BobCad draws the crowd!

[tobyaxis]

I'm now using a 1.5" Diameter Ball End Mill for Roughing and a 1.25" Diameter Ball Mill for Finishing. I though it was for a small model plain not a Large one. Ooops!!!!!!

[lakeside]

Originally Posted by tobyaxis I'm now using a 1.5" Diameter Ball End Mill for Roughing and a 1.25" Diameter Ball Mill for Finishing. I though it was for a small model plain not a Large one. Ooops!!!!!!

I find that a smaller mill witha little step over will give you a better finish on this type of part. Also you can get closer to hub. But we both program finish for moves in Y axis as this will be direction of airflow over surface

[tobyaxis]

Originally Posted by lakeside I find that a smaller mill witha little step over will give you a better finish on this type of part. Also you can get closer to hub. But we both program finish for moves in Y axis as this will be direction of airflow over surface

That is what I did with out realizing it. Nothing a little polishing can't take care of though. I can't believe I didn't check the size of the part before posting a tool path. Must be the Crown Royal


Piet propeller,

As Mike pointed out earlier you may be having a Graphics Card Problem. Call BCC and check with them after updating your Graphics Card Drivers I don't seem to be having a problem posting tool path on your part. Then again with Dual P4 H/T 3.2GHz each 1.5GB RAM and 256MB ATI Graphics Card I shouldn't.

[ger21]

Hey guys, since I route wood every day, here's a little tip. Rough with a straight tool, say 1" diameter, with about a 3/4" stepover and 3/8"-1/2" depth of cut, and climb cut the roughing passes. This should save a ton of time. Then finish with the 1-1/4" ball tool with about .03-.05 stepover, although some trial and error may be necessary here. You should be able to run your finish passes the long way. I ran some parts a few weeks ago with these specs and you couldn't even feel any ridges from the tool.

[lakeside]

Good point he's making it out of wood so forget my path I was thinking it was a Alum.

[tobyaxis]

Originally Posted by ger21 Hey guys, since I route wood every day, here's a little tip. Rough with a straight tool, say 1" diameter, with about a 3/4" stepover and 3/8"-1/2" depth of cut, and climb cut the roughing passes. This should save a ton of time. Then finish with the 1-1/4" ball tool with about .03-.05 stepover, although some trial and error may be necessary here. You should be able to run your finish passes the long way. I ran some parts a few weeks ago with these specs and you couldn't even feel any ridges from the tool.

I'll agree with that Gerry. A larger ball mill always gives a better finish than a small one. I have been looking at the Drawing and finding a lot of mismatch with the surfaces. Also there are entities that shouldn't be there either. This may be the reason for all the trouble he is having. It's a beautiful design but there are some small surfaces that overlap. I have no idea why they are there and will be calling BCC Tuesday Morning about this. It could be BCC or the original designing software. Can you open this file and check it out? The extra overlaps may be confusing BCC and making his crash.

BTW; 584 Hits and it's only Saturday September 2, 2006

[tobyaxis]

Originally Posted by lakeside The main deffernce between Toby's file and my own is that I skipped the center hole and lowwer part so top of part is at z zero also I have two paths So mine is BIGGER than Toby's

BTW: Mike, You Wish!!!!!!!!

[HayTay]

Originally Posted by lakeside So mine is BIGGER than Toby's

Mike didn't specify exactly what of his is BIGGER than yours, Toby. I used to go out with a girl that always proclaimed "The BIGGER the BETTER... The tighter the sweater!". LOL.

You never know, his waste might be BIGGER because he's full of it!!!

(Oops, my bad! I'm such a horrible speller, I meant waist .)

Sorry, guys (especially Mike), I couldn't resist. I'm getting punchy, it must mean it's time to get some sleep.

[tobyaxis]

Originally Posted by HayTay Mike didn't specify exactly what of his is BIGGER than yours, Toby. I used to go out with a girl that always proclaimed "The BIGGER the BETTER... The tighter the sweater!". LOL. You never know, his waste might be BIGGER because he's full of it!!! (Oops, my bad! I'm such a horrible speller, I meant waist .) Sorry, guys (especially Mike), I couldn't resist. I'm getting punchy, it must mean it's time to get some sleep.

No way, your getting Funny stay and post more

[Piet propeller]

Good morning gentlemen,
Its a beautifull morning in sunny SA

My thanks to Toby D, Mike M and Gerry for the help and suggestions. I shall certainly explore all the mentioned avenues. I am busy downloading the suggested toolpaths from Mike
The file of the propeller is typical of the smaller sized propellers I carve by hand. I apologise for not mentioning that the material is a hardwood type. The machine that I have bought - which is being built for me in Elko, MN is a Shopsabre with a 3hp Colombo spindle and 9" z - axis 48" x 96" table. It will be shipped on the 8th of September and should be installed here by end October.
The reason for my frantic learning curve is that mt lower back has collapsed - vertebrae squished and so I can hardly carve the propellers by hand anymore.
In 3 months at age 54 it took a damn long time to assimilate all the data of Rhino and BOBcad - which I really like - so inthe end it may well be that I am wanting inthe design and cam systems but with the quality of help from gentlemen like yourselfs I may be able to overcome these stumbling blocks. I also meant no offence to whatever Software company I metioned beforen

In all the simulations I used a 16mm ballmil with 3mm oversteps for roughing and a 12mm ballmill with a 1mm overstep for finishing - which is fine as this allows some wood material to be removed by hand to assit in the balancing process of the propeller. Would it be possible for Mike, Toby or Gerry to develope a toolpath using the abovementioned cutters. Feed rates and spindle speed suggestions for wood will be GREATLY appreciated as tables for feeds/speed in metals is in abundance.

Gerry, it seems to me you are more knowledgeable in wood material so could I implore you to have a gander at the file and suggest methods of correcting the overlaps and the excess entities present in the prop?
Any graphics cards you gentlemen would suggest?
Should I purchase a dual core P4?

Best regards,
Piet Propeller
If it is of interest to anybody - the website is www.p-prop.s5.com. If anyone needs help in designing a propeller for their aircraft I would offer my help and advice no charge.

[tobyaxis]

Sorry to hear about your Back. That has to be pretty scary. I forgot about finishing your File. I will take those end mill sizes and re-post the code if you would like.

The Feeds and Speeds are kind of up to your machine, part rigidity, and tooling for the most part. I'm sure Gerry has some good starting points though. I will follow up and re-post sometime tomorrow.

Have you logged in on BobCAD's Forum yet? There are a lot of really good BCC users there that can assist you and would be very interested in your propellers. I have to admit it is really cool to see a hand craftsman such as yourself learning software and CAD/CAM.

As a note V22 is going to be the Show Stopper for BobCAD-CAM.

Sorry I had to pull the file. I didn't realize how big your propeller was at first and went to repost. I wound up getting side-tracked.

Hope to see you on the BCC Forum.
Which Version of BobCAD are you using?

BTW: We have beer here

[Piet propeller]

Good morning Toby D. Your input and help is really appreciated. I purchased V21.4 a month and a half ago and forging ahead slowly but sure. The back needs surgery and rest so hopefully the cnc router will do most of the hardwork. If ever at any stage you visit SA you are most welcome to stay over
Piet propeller
Ps yes, i recieved the registration e-mail and have rgegistered at the BCC forum and at present are reading the posts, thanks