JB's 3D CAD & Printing bench

John Baker

Western Thunderer
I'm relatively new to Fusion 360, and am self taught through various YouTube tutorials. I understand the basics of the 3D design process, but come unstuck when things 'don't work'. Many hours are spent trawling the internet and watching semi-relevant videos, only for me to end up not much further on than when I started. So, I'm turning to the wealth of skill, knowledge and expertise we have here.

I am about to delve into the world of 3D printing and want to create a few things to adorn a Manning Wardle Old Class I. So far, I have knocked up a wheel centre, chimney and the later version of the safety valve cover. Nothing too complex (though the wheel centre took me an age), but I'm happy with them nonetheless.

376865322_Latersafetyvalvecover.png.eee03334051291ae61762bdea9e0498e.png
1333409239_Chimeyrender.png.af4ad87369893d57884b70195a8e5c64.png
1425671310_Wheelcentre.png.987cfc6553b602e518ab5cbbde63d7b5.png


However, it's the older earlier version with the flutings that I'm struggling with. It's meant to look something like this:

post-6979-0-72760600-1514720917.jpg.72887592430532b0b708a0eada6e33f9.jpg
(apologies that's rather small)

It's the flutings that are causing me the problems. I have the basic shape of the cover sorted (I know, I still need to sort the top surface out and the fluting itself is not yet quite the right shape), and I can 'cut' the fluting into the main body of the cover. However, when I try to repeat this by using the 'pattern' feature (to get 12 of them, evenly spaced around the surface), I get an error:

314082243_Screenshot2019-12-31at21_19_00.png.1f22c736e16b45c909f7544ca5f52d60.png
1997670943_Screenshot2019-12-31at21_21_00.png.dac86ef0a64fffb3c40b7816f16a7bd4.png

I think it has something to do with the fact the main body of the valve cover is tapered, getting narrower the further up you go. I tried repeating the same process with a parallel sided version and it worked no problem at all. It's driving me slowly mad, so if anyone has any ideas, I'd love to hear them. Just keep any replies in layman's terms, as anything too complex will fly right over my head!

Oh, and once we've found a solution to this, I have another problem too (my wife tells me I have many problems) regarding the smokebox door.......
 

Dan Randall

Western Thunderer
Hi John

I’ve not yet used Fusion 360, though both it and a new laptop, are top of my shopping list for 2020!

David Lane, over on RMweb, uses it and seems to be pretty proficient with it....

https://www.rmweb.co.uk/community/index.php?/topic/122847-any-wheel-any-size/

It might be worth sending him a PM and asking if he has the answer?


This week, I discovered some Fusion 360 tutorials by Kevin Kennedy....

https://www.youtube.com/watch?v=qvrHuaHhqHI

I’ve found them to be very easy to watch and most informative, so if you’ve not seen them yet, they could be worth checking out, even if the content of the tutorials bears no relevance to your current dilemma.


Regards

Dan
 

simond

Western Thunderer
no experience in this software, but have a bit of CAD under my belt:

Do your patterned recesses intersect? If they do, it’ll probably throw a wobbly.

Try making them much shallower (or narrower) and see if that fixes it.

HTH & HNY
Simon
 

SARSn3.5

New Member
A first post, but not a new member: rather a lurker and learner. So thanks to everyone who has provided the learning opportunities. And now an opportunity to contribute.

John, I have assumed that you created the cone at the centre of your valve cover with the loft command and tied it to the origin. Proceed as follows:
Construct a tangent plane tangent to the cone surface.
Create a new sketch on the tangent plane. Project the top and bottom circles used for the construction of the cone and the axis of the cone onto the sketch plane. Sketch and constrain the sketch of the flute such that it is symmetrical around the projected axis. Close the sketch.
Use Modify: Push/Pull (Shortcut Q) to cut the flute profile to depth.
Use Modify: Fillet (Shortcut F) to fillet the edges of the flute.
Use Create: Pattern: Circular Pattern to create a radial array based on the push/pull feature and the fillet feature.
The Circular Pattern dialog box will open -
Set Pattern Type to features,
Set Objects by clicking on the push/pull feature and fillet feature in the time line,
Set Axis as the Z axis, assuming you initial circles were drawn of the XY plane,
Set Type as full (360 degrees),
Set Suppress as ticked (the default setting),
Set Quantity - the default is 3; change that to 12,
Set Compute Option at the default setting, Adjust,
Press OK.​

The software will take a few seconds to update, but it will reward you with a fully fluted component.

I hope that helps.

Gavin Beaumont
 

John Baker

Western Thunderer
@Dan Randall , thanks for the links - I'll be sure to check them out this evening!

@simond , the recesses do not intersect or overlap at all - I wondered this so tried the patter with just two or 3 recesses rather than the 12 I'm aiming for, but had the same result.....

@SARSn3.5 thanks for these comprehensive instructions! I'll have a go at following them either this evening once the little one's in bed, or maybe later this week :)

Hopefully I'll be able to show a completed, fully fluted safety valve cover in the not too distant future!

John
 

John Baker

Western Thunderer
Et Voila!
Screenshot 2020-01-01 at 22.15.28.png Earlier dome fiddling v3.png
Thanks Gavin for the walkthrough - worked first time :) I think I'd gone wrong because I did the sketch of the fluting on an offset plane which I then projected onto the 'cone' of the valve cover, rather than creating a tangent plane and doing the sketch from there.

Now all I need is a 3D printer.....
My next challenge, which I have yet to find a solution to, is creating the semi-circular dished smokebox door. Tried a few methods already, however I thought of a potential solution whilst in the shower this morning...I'll ee what I can come up with.
 

Attachments

  • Screenshot 2020-01-01 at 22.15.28.png
    Screenshot 2020-01-01 at 22.15.28.png
    167 KB · Views: 1

Dan Randall

Western Thunderer
Well done John (and Gavin).

Out of interest, do you use a Mac, PC or laptop and if so, what make/spec please? I favour a laptop myself from a portability point of view, but don’t really want to flash out over a grand for a gaming one (I’ve no interest in games, whatsoever), which would obviously be great for Fusion 360, but overkill perhaps? It’s just that every time I search for “Best laptops for Fusion 360”, there are always some gaming ones in the mix!


Regards

Dan
 

SimonT

Western Thunderer
Dan,
that's because you need the assets of a 'gaming' computer to run a big CAD program with a big CAD file. I am on my second desktop that was specifically built for this work and it will be replaced by a similar updated machine after three years. I have tried the same files on Madam's conventional laptop and quickly get pissed off with the pauses as occur as you manipulate the view. Go and see the chap at 3D Computers in Chippenham (Just on the north side of the viaduct). He is now supplying professional design organisations off what he did for me. And I wouldn't touch Apple for this work; they are good for the raster graphics of publishing type artwork but not as good for the vector stuff.
Simon
 

John Baker

Western Thunderer
I just use my MacBook Pro laptop, which has 16GB of RAM and a 3.1GHz processor - not bought for the task though. Just a general purpose laptop which I use for work (teacher, needing to produce several decent videos each year + the usual paperwork & powerpoint stuff) and home use (no gaming). This appears to be more than enough for the very small-scale Fusion 360 stuff that I'm dabbling with. I must stress though that these are tiny files I'm creating. I've no idea how it will perform if the models get really big and complicated, however there's very little prospect of me getting to that stage!
 

Nigel Cliffe

Western Thunderer
I run Fusion360 for modest projects happily on my two machines.

The desktop is now at least six years old (likely seven or eight) - Shuttle SB67H3, with an Intel i5 processor. It has solid state main drive (programs, operating system) which has been replaced once (larger size), and conventional magnetic user storage. Careful choice of other internal bits to keep the speed up when it was purchased. Uses the motherboard integrated graphics.
The laptop is a low-ish ThinkPad (so still best part of £1000), with a graphics board. Also an i5 processor, and fully solid state.

So, those are "mid range" and certainly not multi-thousand pound gaming or CAD workstations. The only tasks they'd be obviously slow-ish at doing would be coloured renderings from CAD files, which I don't need to do.

Both running current Windows10, the shuttle is on the "home" version, the Thinkpad on the "pro".


And writing this has me wondering when the Shuttle will need replacing.


- Nigel
 

Dan Randall

Western Thunderer
Simon, John & Nigel - thanks for your replies and advice.

Having thought about it (and given my current woes with TurboCAD taking ages to do anything on my current laptop, which is at least 12 years old!), I probably ought to invest more than I had anticipated and get something that will last me a good number of years. More importantly, it must be able to do what I ask of it, without slowing down and/or crashing all the time. The system requirements for Fusion 360 are readily available online, so I hope to find a suitable machine in due course.

Simon - Thanks for the heads-up on 3D Computers in Chippenham. This is only about 25-30 minutes from me, so I may well pay them a visit. :thumbs:

(With apologies to John, for hijacking his thread....:oops:).


Regards

Dan
 

SimonT

Western Thunderer
Dan,
as a guide I paid around £650 for a bespoke desktop. Intel i5-8400 CPU, 16GB of RAM, solid state hard drive for the OS, conventional drive for data and a NVIDIA GeForce GTX 1050 Ti graphics card. I use a twin monitor set up. I also use a 3DConnexion 3D Space Mouse Enterprise to manipulate the model, a Razer DeathAdder Elite for the right hand mouse.

John, thank you for the hijack.

Simon
 

SARSn3.5

New Member
John, I note your success with pleasure!


... don’t really want to flash out over a grand for a gaming one (I’ve no interest in games, whatsoever), which would obviously be great for Fusion 360, but overkill perhaps? It’s just that every time I search for “Best laptops for Fusion 360”, there are always some gaming ones in the mix!
Dan

Dan,

When my previous machine suffered a major motherboard disaster some 3 years ago, I replaced it with a bespoke computer whose builder had it on offer for a very good price after the contract with its intended purchaser fell through. It was intended for industrial design work. It main characteristic was the inclusion of a good quality graphics processor. When I decided, in preparation for retirement (from a career in health services), to "re-train" as a CAD draughtsman, I enrolled in a couple of units offered by my local trades-training authority. Initially, my old machine was able to update the screen display faster than I could think through design decisions, so it seemed to be perfectly fit for purpose. Once some formal training got me quicker than the machine, waiting for it to update the display got really frustrating - it kills the enjoyment!

Currently the most serious work that I am doing is designing etch tools for an S scale model of a South Australian Railways prototype. I use AutoCAD LT and Fusion 360, the later for doing a virtual test build of the etchings. I've intentionally built it as a set of sub-assemblies, that are brought into the final assembly as such, to keep files as small as I can, but they do slow graphics processing a little, even if not intrusively. And Fusion has the capacity to do interference analysis which is great for finding design errors - as the song goes, I've had a few!!! - but it is hungry for processor power.

I also use the software for cut files for laser cutting card, paper and MDF for modelling buildings, making dioramas, making storage boxes... I am soon to have access to a CNC engraver / router at my local Makers-space: it requires tool path files to be created.

On the basis of my experience I pose a few questions. What are you currently using these aids to modelling for? What are you thinking about using them for? More generally, what might you use them for?

As an analogy, I am reminded of the model engineering recommendation, when someone is thinking about getting a lathe, "Get a lathe that is a bit bigger than you think you need: its possession is likely to expand your goals."

Gavin
 
A

Arun

Guest
At #14 Gavin wrote, "On the basis of my experience I pose a few questions. What are you currently using these aids to modelling for? What are you thinking about using them for? More generally, what might you use them for?"

I use 3D Systems Design X for reverse engineering scans* of full-size and sometimes, smaller than full size objects - i.e., turning .stl files into executable Autodesk Inventor and/or Parasolid files. Similarly, I use Inventor and DraftSight Pro for 3D and 2D design de-novo. The two models currently on the member's area workbenches viz., HST power car and JCB 3Mk2 were both drawn from scratch in Inventor.
Eventually the HST power car's components will also be 3D printed in hi-res FDM/SLA as appropriate by an external agency and these parts will then be used as masters for lost wax/resin/white metal castings for a couple of cars. At this point they will be combined with N-S etches drawn in DraftSight** .
Unlike most of my similar models, the HST will be solely for my personal enjoyment. The JCB and most other patterns produced are however for retail sale as parts of, or full kits.
Such kits and patterns are sold by a variety of people under a variety of labels........

The point is that if you want something that isn't already available, you can either wait a really long time or you can make it yourself. My experience is that I have a greater bond with stuff that I have designed and built myself than someone else's kit that I have built - Let alone [horror of horrors] a kit that someone has built for me. The only exception is the Met Bo-Bo that Ken de Groome built for me - But then I did design most of the castings for that kit!

* There are also a variety of scanners for 3D scanning of objects from very very small to really quite large.
**Personally, I have found that DraftSight is more user-friendly than AutoCad Lt when exporting .dwg files to external agencies for etching. No messing with confusing "World Views" and "Model Views" or "Paper Views". Otherwise these two CAD programmes are functionally identical
 

John Baker

Western Thunderer
Had the safety valve cover above printed for me from Shapeways in their fine-detail plastic, and I was pleasantly surprised by the detail. The top end of the flutings are only a fraction of a millimetre deep, and this detail has been retained.

Apologies for the grainy photo......average camera-phone and poor lighting hasn't done the part any favours, so you'll have to take it from me that the quality of the print is good.
IMG_1540.JPG.dbdaddda4d39df3d7631490b95c1d290.JPG


By way of comparison, and purely for interest value, I also ordered one from Xometry.com which hasn't arrived yet. They don't offer the same material as the Shapeways printed one (fine detail plastic), so I chose something that's hopefully similar. I added the plinth to the 3D model before ordering from Xometry - I realised I'd left it off the Shapeways order. I'll post a piccy of that when it arrives.

As previously mentioned, I want to cast these in brass, however I don't want to pay the exorbitant prices for one of the above companies to do that for me! Plans are afoot to construct a home 'foundry', where I can print in castable resin, and then cast in a suitable metal (brass or otherwise). And yes, I realise I can have many parts printed for the cost of building a foundry, but fun and satisfaction are sometimes priceless. I find a model far more satisfying if it's all metal, rather than having lots of plastic/resin glued to it. Nothing wrong with those that do make use of plastic parts.....just personal preference :)
 

AndyH

Active Member
Looks good John,
Sometimes we’ve found standard formlabs resin is better than the castable for some jobs when investment casting (vacuum). Simplistic response.

We have minimal shrinkage too, which is okay for decorative items, but need to factor it in for precision items.
Cheers,
Andy
 

John Baker

Western Thunderer
Nice result! :thumbs: Perhaps a little waft of grey primer will show up the detail a little more.

I'm sure it will - the material is translucent so difficult for the camera to pick up the detail. No rush though - the etch artwork for the loco itself is progressing at less than a snails pace, so nothing to put it on yet.
 

John Baker

Western Thunderer
The Xometry version came today......not the finish I was hoping for. Probably down to my choice of material.

IMG_1552.JPG

Maybe OK of the loco has been sitting outside in a snowstorm for a few days ;)
 
Top