Inventor Pro Help if Possible

[docdavies]

Folks,

We have just moved to Inventor Pro this year after doing most of our past work in PowerPoint if you can believe it.

Needless to say, we're facing a stiff learning curve. If there is anyone who would be willing to hand - hold a new team and answer all our newbie questions, it would be greatly appreciated.

In particular, we're have quite a few problems modeling the various connectors, DB37, RJ45 etc. And placement of parts and constraints, are still not registering with us.

Any and all help would be appreciates.
Doc

[kramarczyk]

If you have specific questions feel free to post them here or PM me. I can't guarantee my availability, so posting here may be more responsive. Of course, posting here could be like drinking from the fire hose. Pictures are worth a thousand words... cell phone pics are worth 750.

[Trent B]

A few things to check out
http://team1323.com/cad/index.html

and assuming you acquired your autodesk software via students.autodesk.com and the FRC promotion check out this link
http://students.autodesk.com/?nd=kitofparts_view - autodesk provides much of the Kit of Parts in inventor files, you can download individual pieces or sets such as chassis sets

Also check out http://www.3dcontentcentral.com/ they have lots of manufacturer designed parts to download in multiple formats. Additionally sometimes McMastercarr has 3d drawings. When you click on the specific part you want (I chose a random screw) it may have a 3d drawing on the side.


Feel free to skype me if you have some questions, I can try to answer them though I haven't used Inventor for a while

[mplanchard]

For common electronics, hardware, motors, gears, you really want to find the model - not make the model. A DB 37 and RJ 45 connector are available on www.3DContentCentral.com in any model format you want SolidWorks is the default, but you can select Inventor.

For the case of the DB37 and RJ 45 you must decide what type of mounting. There are a few options.

In assembly parametric modeling here are my rules of thumbs.

1. If there are mating holes - use the cylndrical face of the hole from two unique parts. This is the face that looks like a soup can label. When you mate holes - you can find issues, like fit and tolerance.

2. When you complex plastic geometry like some of the casing on an RJ45, then you need to use planes. Planes can really be your friend.

3. If you can find a model created by a vendor - use it. This is even better than models created on the fly in software - for example, if I was going to work with a gear from Boston Gear or pneumatic from SMC - I would go to their supplier catelog directly or from 3DContentCentral. No one is going to pay you to design something already created and in robot competitions you have no time.

4. It has been a while since I taught different CAD tools, but SolidWorks can help you understand what is the "assembly process" and "different types of mating techniques" for you robot. Go to www.SolidWorks.com/roboticstutorials. Select on Unit 3, Assembly and watch the video.

Marie

[docdavies]

Marie,

Thanks for the response. But like I view the Inventor Pro tutorials, it really works better if you speak English.

If I spoke your language, I'd probably be able to understand my own problems.

So in simple language. I'd like to stick some of the electronics modules on the surface of a transparent "plastic" sheet I created in much the same way we use velcro.

I know I can use constraints, but I don't know exactly how to use constraints to "stick" things on the plane of the plastic sheet.

Thanks,
Doc

[RoboDesigners]

Just like in real life, constraints are used to link parts or assemblies together in an assembly. So, constraints are only available when you are working in an assembly file (*.iam)

As far as I know, constraints just "anchor" a piece in one axis. (I'm new to CAD too, so I there may be more to constraints than just that...) So, if you want to just anchor a module on a piece of plastic, you must constrain it 3 times:

Constraint 1. Bottom of module to plastic piece (offset = 0in)
Constraint 2. Front of module flush to front edge of plastic sheet (offset = However many inches you want, I used 5in)
Constraint 3. Side of module flush to side edge of plastic sheet (offset = However many inches you want I used 5in)

Here are some pictures to illustrate.

If you can't get the constraint tool to select what you want it to, (i.e. it's selecting an axis instead of a plane), hover the mouse and click the arrows that appear below the current constraint. (Constraint3selecting.jpg)

Hope this helps!
Andrew

[docdavies]

Folks,

Thank you all, after a punishing, but rewarding weekend (and all of your great advice), I have a much better handle on constraints and such. And Marie, after reading my book, I now know more about your advice and it is very helpful.

Couple more things:
1. How do you switch views quickly to be able to pick the appropriate surfaces for constraints. Some times when I use planes I get very "unusual" results.
2. The 8020 CAD model I use does not have nice clean edges to use for constraints. Is there a best practices for using 8020 tubing.
3. No matter how much I try to hold dimensions to fixed numbers, I run into the problem that things don't align completely. Is there a way to edit a piece of 8020 in an assembly so as to either "stretch" it or "shrink" it?
4. I've found that putting 8020 together using constraints based on holes and the center of the 8020 tube works well. I'd like to go back and edit past drawings using this technique. Is there a way to pull a deep seated piece of tubing (which has constraints associated with it) out of the morass to add a few holes when I can't get a view of the piece?

Thanks for your patience everyone..... GP lives on!!
Doc

[kramarczyk]

Originally Posted by docdavies

Couple more things:
1. How do you switch views quickly to be able to pick the appropriate surfaces for constraints. Some times when I use planes I get very "unusual" results.

I like to use dynamic viewing. Hold down F4 and then click and drag with the mouse. When you press F4 a circle will come up and starting the drag from different areas will give you different results. Selecting inside the circle will let you spin in all three axis around a point. Selecting outside the circle at the top and bottom quad hashes allows you to spin around a horizontal axis. Selecting at the right and left quad hashes allows you to spin around at a vertical axis. Selecting just outside the circle but not on a hash allows you to spin on an axis coming out of the screen. Without F4 you can click and drag with the middle button and pan the model. If you have a roller mouse that will take care of the zoom. I have a 3D space ball and prefer to use the mouse.

2. The 8020 CAD model I use does not have nice clean edges to use for constraints. Is there a best practices for using 8020 tubing.

Can you use the faces? I imagine this would be situation dependant.

3. No matter how much I try to hold dimensions to fixed numbers, I run into the problem that things don't align completely. Is there a way to edit a piece of 8020 in an assembly so as to either "stretch" it or "shrink" it?

I don't follow. Can you elaborate or include a picture?

4. I've found that putting 8020 together using constraints based on holes and the center of the 8020 tube works well. I'd like to go back and edit past drawings using this technique. Is there a way to pull a deep seated piece of tubing (which has constraints associated with it) out of the morass to add a few holes when I can't get a view of the piece?

It sounds like you want to work in context. (i.e. Edit a part while viewing the assembly.) To do that double click on the part in the Model Browser or select the part -> right click -> edit You should see the rest of the assembly take on some tranparency that allows you to see your work part. This is a highly valuable technique.

[docdavies]

Mark,

Again thanks. I've also learned some valuable things about making components that are in the way, "invisible" which seems to help some situations.

I will post an image about "stretching" later today.

When you folks, try do the power wiring on things like the modem (with the concentric +/- connections) how to you set up it's pins. Similarly, when trying to wire/cable an RJ45 Ethernet cable, how do you set up the pins on the jacks?

Doc

[docdavies]

Well, you know, if you just do your homework a lot of your questions will be answered.

I was doing my usual web trolling for information and came upon this VEX site

http://www.vexrobotics.com/vex-edu-cad.html

Although it's VEX, it has several nice Unit presentations on CAD dealing with the problems I've been posting. Those presentations have nicely filled in a lot of the gaps I've had because I have been learning it piecemeal.

Does Autodesk have a similar curriculum for FRC?

Doc

[docdavies]

Welcome to Reality.

I was making progress and beginning to feel like I was getting some traction when it came to doing the CAD for our wiring systems.

I asked a mentor from another team what he thought of my work.....

He was polite, but mentioned I have a LOOOONG way to go.

Is there anyone reading these forums who would be willing to share one of their "professional" CAD pictures of a robot?
I'd like to get an idea if there is a light at the end of the tunnel, for getting my kids to a CAD design award in a couple of years....or...well....we're just going to get run down by the train!