Rhino dislikes anything that is multiples of a shape even a bolt thread let alone an array of them

I have a bolt with nut, the thread is obviously a repetitious thing that Rhino dislikes. I realise Rhino might not like what I am about to do.

I have to make a ring of 40 of these items that are already causing brain ache in Rhino, I think oh oh need to try block instance, which I never can seem to get on with, I cant change colour of it for example, and other things, like layer allocation. I end up wishing I never used it.

I brave it. Create a polar array of 40 bolts and nuts. A few weeks later I need to alter its location and length, selecting one it says block instance, one should work with the master not the ‘offspring’,

Q1.how do I find the master, it might be one of the 40 in the array polar. ?
I need to alter it, see offspring all update hopefully then do a new array polar with it., so delete the array and do a new one.

Q2. Should the master be created elsewhere in the project or in one of the array positions before array is done ?

I now need to remove the bolt head, and array polar a stud and nut instead.
I go to my nuts bolts file and copy paste such in, and wait 30 secs for it to appear. Thats a bit worrying, very simple project so far with only a few objects, yet I get that.

In itself a bolt thread is a repetition that Rhino dislikes.
Is this dislike of such standard in the CAD world ?

Q3.How do I find master of a blockInstance ? I tried block instance manager but couldnt see a way of finding it to edit it, replace it with the larger sized headless bolt/nut I pasted in and relocate it for the new array. Can one in fact replace a master with a new object and see the instances become the new item ?



Hi Steve - Use BlockEdit and pick the most convenient instance to edit.


To edit a block you have to double click an instance (you don’t need to find a “master”).
After editing the block instance, all the other instances will be updated.

Edit: doh! Pascal is too fast… :sweat_smile:

You can use replaceblock command.

Thanks I will give it a try, .
Should one be able to move instances to a different layer or alter their colou once made ?
I seem to come up against barriers to doing thus when normal objects not a problem.

Also should one use instances when making a bolt thread, take one revolution of the thread and instance it, bet thats fun do do… as Rhink dislikes anything repetitious it seems, especially circular.

As asked is this normal in the world of CAD, are all progs needing block instance etc ?


Yes, you can put the block instance in different layer and use them like other objects in Rhino (if you turn off the layer the block instances will hide like other objects).
Remember that the object’s properties (color, isocurve density, materials etc.) are inside the block definition.
Attached a file with some block instances that are on different layers (also the objects in the block definition are on different layers).
Give it a try turning on/off the layers to see how Rhino show/hide the block insances and the objects inside the block instances.

Block_LZ.3dm (117.3 KB)

Yes, you can make nested blocks (blocks that are inside other blocks).
For example you can make a big assembly joined as a block and each part inside is a block made of other blocks… there’s no “limit” (until you don’t nest too many objects and the thing become a mess to manage).

Well, yes, “blocks” are used by multiple cad programs and are very useful for big projects (they take the file’s dimension very small) .
The only problem is that Rhino has a very old Block manager that need to be updated to work easily on nested blocks and to be more powerful in block editing (there are a lot of threads where users ask a better block management).

Note that you can control also the material of objects inside blocks to some extent. Before creating a block of an object set its material to be controlled by the parent (Use Object Parent)


Once made into a block you can put different instances on different layers. Set the block instance material either directly or to layer material.

See the attached file. It has three block instances of the same block. The block has the box with material set to Use Object Parent. The block instance is now the parent for that box. Whatever you set to the block instance as material will be used for the box.

blockinstances_material_controlv6.3dm (186.1 KB)
blockinstances_material_control.3dm (186.1 KB)


For embedded blocks all instances are equal, no master.

But if you like the idea of a master, you can create your block in an external file and then place it as linked instances in your drawing. If you try to edit one of the instances a new copy of Rhino opens to edit the master.

The big advantage of an external block is that it can be used in any Rhino model.


thanks Lucio, I will explore when I get 5 mins.
Nathan, they are not opening in V5. can you backwards export them ? ( I have v7 but no win10 as yet)
Jeremy, makes sense though just pasting an array of 40 bolts/nuts saw me have to wait ages whilst the paste came into a blank file, 2.7Mb for 40 instances of 1 bolt/nut I fear the project is dead before even getting going.
Jumping layers, understanding how to change colours, they dont seem to be intitive, I need to take time out and simply experiment.

why is it that 40 same items can cause rhino processing problems when 40 different items dont do so ?

If one created each of the 40 separately would that be better than copy command ?


Hi @Steve,

Here is a Rhino 5 file with 40 instances of a bolt block and 40 instances of a nut block, plus Rhino 5 files for the bolt and the nut “masters”. On my six year old laptop there are no noticeable performance issues. Rhino seems perfectly happy, threads and all.

The two masters have been edited to use their parent’s Display Color (blue in this case) and Material (silver metal) as recommended by @nathanletwory . Take a look at the file and see how the model and the masters display differently.

_T_1-8 Hexhead (Length 6).3dm (3.0 MB) _T_1-8 nut.3dm (316.3 KB) 40 Samurai Bolts.3dm (114.1 KB)

The bot and nut were produced using Boltgen. I removed unwanted options from the nut (it generates a threaded nut, an unthreaded nut and a thread cutter for making threaded holes).

I would recommend using Export Selected rather than Copy and Paste. The former, (having done Select All), produced a new file of 111 KB instantly. Attempting to Copy and Paste into a second simultaneous instance of Rhino 5 locked up on the paste. Pasting after closing the original and creating a new empty file produced an instant copy, but messed up the nuts’ layer display settings (but not the bolts’).

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