3D printers/CNC mills

Potatoes last one shot, so build reusable! Discuss ammo designs and ideas. Tough to find cannon part or questions? Ask here!
User avatar
ramses
Staff Sergeant 2
Staff Sergeant 2
Posts: 1679
Joined: Thu May 29, 2008 6:50 pm

Sun Nov 13, 2011 9:38 pm

I've seen a lot of people get by with delrin acme nuts.


Now I need to convert my RF45 clone...
POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name :D
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25839
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 158 times
Been thanked: 94 times

Donating Members

Sun Nov 13, 2011 10:56 pm

Fnord wrote:Like my gun, guys? Print out a copy and give it a whirl!
Yep, this is definitely where it's going! At this rate I would wager that within the next decade, 3D printers will be a common household item.
just grab this whole mill for less than the price of a conversion


Ah, that's the one you meant, missed it :-/ ah well, it doesn't seem the seller was willing to ship outside the US anyhow, plus shipping and customs it would have come to over $1000.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Mon Nov 14, 2011 12:15 am

Fnord wrote:This thread is one of the reasons I'd like to see SF still online 10-20 years from now. I can just see us uploading cad files with our finished launcher posts...
Like my gun, guys? Print out a copy and give it a whirl!
On 04/10/09 I stated this in the Sketchup Model Library Sticky this:

Just think! In the very near future SpudSketch 2020 will be released!

It will have 3D modeling capabilities with the legendary GGDT and HGDT interfaces available.
Optional modules availabe are Failure Mode Analysis, Thermal Stress Analysis and Optimal Power to Weight Analysis with output
available in Rendered 3D Holograms, and CNC Data formats.

This could be accomplished, but I am sure by no means that it would be available at low cost.

Let us start simple with Sketchup and get these youngsters to comprehend 3D modeling and it capabilities.

For they are are truly the ones to develop "SpudSketch 2020."
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25839
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 158 times
Been thanked: 94 times

Donating Members

Mon Nov 14, 2011 12:25 am

That is certainly within the realm of possibility of what the future holds. My one fear is that increased capabilities and ease of manufacture will go hand in hand with increased government interference and regulation.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
evilvet
Specialist 2
Specialist 2
Posts: 266
Joined: Sat May 01, 2010 2:48 am

Mon Nov 14, 2011 2:16 am

@JSR

This is the starting point

Basic system design
Electronics bundle & the x/y lead screws

Sorry for the crappy image of the table design but CAD to JPG does not work too well for me.

The design is a moving table / fixed gantry. Initially I will use a standard 1/2Hp router as my cutter but will move up from there.

As to online plans, I cannot go past CNCzone. Have a look at the sections on DIY builds, particularly the JGRO concept. It is all about creating a CNC router but if you are talking about HDPE or non-ferrous then it is basically a mill by another name.

Please feel free to PM me if you want to talk about this in more detail or if the other members don't mind CNC chat in the spud forum i am happy to update this thread from time to time on progress.

Cheers
Attachments
Sketch
Sketch
Electronics & motor bundle
Electronics & motor bundle
The big picture
The big picture
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25839
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 158 times
Been thanked: 94 times

Donating Members

Mon Nov 14, 2011 2:17 am

Ballscrews or Delrin... hmmm...

o_0
POLAND_SPUD wrote:yeah get a CNC kit.... bi##### love cnc mills
If you found the colour code, it's not real PUI ;)

This company offers what looks like a very promising produce, but not currently available.

At this point I feel more inclined towards something like this as opposed to converting the Sherline.

Anyone aware of other affordable CNC mill platforms, possibly cheaper by being available in kit form?


Edit by MrCrowley: Not a double post, just the last post from a merged topic.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25839
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 158 times
Been thanked: 94 times

Donating Members

Mon Nov 14, 2011 2:22 am

I've renamed the thread.

Mods, could you kindly move all the CNC related stuff here to this thread? There are two parallel tangents and the other thread is meant to be about something else.

Evilvet, do you know of anything similar tothis available in kit form?

I don't need something big, and would prefer a kit with prefabricated parts in order to be confident about alignment.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
POLAND_SPUD
Captain
Captain
Posts: 5402
Joined: Sat Oct 13, 2007 4:43 pm
Been thanked: 1 time

Mon Nov 14, 2011 4:42 am

Ballscrews or Delrin... hmmm...
you might as well buy electronics first and convert your lathe/mill

Experiment with the setup, get some experience and stuff and then use the parts you already have to build a seperate cnc mill
Children are the future

unless we stop them now
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25839
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 158 times
Been thanked: 94 times

Donating Members

Mon Nov 14, 2011 5:33 am

POLAND_SPUD wrote:Experiment with the setup, get some experience and stuff and then use the parts you already have to build a seperate cnc mill
I prefer to have a separate manual and CNC mill, possibly with a similar T-slot and spindle arrangement to the sherline in order to use the same attachments.

What I should really do thought instead of thinking of buying more stuff is get off my arse and complete a bunch of projects with what I already have, and maybe start making this thing pay for itself in the meantime ;)

There's the hybrid cartridges to figure out, and I want to remake the sentry gun "properly".
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
USGF
Specialist
Specialist
Posts: 173
Joined: Sun Mar 08, 2009 5:39 am
Contact:

Mon Nov 14, 2011 8:18 am

JSR,

You got the machining bug REAL BAD. Mike has it pretty bad too. I've had the same bug for over 35 years.

In a nutshell, I'd start with a cast iron machine for a CNC conversion. If that is not doable, then a machine built up with linear ball or roller bearings. Taigs, Sherlines, Maxncs and others based on aluminum extrusions or castings are not up to the rigors of CNC IMHO.


USGF
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25839
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 158 times
Been thanked: 94 times

Donating Members

Mon Nov 14, 2011 8:56 am

USGF wrote:You got the machining bug REAL BAD. Mike has it pretty bad too. I've had the same bug for over 35 years.
I should have done this years ago, but now that I've taken the plunge I'm trying to make up for lost time :)
In a nutshell, I'd start with a cast iron machine for a CNC conversion. If that is not doable, then a machine built up with linear ball or roller bearings. Taigs, Sherlines, Maxncs and others based on aluminum extrusions or castings are not up to the rigors of CNC IMHO.
What about something like this fitted with a Sherline type spindle?

Remember I'm quite happy to stick with brass, aluminium and delrin so that's the sort of abuse it would see.

Are there any kits you know of out there you might recommend?
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Mon Nov 14, 2011 9:43 am

JSR;

The horse as spoken! :D
Probably some reliable advice given.

USGF;

I suggested JSR talk to you.
See page 2 of this post for reference. :)
User avatar
USGF
Specialist
Specialist
Posts: 173
Joined: Sun Mar 08, 2009 5:39 am
Contact:

Mon Nov 14, 2011 5:32 pm

Gents,

CNC machine builds - it's a huge world in itself. Then you add software, tooling, techniques, materials, projects, products. You get the idea. I'll start with insights on a basic machine build.

I have ended up with giant machines. Even by industrial standards, my machines are large. It's simply a response to growing needs. So first off, try to assess honestly how big a work envelope you are likely to need. This is important because price and performance will grow or suffer dramatically based on these decisions.

Will you cut plastic? Brass? Aluminum? Steel? Chrome Moly? harder? Gantry style machines - usually called routers, are for lighter materials. C frame machines like RF-20s, RF-45s, Tormach etc are true mills and are set up with smaller travels but with more iron holding the spindle steady.

Stiffness of the machine is what it is all about. Stiffness without dampening will cause chatter at the cut. This is where cast iron is the most (traditional) effective material at cutting down on chatter. There are DIY and industrial machines made with Polymer concrete. This is EPOXY :P mixed with aggregate.

I will not deal with anything less than a high quality ballscrew based machine. The screw is the accuracy of the machine and hence your parts. It is the part that dictates how efficiently your motors will convert power into motion. All the delrin style and acme screws I have used in the past died real fast. Or I thought was fast. Turns out, the amount of travel a CNC machine will make in a day would take a manual machine months if not years to go.

So, along with ballscrews, the ways are subject to a lot of wear too. Cast iron dovetails or box ways are pretty stiff. They also dampen vibration well. They use a lot of power since you are dragging two oiled surfaces against each other.

Linear ball or roller ways can be as stiff but will not dampen vibration as well as a cast iron way. The aluminum machines, they are not stiff and they do not lend themselves for heavy cuts for the most part. It can be done but it is not the ideal material.

Well, that is a lot for one post. I will add some more later. Lets hash on this material for now.

USGF
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25839
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 158 times
Been thanked: 94 times

Donating Members

Mon Nov 14, 2011 5:59 pm

Thanks for that :)

I appreciate that the scale of what you deal with today is far beyond what I will probably ever deal with.

My immediate requirements (that will probably hold true for a good few years to come) are materials like delrin, perspex, aluminium and brass, most likely the 6" x 4" x 4" travel this offers for example is adequate for what I have in mind.

Is a "gantry" type setup adequate for this sort of work?

I'm not too keen on the wooden framed designs, especially living in a high humidity environment.

Building small is someting I've always enjoyed and space is always an issue so going "industrial" will mean that my life situation in general would have changed considerably.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
USGF
Specialist
Specialist
Posts: 173
Joined: Sun Mar 08, 2009 5:39 am
Contact:

Mon Nov 14, 2011 6:20 pm

JSR,

Regardless of size, you want accurate and smooth tool movement. The machine you linked too has in my opinion too many plastic parts. That basic design made with aluminum or better materials is exactly what you need. If you make the decision to go with ballscrews, note that most small machines like a sherline do not have enough space inside for a ballnut / ballscrew assembly. I ended up making a lot of those things from scratch in those kinds of conversions.

USGF

A shameless plug here for Bob at http://www.cnccookbook.com/ Lots of CNC and general machining
Post Reply