CNC lathe bed & headstock project

[The Blight]

First a little explanation of what I'm trying to do, and why.

I have just started working on a project at my school, where I'm supposed to design a lathe bed for DIY purposes. I am to figure out what people want from such a machine, and construct it. So that's why I need your help to figure out how this machine will be constructed (features, size..etc).

[Update with more information about the project]
This is a fictional project where I'm supposed to design a potential product for sale. In this case, I have targeted the DIY group, and perhaps some benchtop cnc companies. For this project I need to get information from the target group, and thats what I'm doing here now with this topic. When I have enough suggestions, and features that people want, I can start drawing the lathe bed.

I have made two topics here, and one of these is this one, and the other is in the "Vertical Mill, Lathe Project Log forum". This topic is for those who have bought some sort of mini lathe, and have or are planning on modifying it for CNC. I will be asking a few questions, and you can answer these with as much details as you want. The more information I can get, the better.

If the project turns out to be something I can actually produce, and looks feasible, I might make a couple and sell them to those who want it. This is not something that is demanded of the project, but it could be fun to do as a learning experience. I will also have to say that I love these little machines!
You can use these questions as a guideline, but if you can, please just tell me what you want from a machine like this.

First some questions related to mini-lathes and CNC conversion.
Are there any limitations when using one of these lathes as a base for CNC?
A couple examples: Not optimal placement of motors, poor placement of cables, way placement (messy chips), rigidity, precision...etc

Are there any good things about using such a machine for a conversion?
A couple examples: Price, simplicity, conversion kits designed for the purpose ...etc

Please post a link to your conversion, tell me about the project, and tell me what experiences you have gotten from it.

And some questions related to the design of a machine bed specific for CNC projects.
If you were to buy a bed for the purpose. Size & shape.
Z axis length:
X axis length:
Swing over bed:
Max Weight:
Way placement:
-Vertical, horizontal or at an angle
Other:
 
Components for conversion.
What type of ways would you use?
-Linear rails, dovetails, box ways...etc

What type of spindle would you use?
-Mini lathe spindle or other?

How should the spindle be fitted?
-Installed from factory, bearing mount, machined by user...etc

What type of axis motor?
-Servo, stepper, NEMA size..etc

Placement of Z axis motor?
-Headstock side, or tailstock side

Connection type
-Coupler or timing belt

End support for leadscrew?
-Mounting holes, block..etc

And some general design questions.
Should I focus on making it simple for the user to make an enclosure for the machine?

Handles for lifting? Should it be so light that a couple people can lift it without the aid of a winch or other equipment?

Cable canals for placement of cables throughout the machine?

What would you focus the most on when buying a lathe?

How much would you pay for it?

Anything else you would want from it?

Thanks for your help guys! I hope I can make a good and fun project of this. I will be posting the results here in the end.

Questions, comments and everything you want to say regarding this project is welcome.

PS. For the admins/mods/JRouche:
I sent you a PM JRouche some time ago asking about making these topics. Please move or remove if you feel it necessary. Thanks.

[harryn]

Hi, at the risk of sounding silly, from what I have seen, most small hobby machines do not actually produce very good results "out of the box". This means many end users spend a lot of time on tuning and part replacement.

Based on this, I would suggest that you design it in a way that makes it relatively easy for a factory to produce it in volume, with good results "out of the box".

[The Blight]

Hi, at the risk of sounding silly, from what I have seen, most small hobby machines do not actually produce very good results "out of the box". This means many end users spend a lot of time on tuning and part replacement.

Based on this, I would suggest that you design it in a way that makes it relatively easy for a factory to produce it in volume, with good results "out of the box".

Thanks! This is a good reason for doing such a project, and it's good to get feedback like this. It tells me that I might not be entirely wrong in assuming there might be a market.

Again thanks!

[harryn]

I started to think some more about your project. Perhaps rather than considering the "features" from a lathe perspective, it might make more sense to consider "what is it that people will want to make".

One of the interesting aspects of the rise of the internet, and shift away from retail shopping, at least here, is a rather steep decline in the assortment of stocked items. This can be:
- screws
- bolts
- nuts
- small tools

For someone that lives even slightly away from a major city, substantial delays are going to start happening for people to do simple tasks if they don't have the tool or part already.

An example: I needed to change a hard drive in a laptop, and it had a # 8 torx screw. I had larger torx tips for my screwdriver, but not a small one like this. As it turned out, I spent 4 hours finding one locally.

If I had a "machine" that I could have just inserted a "blank" rod of some size, and selected "make a torx tip this size", that would have been really handy. Of course, it would not necessarily have been perfect hardened tool steel quality, but probably good enough for the job at hand.

Similar things come to mind for various screws and bolts, taps (esp for use on non ferrous metals) from a range of 1.5mm up to about 50mm dia.

I guess my point is that I don't take exceptional interest to machining itself, but I would be very interested in a menu based system that let me easily make household tools, screws, etc. while I did other things, on demand.

It seems like a well designed machine with perhaps some extensions of Mach III software could do this.

Take a look at the mcmaster.com web site, and start searching on screws and bolts. The variation is astounding, but all have their place.

Just some ideas.

Harry

[The Blight]

Sorry for the late reply Harry!

I had to move along with my project, and so I'm basically done with the research.

If I had enough time for this, I would have loved to look into expanding the project into software. I can however note that a control system like this could be desirable for a part of the market.

I have been looking at the mcmaster site before with awe.

[jdchmiel]

if you think the site is amazing, you should see their printed catalog. Bright yellow 5" thick book of bible thin pages..