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Author Topic: Seabex one crane help  (Read 1582 times)

MrD1963

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Seabex one crane help
« on: August 15, 2021, 07:19:02 pm »

Hello All
I have a seabex which requires the crane to be re strung. Any pictures of the pulleys or advice on stringing to allow the jib to be raised and lowered via the motor drum already installed.
Thanks in advance.
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Andy M

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Re: Seabex one crane help
« Reply #1 on: August 16, 2021, 10:48:36 am »

Hi, I noticed you havent had any replies to this. I dont have any experience of the seabex crane but I am scratch building a crane for my four ways cargo ship so might be able to help you work it out. Could you post a photo or two showing the crane?

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MrD1963

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Re: Seabex one crane help
« Reply #2 on: August 16, 2021, 03:19:13 pm »

Hello Andy M


Thank you, I will attempt to photograph and post. I’ve been looking at YouTube videos of various other seabex and some have a single line, which may work. It has two sets of pulleys, a twin on the main body with another twin on the boom around two thirds up. I don’t mind how it is done as long as I have the ability to raise and lower the boom via the motor drum which had the string attached.


All the best
Michael
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John W E

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Re: Seabex one crane help
« Reply #3 on: August 16, 2021, 05:36:26 pm »

hi there


I know this is not the exact crane for the seabex - it comes from the Seaforth model which I built.  This is very similar.


The way I managed to operate the movements on the crane on my model was through 3  servos.  These rotate 360 degrees.   I purchased the 3 servos from Ebay.    One large standard servo which fits under the deck and it drives the actual crane through a gearing system - this slows the movement of the crane down.   I think it is about a 10 to 1 ratio gearing. 


Built into the actual structure of the crane body there are 2 small mini servos.    These have small aluminium drums which are made from washers and aluminium tubing.     One servo lifts and lowers the jib and the other servo lifts and lowers the hook.


I did try and take some decent photographs of the rigging of the crane but I found its the most difficult thing to get clear shots of.  Some of the photographs I will try and improve on; you would think a drunken sailor had tried to take the pic - but these pics are the ones I took during the building of my model.


John
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MrD1963

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Re: Seabex one crane help
« Reply #4 on: August 16, 2021, 06:46:28 pm »

Hello John
That’s a very fine looking boat. Excellent work on the crane, I may just pinch that idea. I’ve been playing with the rigging and I can get it to work in a couple of different configurations, I am just concerned that without using the right number of returns / pulley wheels I might burn out the motor or controller.
Michael
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John W E

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Re: Seabex one crane help
« Reply #5 on: August 16, 2021, 07:11:15 pm »

hi there


if this works - here is a quick scribble of how the jib works. 


One servo (we will call it the hook servo) the cable comes from the hook servo drum, over the top pulley and out over to the pulley on the end of the jib.    It goes straight down to the end of the hook.


The 2nd servo (we will call it the jib servo) the cable comes up, out off the drum, over the top of a 2nd pulley on the top.   Then out over to the jib around the 2nd pulley and back towards the first pulley and is made fast to a securing point.


I do hope that is clear.


Now, a couple of things to consider (which I myself found out).   With these types of vessel, we have to be very careful of the weight we lift.  Very small weight.    We are going into grams.     The reason for this is, as we swing the jib out over from the vessel - you will see that the vessel will begin to tilt - and it is alarmingly in some cases.  Sometimes even moving the jib of the crane off centre of the vessel will cause the vessel to list - so I strongly advise sticking your model in a bath/test tank and play around with the crane before actually committing the model to open water.


I have an idea, which I may experiment - whereas using a 2nd servo in the vessel with a counter-weight on it.  The counter-weight will move in an opposite direction to the crane jib.  Thus counteracting the list.   As I say, this is in the experimental stage, don't know if it will work or not.
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MrD1963

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Re: Seabex one crane help
« Reply #6 on: August 16, 2021, 07:54:08 pm »

Thanks John
The crane will only be used occasionally and I have a couple of ultra lightweight boxes ( containers) of a few grams. In the test tank there was no real list with the jib extended outward. That is with the current motor arrangements. I will let you know if this changes once it’s rigged and with my load attached.
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Freshwaterdiver1

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Re: Seabex one crane help
« Reply #7 on: August 23, 2021, 08:51:51 pm »

Hello All
I have a seabex which requires the crane to be re strung. Any pictures of the pulleys or advice on stringing to allow the jib to be raised and lowered via the motor drum already installed.
Thanks in advance.
Hi MrD1963: I have a Seabex One which is the original from 40 years ago undergoing a refit this past 12 month.I also have the original plans for her - thank G. i kept them!!
I see you have already roped / chained up the Crane from what i see but will add the photo here from the Original 1980s plan as it may help someone out there.
Your ship is coming along fine.

Kind regards to all
This Verification is painful - dont have time for it guys :-(
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MrD1963

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Re: Seabex one crane help
« Reply #8 on: August 24, 2021, 07:06:21 pm »

Hello Freshwaterdiver1
Thanks for the message, I have managed to sort rigging of a kind which seems to work. My seabex if not one of the original kits certainly has age to it. Most of the plastics have colour faded, the electronics were old futaba units, switches and miles of wiring.
I will post a pic or two when it’s presentable, at present it’s in pieces all over the shed…
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Freshwaterdiver1

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Re: Seabex one crane help
« Reply #9 on: September 01, 2021, 10:28:08 pm »

Hope i can get these photos uploaded from my PC - here's fingers crossed.
Guys i get a picture of the Titanic and asking for my User name and Password - but it says wrong password / User name ?!
Is this a separate password from that used to log in ??
How do i upload the photos from PC please?

Club members boats on the tarn  :-) https://www.youtube.com/watch?v=CdXSV2pfBS4
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derekwarner

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Re: Seabex one crane help
« Reply #10 on: September 01, 2021, 11:16:31 pm »

Thanks for sharing the video FWD1........impressive pond and great to hear some laughter......that Red Rocket 'Universal' appeared a little twitchy  <*<
There are a few links to uploading photographs....some kind would will provide these
Stick with the log-in protocol...it won't last long...and certainly keeps the unwanted out  :-))


Derek
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Derek Warner

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Re: Seabex one crane help
« Reply #11 on: September 02, 2021, 10:09:06 am »

Thats the wrong thing to say - Not the unwanted - the less committed  O0
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Freshwaterdiver1

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Re: Seabex one crane help
« Reply #12 on: September 03, 2021, 10:43:33 pm »

 {-) {-) {-)
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Freshwaterdiver1

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Re: Seabex one crane help
« Reply #13 on: September 03, 2021, 11:34:24 pm »

Hope i can get these photos uploaded from my PC - here's fingers crossed.
Updated got the photos uploaded to mayhemimages:

Seabex Crane Plan" border="0
Down at the tarn during a club sail end of August 25th v2" border="0
DCIM\100GOPRO\GOPR5034.JPG" border="0
Seabex in the Dry Dock lol IMG 0008" border="0
DCIM\100GOPRO\GOPR5087.JPG" border="0
DCIM\100GOPRO\GOPR5089.JPG" border="0
Club members boats on the tarn  :-) https://www.youtube.com/watch?v=CdXSV2pfBS4
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