Hi folks, slight delay while Greg gets connected...
Hello Dan, I've got spotty wifi right now hoping it will improve
Looks like we're ready to go. I'd like to welcome Greg Zumwalt to the Hack Chat today. Looks like he's having connectivity problems, but we'll try to make do.
Can you tell us a little about your background, Greg?
I went to college at the University of Tulsa for Business. While there I worked fixing arcade games to pay the rent.
After graduation I went to work for an aircraft simulation company
Cool, I worked in an arcade when I was in my teens. Always wanted to get into the repair side.
After 5 years of that Tandy asked me to write video games for them
hey! my first 'puter was a Tandy 1000
I wrote 37 video games for Tandy Corporation, Atiari, Sega of American and electronic arts.
and more that I can't remember '
One of my first games was a game called Star Blaze for Tandy Corporation for the first color computer
Games have become such big productions now. Must be so different from the days with one developer or a small team doing everything.
A few games later Tandy asked me to program Tetris created by a Russian Mathemetician
Yes it is a lot different if you wanted a graphic engine I had to write it my self
If I wanted to drawn a line I had to write my own algoryth
Did you think up the games? Like Star Blaze, was the gameplay your idea?
and there was no Wikipedia to copy-paste Bresenham from :P
When an arcade manufacturer wanted a game moved from the arcade to the computer Tandy would line me up to do it for them.
:) correct no Wikipedia
I created a few original games Varloc was one of them it was a 2 demontional chess algoryth
Flight Sim1 was another one I created. It was a flight simulator
Why do kids and people like to play for hours, but when it comes to school almost everybody wants it to be over instantly.
I always loved flight sims. Thought it must have been challenging to make it realistic without making it unplayable.
For a lot of people school isn't entertaining. But I enjoyed it I enjoyed math and science
@Sylvester Demmel because games give you a sense of agency and freedom, a sense of achievement, and a sense of belonging, and schools actively work to take all those away from you
Yes, at that time my graphic engine was line based and it was the best you could do on a 1 MHZ color computer
I always looked at it as you're happiest when you're doing what fits your brain. Sometimes that's solving problems in a game, other times that's solving problems in classes. Usually the games win, though - they just fit my brain better.
And controllers fit my hands better than a pencil
I feel kind of the same way it just all made sense to me the ones and the zeros all made sense. That is the way my brain thinks.
@Greg Zumwalt you have been working with digital games for years now... any works on physical mechanical devices as well ??
I designed flight control systems for military, business and commercial aircraft and the training.
and 4 degree of freedom and 6 degree of freedom hydraulic motion systems
Stewart platforms? Those things are cool
Can you describe some of your hobby projects?
Yes, please - you seem to have a lot of automata builds.
Its a motion base that provides pitch roll yaw and heave on a 4 degree motion base and adds latitude and longitude on a 6 degree
While doing all this I collected tools so that i could do all the mechanical stuff I wanted to do.
I machine gears and parts using a CNC mills and lathes and it took a long time
Do you like the ease of printing gears instead of milling them?
when 3 D printers became available it became so much easier taking much less time to get from in your mind to in your hands
The gears I've seen on your stuff look pretty nice. How are you designing them?
I use Autodesk fusion 360 the gear add in as a template
I use the gear add in as template to which i can add spokes, hubs, threads and other attachment points.
I tried the add-in for Fusion 360 with only mixed results.
Maybe I wasn't trying hard enough...
@Greg Zumwalt how do you ideate your projects and come up with concepts
What were you having difficulty with?
I think it was the initial learning curve, honestly. I sort of jumped in without really understanding what I was doing.
@Dan: Were the gears binding? I find that most online gear generators create an exact size gear, but it usually needs to be bade slightly smaller for 3D printing.
made slightly smaller
sometimes I see a pieces in a museum piece. Darth came from a museum piece. And hummingbird was inspired because my wife likes humming birds I get my ideas from different links i see or want to create.
I generate gears using Gearotic and set the tooth size to 48%. This gives 2% backlash and runs smoother for printing.
Yes, I use the calculated pitch radius plus .4mm with a .4mm nozzle.
sorry no links but things I see
While on a recent family vacation (all 26 of us), the wife and I took the family members to a variety of attractions, one of which was a museum with a fascinating automata. The kids and grandkids suggested I design and 3D print a version of the automata using Darth Vader as opposed to the generic figure of the museum piece, and "Darth" is the result.
A remix of this with the death star would be great
Long before the concept of A.I., as we know it today existed, humans started building machines that seemed to move and even think by a will of their own. For decades we have been building automatons, self-operating machines, designed to resemble humans and animals.
I and get asked many time to create all sorts of things i.e. Fablab asked me to design a boat for them.
thanks for the pictures
Those parametric print-in-place hinged boxes are pretty cool too. I've never done print-in-place - how does it work?
The eight different size and color 3D printed "print in place" hinged containers appearing in the cover photograph of this tutorial do have one thing in common; they were all printed from a single Autodesk Fusion 360 model using "parametric modeling".
Primarily the design has to be self supporting
@Dan Maloney @Greg Zumwalt @Steve how do you guys plan movement in your automata . I mean its one thing to get the stuff to move but do you also plan the flow of movements to convey the mood. For instance a robot although it moves might not look like a person walking .... is it just experience and intuition based ?
In this example the hinge sockets and hinge balls were designed with user specified tolerance to account for print accuracy.
It was my first 100% parametric design
My view on games is, players learn a lot about the game their characters and properties. I think the reason game playing is so much fun is that it is demanding for the player, problems that are in the reach to be solved by the player and then getting rewards - that keeps your motivation alive.
Make it too demanding or too easy and the motivation will be gone very fast.
Why not use the same approach from the games to teach something usefull ?
What is your thought on this?
I watch people and animals as they move and I use fusion 360s joint animation to build and test my models using parametric modeling I can adjust a few parameters and fusion rebuilds the model instantly and I animated it to see if I like it
Kind of blows my mind that articulated parts can be captured together like that. Saw a print-in-place parallel pliers today that was kind of amazing.
before fusion I wrote my own modeling software to animate Saber.
So I gained a real appreciation for Fusions joint and animation modeling.
Fusion joints and assemblies are a HUGE time sink for me. I've spent hours trying to get an assembly just right, for no real reason other than learning ho to do it.
Did you see my 2 gear demonstration that I recently published on YouTube?
The floating pinion demo?
No its a simple 2 gear tutorial how to animate joints in fusion
yes that's the one
@Dan Maloney feel free to reach out to me if you need help with joints.
OK, good - I like tutorials. I'll take a look
It takes a little getting used to, but once you do it’s actually super powerful
@technolomaniac - Thanks!
it shows you the use of spur gear add in and revolute joints and motion links.
Just feel free to email me at work, it’s first name . Last @ autodes
We can screen share and I can show you some tricks.
My wife reminded me of the time a little over 2 years ago I came screaming that it was too complicated and 2 years later I'm still learning
I can see that our "official" time is almost up, so I want to thanks Greg for joining us today and showing us around some of his projects. You've had an interesting career and it looks like you're not slowing down in retirement, which I respect immensely.
Feel free to continue the chat as long as Greg wants to hang around. And don't forget to stop by next week for Quinn Dunki talking about how to set up a home machine shop: https://hackaday.io/event/164060-the-home-machine-shop-hack-chat