Playing around with Fusion 360

[Upnorth]

I use fusion 360 on and off. I am competent with individual components but never really got the hang of their assemblies. The progress tree gets enormous fast. I originally learned CAD and CAM with solidworks but eventually lost access to it. With the cost of solidworks Cad/Cam being in excess of $20k I had to use something else. So fusion 360 it is.

No real point in this post other than to maybe spark some conversation about Fusion 360. The part in the photo is a computer rendered image of three out of 4 crank case parts for a 18 cylinder double row radial engine. I was hoping for it to be a retirement project but with the cost of material it would be an expensive build.

 

[Xyphota]

Yeah Fusion requires a bit of foresight to make assemblies manageable unfortunately. One tip for top-down modelling assemblies is instead of creating new parts in the main assembly file, create and save a new part in it's own file instead, and then drag it into the assembly (even if the part file is otherwise empty). From there you can activate the 'blank part', do all your in-context modelling, and then when you reactivate the parent assembly, none of the child part's features show up in the tree.

 

[Susquatch]

I use fusion 360 on and off. I am competent with individual components but never really got the hang of their assemblies. The progress tree gets enormous fast. I originally learned CAD and CAM with solidworks but eventually lost access to it.

I have the same problem. But I migrated from CATIA. I can't even remotely afford a CATIA seat. Not happening.

But you are WAAAAY ahead of me making a part like that in Fusion. My compliments!

Did you mean 16 cylinder? I can only count 8 cylinders per bank. Still an amazing build if you can pull it off! I think farming is easier.... LOL!

 

[Upnorth]

Yeah Fusion requires a bit of foresight to make assemblies manageable unfortunately. One tip for top-down modelling assemblies is instead of creating new parts in the main assembly file, create and save a new part in it's own file instead, and then drag it into the assembly (even if the part file is otherwise empty). From there you can activate the 'blank part', do all your in-context modelling, and then when you reactivate the parent assembly, none of the child part's features show up in the tree.

You might be right. The way you describe is how I created assemblies in Solidworks. My tree got absurdly over filled as soon as I added the bushings in the rear crank case. I used a circular pattern. Each bushing got it's own entry in the tree.

 

[Upnorth]

I have the same problem. But I migrated from CATIA. I can't even remotely afford a CATIA seat. Not happening.

But you are WAAAAY ahead of me making a part like that in Fusion. My compliments!

Did you mean 16 cylinder? I can only count 8 cylinders per bank. Still an amazing build if you can pull it off! I think farming is easier.... LOL!

I have heard of Catia but never used it. From what I hear I would have to sell my house to pay for it. Fusion does some things well. A radial engine looks complicated but it's all logical geometry so not as difficult as it seems. My ability falls apart if I have to do something with compound curves. To me that is almost like art and I just cant do it.

It's definitely an 18 cylinder. Due to the way radials work every bank has to be an odd number of cylinders. So every double bank has to be twice an odd number of cylinders. 16 cylinders is impossible in a radial engine. I can't remember exactly why. Although I'm an aircraft mechanic and I started my career working on radial engines I have mostly forgotten the theory. I only work on turbine engines now. I'll attach a rear view of the cylinders to make counting them easier.

 

[Susquatch]

Although I'm an aircraft mechanic and I started my career working on radial engines I have mostly forgotten the theory. I only work on turbine engines now. I'll attach a rear view of the cylinders to make counting them easier.

Although I designed automotive engines for a part of my career, I have no idea why radial engines require an odd number of cylinders either. Didn't work on radials. Might have something to do with maintaining a smooth firing order.

I can see 9 cylinders with that layout. It looked like 8 in the first drawing. Thank you for doing that.

Ya, I'm not doing complex curves in Fusion either. Maybe not ever! But there are guys on here who do!

 

[Susquatch]

Due to the way radials work every bank has to be an odd number of cylinders.

You realize you have ruined a perfectly good night's sleep. I'm laying here visualizing the inside of a stupid radial engine. It ain't pretty and it sure isn't peaceful in there!

I think my first instinct is probably correct. It's a bit like why are most 90 degree engines an even number of cylinders.

For good balance and smooth operation, your firing sequence is best done on every other cylinder. So an 8 cylinder would be 1 3 5 7 1 3 5 7 1 and you wouldn't get the even numbers firing. With 9 cylinders it's 1 3 5 7 9 2 4 6 8 1 3...... and everything is hunky dory. That's still a WAG cuz I really don't know but that's my guess till I wake up tomorrow with a headache..... LMAO!

Are you planning to run that thing someday? If so, I just gotta see it!

 

[PeterT]

SW has features to significantly reduce memory/computational overhead of sub-assemblies using variations of 'lightweight' components. Generally, unless you are doing a motion study or simulation requiring all parts within an assembly to be 'live' meaning with respective mates, it usually always makes sense to use lightweight features. I'm not sure if F360 has something similar.

Lightweight Components - 2021 - SOLIDWORKS Help

help.solidworks.com

Guessing that is a Hodgson? You should build it! My 'simple' 5-cylinder only took me how many years LOL. (Next one will be quicker).
Here is some inspiration. BTW I made a combined PDF of his HMEM build post. PM me if you want a copy. Its 1207 pages so I'd have to park on my Onedrive.

 

[PeterT]

I keep waiting for someone to click buy on Solidworks Maker so I can see firsthand what the limitations <ahem> 'features' are beneath the sales fine print. It's $99USD/per year. I think this was chatted in another post on the forum, but my recollection was: its technically not 'cloud' files in the way other apps work. The program is on your device, as are the files, which is a big plus. But I think it shakes hands with The Mothership to validate you are a subscriber. No pay, no play. It stamps a 'non-commercial' watermark on drawings. No biggy there. It does not export models to common CNC readable formats which is their way of controlling maker vs regular commercial. That usually stops most F360 users who want the CAM module. I haven't figured out if the SW limitation extends to 3DP formats or not. Really, as a manual machinist carrying my paper drawings to the shop, I'd be hard pressed not to give SW-Maker a try.

https://www.solidworks.com/solution/3dexperience-solidworks-makers

 

[Upnorth]

You realize you have ruined a perfectly good night's sleep. I'm laying here visualizing the inside of a stupid radial engine. It ain't pretty and it sure isn't peaceful in there!

I think my first instinct is probably correct. It's a bit like why are most 90 degree engines an even number of cylinders.

For good balance and smooth operation, your firing sequence is best done on every other cylinder. So an 8 cylinder would be 1 3 5 7 1 3 5 7 1 and you wouldn't get the even numbers firing. With 9 cylinders it's 1 3 5 7 9 2 4 6 8 1 3...... and everything is hunky dory. That's still a WAG cuz I really don't know but that's my guess till I wake up tomorrow with a headache..... LMAO!

Are you planning to run that thing someday? If so, I just gotta see it!

I think you are correct about the firing order. I do remember that on a single row it's the odd number cylinders that fire first in sequence then the even numbers go on the next rotation in numerical order. Gets more complicated when you add in a second bank of cylinders because then it alternates the firing order between the front and rear bank of cylinders also. Should make for a smooth engine though as the cylinders firing are closely spaced.

I do plan on making this engine some day. There are a few other designs available from the seller of the plans. I think it would make a lot more sense to start off with the single row 9 cylinder engine. At this point I need to get better at making parts flat. Like when you face and bore one side of a part. Then you flip it in a 4 jaw chuck and need the opposing faces to be perfectly parallel to each other. At this point I don't know how to do that without modifying my lathe chuck.

The cost of the material is crazy. The bronze to make the bearings is $400 for a piece. I have access to a lot of bronze turning chips so I may look into casting my own round. There are a couple of internal ring gears that are a few hundred dollars each also. Might be able to cnc those. If I build it there will be a combination of manual machine and cnc to complete it. It would be nice to use cnc for repetitive stuff like the cylinders. There is also a casting to build the engine for the rear cover. I have already bought one but if I screw it up I can make another one on the mill.

 

[Upnorth]

SW has features to significantly reduce memory/computational overhead of sub-assemblies using variations of 'lightweight' components. Generally, unless you are doing a motion study or simulation requiring all parts within an assembly to be 'live' meaning with respective mates, it usually always makes sense to use lightweight features. I'm not sure if F360 has something similar.

Lightweight Components - 2021 - SOLIDWORKS Help

help.solidworks.com

Guessing that is a Hodgson? You should build it! My 'simple' 5-cylinder only took me how many years LOL. (Next one will be quicker).
Here is some inspiration. BTW I made a combined PDF of his HMEM build post. PM me if you want a copy. Its 1207 pages so I'd have to park on my Onedrive.

I don't have any computer issues with Fusion 360. My computer is modern and powerful enough to process anything I have thrown at it CAD wise. I just get confused with the tree. With solidworks I just drew each component in its own folder them imported and assembled them one at a time. With fusion they say to just design it all in one folder as an assembly. I don't see the reason but I'm very new at fusion assemblies. When I learned solidworks I started with steam engines. I had them assembled and even made movies of them running with solidworks.

Yes it is a Hodgson engine. It was the only one I could find when I was looking for plans. I now have found a few more. I would like to see pdf of the hmem build post. It's always good to see how people make things. I want to make a major but cosmetic change from the original plans. I want to make the cylinder heads look more like the real thing. The original ones in the plans are too round to look good in my opinion. I think all of the engines use the same cylinder design. I like to draw things in CAD so I can see if there will be any expensive mistakes before I start cutting expensive stock.

 

[Upnorth]

I keep waiting for someone to click buy on Solidworks Maker so I can see firsthand what the limitations <ahem> 'features' are beneath the sales fine print. It's $99USD/per year. I think this was chatted in another post on the forum, but my recollection was: its technically not 'cloud' files in the way other apps work. The program is on your device, as are the files, which is a big plus. But I think it shakes hands with The Mothership to validate you are a subscriber. No pay, no play. It stamps a 'non-commercial' watermark on drawings. No biggy there. It does not export models to common CNC readable formats which is their way of controlling maker vs regular commercial. That usually stops most F360 users who want the CAM module. I haven't figured out if the SW limitation extends to 3DP formats or not. Really, as a manual machinist carrying my paper drawings to the shop, I'd be hard pressed not to give SW-Maker a try.

https://www.solidworks.com/solution/3dexperience-solidworks-makers

I'm not familiar with solidworks maker. I signed up for Fusion 360 when they had a special that locked in the price for life. I got it earlier than I needed it thinking I would get access to all future updates. Unfortunately they came up with something called "extensions" which moved some of the features into a paid tier.

If anyone want's to get into solidworks cheap there is a way. You can join the EAA (Experimental Aircraft Association) and get really cheap access to solidworks. It's a student version and I do think even the machining G code generating part is there. Unfortunately who knows how long this deal will be available. If the deal ends I don't know too many people who can afford solidworks for a home shop.

 

[Susquatch]

With fusion they say to just design it all in one folder as an assembly. I don't see the reason but I'm very new at fusion assemblies.

One advantage of combining them all in one drawing (sketch) in Fusion is to facilitate using the free hobbiest version. You are only allowed so many sketches before you have to pay. You can get around this by filing them elsewhere, but combining a large number of sketches might exceed your file limits. Hence putting everything in one file up front. (caveat - somebody more familiar with this like @PeterT should review and correct my understanding).

When I learned solidworks I started with steam engines. I had them assembled and even made movies of them running with solidworks.

I think there is something to be said for starting your design career with 2D paper drawings like I did. It trains your mind to think 3D from 2D in a way that going straight to 3D could not do. This is especially true for intersecting planes and material properties. I think it is better to see such things in the mind than to see them on a computer screen. Let us never forget that the computer screen is really a 2D projection not really 3D. The difference is like holding a real sectioned part in your hands. Rapid prototyping is far closer to what your mind can do but still has to be sectioned which takes time that the mind does not need. What I'm trying to say is that the mind has the potential to be an extremely powerful tool but to reach its potential, it needs training, education, and experience. It is my personal opinion that learning to make and use 2D drawings is a big part of that process.

 

[gerritv]

In gr 7/8 (1960's) we were taught to visualize 3d objects by projection sketches. While it might seem that a few formal courses in drafting on paper/real drafting tables is a good start for 3D CAD, it also can hinder you. E.g. doing too much in a sketch in Fusin360 will often result in no end of issues later if you need to adjust the model. It took me a while to 'forget' my drafting skills and do 3D modeling in an assembly. Lots of components inside an assembly. If your design is really complex (as in lots of parts), break it into sub-assemblies, then build those into an assembly. Esp. for the Free Fusion360 license this has the added benefit of less faffing around with the 10-open-file limit.
As an example I am presently drawing up a Synchronome clock dial movement in 1 assembly with lots of components. Front plate first (t has all of the pivot and other holes), then locate and build additional components from there. Everything is projected from the points on the front plate meaning that the sketches are mostly trivial after the first one. All in 1 'file', can make drawings from the components as needed and even an exploded diagram. CAM for the parts flows from the components.

My experience with the EAA offering of SW was less than pleasant. Their CAM is terrible if you previously got used to Inventor/Fusion360. Their SW is now the 3D Experience for Makers at 50% off retail (so US$50/yr). Siemens Solid Edge is free via EAA but not sure if that has CAM. Basically the free SW is gone.

 

[Susquatch]

In gr 7/8 (1960's) we were taught to visualize 3d objects by projection sketches. While it might seem that a few formal courses in drafting on paper/real drafting tables is a good start for 3D CAD, it also can hinder you.

We can certainly agree to disagree on this Gerrit. Every mind is different. Your experience is no doubt true for you but not for me. I didn't do any formal drawings until first year engineering, but I started doing my own freehand stuff in grade 5 or so.

They didn't have CAD when I started engineering in industry. That arrived a decade later or so and it was a piece of cake to learn the Corporation's proprietary CAD because I helped develop it. Migrating to Catia much later on was also easy.

Whether we agree or not is really no big deal. My whole point was about learning to see parts in your mind not in the computer. The mind is faster and more powerful than the computer but only if it is properly trained. I don't think 3D CAD provides that training. In fact, I think it sidetracks that skill so it never develops to its full potential. Sort of like learning math with a calculator in hand. On the other hand, I think 3D CAD is a fantastic communication and documentation tool - especially when combined with Rapid Prototyping. Certainly WAAAAYYYY easier than trying to describe in words what you see in your mind! LOL!

 

[Susquatch]

While it might seem that a few formal courses in drafting on paper/real drafting tables is a good start for 3D CAD, it also can hinder you. E.g. doing too much in a sketch in Fusin360 will often result in no end of issues later if you need to adjust the model. It took me a while to 'forget' my drafting skills and do 3D modeling in an assembly. Lots of components inside an assembly. If your design is really complex (as in lots of parts), break it into sub-assemblies, then build those into an assembly. Esp. for the Free Fusion360 license this has the added benefit of less faffing around with the 10-open-file limit.

Just some more thoughts Gerrit. Could it be that your learning difficulties were imposed by Fusion itself and not necessarily 3D CAD itself?

To be frank, I was a fighter jet pilot in Catia. I could literally do anything. But I'm still struggling to learn Fusion 360. It simply isn't intuitive to me. Maybe you experienced Fusions barriers in a different way. But perhaps it is Fusion itself that is at fault and not where we each came from.

Regardless, I am determined to learn Fusion because it's the only affordable tool out there that can do what I need it to do.

 

[PeterT]

Regardless, I am determined to learn Fusion because it's the only affordable tool out there that can do what I need it to do.

I assume you want to do CNC or job out 3D parts in appropriate file formats? If not, if you want robust CAD & plan on staying in manual machinist mode, SW Maker seems like a viable alternative at $99USD or 50 or whatever the promo. That's what makes me wonder why more people aren't pursuing it. Maybe there is a strong connection to 3DP & SW has plugged that valve?

 

[jcdammeyer]

@David_R8 started using Alibre Atom. I'm pretty sure it does assemblies too and it's not super expensive. The full blown Alibre Pro can do assemblies and sheet metal. The assemblies are just made from part files. The part files can be imported STEP files saved as part files.

The down side of Alibre is that each time they do a yearly 'enhancement' or 'bug fix' they change the revision. So for example I was using Alibre Design 25 on my WIN-7 system and my WIN-10 laptop. When Alibre 26 came out I updated the laptop but not WIN-7 as it wouldn't run on it anymore.

Then I made the mistake of doing a bunch of work on the laptop with Alibre 26. A couple of months later I went to look at those files on the WIN-7 system and discovered they wouldn't load because they were created by Alibre 26. The Alibre ATOM that @David_R8 is using also saves as Alibre 26 format. So his files weren't loadable on my WIN-7 system either. Ultimately I upgraded to WIN-10 but have stayed with Alibre 25 for now. I guess I should install it on the updated WIN-10 system and switch over.

Comment directly from Alibre was pretty simple. "If we didn't change the revision every year then no one would buy our maintenance". A form of planned obsolescence. But aside from that the software at whatever version I stop at is mine. It doesn't vanish from a cloud if I stop paying. It doesn't stop working if I stop paying for maintenance. I just may not be compatible with the rest of the world in the native file format but I can still save as or import STEP and IGES.

 

[gerritv]

Just some more thoughts Gerrit. Could it be that your learning difficulties were imposed by Fusion itself and not necessarily 3D CAD itself?

I don't think Fusion was my issue, I had the same with Inventor, SW and OnShape. I have no problem visualizing stuff in 3D in my mind, I even visualize source for software architecture. It wasn't until I stopped doing everything in sketches that I moved ahead. That along with projecting features from one component to the next and using a Space Mouse for easy viewing made a huge difference.
We are all wired differently, and change can be challenging 4 years of drafting classes in high school plus untold hours at home designing sports cars was difficult to unravel. I no longer really miss my drafting table so I think I am past that now.

 

[Susquatch]

I assume you want to do CNC or job out 3D parts in appropriate file formats? If not, if you want robust CAD & plan on staying in manual machinist mode, SW Maker seems like a viable alternative at $99USD or 50 or whatever the promo. That's what makes me wonder why more people aren't pursuing it. Maybe there is a strong connection to 3DP & SW has plugged that valve?

CNC - Never
Job Out - Unlikely
Stress & Heat Transfer - Prolly
Nice drawings like yours - Yes
Sectioning & interference - Yes
2D Work Drawings - Must have
3D Printing - Must have