Detrmination of the correct size of blocks and ropes for your model

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Dear Modelers,

Based on previous request HERE, I decided to make this topic and share with you slightly modified version of the text from my
website where you can find the infromation about size of blocks and ropes for models, whose calculation can be found in the attached TABLE - sizes of blocks and ropes.

One of the basic elements of a good model of historic ships are blocks for rigging. It is relatively difficult to produce high quality blocks, especially in larger quantities. That is why our company HiSModel produce and offers top-quality blocks from walnut wood on CNC machine. We produce a wide range of blocks in sizes from 2 to 12 mm. Standard single, double and triple blocks are available in sizes from 2 to 10 mm. Moreover, we offer violin, ramshead and heart blocks in sizes from 4 to 12 mm. Deadeyes we offer are from the production of Amati company. The dimensions and marking of blocks are in the attached table. We produce blocks, which correspond in shape and size to the British standard around the turn of the 18th and 19th centuries. We are also preparing to produce a second set of blocks that will match to the continental standards according to ANCRE.

For right choice of blocks, it is important to know which, where and what size of blocks should be used.
The best way to determine the right sizes of blocks is to use professionally prepared plans. If you do not have this option and you are unsure about the block sizes you need for your model, you can use an attached table. The table is based on information and tables from the book “Historic Ship models” by Wolfram zu Mondfeld, from pages 272 and 308. You can download the table with calculation of ropes diameters and blocks sizes HERE. In this Excel spreadsheet you just simply enter the required scale of the model and the actual diameter of the main mast on the main deck. All dimensions of ropes and blocks are calculated based on this table.


Based on the above mentioned sources here is the method to calculate all sizes of ropes and blocks (similar text you will find in the afroementioned table):
The starting value (parameter) is the diameter of the main mast in the plane of the main deck from which we derive the diameter of the Main Stay. Diameter of Main Stay is 0,166% from diameter of main mast in the main ship deck point. And the Main Stay diameter is 100% for calculation of the thickness of all other ropes on the ship. These values are variable based on historical time and nation. In the case of a mainstay made of steel rope, the values in the table above are still based on the use of hemp rope. Each rope diameter also corresponds to a certain size of blocks (according to tables - these was based on experience of the ship builders and subsequently the national regulations came out of them). So based on rope diameter you find out also in my table which block size you should use.

In order to make the use of blocks easy for you, I am preparing ready-made rigging plans for you according to the original documents. There are recommended blocks drawn according to clear symbols in these plans. You can find these ready-made plans for individual models together with other accessories on my website HERE. You will find all the sizes of the needed blocks in my plans. And based on the table above also corresponding diameters of ropes.

I will add some more infromation about building of ship models in the future.
If you have further questions, write them here on our e-mail. I wish you beautiful models.
 
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Hi. Can someone explain how to measure a thread diameter for rigging? For example the spreadsheet says that for 2mm high blocks we should use 0.16 mm rope (thread). Do I measure just with caliper? But how accurate is it going to be when thread is soft and gets deformed by applying a caliper?
 
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An easy way to measure string and rope diameters. At the very tip about 1/4" put a tiny drop of CA let it harden naturally do not touch the end, once hard you can measure it. drag it across something to remove any excess if you put on to much

Another method is to compare it side by side visually to brass wire get as close as possible if your off a hair one way or the other no one will be able to visually see that
 
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Another method is:
For example, you wind ten turns of thread close together, and then measure the width of the winding. And final width divide it by ten.
This is the most accepted method for measuring the diameter of the thread. I've been using this method for a long while.
Janos
 
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wouldn't you still be able to crush the winding? also how much you wind determines size so if you do a loose wind its larger a tight wind smaller? Just trying to wrap my head around this method. if its better then mine I always willing to try and improve and will use it
 

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wouldn't you still be able to crush the winding? also how much you wind determines size so if you do a loose wind its larger a tight wind smaller? Just trying to wrap my head around this method. if its better then mine I always willing to try and improve and will use it
Joe, this method works well, specifically on very thin ropes. The key to success is to wind as close as possible (10 times), obviously, it shouldn't be loose, and you can use any dowel.
 

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ok so wind around the dowel close wraps then measure the width of the coil divide by 10? using something to wind around was the missing key for me if this is correct. I pictured trying to hold the wraps in my fingers
Yes, that's correct. You can use even a finger, But if you need more precise measurements, use a dowel.
 
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Yes, that's correct. You can use even a finger, But if you need more precise measurements, use a dowel.
All good advice but my question is, "how much accuracy are you seeking: historical or visual"? That may make a difference and a few thousandths may not be visually noticeable but trying to thread the block may be of something that you may have more preference let guide you. Just some thoughts. Rich (PT-2)
 
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It is not really the exact diameter of the thread which counts. Rather the ratios between different lines and the corresponding blocks make a different look if they are correctly done. It is very disturbing to see if ie. the ratlines are done from the same diameter as the shroud or if the stay is thinner than the shroud. And the size of the block is determined by the size of the line going through it, very much oversized or undersized blocks ruin the accuracy of the model. And don't use a block for a cannon the size of which is 3 times the diameter of the truck, etc. etc.
János
 

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All good advice but my question is, "how much accuracy are you seeking: historical or visual"? That may make a difference and a few thousandths may not be visually noticeable but trying to thread the block may be of something that you may have more preference let guide you. Just some thoughts. Rich (PT-2)
It is not really the exact diameter of the thread which counts. Rather the ratios between different lines and the corresponding blocks make a different look if they are correctly done. It is very disturbing to see if ie. the ratlines are done from the same diameter as the shroud or if the stay is thinner than the shroud. And the size of the block is determined by the size of the line going through it, very much oversized or undersized blocks ruin the accuracy of the model. And don't use a block for a cannon the size of which is 3 times the diameter of the truck, etc. etc.
János
I guess, Janos @janos explained. Thank you!
 
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Again, I must emphasize, keep in mind that the table is not a dogma. And the diameter of the rope in hundredths of a millimeter is only based on a calculation. Based on the rope diameter, you deduce the size of the blocks on the second page of the table. At the same time, you adapt the rope diameter to the closest possible rope diameter that is available. That is why I also state the diameter of the ropes that I offer from the Amati company. And certainly there are other manufacturers who offer other different diameter ropes.
And those of you who make the ropes themselves certainly know how to measure their diameter.
Regarding the suitability of the size of the blocks diameter. For example, for hoists of guns on the HMS Victory 1:100 model, blocks with a size of 2.5 and 3 mm are suitable. Based on my offer, these are blocks with the designation: single blocks WaB-SB1/2,5 or WaB-SB1/3. And double blocks WaB-DB2/2.5 or WaB-DB2/3.
Next time I will bring you information about the size of the blocks for the HMS Victory model based on historical tables from the book The 100 guns ship Victory.
 
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