# Easy CAD software for modest requirements: Fusion 360? Other?

### Help Support HomeBuiltAirplanes.com:

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
If you have a full up plane model with any level of detail, 8 gig isn't enough RAM if you want to run quickly.
Seems to be pretty much my experience as well. The only time I've used up my memory (16) was when I had several open sketches at one time with fairly large JPGs underlayed while redrawing the AV-36 plans. SW started to 'lose' the JPGs. They were still there, just wouldn't display no matter how long I waited.

I also get some poor display (faceted curves/splines) at times, but a real graphics card would take care of that little problem.

I've never had an SSD in any of my machines so I don't know if they are really needed. I can say that I've started to use the local hard drive storage more with the larger files. In the past I was just working off the NAS and it would get pretty slow. I've got my automatic backup software set to back up the files every 10 or 20 minutes minutes if there are any changes. That also slows things up for a few seconds when it does it's thing.

I've also seen some slowing if I have more than 20 or so individual parts open along with the main assembly, but it isn't memory related. Pretty sure that is slow hard drive?

I've been working with this system for several hours per day and the limits of the machine haven't impacted my productivity much.

#### Jay Kempf

##### Curmudgeon in Training (CIT)
If you have a full up plane model with any level of detail, 8 gig isn't enough RAM if you want to run quickly. I started out with 8, but quickly went to 24. If you're an impatient person, you'll be cussing at your computer while your model regens with 8 gig.

Ditto for SSD.

My CFD and FEA run fairly quickly with just that 24 gig.

The last time I checked, SW didn't take advantage of multi-core processors.
SW FEA, Graphics like rendering and CFD all use all the processors available. Fans go nuts. Regular running of just editing solids in SW uses randomly selected processors by my monitoring. I have dual quad core 3.0GHZ processors in a 2U Dell rack workstation. I run 32 gigs error checking server ram 500G SSD and terrabytes of rotating plattens. Some also run a small flash drive for primary software installs. The real key is Nvidea Quadro 6000. I have upgraded cards about every 2 years as the darling of the industry plummets below $200 on ebay. These cards are expensive when they are introduced. But clever people build machines for no real dollars. I also have 2 large monitors, a collection of trackballs, my favorite being the new Logitech Ergo and of course 3D connexion 6 dof mouse in my left hand always. Also am a keyboard snob always have a Microsoft Natural 4000 and I prefer wired usb for everything into a wired hub. You can go bigger than this but really it isn't necessary. I benchmark against the latest stuff fairly well including hotrodded processors. What I like about the Dell rackstations is that they are bulletproof, I have spares of everything. But I have to because I live at the other end of civilization with no support or stores to get anything so I have to provision by the brown truck. The machine I am building is the later 7910 chassis with two 12 core 24 thread processors. It has capacity for 256G of memory and stacked video cards with enough redundant hot pluggable power to handle it all. But that is extreme. When you have a recreational CFD problem you want massive power. #### Hephaestus ##### Well-Known Member These guys are the working extreme Just as a reference... I run fusion mostly on an old hp mobile workstation (laptop), i7 12gigs ram, Nvidia GPU (4gig?) It works. Sometimes it has to sit and think about things with the fans blasting for a while... Last time I played with the FEA module it took a few hours - but it did it. #### Jay Kempf ##### Curmudgeon in Training (CIT) Lifetime Supporter Yup, just wanted to present the extreme end. But that is what is required to keep up with clients needs. And for my own projects it don't hurt. If we aren't fast enough we bid to high and we don't get work. Cheap horsepower and the experience to keep it working and use it is a huge advantage. So BTDT. 8 gigs is enough to learn on. Spend money on a decent video card first. SSDs are a significant bump as well. Cloud accounts are a continual pain in the neck for me. Useful but slow. Supposedly I am getting fiber optic soon her in the middle of nowhere ski country. #### Hephaestus ##### Well-Known Member They dug fiber in installed right into my basement. 300mb service. Pretty sure my phone tether is faster. #### PiperCruisin ##### Well-Known Member lolololol Don't get me going, because this is a true story: on one of the JSF efforts, one of the structures leads didn't know how to use the 3D CAD system. So he would superimpose Word 'shapes' like these over real CAD images and drawings to try to convey his ideas. I freely admit to being guilty of this one. I've seen aircraft built off sketches on with colored pencils on engineering paper. CAD is nothing if the design makes no sense. I'm no CAD jockey, so I have typically let others do that. I'm usually telling them what to design. Otherwise everything turns out to be a rectangle. I'm mainly an FEA guy. I will use it if the designers are busy or the concept is hard to explain. I have worked with AutoCAD, ProE, Catia, and NX. I've been wanting to use SW, but never had the chance (professionally anyways...I drew my avatar in SW). I will go with the EAA SW, but need to upgrade the computer. Our plant is being shut down so hoping for some deals on excess work stations. Btw. The built-in FEA is typically only good for discrete, low-aspect ratio component analysis. Complex, shell assemblies, not so much. Pro/mechanica wasn't too bad, but required a lot of customization only a forture 500 company could afford to make it truly useful. #### 12notes ##### Well-Known Member Lifetime Supporter Log Member I bought the cheapest laptop I could find in lower Manhattan 7 years ago for$400. 2GB RAM, don't remember which processor but it's not a nice one, Intel on board graphics chip, but it will run Solidworks 2019. I haven't done anything big or complicated in it, and FEA would probably bring up an error box that just says "Ha! No.", but it runs simple tasks fine.

Work computer has 16 cores and 32GB RAM with a Nvidia GTX660, way more complicated designs here, but we use IronCad.

A second monitor is way more helpful that you might realize. A TV with a HDMI input works fine if you don't want to invest in one.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
Been paying more attention to my system today as a result of this discussion. Decided to defrag after a recent Win update and it really slowed down my work. So it looks like an SSD might be a worthwhile upgrade!

#### Topaz

##### Super Moderator
Staff member
Log Member
Been paying more attention to my system today as a result of this discussion. Decided to defrag after a recent Win update and it really slowed down my work. So it looks like an SSD might be a worthwhile upgrade!
They are. First upgrade I did to this computer was to pull the spinning-platter system drive and replace it with an SSD. Pretty big bump in performance. Certainly worth the relatively small cost.

#### Vigilant1

##### Well-Known Member
I bought the cheapest laptop I could find in lower Manhattan 7 years ago for $400. 2GB RAM, don't remember which processor but it's not a nice one, Intel on board graphics chip, but it will run Solidworks 2019. I haven't done anything big or complicated in it, and FEA would probably bring up an error box that just says "Ha! No.", but it runs simple tasks fine. The machine I run my 2012 on is OLD. It balks on assemblies with 1000+ parts. Yes I have a few. It doesn't crash. I've used up most of the memory a time or 2. Specs: 2.8Ghz AMD A6 5400K dual core cpu (built in graphics) 16 gig of memory, 1Tb main HD and 2TB of raid for local storage all under Win 8.1. Point is if you are just starting out the machine you already have may be good enough. A good main monitor and a 3D mouse are better investments to start IMHO. I also like a track ball in the right hand. My daily use machine is a cheap 3 year old Lenovo laptop with an AMD A8 2.0 GHz processor with onboard graphics, 6 GB of RAM, and a 1TB HDD. So, no real graphics card, no SSD, deficient in RAM. Based on 12notes' experience, maybe I could just buy a used large monitor and the 3D mouse, load and run SW 2019 on this laptop, do simple stuff, and see if CAD is for me. If so, I can spring for a (cheap) more capable workstation like the one described in the previous post for about$350 and it will seem lightning fast and I'll already have the large monitor and 3D mouse for use with it. The only downside: setting up SW 2019 twice, moving the data, etc.

Scuttlebutt online says previous editions of SW didn't take full advantage of powerful graphics cards, and money was better spent on just a basic graphics card and a faster CPU. SW 2019 is supposed to do a better job of using the dedicated graphics cards, so investing in them has a better payoff than before.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
I must have been living in some kind of self imposed cave.............maybe I qualify for a Geico commercial?
I had no idea the price had come down so much on the SSDs. Looks like it's PayPal time.
Edit:
Done. I just upgraded my 8 year old cell phone last week. Maybe fire is next?
Just a bit of feed back on my SSD upgrade:

It arrived a few days ago, was cloned (Macrium Reflect free), and installed. Kind of miss the audible feed back that the HD is doing it's job but I still have the blinky LED.... I hate computers with no operational feedback. No complications other than it messed up my desktop icon arrangement. The cloning process did take well over an hour.

The SSD trimmed my ~10 minute boot to post on HBA time to under 2 minutes. SW also loads much quicker, by about the same factor. Large assemblies load somewhat faster as well but my processing power, or lack of, is still a factor. Updating child parts after a change to the parent is also noticeably faster.

Manipulating large assemblies, even in lightweight mode, with the 3D mouse didn't seem to be helped much. Probably the integrated CPU/video is limiting this function?

Will add here: I have 'discovered' the joys of copying the master/parent body loft several times so I can carve out child parts from one body that would normally be very difficult and processor intensive if trying to generate the same child parts from one body. This has done as much to speed up the rebuild process as the SSD upgrade. No more cut and paste to a new part file!

#### Jay Kempf

##### Curmudgeon in Training (CIT)
Time for a video card. There are a ton of GTX cards out there. Little known but there is a registry hack to fake these game cards into thinking that they are engineering cards. If you only have or intend to use one monitor then these are good budget cards. Ebay for like $50. Nvidia quadro series are also pretty inexpensive on ebay now depending on your needs. I have my last two video cards here if someone wants one cheap let me know. One is a beast, the other older one is pretty OK as a starter card. The new one I have installed is just silly powerful and it was less than$200 on ebay. The big ones require a robust power supply and sometimes an extra power cable.

Your SSD is a great start. Max out your memory, max out your processor for whatever socket your motherboard has and add a decent video card and the whole experience changes.

When it comes to managing an OML, there are tricks. Mainly you have to figure out how to build configurations in a master file. Then distribute the configured parts to individual sub assembly starter files. Then if you update the base OML it carries through the subs automatically. We do this every day. It is the only real way I have found to do a big aero project in SW. Once you lock down your OML you lock all the external links to save update time and memory. Some say it can't be done in SW. WRONG!

Last edited:

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
Your SSD is a great start. Max out your memory, max out your processor for whatever socket your motherboard has and add a decent video card and the whole experience changes.

<< >>Then if you update the base OML it carries through the subs automatically. We do this every day. It is the only real way I have found to do a big aero project in SW. Once you lock down your OML you lock all the external links to save update time and memory. Some say it can't be done in SW. WRONG!
There comes a point where it's just best to start with a bare case and power supply. I think I'm at that point with this box, but it's not significantly impacting my productivity - like HBA - so maybe later.

<< >>
The master OML (body in my speak) is my foundation, but simply 'inserting into another part" doesn't transfer my underlying sketch. In the past I would just copy/paste and then go about the process of redefining the sketch in the new part. That was slow and tedious and if the base sketch changed then the process repeated.

What I now do is make all of the little parts in ONE part file with the multiple bodies and then export those to the child parts for further work. If there is a way to simply copy/past an entire part file with the various sketches/planes etc. to a child that will update with the parent I'd be REAL interested in how!

My current project has 4 OMLs - Fuselage, inner wing, outer wing and rudder/VS. Each of those, except the rudder, gets broken down into a few children that then beget grandchildren.

#### Jay Kempf

##### Curmudgeon in Training (CIT)
Grasshopper... OML is one big part with all the parts in it. All related to each other however you did it. It is not an assembly but one single part file. That is the best way to start. If you have a wing stub in one file and the wing in another you already duplicated at least one airfoil sketch. Learn configurations. There are YouTube videos. It makes no sense at first then the light bulb comes on and there is no going back.

The insert part command allows you to control what of the original you want to import and how. I always put the children on the world coordinate system. Sometimes I bring in key planes and sketches, sometimes not. But you always edit the OML in the original OML file not in the children. That is the whole point. So all airfoils and the positions of all the things that make it an airplane are all in one place that is easily updated. For me composite parts are designed this way. One surface file for half the airplane and always the left half, dunno why.

#### ScaleBirdsScott

##### Well-Known Member
I'm a gamer in my fleeting spare time (Mostly War Thunder and Hell Let Loose these days) so I have always just built my rigs to gaming spec, using Nvidia GTX cards, and I've never had any problems running CAD software using such cards. I do know you can even get "productivity focused" drivers for them which are likely mostly for people doing video and graphics rendering and the like, but if I was getting a GTX and did not intend on getting 100fps 4k on ultra, I'd go for those productivity drivers, and maybe that would save me from one or two crashes but I doubt it would make a huge difference. I've had great luck just doing the work on a machine rigged for games.

16-32GB of RAM is probably the golden zone right now, anything less you do risk slowing down. If you aren't running super detailed models and you don't multitask like crazy, 16 is probably plenty fine for standard CAD work. I tend to run 10 Chrome tabs with a few of the YouTube and one or two AirCorps Library pdfs up, a bunch of big images loaded from my reference library, two instances of CAD for two completely different projects, some graphics editing software, Foobar2000 for music, and then with all of that chilling in the background load up a session of the aforementioned War Thunder to take a quick break. So on average burning 14-24gb of memory at a given time.

Since I take it a lot of people aren't trying to do eveything at once all day every day for months, those numbers may be a little high.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
Grasshopper... OML is one big part .
I've presumed the OML stand for Outside Mold Line? If so then we are both using the same process, just having trouble with words over the internet.

Configurations? I could use them more than I do but for the kind of parts I generally am working with there is and will only ever be - one - configuration. If I were building up a family of special fasteners of various length and diameters, most definitely.

definitely - a word I can never seem to spell even close enough for the spell checker to find.

#### Jay Kempf

##### Curmudgeon in Training (CIT)
I didn't mean OML is one big part is what the acronym stands for, yes OML is Outer Mold Line. For the purposes of what I am trying to say lets just say the whole point of a relational database or relational 3D modeler is to have a minimum of input and get the maximum amount of utility from it. So if you create a sketch in a second part that is say a rib that they both share you have to update both if they aren't related still. If you put them all in one part file then you only have to enter the rib once. You build the whole wing right on the fuselage. Then you configure out only the outer wing to add to a new part and insert it in a new child part. I only use the surfaces that I need. You can always go back to that configuration and pull out something you missed. The nice thing about this way of doing things is it updates all children when lets say you find out you need more wing twist. You go fix it at the top level and let it populate throughout the project.

Configurations in SW are not what the word configurations typically means in aerospace. It just means versions of the same thing that come from the same feature tree. You can suppress, delete/keep body, etc... to make lesser complete versions of the top OML surface or solid.

Imagine it this way. You need a whole lump that is the airplane to hand off to the CFD guys. So you start there. Then you need to make sub assemblies. So you cut up the lump wherever you want. Then the parts you cut off become their own parts but are still created in the top level. All threads flow down from there. At the beginning of a project that organization saves a ton of chasing around and fixing related things. This is considered "top down" modeling and it is appropriate for this sort of project. You don't want to use top down for more than just establishing the initial relationships of the whole OML. You detail bottom up from there. At the end you build an assembly with all those separate parts.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
lets say you find out you need more wing twist. You go fix it at the top level and let it populate throughout the project.
We pretty sure we are doing the same thing. When I want more twist I change ONE sketch. Then when I open the aileron hinge bracket, for example, it has already changed - maybe 3 generations down.

My current project just happens to be broken up into 4 non linked units because the relationship between them - the mounting points - will never change. This does leave a couple of fairings that need to be done, but that is a small project.

Things like ribs, once they go off to be an "independent" child, do get designed bottom up. This gives me the option to build the rib in wood, aluminum or composite. If I need another rib I just go back to the parent, move the others and put in the new one. At this point I can see the value of creating a different configuration.

2