[KKutt]

You may be able to solid model the prop from points at several cross sections of the airfoil and generate code from that model, save alot of probing time.

[mohop]

to keep up with resurrecting an old thread....here's an interesting youtube video of a wood propeller with a Routech Chronos 5axis
[ame="http://www.youtube.com/watch?v=Cm_9LmXz4Mk"]http://www.youtube.com/watch?v=Cm_9LmXz4Mk[/ame]

[txcowdog]

5 axis machining... that absolutely ROCKS!

[atypicalguy]

I'm figuring out how to machine a T-shaped hydrofoil on a 3-axis router. Ideally I would begin with a carbon fiber blank not unlike the wood blanks the propellers are made from, and mill the vertical strut and the lifting foil as one piece from the T blank.

Dimensions are about 60" tall, 50" wide, and 9" fore/aft. The part would obviously have to lie flat on most 3-axis routers, meaning the routing would occur with the spindle sideways. Mounting a fourth axis on the Z slide would permit me to rotate the spindle about the Z axis and turn the corner to mill the top and bottom of the lifting foil. Final surfacing will likely be done with a bunch of ballnose mills.

Has anyone mounted their 4th axis this way on a ShopSabre? And how difficult is it to describe this configuration to a CAM program like RhinoCam or MasterCAm, assuming the machine control is with WinCNC?

I think the limiting factor may be running out of gantry clearance over the part, as it will have to be mounted above the table to allow the spindle to get low enough to mill the part without the spindle housing hitting the table.

I have been hoping to find a gantry with more Z, but 12" seems to be about the max most regular low-end industrial machines can clear. That might do the trick, but it would be close and depend upon the spindle size.

Thanks,
Karl

[bostosh]

Karl, I've programmed both of these types.

This is a machine which can do the part. They have been used to machine large ship props. I was most impressed by the 7-axis version. machining a 6' tall single blade.

SCHIESS-FRORIEP Vertical Turning and Milling Retrofit with SINUMERIK 840Di

another choice is this:
GIDDINGS & LEWIS VARIAX 840 (5) AXIS HORIZ. BORING MILL
CONTINIOUS PATH 5 AXIS PROFILER FLOOR TYPE
RETROFIT WITH DELTA DYNAPATH 20 CNC CONTROL
CONTROL ......................: Delta Dynapath 20 Retrofit
SPINDLE QUILL DIA ............: 5"
CROSS SLIDING ANGLE PLATE ....: 48" High x 162" LR
CROSS TRAVEL (X)..............: 170"
VERTICAL HEAD TRAVEL (Y)......: 51"
SPINDLE TRAVEL (Z)............: 18.5"
SPINDLE SPEEDS (32) STEPS.....: 17-3600 RPM
SPINDLE MOTOR.................: 30 HP
SPINDLE TAPER ................: #50
A AXIS HEAD TILT UP/DOWN......: +- 22 DEGREE
B AXIS COLUMN SWIVEL .........: 20 DEG. RIGHT- 60 DEG. LEFT
MACHINE OVERALL HEIGHT........: 29FT 11" FLOOR TO TOP OF MACHINE


EQUIPPED WITH:

ELECTRICS-460 3/60
CROSS SLIDING ANGLE PLATE WORK HOLD SURFACE
B AXIS ROTATING COLUMN
A AXIS SWIVEL SPINDLE HEAD UP/DOWN
Z AXIS SPINDLE IN/OUT
PIT MOUNTED COLUMN
PIT DIMENSION: 256" x 102" x 24" Deep

[Pieterjosia]

Well, I know a 5 axis cnc machining center could do the job quite nicely with the help of MasterCam 9 or 10. SS boat prop's are made this way. As are the molds for aluminium ones. How many axis on the ShopSabre?

Hi, The SHOPSABRE is a 3 axis machine and cut up to 4 meters (in length) propellers.And over 4700 propellers was cut on this machine. I design and do the CAD files myself as well as laminating, and then CNC cutting. On average it takes about 4 hours to complete a 74"type propeller for typically a CESSNA 172. However, now that I a, 69 goimg on 70 I have slowed down and enjoy Tremendously!! retirement. Anybody anywhere mayask me anything about aircraft propeller design etc.

[Pieterjosia]

Hi KKUTT,
I never ever probed anybodys design or copied any brand name propeller. The shape, thickness and pitch of any aircraft I did the CALCULUS / mathematical calculations myself and had great success. I do have the probe that is sold by WINCNC with the 1mm dia. ruby tip. It took a looooonnnng time to probe a small object, and the picture had to be done in Rhino, after pulling a million little dots into Rhino.
That was NOT accurate enough - I work at a level of 0.3mm accuracy. So the probe is laying in my showcase looking pretty but useless.
Kind regards, Piet de Necker
Home - Peter de Necker

[Pieterjosia]

Wel, well, can you believe it... it is now 16 years later and 4700 propellers cut on the SHOPSABRE without any problems. The SHOPSABRE has done approx .28 000 hours at 6 hours per propeller on average. I cut at 18000 rpm at 4800 mm per minute takin 0.75 mm overstep and left 0,5mm meat on every blade. This was then sanded down (after having sprayed the prop a bright dye. This we did to ensure that the prop blades where not sanded beyond removal of the 0,5.
Well, havving said that, I am looking at my posts of 16 years ago and was renindded of all the school fees I paid in those days to get sarted. but todsy things go much easier!!

[atypicalguy]

Thanks very much for this reply. Sorry I am 12 years late in the response :-)

Karl, I've programmed both of these types.

This is a machine which can do the part. They have been used to machine large ship props. I was most impressed by the 7-axis version. machining a 6' tall single blade.

SCHIESS-FRORIEP Vertical Turning and Milling Retrofit with SINUMERIK 840Di

another choice is this:
GIDDINGS & LEWIS VARIAX 840 (5) AXIS HORIZ. BORING MILL
CONTINIOUS PATH 5 AXIS PROFILER FLOOR TYPE
RETROFIT WITH DELTA DYNAPATH 20 CNC CONTROL
CONTROL ......................: Delta Dynapath 20 Retrofit
SPINDLE QUILL DIA ............: 5"
CROSS SLIDING ANGLE PLATE ....: 48" High x 162" LR
CROSS TRAVEL (X)..............: 170"
VERTICAL HEAD TRAVEL (Y)......: 51"
SPINDLE TRAVEL (Z)............: 18.5"
SPINDLE SPEEDS (32) STEPS.....: 17-3600 RPM
SPINDLE MOTOR.................: 30 HP
SPINDLE TAPER ................: #50
A AXIS HEAD TILT UP/DOWN......: +- 22 DEGREE
B AXIS COLUMN SWIVEL .........: 20 DEG. RIGHT- 60 DEG. LEFT
MACHINE OVERALL HEIGHT........: 29FT 11" FLOOR TO TOP OF MACHINE


EQUIPPED WITH:

ELECTRICS-460 3/60
CROSS SLIDING ANGLE PLATE WORK HOLD SURFACE
B AXIS ROTATING COLUMN
A AXIS SWIVEL SPINDLE HEAD UP/DOWN
Z AXIS SPINDLE IN/OUT
PIT MOUNTED COLUMN
PIT DIMENSION: 256" x 102" x 24" Deep

- - - Updated - - -

Nice. What is the name of your company? I may need a prop for my Cessna 140! Cheers, Karl

[Pieterjosia]

Hi Karl,
Its Home - Peter de Necker. Cessna 140 hey? Lovely, lovely beautiful aircraft... very, very scarce in SA. I think there is only two of which one is in a sorry state. Which engine is in it? The 0-235? or the C-95? Ok, good, depending where you stay in altitude - i.e. at sea level or above 5000 ft ASL there may be two different props 72 x 46 for over 5000 ft ASL or the 72 x 48 for SEAL level. Have a look at my facebook pages. There are a hundreds of fotos if you take time to scroll down - lol. But eitherway keep well, fly safely always hey.
Kind regards, Pieter