Messages

31

Show"N"Tell ( What you have made with your CNC machine.) / Re: Cutting 2 Morse Tapers on my DIY CNC Lathe

« on: March 18, 2013, 05:19:11 PM »

Hi Guys,

Brett,

I swear I didn't steal your saw.  I've had it for around 10 years.  I've done a few modifications including John Stevenson's adjustable stop on the jaws for gripping short stock. I have also extended the movable jaw to just brush the blade so I can cut even shorter stock.  When cutting very short stock, I fix a piece of 25 x 10 bar to the bottom of the rear jaw that also extends to just brush the bi metal multi pitch sawtooth blade.

Bud,

Good idea.  I'll try that.  I am very happy with the result as, when I lightly tap the taper home in the rotary table, I have to use a brass drift with considerable force from the under side to eject it.  I think it is very close thanks to CNC.

Regards

Chrisjh

32

Show"N"Tell ( What you have made with your CNC machine.) / Cutting 2 Morse Tapers on my DIY CNC Lathe

« on: March 18, 2013, 05:02:27 AM »

Needed a 2MT post for my new manual rotary table so I thought I'd have a go with my CNC Lathe.  I am very happy with the results.

 I am now confident to tackle any other Morse Taper (or other tapers).

http://youtu.be/Uw2aKu5sYNw

Enjoy

Chrisjh

33

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: March 11, 2013, 05:32:30 PM »

Hi,

The design intent is to be able to generate DC power to charge a battery in remote areas I visit where my solar panels are shaded.  I have a wood fired boiler design in mind, but won't build it until I am satisfied that the current engine will generate sufficient power using compressed air.

I learned a bit more.

It runs very smoothly now since I attached a machined 5Kg gym weight as a flywheel and re-timed the slide valve back to around 14° angle of advance. This is more in line with the Bilgram diagram I drew up.  I had it set by eye to around 27°, far too advanced.

I can get it to run down to 60rpm smoothly and 50rpm with a bit of variation in speed as the flywheel effect takes over at the end of strokes.

I now know that I can generate approx 4A into a 12V system.  I hooked up a car alternator to the 130mm drive pulley (I had to make a new 45mm pulley for the alternator to get enough speed).  Problem was that all of the energy being generated was being used to excite the field windings in the alternator and not enough speed to get some output for the charging system.

The plan is now to make a permanent magnet alternator which will substitute for the flywheel.  Solidworks tells me that the mass of the alternator flywheel is roughly the same as the current flywheel (4.5Kg).  I am going to use an axial flux design approach.  I have the design done in Solidworks but have had a devil of a time trying to find a steel supply place to cut me 2 pieces of 5mm plate 216mm square.  After approaching no less than 4 suppliers I finally found someone who actually got back to me with the plates.

The intention is to make the 216mm square plates into 215mm round plates with mount holes for the magnets and hub.  The hub will attach directly to the 12mm engine shaft by means of a 4° taperlock that I make myself, the same arrangement I currently use for the gym weight flywheel.

When I get the plates machined, I'll order the magnets from China.

I'll keep you posted with further progress.

Regards

Chrisjh

34

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: December 30, 2012, 05:42:42 AM »

Finally got it functioning!!

Still some work to do but at least it works.

The parts that were CNC machined using Mach3 were:

Both Conrods

Lower Cylinder Head incorporating the Piston Rod Gland Stuffing Box.

All the other parts I machined manually.

http://www.youtube.com/watch?v=Xo2soYAUao4&list=UUH2jXGbTHQPG5XGYQ9FYxDA&index=1

Regards

Chrisjh

35

*****VIDEOS***** / Re: Using HSMXpress Adaptive Clearing

« on: December 23, 2012, 05:11:28 PM »

Here is a photo of the finished parts.  The filter body was also programmed using HSMXpress and machined on my Syil CNC Mill.  I would not have even attempted to program this with my previous methods.

Right pain of a job,  the cavities are 14mm deep with only 4mm of clearance between the centre posts and the walls.  I ended up using a 1/8" 2 Flute long series cutter with 15.875 cutting edges and going very, very slow with light cuts.  Each cavity took 15 minutes.

The customer was desperate.  I advised them the correct way to do this job was to make the posts separately and bolt them in after the cavities were machined.

Regards

Chrisjh

36

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: December 23, 2012, 04:27:52 PM »

More Progress. 

Completed the chromate conversion of all the aluminium parts, made the piston and rings, fitted everything together in a mock up to make sure I haven't stuffed up.

I painted the base cottage green & the steel components Ford Satin Black.  The brass and stainless components will remain natural.

Xmas is now taking priority so it will be some time before I can make more progress.

Below is some progress photos.  Enjoy and have a Happy Xmas and a Great 2013!!

Regards

Chrisjh

37

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: December 18, 2012, 07:42:19 PM »

Starting to get there now.

Found a few errors in my design that need correcting.

1.   The reciprocating crosshead bar fouls the rocker, someting I missed in the Solidworks model, during my design effort.  The solution is to add a heavy 5 x 45 degree chamfer to one corner to give clearance.

2.  I drilled and tapped the steam input port on the steam chest on the wrong side.  I've added a plug to correct my error.

Yet to make is the aluminium piston, Ertalyte (PET) piston rings, Crankshaft Bearing housing, the PTFE stuffing glands, some stiffening plates and spreader bars for the base, and some bracing for the steam inlet and drain cock plumbing.

I found a temporary flywheel I need to add to the crankshaft to test all works before making the final designed flywheel.

Regards and happy Xmas.

Chrisjh

38

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: December 14, 2012, 08:03:42 PM »

More Progress.

Just completed the Cylinder Block. 

Made in 2 halves, bolted together, bored to suit 50.8 (2") Stainless Steel Tube, unbolted, insert stainless steel liner,  bolt back together and complete steam porting and cylinder head screw holes.

Next to make the Slide Valve and Valve Plate.

Regards

Chrisjh

39

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: December 11, 2012, 01:14:37 AM »

Below is the Solidworks Simulation Video.

I've described most of the details in the text associated with the video.

Today I made the bearing caps to go with the conrods.

I will have to make the eccentric bearing cap again because of a design flaw.  I drilled 4mm holes through 5mm thick material.  I have now changed the bearing cap design to use M3 instead of M4 fasteners.

http://www.youtube.com/watch?v=AZz3DWLOitE

40

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: December 10, 2012, 07:36:31 PM »

Top Secret

Here is another clue.