Hardware store design CNC router #1

[CNCadmin]

OK start the ball rolling on a hardware store design CNC router.

[mikeschn]

Well, here we are in the hardware store design thread... Does that mean another black pipe design? Or is there a better option?

I'm not sure we want to go backwards to drawer slides...

And it'd be mighty difficult to do a conduit design like Ger21, cause we don't have a cnc machine to cut all the parts with.

Are we talking improved black pipe designs? Fixed gantry? Moving gantry?

Your thoughts...

Mike...

[greybeard]

Hi Milke,
As a newbie with no machinist knowledge but plenty of electronics and lab experience, I've been forced to use the local hardware as a major source of raw material.

For me small means a small workpiece, so it makes sense to move the work not the spindle. I'm heading for a 2.5D axis setup with the z axis movement of the workpiece coming from a separately controlled arm. But I would put the z axis movement on the fixed gantry if I needed to use the spindle in 3D.

As the only source of steppers at the moment is old printers or ebay(limited funds) the timing belts will give me my transmission.
I do have a supply of old display framing - aluminium extrusion - so I plan to use 19mm chrome steel tube ( wardrobe fitting dept) epoxyed into the channel. This will be bolted down onto an offcut slab of formica clad 38mm kitchen worktop.
I'm using miniature bearing from the scrap box augmented from ebay, but would try skate bearing otherwise.
Any thoughts?

[CNCadmin]

Drawslides work pretty good for the X and the Y. You can even you steel wire wrapped around a plastic wheels to move the gantry, like pulling a curtain.

[mikeschn]

Buying your hardware from ebay is definitely a good option.

As for using the components that you've gotten out of old printers, you'd have to include some photos and descriptions so that we could better understand what you have.

Mike...

Hi Milke,
I've been forced to use the local hardware as a major source of raw material.

As the only source of steppers at the moment is old printers or ebay(limited funds) the timing belts will give me my transmission.
Any thoughts?

[Dom]

I'm looking to build a machine using drawer runners. I've located a source with 450mm travel and minimal play in the bearings (heavy duty ball bearing runners).

I've got plenty of stepper motors now from 100oz in upwards and some toothed pulleys/timing belts.

Just need to build a workshop to house it all in before I can start building the machine.

[achiestdragon]

hi
I am currently building a machine , mainly using MDF , but i guess the problem is some of the parts , like 20mm*20mm L section steel at 3mm thick that im using for the runners and supports and 20mm stainless steel bar for the bearing slides, are not available in most hardware shops , (but are available on the web ) and bearings are a problem also,

i thought about using unistrut , that is an excelant matirial for making the frame work , even if a tad expencive , but would require minimal machining
and m10 threaded bar for the lead screws

although i guess all the bits are not available from the big diy hardware stores here in the uk like B&Q and homebase ,but i have found that CEF(city electrical factors) in the uk (have shops in almost every major town) stock items like the treaded bar and unistrut and fittings

i designed my machine to use minimal machining as i only have access to a electric hand drill and the router that i am going to use as the cutting tool and hand tools like saw, file

sorry no pictures yet and its still a few months off compleation but looks like its going to be finished within the £400 budget i set for it and its got a workspace size of 900mm*500mm*100mm

i originally started with the same idea that i should be able to get all the parts from the local diy/hardware store but in the end found that way too restrictive on parts , threaded bar for example was not available , and local steel stock holders can supply steel some places will cut it to lenth also

i can only speak for what the uk hardware stores will stock , and not shure whats available in stores elsware things like good quality draw slides for example are not available

i need to solve a dfx export problem with my cad package (total cad ) to get the fonts right then i will post my design

Dave

[rippersoft]

My first machine used a combination of drawer slides for the X axis gantry and ball bearings and gas pipe for the Y axis table. I like the drawer slides and am in the process of modifying the table to use slides.

The combo I have worked out is one heavy duty full extent slide mounted 180 degress around and on top of another slide. This means that the table will always have support and the travel is obviously doubled. This will be interesting to test.

[Jimmy Southern]

mikeschn,

Ger21's conduit design can be done without cnc If you have a good router and a laminate trimmer bit with a bearing. All you have to do is make a simple jig to hold the form that the bit follows & the work piece.

This reminds me of the Dave Gingery books. He talks at length about how some one had to build the first one. It's the old "which came first the chicken or the egg." In this case it is the egg because without the egg you can't make the chicken out of the hardware.

Also the draw guide system is not that bad. For a first time machine and a learning experience, I believe most beginners would be very pleased with the machine. I have read about many machines getting 1/32" accuracy from drawer guides. This is far more accurate than most cabinet shops could ever hope for.

I am a newbie my self and I do not have an unlimited budget to build with so I really hope that people will come to the cause with some new "cheap" ideas for the beginner.

Thanks so very much
Jimmy Southern

P.S. don't be afraid to throw out very crazy ideas, sometimes they work!!

[yukonho]

Having built a few machines now and used several different hardware store solutions for the slides, I would say that the number 1 consideration is rigidity.
This being said, the easiest way to make a rigid machine is to make a small machine. Drawer slides can work OK on a moving table if the travel is kept small enough. Drawer slides on the Z axis do not work well at all though, another solution is necessary there.
Also a moving table design with a fixed gantry will be far more rigid than a moving gantry design.
So, if I may suggest, lets work towards a small (8" X 12" travel??) fixed gantry moving table design.
Colin

[mikeschn]

Wow, I didn't realize there would be that much interest in a drawer glide cnc router.

Do we have 2 cad users here that would be interested in working on a drawer glide machine?

Mike...

[mikeschn]

mikeschn,

Ger21's conduit design can be done without cnc If you have a good router and a laminate trimmer bit with a bearing. All you have to do is make a simple jig to hold the form that the bit follows & the work piece.

Doesn't the laminate trimmer force you to cut the entire 3/4" thickness at one pass? Can you cut that much plywood or mdf at one pass?

Maybe we should look at a pattern bit.

Mike...