Author Topic: Imara /Perseverance new thread 2016  (Read 5982 times)

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Toby

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Imara /Perseverance new thread 2016
« on: November 27, 2016, 17:51:13 »
Hello everyone

Just having a change from Danube and getting  and old second-hand Imara kit dusted and underway and trying to decide whether to build it as Imara or Perseverance.
I have looked through all of the posts from years ago but wonder if any pictures and info are now available or is now willing to be shared (even privately) as well as pictures of members Perseverance models and the differences to Imara.
There was certainly a lack of info etc back then.  Anything come to light in the interim?

What is the colour of the boat under the RN use?

What are the latest brushed motors (twin independent) being used as Graupner and Actions seem no longer to do 900bb and equivalent respectively which some had been using successfully.
Probably need what about 5000 rpm per motor? 6v or 12v?
70 mm brass props?  4 blade or 3 blade to be correct?

Any tips etc gratefully received as always.
Those with a Perseverance I should be glad to see photos of the changes.
But equally interested in modifications or corrections needed for an accurate Imara.


Thanks in advance.
Toby

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #1 on: November 27, 2016, 18:00:21 »

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #2 on: November 27, 2016, 18:13:50 »
http://www.clydeships.co.uk/view.php?ref=7579

The photo on this Web page seeks to state  Imara as Perseverance but is there not a mast missing?

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #3 on: December 02, 2016, 19:52:42 »
Hello

Can anyone tell me whether or not the oval (Panama? )ports should show riveting around them or were they fastened differently.

Also the large rectangular wash ports should they show evidence of riveting and how does the flap operate. Presumably hinged at the top but were they free to flap about (and drive all aboard mad with the noise) or did they have fastenings. Could they be locked/propped open? If so how?

I note that there is evidence of an occasional rivet above the rubbing band but surely there must have been more rivets holding the angle on to hold the rubbing band.

Toby

There seems to be a problem of uploading picture to the forum at the moment.  UPLOADED  NOW  DEC 5th
« Last Edit: December 05, 2016, 11:22:50 by Toby »

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #4 on: December 04, 2016, 18:34:03 »
.
« Last Edit: December 04, 2016, 18:40:13 by Toby »

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #5 on: December 05, 2016, 11:17:40 »
Prop shafts and stuffing tubes replaced as those enclosed would only serve to be an inlet via which the hull could be flooded as soon as the boat went for a swim.

The model is listed as 1:32 and so am curious as to the planking sheets for while the width of the planks is close, the length appears to be over scale of the standard 12ft x6" x 2" plank.
1:32
so 12ft x12" =144" 32=4.5" ~ 114mm
      6" ~ 154.2mm 32 = 4.76mm
      2" ~  1.58mm

Also were the ends of planks actually tarred like the length of the plank?
There also seems to be variations on the layout of the photos online day anything.  Anyone have the definitive arrangement and positioning of planks?

A quick mock up of one of the companion ways confirms that no thought seems to have been given as to direction of grain or the fact that the ply used has open grain giving a vulgar appearance.
Do I assume that others have got out their veneer and scalpel to rectify  these problems and the over all appearance?


« Last Edit: December 05, 2016, 11:38:41 by Toby »

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #6 on: December 15, 2016, 16:35:24 »
Looking at the molded superstructure I note that some windows and doors etc when fitted will effectively 'cut through' the riveted panel lines. Is this correct? Were say windows placed so,  were the struts to which the panels were riveted cut at such points. If so did the riveting divert about the edge of the window?
Perhaps Jotika has just put rivets anywhere for effect rather than a correct or more likely position?  With the amount of effort most modellers or in I cannot believe others have not pondered this matter. Have other builders of this tug whether as Imara or PERSEVERANCE made changes?
Toby

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #7 on: December 28, 2016, 09:59:21 »
Prop shafts in.
Props balanced using the Dubro balancer.
Shafts from Model Boat Bits 8mm o/d Tube with 5mm shafts.  Super shafts/tubes with bronze bushes and oil filler tube.

70mm props from Maritime; left and right hand as this is twin screw version.  Props set for inward ie top turning inward. Trust this is correct.

Rudder set -up. Rudder shaft brass.

The keel support for rudder : I have drilled out a hole and inserted a brass tube into the white metal support. Could not imagine white metal lasting very long as a functional piece.

The supplied white metal support has a rod- like lug on the end which is to be inserted into the keel end.
The hole in the keel was very much larger than the lug and so was bound to let in water and sink the boat in minutes. Not sure why this was the case. 
As this support prevents rudder removal, thinking ahead I thought it best to fashion something to make the removal and replacement easy should the rudder need to be removed. 
To solve this problem I thought a metal insert sealed in situ would be best and most secure; watertight. 

I waxed the lug with hand cream for I could not find a candle. I then inserted the lug into a copper tube which was a good fit.
Next I put the rudder support in position on the keel and taped it in situ.
Then I mixed some epoxy and filled from inside the hull the area about the lug. Once this was set I was able to remove the support because the cream had prevented the epoxy sticking to the lug and support edge; but held the copper tube in place with the end sealed too. This left a perfectly shaped edge to the keel and a sealed copper tube into which the lug on the support could be inserted and removed at any time and without the need for re- sealing each time, when the rudder needed to be removed or repaired. Simple and effective.  Will not damage the consistant, watertight and accurate locater for the rudder support.




Toby

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Re: Imara /Perseverance new thread 2016
« Reply #8 on: December 28, 2016, 10:17:14 »
Now to consider a watertight method of holding the rudder support in position.
Once the support has been seated into the tube and against the keel the only way to hold in place appears to be too screw up through the support and up into the keel.
This seems simple until thinking of keeping it watertight.

I am wondering whether to use a tubular insert with an internal thread and sealing and fixing in place with more epoxy. This would mean that the screw or bolt used could be screwed and unscrewed with out affecting the watertightness of the keel.  Applying the same principle the bolt could be waxed and so epoxy could be used to fix insert and seal the end of it. Using a longer bolt than required at this point will mean effectively that a gap will be created between the seal at the end and the end of the bolt so that any over-tightening will not break the seal. Perhaps the water would not make any ingress via the threads but........

Any thoughts?


« Last Edit: December 28, 2016, 15:36:59 by Toby »

west coast tug

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Re: Imara /Perseverance new thread 2016
« Reply #9 on: December 28, 2016, 10:51:32 »
Your method sounds good , How strong is the hull in the area . Will it become the week link if it gets hit .
I normally back fill the area with resign and in tomb the bolt from the in side with a washer and nut inside.This makes it not removable .
A keel made from soft wood balsa is a problem waiting to happen again , Glass on the outside would be the only strong point, But if its a ABS hull.The strength is from the bulk of it .
For it to be removable your method sounds good .
Gary

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #10 on: December 28, 2016, 11:43:49 »
Hello Gary

It is the 'fiberglass' hull of the kit I am using.
I would not say the kit is worth the money so far and so glad I found this second-hand one for 1/3 of the price. Once faults have been addressed then much of the detail lost has to be restored.

Because of the thickness of the 'fibreglass' the blue line represents a supportive block of wood to be glued in situ at the same time as the insert.

I am considering filling the area with lead shot and epoxy not only for strength and weight but also for stability in the water. Likely do similar with the bow. 

In my other models I have found it better to have weight throughout the model rather than just a battery or similar in the centre of the boat.  I believe it gives more resistance against the effects of the full-size water characteristics it is sailing in.

I am not sure what to do with the a-frames for the prop shafts. Those supplied in the kit are not even closely similar.  They look very Heath-Robinson.  Also I find it hard to believe that such components on the full-size boat would be held on by one 8 1/4" headed bolt either side.


Had anyone else revamped the a-frames for this model?

I shall hopefully fix in the insert tonight.

Toby

des

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Re: Imara /Perseverance new thread 2016
« Reply #11 on: December 28, 2016, 14:00:32 »
Hi Toby

I noticed that you have set up your props as inward turning - the tops of the props revolve inwards when travelling forward.  This is likely to give you some instability while trying to steer in a straight line, and especially when trying to steer while travelling in reverse.  I have never seen either a real boat, nor a model, with props turning inward - I read a paper on-line, probably a tear or so ago, about why this should never be done unless there is some over-riding reason to do so;  unfortunately I don't remember where I read it.

Fix is relatively easy - just swap your props from side to side, and reverse the wiring to your motors to reverse the direction of rotation.  (I am certain that a tug would have outward turning props - even early steam era tugs.)

Happy New Year to you.

Des.

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #12 on: December 28, 2016, 15:18:41 »
Hello Des
Good to hear from you. Clearly I had better research this prop matter in order to understand the difference in the water.  I have heard about the comment that one way the ship is drawn down to the water and the other way lifted up and also that one way gives better speed and the other better stability.

I will look on the forum to see what has been covered before on the topic and if nothing perhaps had better start a new topic about the matter.  It is all very interesting.  For presumably one direction may give better control when docking with props for I assume it is impossible to dock with the rudder use as there would be no water flow to make a difference unless one was propelling astern and then the rudder would need to be dead set neutral.
« Last Edit: December 28, 2016, 15:24:34 by Toby »

Toby

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Re: Imara /Perseverance new thread 2016
« Reply #13 on: December 28, 2016, 15:29:43 »
Stuffing tube A-frames.
I am not keen on these white metal parts for they are not identical and not the same size. Rather poor for a supposedly top range kit; by price tag at any rate.  I cannot believe either that this important piece would on the real boat be only held on with the equivalent of 2 x 8 3/4" bolts.

What have others done with these white metal parts?

« Last Edit: December 28, 2016, 19:04:04 by Toby »

2tugboats

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Re: Imara /Perseverance new thread 2016
« Reply #14 on: December 28, 2016, 16:30:31 »
Good posting and information Toby. Here is an excellent prop information
site that has pictures of how twin props should be mounted.

http://www.action-electronics.co.uk/pdfs/Twins%20Ver2.pdf

Michael
Yet another case of why men and women go down to the sea in ships. . .A pleasure to be here and smell the salt air. Thank you Tugboat Forum. . .Michael in Anacortes, Washington www.twotugboats.com