52 replies to this topic

[Dennis David]

I posted some pictures of a desktop CNC machine I was planning on buying and there was some skepticism regarding whether it was rigid enough.

It would be easy for me to take my marbles and go home but rather I thought why dont I instead demonstrate the pros and cons of this type of machine and for those that are interested, well maybe I can answer some questions they may have. The other benefit is they can avoid the mistakes that I make as well so here goes.

[Dennis David]

The machine I am planning on getting is the Yoda 2 by Source Rabbit of Greece. The materials I will be using initially are Aluminum (6061, 7075) Brass (C260, C280) and Carbon Fiber.

I will also be using RenShape Styling and Modeling Boards (Thank you Sandy Grant).

I am looking at Onshape as my CAD software and ESTLCam as my CAM software and G-Code Sender to send the g-code to the mill.

[Dennis David]

This is the mill I plan to be using. The mill will be located in my family room and the dust collection will be on casters. These are the limitations I work under. The desktop gantry mill will allow for a larger work area but of course it is not as ridged as a traditional mill. It will be fine for the materials I have in mind. Any other part I need will be sourced.

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[eshorer]

Will you be using this to make Klasse 1 type chassis, or just anything that suits your fancy for bodies you like? 

Eddie

[Dennis David]

Just so that everyone understands I have absolutely zero experience with machinery beyond using a Dremel so everything I present here is based upon my research or recent experience.

 

The first question many people have is I know that the computer is supposed to control a machine but is this really scratch building? Well let's begin with what we have, a plate of one or more pieces material and a blank computer screen. To begin with you need to make a vector drawing of your parts. I will be starting with making flat pieces and will purchase axle and motor holders as well as suspension parts.

 

The drawing program I will be using is an online CAD program called OnShape that is free (for now) when you allow your project files to be open to the public. This is a commercial grade software by some of the same guys that worked on Solidworks. Once you have the drawing completed you need to import the project into a CAM program that will build your tool paths. These are the commands that actually run the mill. These tool paths will be in the form of g-code that you can send via a driver or a g-code sender program. I will do the latter if and until a driver is created. Not a major issue. There are actually simulation programs that allow you to run and test your g-code which are really cool. 

 

The next step is to test on some practice material and this is where the styling ad modeling boards come in.

 

Onshape CAD Software

https://www.onshape.com/

 

ESTLCAM CAM Software

http://www.estlcam.com/

 

G-Code Sender Software

https://www.sourcera...m/GCode-Sender/

 

Online Metals

http://www.onlinemetals.com/

 

Freeman Manufacturing and Supply Company

https://www.freemansupply.com/

[Dennis David]

Klasse 12 Standard requires Scaleauto Chassis but Klasse 1 Advanced is open chassis. I also plan on making chassis for MiniZ and the 1/24 Carrera. Area71 is coming out with some super Nylon Bodies which i hope to make metal chassis for but I can even see making them for American Hardbodies where I would make a standard (IROC) type chassis for scale wheels. I could see these made of brass with only a few or no screws. LOL  

 

I can easily see making brass pans for retro chassis as well.

[rvec]

Dennis,
This is very cool. Sorry is I don't understand all of the nomenclature so pardon me if the question has already been answered. It would be neat to create an H bracket chassis using .05 or .062 brass (The .062 is readily available). Can the machine handle brass that thick? If so, the center section as well as brass side and front pans could be cut. Can the machine cut holes in the brass? Can it countersink?

Keep the group informed. Maybe a DDavid chassis is in the offing!

[Dennis David]

Rich it can do all of that and more. It can counter sink and thread the hole. Heaven forbid but if you wish to be involved you'll need to go over o the dark side and work in millimeter. 

 

A lot of this is still a mystery to me so hopefully a few of you can join me on my journey of discovery. For now here is a video showing you how threaded holes are created. A lot of this is already available in the forum or you can create your own and save it for future use. I will be doing my own presets.

 

[Samiam]

 

 

The first question many people have is I know that the computer is supposed to control a machine but is this really scratch building?

 

Dennis,

As far as parts for Retro racing the rule is this:

 

Chassis parts, such as

pans, brackets, guide tongues, etc., that are

made using EDM, laser, or water-cutting

techniques are allowed only if they are individually

commercially available components or

components of chassis kits (i.e. these

techniques may not be used in the private

manufacture of one-off components)

 

So I believe anything you make will be legal for Retro use.

[Eddie Fleming]

 

Dennis,

As far as parts for Retro racing the rule is this:

 

Chassis parts, such as

pans, brackets, guide tongues, etc., that are

made using EDM, laser, or water-cutting

techniques are allowed only if they are individually

commercially available components or

components of chassis kits (i.e. these

techniques may not be used in the private

manufacture of one-off components)

 

So I believe anything you make will be legal for Retro use.

 

Sam I am not so sure I agree with you. I need to think about it but parts produced would still be machine made so just because the mill is not mentioned does not mean it is within the intent of the rule.

 

That's one for the folks making the rules to ponder.

[Dennis David]

Good question but how about if I make the pans on a band saw? How is that all that different?

 

Using EDM, Laser or water-jet cutting would require machines beyond what a regular scratch builder have available but with these new desktop milling machine available for under $1000 maybe technology is catching up with retro. Do we ban band saws and how do we do that?

 

Anyway Retro is not really my target audience. I'm more interest in scale racers and adjustable chassis.

[Eddie Fleming]

The band saw is not computer driven and capable of that kind of precision or repetition. But it is not up to me to make the call.

[Eddie Fleming]

One more thing, the band saw is much more affordable for many than the CNC mill.

[Eddie Fleming]

If you create a part and run it through tech I bet it will pass unless it is some kind of thing that could not be created by hand.

[Dennis David]

You have no argument from me. Of course all I would need to do then would be to make any part commercially available. Still Retro is not my target audience and there are enough excellent kits available.

[Dennis David]

What interest me more is Euro Scale racing and proxy racing. You find 3dp chassis showing up. But the issue I have with these are they are too flexible and I want a stiffer chassis that brass and aluminum will provide me.  

[Dennis David]

Back on topic certain major decisions are required.

 

Material

Mill

Software

Dust Collection

Lubrication

 

 

The main reason I went with a mill instead of 3DP is the material I can use with the machine in my price range which is under $3500. I went with the Yoda 2 because of my space requirements and I wanted a machine that would cut Aluminum and Brass. The fact that it used a proper spindle rather than a router was also important. A German Spindle doesn't hurt. I looked at the frame and this one uses a fairly stout steel frame.

 

Software had to be cheap and relatively easy to use or at least understandable. I don't consider myself a maker and don't want to tinker with the machine or software. 

 

Dust Collection is important and it needed to fit in the space I have or be moveable. It also needed to work with metal so bag type collectors were mostly out. I wanted CFM to be at least 125 but preferable at least 200.

 

Lubrication could wait and be applied by hand in the meantime.

[Ecurie Martini]

I think this is an excellent project and shall be watching developments very carefully.  So far as some other questions - in my opinion, if you design it, set up the tool to make it and control all aspects of the process, it is "hand made"  A tool is a tool.  Is there a difference, for example, in chassis pans cut from sheet brass by scoring and bending, cutting with a jeweler's saw, or using a table top bench saw with a metal cutting blade?  How about using a digital caliper instead of a machinists rule?  I use a miniature "chop" saw to get square cuts on brass tubing.

 

If you are cutting, not grinding or sanding, dust will not be much of a problem.  For wood, CF, pc board and plastic a small vacuum nozzle in the vicinity of the cutter will work.  For brass and aluminum, use a bit of cutting oil applied by hand during the process.  The swarf will stay near the work point and can simply be wiped off when done,  Cooling in the conventional sense is not needed especially if you use carbide cutters and modest cutting speed.

[Half Fast]

I am learning new things on this Blog, like new words:

 

SWARF: fine chips or filings of stone, metal, or other material produced by a machining operation.

 

Dennis have fun. looking forward to seeing your results

 

Cheers

[Dennis David]

Alan is a man to be listened to. 👍

I think dwarf is an old Yiddish term LOL

[Dennis David]

600 CFM bags are $25

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[Dennis David]

400 CFM Uses tray which is good but filter is $250 Replaced maybe yearly.

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[Dennis David]

These two machines are used in the jewelry business which approximates my usage profile.

[Ecurie Martini]

There is no reason why these devices won't work but are they overkill?  In jewelry manufacture, you are dealing with all day, every day activity and associated risk mitigation and also, creation of waste (gold, silver, platinum) that is probably valuable enough to warrant recovery.

 

Of course, keep in mind that I grew up and began these activities in the days before OSHA.  My father and I would clean the brass rails of our HO layout with rags soaked in carbon tetra-chloride held in bare hands. (70 years later my liver is still quite functional - accommodates my evening single malt with no ill effects)

 

EM

[swodem]

What’s wrong it’s a Taig CNC mill?


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