Mentor needed as well as help on a school project!

[Robo_Pi]

What I found was that the investment in lathe and mill were minor in comparison to all to the tooling to go along with them!

Buying a machine is cheap.... Buying tooling for the machine will absolutely never end....

What you guys are talking about is building up an entire machine shop.

All Racer wants to do right now is build a Curta Calculator.

It's not like he's going to need to be running out buying things like a $1000 precision Kurt vice to hold something in Bridgeport.

 

[Cobra]

What you guys are talking about is building up an entire machine shop.

All Racer wants to do right now is build a Curta Calculator.

It's not like he's going to need to be running out buying things like a $1000 precision Kurt vice to hold something in Bridgeport.

Agreed James, but on a short time line he doesn't get the benefit of making much of his own tooling and therefore is buying everything. He won't need a Kurt vise, but then, most of us don't but he will need a lot.

 

[jwmay]

Brings to mind something Mr. Lyle Peterson often says after finishing the machining of some small item. All you need to make this yourself is 10,000 dollars worth of equipment.

Paraphrased of course.

 

[Robo_Pi]

I'm methodically looking over the drawings for the Curta Calculator. I have a long way to go yet, but thus far I haven't seen anything that would require any expensive tooling. I could be wrong. But I think it's premature to just jump to the conclusion that this is going to require expensive tooling.

The only thing I can see at this point is the need for a small x-y vice for milling on the lathe. Yes, we could run out and pay a lot of money for one of those, or we could build one that will do the job for a few dollars. In this case the latter choice would work, so why not make that choice?

It would also be nice if Racer could have a full set of collets. But again, that's more of a luxury than a necessity. Everything can actually be done in the chuck. There are some parts that would be easier done in a 4-jaw independent chuck. But there are ways of getting around that as well.

I won't know until I go through all the drawings exactly what might be needed. I'm only on part #6 and there appears to be 162 different parts. So I have a long way to go yet.

By the way, if he runs into any parts that he can't make he can always farm out those few parts.

In fact, I might be able to make a few parts for him if needed. We'll have to see how things go.

 

[Robo_Pi]

@ Racer,

I've been going through the parts drawings. I'm going down only the PDFs right now. I'm down to PDF #10023

I noticed that PDFs 10013, 10016, & 10017 are missing? Don't know if you just skipped over those numbers or if those parts drawings are missing.

In any case, I haven't seen anything yet that appears to be too challenging. There are a few items that are going to take quite a bit of various set-ups to machine. But it all looks to be doable so far. But I'm only 23 parts into it.

Fortunately the most difficult parts to make only require a quantity of 1 each. So since the set up for those parts is going to be quite extensive it will probably pay to make quite a few of them while the machine and tooling is set up for that particular operation. These are the main body and framing parts. It probably wouldn't hurt to make ten of each. That way if you ever decide to make more of them you'll have the most difficult machining out of the way in those body parts.

Some of the other parts are going to take a lot of set up too. But fortunately we'll be able to stack those parts together and make 10 or 15 of them at once. Which is how many are needed for just one calculator. If you want to make more than one calculator you'll need to make a stack of 10 or 15 of these parts for each calculator.

It's a really interesting project. I hope we can see this through to completion. And I hope it works after all the effort.

 

[Robo_Pi]

Just for the record, I just tried uploading a Solidworks 3D parts drawing into Fusion 360 and it opened very nicely and I'm able to view the part in 3D from any angle and measure it precisely. So I'm all set as far as the drawings go.

I still want to go through all those PDF drawings first though to get a good overview of exactly what I'm building. I only have 120 more parts to view.

 

[racer8412]

10013 and 10017 are crossed out on the BOM and arent used in the mass produced curta, i believe they were part of the prototype but not the final product. 10016 is a part i think could be made as part 10011 which is what was done on the 3d printed version but is included as part 10027.

 

[racer8412]

It was not translated so the drawings for parts 10016 and 10027 are in the original drawings folder. After examination they are NOT the same part.

 

[Robo_Pi]

Morning Report

I got another 20 some parts examined. I'm renaming the files by part name and organizing them in folders according to their general functions. I also started a spreadsheet to keep track of each part name, number, quantity, and level of difficulty. I'm only guessing at the level of difficulty. Most parts are fairly easy. Some I have marked as "Interesting" which basically means they are fairly complex but shouldn't be too difficult to make. Some I have marked "Cumbersome" to mean that they could be made really easy save for one feature that will tend to slow down the whole process.

I'm up to part# 10044. I have 91 more parts to organize and examine. It takes me about an hour to go over 25 parts. I'm only doing this because I'm interested in building this project myself.

Although I should warn you know. This isn't going to be an easy project. It's going to be extremely time consuming. One thing for certain, if you decide to make this calculator you will learn very much about machining. You're going to need to employ just about ever trick known to machinists to get this done. Especially working with just a mini lathe. Which I think would be a really good idea because that will force you to learn how to do things without fancy equipment. For example a dividing head would make a lot of operations much easier. But learning how to get around from having to use a dividing head would be a far greater learning experience.

Oh, by the way, who drew up these plans? Were these specifically designed for 3D printing?

The reason I ask is that there are actually better ways to design a lot of these parts for machining them from metal.

 

[racer8412]

After examination on the parts and how they fit together, it does not seem to matter which is used in the assembly, 10027 seems to be the most simple to make and is what I would recommend making. The drawings were obtained via the curta online museum and the ReCurta project, they are designed with machining in mind and are only translated from the original german and recreated in solidworks.