Mentor needed as well as help on a school project!

[racer8412]

Ive got a basic go fund me description worked out, The Curta, created in the 1950's, was a fully mechanical (no wires or electronics) handheld calculator that was designed by Curt Herzstark during the height of World War II when he was imprisoned in Buchenwald. In the past few years, a 3D printed version at 3x the scale of the original appeared on Thingiverse by creator Marcus Wu. To me this seemed like a shortcut, and didn't pay true homage to Curt and his amazing creation. I'm raising money to buy the required equipment and machines in order to mill and machine an exact replica of the Curta calculator, providing video and typed documentation of the steps taken, resources used and thought process throughout the build. After completing the first iteration. I would create more to send to museums and create copies for individuals wanting to purchase one. Donations would go directly towards a lathe, milling machine, cutting bits, personal protective equipment, materials, and tools. Please don't let this beautiful piece of machinery disappear forever!

 

[jwmay]

I'm interested to figure out how we went from a cheapo 575 dollar lathe with pocket change for tooling, and completing it in a few months, to machinists are saying 2500 dollars will cover it and it'll probably take a year, and oh by the way you'll be a master machinist by that time. I've been "hobby machining" about an hour a day for 3 years, with at least one 10 hour day a week. I've easily got a few grand in my basement shop, buying almost all used and significantly discounted merchandise. It's also taken me 5 years to get to this point.

You cannot compress the learning curve. Reading what somebody wrote on the internet is not the same as mentoring. It's a typed suggestion. You cannot catch the kid doing something wrong at the moment he does it wrong, and make the correction on the spot. THAT is mentorship. Watching, teaching, correcting, repeating....as long as it takes, until the student no longer makes the mistakes. One thing at a time, one skill at a time, one time at a time. I'm all for highly motivated students, and big dreams. But let's remember Mr. Miyagi for a moment. Just paint the fence kid. Choose something simpler. There are books FULL of engineering projects that require minimal tools.

Another thing I appreciate is a can do attitude. RoboPi is full of can do attitude. But can he do it? Well he says he doesn't know. Is that the person you want leading your charge? I really enjoy his posts. He takes on hard stuff. He uses a machine that doesn't have a super strong following, and he succeeds! That's great, truly. But the facts of the matter are that a young man with no money, and no skills wants to learn something that requires supervision and money. If we want to help him, we ought to try to find him a mentor, just like HE ASKED FOR at the beginning instead of telling him to start buying machines. But the Curta Calculator is NOT the thing he'll make. He'll make a 3 Morse Taper, and a perfectly square block, and a screw, and a hammer, and a screwdriver. And a hundred other things before he makes a Curta Calculator. There's a natural order to things. You have to learn the easy stuff before you can learn the hard stuff. That's life. Young people don't need adults blowing rainbows and sunshine up their you know whats. They need facts. You have to temper dreams with reality. And you have to WATCH every move they make in a machine shop.

We are advising a CHILD. So here's my final advice to the OP: Go ask your parents. When they sign a legal document stating they are aware of the dangers of machinery, and are totally not gonna sue us all if you get wrapped up in your tiny super cheap import Amazon lathe and die, while we waited patiently for your internet update on what you did today, I still won't be here telling you to go ahead and do it. But maybe somebody will. Best of luck in your endeavors!

 

[Robo_Pi]

Personally I would choose either of the first two.

If you want to make an educational video on how to build one you could justify it being under education. Do you have a video camera that you can use for that purpose you might want to consider that in part of your budget?

You could also potentially choose creative arts. I think any effort to maintain skills and technology from by-gone days could probably qualify as creative art. This will certainly be machinist artistry. In fact, if you build this thing I highly encourage you to think of it as "art" because you're really going to need to treat every piece as though it is a work of art if you expect this thing to function properly. This isn't something you can just hack out, toss together, and hope it works. If you complete one it will indeed be a work of art.

I just watched this video. Adam Savage has 3 Curta Calculators. A type 1 (which is what I think your drawings are for). A type 2 which is slightly larger and more complicated. And a much larger plastic 3D printed one that someone made for him.

In fact, to get an idea of what you will be making look at this video at 7:50. The man who made the extra large 3D printed one is assembling it. It's extremely complex. Just think, if you are making the smaller metal one your parts are going to be quite a bit smaller. I don't know if I have good enough eyes to put something like this together.

In fact, since I have a full woodshop I've been thinking of making a really huge one. Maybe about 2 feet in diameter first just to get an idea of how the thing works. If I do that I'll probably get a pretty nice penny for that one. I could probably sell it to Adam Savage to include in his collection.

 

[racer8412]

First off, im not inept, I know what i'm getting into, I realize that im not instantly going to make a curta on any machine that I get, also i've been introduced to these machines before, I know how they work, the terminology, and ive created small parts on both of the machines mentioned at school, that said I am still a beginner, a beginner that doesnt want to stick to the boring ass books and projects, I want to make something functional that interests me. I can get a mentor sure, one that will let me use their machines, maybe not, which is why im going to the community. Also even though Robo_Pi "doesn't know" that he can do it, that's fine, at least ive managed to peak someones curiosity and maybe get them off their butt with a new project, and that is something I can be happy about, so jwmay, please reserve the comments to constructive criticism, tips, or help.

 

[Robo_Pi]

@ jwmay,

I totally agree with you. We all mentor differently. That's what makes the world go round. I wouldn't dare think of telling you how to mentor anyone.

This is a public forum and Racer is reading all the posts so he's hearing your advice as well as mine. And you're right, I have stated clearly that I don't even know if I can build this thing myself. I do believe that I told Racer that. It's up to him to decide if he wants to hear anything further I might have to say.

We are advising a CHILD.

I suppose from a purely legal perspective you may indeed be correct. However, I personally consider people based on how mature they appear to be in their conversations and intent. Racer approached us with his ambition. I didn't suggest to him that he should start out building a Curta Calculator. But if that's his passion I'm not going to insult him telling him that he's just a child and should not dream so big.

I know what I was capable of at his age and with the proper mentoring I could have taken on a project like this myself. Like Racer my greatest limitations back then were lack of finances and mentors who would BELIEVE in me.

I also agree with you that most average people do need to learn things on an extremely slow time frame. I'm not one of those people. I was always held back by educational systems, precisely because they didn't want to move forward at a pace that suited me lest everyone else would be left in the dust.

For all I know Racer is a genius beyond his years. Can you say with certainty that he's not?

How many high school students do you know who are even THINKING about making a Curta Calculator from scratch? The mere fact that he even wants to do this speaks volumes to me.

Maybe all he needs is some positive encouragement and a financial kick start. He might be the next Elon Musk for all I know.

If he wants to build a Curta Calculator I'll be the last person on earth to try to talk him out of it.

If he fails, so what? It won't be the end of the world. If he doesn't learn a lot about machining he will at least have learned not to bite off more than he can chew.

And who knows, he might surprise us all and build one of these things better than any of us could do it. You never know until you try.

I'm just trying to help him with what he ASKED for help on. I'm not going to discourage him and tell him he can't do it. He seems to be into it pretty heavy. He must have a passion for it. He's got all the drawings and clearly a desire to do it.

Most kids his age are out on the streets causing people trouble. He wants to spend his summer building a Curta Calculator. Gotta at least give him that much. Tell me this is what your AVERAGE high school student dreams of. I think not.

 

[Robo_Pi]

Also even though Robo_Pi "doesn't know" that he can do it, that's fine, at least ive managed to peak someones curiosity and maybe get them off their butt with a new project, and that is something I can be happy about, so jwmay, please reserve the comments to constructive criticism, tips, or help.

Sounds like a pretty mature response to me.

And yes, I don't know whether you'll be able to pull this off or not. I don't even know if I can pull it off. But that's not the point right?

Trying is the point.

One never knows what one can do until they try.

So try, and try again, and if that fails, just get back up and try some more.

Nothing will be lost if the project is beyond us. Even in that case we will have learned a lot from having tried.

Success is more than just the final goal. A man who refuses to take the first step will never complete the journey.

 

[jwmay]

I don’t think you’re inept. I believe you are a smart, talented, highly motivated person who also happens to be too young to work in a machine shop without adult supervision. You started this post asking for a mentor with a machine shop. That’s exactly what I think you need. I am agreeing with you! Anyways I do wish you the best of luck with sincerity. And I’m quite impressed with your idea. I will though, leave your thread alone from here, as I cannot in good conscience, encourage a minor to use machine tools unsupervised. That stopped about a hundred years ago, and I feel like there must have been a good reason for it.

 

[ttabbal]

If you want to save a few bucks on lathe tools, let me know when you're ready and I'll send you a couple of ground HSS tools. You'll need some sharpening stones or diamond cards to touch them up here and there. They will likely give you a better finish on a mini lathe than carbide will though.

 

[stupoty]

You might want to consider making it 5 times bigger than real size and using ply wood for as much as possible.

You could use printed paterns glued onto the ply and a band saw to cut parts quite acuratly.

If you look into "horology" (watch making) you will see it wasnt uncomon in the past to hand cut gears and quite complex parts using acurate scribed layout and engraved paterns with pantograph reduction techniques.

Also as has been mentioned this could be a good project for a desk top cnc perhaps.

Stu

 

[Robo_Pi]

You might want to consider making it 5 times bigger than real size and using ply wood for as much as possible.

I've been seriously thinking of doing precisely that. I have a fairly complete woodshop. About the only thing I don't have is a wood lathe, but I could obtain one of those fairly easily. I was thinking of making a really huge wooden replica to iron out all the manufacturing bugs. Maybe as large as 2 feet in diameter. Something where the parts would be so huge the tolerances would become easily manageable.

This would be the best approach to be sure. But it would also be quite time consuming just to build the wooden replica.

I've been looking over the parts drawings, and I have found a few parts that are going to be quite a challenge to make. I have some ideas for moving forward. But as you point out, even those parts will best be made quite a bit larger first time around just to work out the manufacturing details.

The biggest problem I see is not the complexity of the parts, but their extremely small size. Some of these shafts are only 2 mm in diameter with a ton of complex features milled into them. Talk about the size of machines. We need a milling machine small enough to sit on the stage of a microscope just so we can look through the microscope to do the milling.

The smallness of the parts may become the nemesis that slays the project. These parts are seriously TINY!

Even the mini lathe I suggested for Racer is going to be a mammoth compared to these tiny parts.

I may have gotten myself into something far smaller than I can deal with.

The complexity of the parts doesn't bother me. But the extremely small size does. These parts are formidably teensie weensie.