailer. ;)

Regards straight line running. Yours may have been affected by your jib setting trying to swing the boat around with too much pressure up front in balance to the rear. In effect she may be on the point of broaching.
Additionally, as she heels over the water will run around the hull profile. So if she is heeled hard over to the right, she will want to go left. This can be mitigated by a little bit of right rudder (this can be done with the trim). But if he is heeling over to the left, everything is revered (including the direction of the trim). Easily sorted  :-))

When you do the refit, go back as close to the manufactureres instructions as you can. The boat has been on the market for years, it has a good reputation  :-)), I think Robbe will have set it up nicely. I think it may be that veering away from the manufactureres instructions was the beginning of some of the problems you are having now.

But there is nothing major wrong with your boat. It just needs tweaking. ok2

Try resetting up your sails first and see how much better she sails.
To give you an idea of the improvements you can get with a longer sail arm try this. Set it up so that with the stick full back the sails are already out 30-40 degrees (jib a further 10 degrees out). This will give you a better idea of how well she will sail  when she is not heeled over heading into the wind, but doing a nice broad reach, and running  :} :}

Logged
The only stupid question is the one I didn't ask

Sailmaker

  • Guest
Re: Comtesse query
« Reply #43 on: October 04, 2009, 09:44:54 AM »

Thanks Tiger, most helpfull.
The biggest problem is that to use the full servo arm travel the servo has to be too far forward to clear the moulded cockpit floor with the stick full back
With the servo too far forward the arm goes beyond and under the pulley and the sheet jams. There does not seem to be a servo position to give full sail movement. In the manufacturers design the pulley is too high and the sheet comes off or gets jammed when the arm goes below it.
In my modified version that does not happen and the sails do go out further but not fully to the stays.
I cannot believe the someone has not noticed this before. When I mailed Robbe they were very dissmissive to me about any problems with the excuse they had been manufacturing the kit for 30 years.

I think the only real option is to use a sail winch which will overcome all the sail problems.
The boat does heel alarmingly in moderate wind  whereas the IOM boats do seems to have a lot more stability.
EDIT,
I just had a thought, lengthen the arm 25mm that will do it.
I am interested to know how you get on Gary when you sail for the first time.
Could you post a picture of your radio/servo installation please.
Thanks.
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #44 on: October 04, 2009, 10:34:06 AM »

Problem solved, an extra 25mm on the servo arm and full sail deploy.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #45 on: October 04, 2009, 11:00:07 AM »

Sorry its a bit out of focus but it shows the layout. Battery pack is temporary as I'm waiting for a NiMh pack to arrive.

You can also see that I have modified the dacron attachment to the sail-arm, by bolting the 'S' ring loosely on the top. This gives a much neater fix than hooking the 'S' ring through the hole in the sail-arm and allows proper movement.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #46 on: October 04, 2009, 11:14:18 AM »

A better picture of the connection. (M3 bolt with Nylock)
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #47 on: October 04, 2009, 02:19:48 PM »

Really neat job, I can see that your servo position is far the best way to do it.
Thanks very much.
Logged

Bugsy

  • Guest
Re: Comtesse query
« Reply #48 on: October 08, 2009, 03:36:05 PM »

Well, visitors gone (finally) so off to our village lake for a sail. Arrived to be greeted my a nice breeze in my face which brought about 'the' smile.

Unloaded the car and set up on the bank and blip, the wind had disappeared.

Sat there for a while with a fag and a can of coke and watched the wildlife.

Eventually a bit of a breeze, enough to get it wet, anyway.
Logged

Sailmaker

  • Guest
Re: Comtesse query
« Reply #49 on: October 10, 2009, 06:45:47 PM »

This is a note for Gary,
Had a 2 hour sail around the lake today in a good breeze, sufficient to put the boat on its side a few times.
The modifications have worked a treat, full sails deploy  completely straight line when running and reaching.
No problems going about, just let the jib out a fraction and around she goes.
I have a short MP4 video to post somewhere, I suppose it needs re-formatting for uploading somewhere.
Ran aground  once while munching at the same time and not concentrating.
Today was club racing day and I seemed to be doing well for speed compared to the larger sail areas on the IOM class boats.
So this is the end of this topic, it turned out fine in the end.

Logged
Pages: 1 [2] 3   Go Up