Bolt created on grey layer jumps to beige 40 instances 3Mb why?

I am trying yet again for block instance as even a simple bolt/nut made as an array of 40 is seeing another different bolt/nut (never ever a block instance, its spirals are not block instance), pasted in take 30 secs !
(should a bolt be made of block instances ?)

I place the pasted in bolt/nut on a grey layer ‘FINAL BOLT STUDS AND NUTS - master for block instance’,
I then block instance it and make a polar array.
Later I select one of these grey bolts, they dont go yellow (my selection colour) so I cant see it compared to the items I need to compare it to,.

I need anything I select to use my selection colour of yellow for the curves etc. To have no indication of selection is surely against chapter 1 verse 1 of using Rhino !

Secondly its showing at bottom of screen layer data as being on a beige layer ‘gasket bolt area’, yet it started life on grey layer and I havent moved it at all, I made the grey layer for it.

I just dont get these block instances and dont see the cause and help I need in the pages on them I am referred to.
I only try them because of the horrendous slowing down of Rhino caused by 40 bolts.
but spend hrs trying to do the basics with them. They are not intuitive at all.


Dunno if this is of any use-


I just read that seeing an old post of mine and found nothing to explain it.

so sorry but no.

can you select a block instance and see it selected ?

does your master jump layer when BlockInstanced ?

here it is copy pasted out to a new file, and now it selects yellow !!!

this took many seconds to paste in, why should 40 block instances start a new project into sloMo mode ??

its supposed to be ‘lightweight’ saving on resources, not cause CPU to have a headache. If I start a project with this, hate to think what will happen as I add rivets, rivet holes, bolt holes and all sorts of other things. it wont work will it.
I see its 2.7Mb how can 40 instances be 2.7Mb when 40 other objects are kb ?

I have three or four variants of these in the project, no wonder its taking forever to save.

Does V6 handle such better as my projects are going to see loads of bolts, rivets and nuts. washers and so on. I fear DoA or is that DaB (dead at birth).

it still though is a layer I never put it on. its supposed to be grey on the grey layer,
bolt block instance.3dm (2.1 MB)


One bolt’s worth of geometry uses roughly a megabyte of runtime memory, increasing towards 2 with a render mesh. All 40 makes a file on disc of about 2 MB. Without threads, the 40 instances file saves to about 230 k.
Do you really need all the threads?

@Steve1 - will this work?
bolt block instance_PG.3dm (216.8 KB)
@Steve1 - updated to include a layer that you can turn on when you want to see where all the bolts are.


afraid so, else I have cylinders in cylinders(their holes), I cant see clearly , neither can clients, where the bolts are, in wireframe or make2d etc.
Surely a CAD prog should work with bolts ?

and why has this bolt jumped layer ?


Not really there’s no actual need unless you’re actually milling oddball threads. Most MCAD systems just work with simplified drafting-style representations or use crude textures. You are absolutely putting too much effort into this.

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Its so I can see where the bolts are, else i have cylinders in cylinders in other shapes, its all a jumble when you have an array of them. I am trying to work out the hole size used, spacing, and distance from edge of an object armed with rough photos and 80 yr old drgs, so to at least see the bolt is VERY USEFUL/ESSENTIAL.let alone show the client there are bolts there. in a B/W 2D drg the bolts wouldnt show at all, a screwthread immediately shows where they are. as was the case in the drgs I am peering at, albeit blurred and pixelated.

I always thought CAD could show bolts as bolts.


Did you look at my last posted file above?


Hi Pascal,
aha thats a thought, spiral,

ok will consider that.

I love accuracy so seeing lovely bolts looking like bolts , project looks good, however as its impact on saves and speed is awful, spiral it must be.



sorry if this is unrelated, but I share this trick every time anyone mentions any type of fastener…

mcmaster carr has a way to download almost any fastener in their catalog.

drill down on the parts you want and look for the cad icon… this takes you to a detail page with a drop down where you can download that exact part. Use the Step format and they come in perfectly… works great for making threads via boolean, etc, etc…

I haven’t modeled a fastener in 10 years because of this.


Think about it. It’s exceedingly rare to actually “need” real 3D threads. Even modern computers are easy to bog down with this level of detail while people have been doing this CAD thing since…the 70s. And people doing mechanical design who do a lot of fasteners usually need a LOT of fasteners. So no they generally don’t.

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So select group and change its layer. Fixed.

Post the file where it doesn’t work, then maybe someone can explain why.

its done it again, layer created for the block instances is light blue, yet the block instances are showing on a different layer ‘default’ when selected, its jumped to the active layer it seems, I have now managed to select the instances and put them to the light blue layer, though they refuse to change to the colour of that layer so not much gained as I need them that light blue colour.

How do I make a block instance take on the colour of the layer it should have been on to start with when moved to that layer ?

Unable to post file here as valuable and confidential.


Select just all the block objects and run Export Selected to create a separate file. A bunch of bolts on their own can’t be that valuable!

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I wondered if taken out of context and influence of the whole file it wouldnt be the same.
However here are the one set of bolts on a layer I then wish to be magenta, but they remain grey.
also with them is a curve which if copy pasted to this file takes 9 secs, why ?

I also posted this slow paste issue to another thread Pascal replied to with ClearAlMeshes which worked in speeding up open file from 30 secs or longer to a few secs, but the copy paste issue remains, a simple little arc then takes 8 secs, and that file had used export selected, it didnt leave behind the slow issue revealed in a copy paste.

export selected method is ok but as soon as I need to bring another item in, it gets clunky as yet another file is made for one small detail, I end up with many files each with a small item or curve etc, and opening that file is not whats needed I need to import the file then that small item is brought in.

bolts on black layer changed to magenta.3dm (2.3 MB) copy paste from file to itself too slow.3dm (1.5 MB)


I do not know why your bolt blocks do not pay attention to By parent display color in V5 - if I make a new one from your geometry, with the components set to by parent, it works as expected in V5.


I find that if you make the block’s layer current before creating the block on that layer, the layer colours can be better controlled.

V5 Bolt Ring.3dm (2.1 MB)

Your file has a whole lot of embedded picture frame images which is probably causing the copy/paste slowdown?


Hi @Steve1,

When you created your first stud and nut you did so on the “FINAL BOLT STUDS AND NUTS - master for block instance” layer and you set the Display Color of each to “By Layer”

When you made them into a block, that locked in the “By Layer” behaviour and the association with the “FINAL…” layer. Subsequent editing of the Block Element and changing the setting to “By Parent” does not break that lock (that seems to be a bug to me), so you are stuck with the original colour.

There are two ways to solve this:

  1. If you just want all studs and nuts to be magenta, change the Layer Color of the “FINAL…” layer.

  2. If you want your studs and nuts to take on the colour of whatever layer they are placed on, then you need to create a new block with the “By Parent” setting in place from the start. To do this:
    2.1 Select one block instance and run ExplodeBlock on it. This takes that instance back to its unblocked components.
    2.2 Select the stud and change its Display Color to “By Parent”. Do the same with the nut.
    2.3 Then select both and run Block to create a new block (give it a new name).
    2.4 Run the Block Manager and use it to select all the remaining incorrect instances (or however else you like to select them) and run ReplaceBlock. Use the “SelectFromBlockDefinitionList” option to get a list of available blocks for the replacement and pick your new Block name. This will replace all the incorrect blocks and
    2.5 you should see a ring of magenta fixings.
    2.6 Run Block Manager again and check the count for the incorrect block. It should be zero: if so you should delete that block definition. Otherwise its a ghost in the machine.


p.s. I haven’t checked but, from memory, linked block definitions don’t have the lock in bug.

EDIT: If you plan to render the model, then in 2.2 also set the render material to “Use Object Parent”