Category Archives: CNC milling

CNC milling, Projects, Uncategorized

Wheelchair cup holder

This cup holder has been specifically designed and made for an electric wheelchair user. I had already made a cup holder for an older wheelchair, but it would not fit the new wheelchair.

Using a mix of CNC and manual machines I started out with a piece of 12mm thick aluminium plate, then drew the basic cup holder shape In Vectric V Carve to produce the necessary toolpaths.

A 6mm end mill slowly cut out the 10mm deep pocket and the outer profile.

Vectric Vcarve is used to create the toolpaths
Pocket has been machined and now the outer profile is cut

With the main cup holder shape cut out, I took a piece of 18mm square aluminium and milled out the hinge bracket.

Hinge bracket

A slot was cut into the main cup holder shape to accept the hinge bracket, this needed some filing to make sure both parts could hinge properly.

Then a 4mm diameter hole was drilled through both the cup holder and hinge.

Drilling the hinge. With creative work holding!!!

A special 4mm diameter hinge pin was made on the lathe, it has a small lozenge shaped head which will fit into a recess in the bracket, this acts as a anti turn device when the nut is tightened up.

To make the cup holder stay in the upright position, I machined a slot in the hinge bracket to accept three small magnets which were glued into place. A smaller slot was milled into the cup holder to accept a small piece of mild steel bar, again glued into place. When filed down to a smooth surface the magnet and steel strip lined up perfectly to keep the cup holder upright when not in use.

Three small magnets ready to be glued into the slot
Milling the slot for the steel bar

After few more test fits and filing sessions to get the fit right, making a keep plate for the two M6 cap head screws, and a final test assembly it was nearly time to paint it.

Final test assembly prior to painting

Painting was by using car spray paint and undercoat. The end result is petty good for me!

The keep plate slides into a ‘Tee’ slot on the wheelchair frame, and is held securely by the M6 screws. The magnets do a good job of holding it out of the way when not in use, but it is easy to drop the cup holder down to use it. And in a test the cup holder stays in the upright position even when going over bumpy ground.

Overall a very nice project which will definitely be used.

CNC milling

CNC tool holders

These are little milling tool holders I have made for my Sieg KX1 milling machine.

Tool holders before blacking

The KX1 is supplied with a 2 morse taper spindle, which allows a range of tooling to be fitted. But one big flaw to this system when using it on CNC machines is that an accurate ‘Z’ height offset cannot be maintained when changing tools. The little tool holders are held in a 13mm ER25 collet which allows rapid tool changes whilst still maintaining the correct tool height offset.

Tool stick out has increased but doesn’t seem to affect accuracy

After a few months of machining various material the little tool holders performed very well. Although not up to industrial precision and accuracy they have made using the machine much more easier.

18 tool holders were made, all in a wooden holder
CNC milling, Uncategorized

RAF Roundel

This is a fridge magnet or toolbox magnet depending where you want to stick it. The roundel is the design used by the RAF between 1942-47 used mainly on the fuselage, with different designs for the wings.

Made from reverse engraving plastic with the four colours painted on the back, it is a reproduction of the fuselage markings on RB396 Hawker Typhoon, the last surviving combat veteran of WWII.

A project to restore the plane to an airworthy state has begun, and it is expected to be airworthy in time for the 80th anniversary of the D Day landings. For further information have a look at www.hawkertyphoon.com.

CNC milling

4th Axis for the KX1 CNC

Latest addition to the workshop is a brand new 4th Axis for my Sieg KX1 CNC milling machine. Purchased from Arc Euro Trade it is 4 inch diameter with stepper motor, plug and play.

4th Axis for Sieg KX1

It’s early days yet and I’m still getting used it, trying to find jobs for it to do!

I am using Vectric VCarve for the CAD/CAM.  Although VCarve is mainly aimed at CNC woodworking, it works great with metal too, I just adjust the speeds and feeds until the machine is happy.

CNC milling, General

CNC KX1 new spindle

The all new spindle assembly has been fitted to the KX1 and is now spinning a lot sweeter and quieter. The run-out is negligible which is okay for a hobby machine tool.

To test it out I have made the complicated ‘Tesla Valve’, which took about three and half hours to machine with a 3mm diameter end mill to machine the curves and tabs. CAD/CAM was done with Vectric Cut2D and Mach3 control.

See ‘Tesla Valve’ in the side menu

CNC milling, General, Projects

Tesla Valve

Link

This is a reproduction of Nikola Tesla’s ‘Valvular Conduit’ more commonly known as the ‘Tesla Valve’.

He patented this valve in 1920 but never actually made one! My reproduction has been copied from his original US patent. Some guesswork was needed as the patent drawings are not very sharp or crisp.

The buckets and diverter tabs are designed to offer resistance to liquid flow in one direction and preferential flow in the other, it works like a slightly leaking valve. It is often incorrectly referred to as a one way valve.

The ball bearings show how the tabs and buckets give resistance to the flow of liquid by getting trapped, resulting in a blockage in one direction. In the other direction the liquid flows very easily due to the angle of the diverter tabs giving a preferential flow.

Made of aluminium and perspex with brass screws and chromed ball bearings. Machined on the KX1 CNC mill.