Guitar Chair final Assembly

[Anonymous]

This is a bottom up design as I have a bigger project coming up that I want to be able to use components in multiple projects.

This was a hand written drawing. The seat seems to be in the right place but the swing leg isn't sitting correctly even though it was correct  before I added the seat.

Also how to I get the bodies to be solid and not disengage from the frame after having jointed them to the grounded chair frame?

Thanks

[jasonhomrighaus]

Part of what is messing with you is the parametric modeling.  It forces everything to certain spots.  For a simple project like this I think direct modeling is a smoother and easier approach, Just my opinion of course.  As to the design its pretty slick but you have some issues.  I adjusted the joints so they perform like I think you wanted them to.  The seat is too long and too wide to nest inside the frame. it also is not modeled to a realistic thickness so it is difficult to set the depths of the various parts and joints to achieve the correct movements.

The McMaster carr addin is great for this sort of thing because you can pull in hinge models and use them to get an accurate representation of how the parts will fit when the hinges are in the mix.

As to the specific questions you asked, it looks like the joint geometry messed you up a little, the parts weren't pivoting on the correct edge.  I suspect also the joints may not have been set between the grounded part and the moving part, but within the part if that makes sense.

I would be glass to fiddle with this a bit and flesh it out if you want.  a nice little diversion.

[promm]

@Anonymous,

Our structure is flat in how we assemble a components in a model.  You can use as built joints and rigid groups to maintain the structure of a subassembly.  The best way for me to explain this it to point to you to a class that I taught with Kevin at AU in November.  Please watch and let me know if you have any questions after.

http://au.autodesk.com/au-online/classes-on-demand/class-catalog/2016/fusion-360/pd19577#chapter=0

Cheers,

Mike Prom

[Anonymous]

Thanks to both of you for your reply.

This was meant to be an exercise to test out what I had learned from tutorials and exercises. The designer of this chair had sent the hand written plans to me. Though I do play the guitar I'm not sure I really want to build this.

So if you do the work for me it would be pointless.

Promm,

Will watch the video later today, no time right now. Thanks for steering me to something. I will let you know if it solves my problems.

[jasonhomrighaus]

Well, I liked it so much I decided to do it anyway(my machine was giving me a headache, needed a little diversion) All the pockets for the back joins are cut out and I tweaked the support on the seat so it semi locks in place in use and during light movement. Really a neat little design.

I might actually build one of these!

Hope you like it!

[promm]

@Anonymous,

Nice work!

[Anonymous]

I just sat down to work on fusion and saw this post.

Yes nice work but how did you do it?

If you are really interested in making this chair you should get the plans. I can send them to you. I don't know if there is any way to send Pms or if it's ok to transmit emails addresses through these. There are a couple of things missing like the foam on the seat and the insert on the brace for the swing leg so it doesn't move. I really don't want anyone getting hurt.

It is a cool design.

[Anonymous]

@jasonhomrighaus

Had a closer look at your design. I really like the fillets and the extended brace for the swing leg, need to add a block on the other side of the swing leg just for safety.

Where did you get the hinges? That would have made the joints go together better when I tried to do it.

[jasonhomrighaus]

First the hinges came out of mcmaster carr catalog.  There is an admin for it or you can go online and find what you want most of their hardware stuff includes cadd models.Most of the time I just use the Addin.

First off I turned off the parametric modeling.  I Cut the hinges to the right length using split body then I took the bodies apart converted to components then assembled them with joints so they would work.  after that I took the chair apart, tweaked the dimensions etc.  For the back, I figured out final width, adjusted all the slats to the desired spacing between the rails and then used joints to position them all.  Then I deleted the joints and extended the slats so they would fit into dado pockets.  then I used the combine command to "cut out" the dados on the side rails.  once all that was working I assembled the hinges to the back piece. then adjusted the position of the seat and leg did some resizing to account for hinges and such then attached them to the hinges.

I reoriented and extended the support and used the combine again to cut out the support piece under the seat to fit it to the leg.  If you look close you will see the support has a tab on it to catch the leg from swinging too far, also it has a groove in it that the leg drops into so it will lock in place when being used and will also hold it if the chair is moved around.  only a little tension would be required to release the leg to fold it. See the pics for some of the details.

I also moved the upper slats to the rear to allow a deeper seating position.

Its actually quite easy to generate a drawing and plans from the parts.

I honestly wouldn't even bother with a cushion, maybe just shape the seat a little.

As to how I would have approached this, I would have created bodies then once i was done with the rough layout I would have promoted them to components and started assembling things just like in real life.  If I was going to ramp this to formal plans I would have taken each component, saved it as a design, aligned it and positioned it at the origin with the widest profile facing forward.  From there its a simple matter to generate an drawings or dxf profiles.  I would then create the subassemblies as new designs using the components.  Creating any internal joints on each assembly as I go.  Then once all my subassemblies are set i would create a final design and assemble all the sub assemblies.  For something more complex I sometimes will use my master design and replace the appropriate pieces with my individual designed bits.

I like this approach because it ensures that the part I am installing matches up to the design and drawing I generate for manufacturing.  I didn't do that my first time out and it really sucked.

I will be honest I have not fully gotten the hang of how parametric modeling is supposed to work but generally I end up with a big mess when I try to revise something, then parts start jumping around and before long it takes forever for anything to update.  Im probably doing it wrong but this approach works pretty good for the work i do.