Help Cad is kicking my butt !!!

[gundog]

I am trying to get the hang of things I have gone through the partworks tutorials and still can't draw my simple parts. I bought Turbocad 12 off ebay and can't figure it out either. My new 4x8 standard is supposed to ship on the 18th and if I can't figure out how to draw my parts I guess I will hire it out.

I think I have learned enough from the tutorials in partworks that if I had the drawings I could import them and set up to cut. I have a lot of projects I want to do and I really need to learn some sort of cad to make drawings.

Can someone point me in the right direction is there a good program that would be easy to learn that includes tutorials? I am also thinking of buying the tutorials for Turbocad but none of the ones listed on ebay are for Vista.

My bot will be ran from a computer with XP pro but I want to do my drawings on my lap top and it runs windows vista.

One of my problems is I am real busy and don’t have time to meet with someone for lessons right now. I work a job that allows me time when nothing is going on to read and study like now but on my days off I am running a small business that lately has been keeping me busy in the shop. So my study time is at work during off times. I operate a power system for a utility company and at night and some times on the weekend it is absolute boredom so I could be learning stuff in cad I just need the right materials.

I can make the shapes in Partworks but I can’t figure out how to edit things to machine pockets and so on. I have posted some pictures of my parts in the past but I can’t right now because I am at work and don’t have access to them some are on photobucket and that site is blocked from here. I can add pictures later from home though.

Thanks Mike

[knight_toolworks]

partworks will do most simple drawings. you have to use workaround sometimes but it is far easier then turbocad.
but we need more info to help you out.
when i need 3d I have a friend draw things in turbocad but for the most part I use vcarve/partworks

[gundog]

The part I have been trying to draw is a puck shaped part. The basic shape is 4" round and 1.25" thick it has a center hole bored through .5" and a counter bore 1.25" diameter and and .750 deep. The other side of that part has a 3" pocket milled in that is centered and is .230" deep. The pocket is open on one side to the outside of the part.

I can explain the pocket better by telling you how it is made now. The 4" round part is chucked in a vise on my milling table and I use a 3" milling cutter set to cut .230" deep cut in from one side to the exact center and then back out the direction of entry. Leaving a U shaped pocket.

I can't seem to draw anything but the circle. I feel like a dummy I have watched people draw my parts in cad in the past and they just wizz through. I have put many hours trying all the buttons and modes and can't make a damn thing.
mike

[gundog]

I don't really need to machine both sides on the Bot but it would be nice. If I can just mill the side with the U shaped pocket and bore the center hole cutting the shape out of flat stock UHMW. I could run each one through my lathe and counter bore them in about 20 seconds each. I believe that is the way the place I was paying to do them made the part.
Mike

[knight_toolworks]

not sure if I totaly know what yoru after. but it jsut sounds like you need to draw a circle in a circle. the U shaped one you would have to sue a ball nose bit with the right curve.

[sawdust535]

Do you have a photo of the part you can post?

[Gary Campbell]

Michael...
The parts that you describe seem similar to your earlier post. I saw the pictures of them and they are fairly straight forward. What you may be missing is in this software (partsworks) you will not see your results until it has been virtually cut after toolpathing.
For ease of my explanation start a new file with a 10" by 10" piece of material that is 1.25" thick
Draw a 4" circle then highlight and click on center in material
Draw a .5 circle, highlite and click on center in material
Draw a 1.25" circle, highlite and click on center in material.
You now have 3 concentric circles in the center of a 10" square.
TO toolpath, click on the .5 circle and click inside profile 1.255 deep
click on the 1.25 circle and do area clear .75 deep.
Click on the 4" circle and select outside profile 1.255 deep.
This should cut out one side of your part and if all the steps I left out are filled in by what you saw on the tutorials, you should be able to see a preview of that side being cut.
I have left out bit selection, speed, stepdown and some other things that you must learn in order to cut your file, but this may help get you started.
Gary

[sawdust535]

Does this look like what you are trying to do. Not sure if I understood your description.

[Gary Campbell]

9019

[Gary Campbell]

9020

[sawdust535]

Michael, I sent you a PartWorks file in your e-mail. Had trouble sending it on here

[gundog]

That is the part but I want to do but I want to do the other side of the part on the bot. That would be milling that 3" pocket and boring the .5" center hole. After the part is cut out I could counter bore them in my lathe. I can counter bore the 1.25" hole in my lathe much faster than milling the 3" pocket with my mill.

I will take a picture of the other side of the part when I get home. I did finally find a way to draw the part in partworks but I am not sure it will cut right the way I drew it. I tried to run it through the tool path but it kept kicking out my tool bit choice and not going any further. I will keep working on it later.

Thank you very much for taking the time to do that Gary.
Mike

[sawdust535]

Trying a JPEG file

9021

[gundog]

Yes George that is the one. If I could figure a good way to do both sides that would be great but if not the milled pocket side would be my choice.

I figured out the problem with my choice of bits I was trying to choose a .25" mill bit in the V carve section. I did not get the pocket milled out though the way I drew it but I may have a solution. How did you draw the pocket section?
Mike

[Gary Campbell]

Michael...
If I was going to do a bunch of these parts, and I dont know how many you have to do, I would do the center hole, recess and profile cutout with 1 bit, at one time. Then I would make a dedicated jig to clear the recess from the back side. Another option is to make a fixture to cut them 10 at a time. 10 (or more)per sheet and a fixture that holds down 10 for the back relief. Then off to the router table for the round over. I have a shop full of wood equipment, adjust your methods to match your equipment. Good Luck
Gary

[sawdust535]

I did it in CorelDraw, then exported the drawings to PartWorks.

[gundog]

I do 100 to 200 of that part at a time every month or 2 depending on my orders. I have been making them from round stock and machining all the profiles with my lathe and milling machine all manual equipment and very time consuming.
Mike

[sawdust535]

Gary, I was just browsing your website. Very impressive work.

[Gary Campbell]

Michael..
This looks like a good application for a high vacuum, low volume fixture that will hold the piece face down for the back recess pocketing. No matter how you cut the front, Whether you cut from sheet or rod vac should hold it unless the face is rough.
I would try a fixture with a center post for the 1.25 recess and 2 concentric donut gaskets at about 2 & 3.5 inch dia. pull vac from between them and you should be golden. It will take 2 layers with a manifold cut between them to do multiple units to save setup time.
Brady has a couple articles on his web column that may help.
Gary

[Gary Campbell]

George.. Thanks
Michael... you are welcome

[sawdust535]

I have an Alpha BT32 and because of the moving table, have not set-up any kind of a vac hold down yet. I think Brady mentioned he ordered a "buddy" and he was going to work on a vacuum system for it. Looking forward to seeing his idea. I'm currently using a table I designed with T-Slots and wooden hold-down clamps.

[scottcox]

Michael,

You should be able to mill those in quantity from a single sheet. Do the recessed hole first (left one in George's picture) and add registration holes to that side of the sheet and then into your shopbot table top. Flip the sheet. Register it using dowels onto your table surface, then do the "U" shaped pocket, then the final cutouts.

I do this often using short 1/8" drill bits for my registration dowels and get very good results.

[gundog]

Gary,
I am sorry I called you George. In my confusion I thought I was dealing with the same person but thanks to both of you George & Gary and the people who emailed me also you guys are a very helpful group. I hope I some day have some way to help myself.
mike

[dana_swift]

George, if you are interested in discussing vacuum for the BT32/48 we can start a separate thread. I have made several fixtures for mine, I would be happy to post some pics.

Michael- best wishes on learning the software. It may be confusing at first, but the time invested in learning is so worth it. A few months from now you will probably be amazed at how it has changed the way you think about producing any part, a one-off or full production.

Dana

[sawdust535]

Dana, I would be interested in that. I can make some pics also that I can post.

[dana_swift]

George I posted a new thread:

http://www.talkshopbot.com/forum/messages/312/29612.html?1207591461

[brian_harnett]

I have found Alibre cad to work well and the express version is free it is a parametric cad so changes and refinements are a breeze.

I do have a 10 year background in solidworks a much more expensive program with a very similar interface.

Here is the link
http://www.alibre.com/

I own turbocad and find the interface frustrating .

[kirkkelsey]

I would like to second Brian's recommendation for Alibre. We have been doing woodworking design in Alibre for quite a few years, as well as coding for the ShopBot.

There are free video and written tutorials at the software website, as well as woodworking specific tutorials at www.instructables.com/groups/cad (http://www.instructables.com/groups/cad) and our website www.kelseywoodworks.com (http://www.kelseywoodworks.com).

If you need additional help beyond those tutorials, we do contract design as well as providing assistance and instruction to new Alibre users.

It is quite easy to create DXF files, and create code from those files using the PartWorks software.

Start with the Free Xpress version, and only spend money for the software if you are satisfied with the way it works. The Alibre forum (www.alibre.com/forum (http://www.alibre.com/forum)) has a woodworking section and friendly and helpful users similar to this forum. You will find me in the Alibre forum with the username of WoodWorks. My wife "WoodKnot" is the author of the woodworking specific tutorials at the instructables website.

All CAD software takes a bit of effort to learn, but it helps when there are others available to answer your questions.

After working in 3D with Alibre, we will not go back to 2D CAD or standard woodworking programs.

[sawdust535]

Dana,
Tried to e-mail you some pics but got this message . . .

*** ATTENTION ***

Your e-mail is being returned to you because there was a problem with its
delivery. The address which was undeliverable is listed in the section
labeled: "----- The following addresses had permanent fatal errors -----".

I'll try again later.

[butch]

Alibre Design
After reading the posting here, I tried to download Alibre lately and a year ago. But as I am on 'Dial-up' and the file is 100M plus, I would get to 3 hours in the download and the server would cut me off. I wasn't able to append this file, so each time it started over at zero, and 3 hours...etc.
I e-mailed the sales department at Alibre. I didn't get an answer, but today I got a disk in the mail. I thought that was pretty considerate for a free program I am just trying to test out. Anyway, I just wanted to pass this along.
If the program is as good as their initial service I am impressed. I was in software for so many years, and got disgusted with most of the companies I had to deal with, so this was a pleasant surprise.
Anyway, thought others might like to know. Maybe not as good as Vetric, but few are.

[seana]

Butch,

Were you ever able to get a trial copy of Alibre?
If not i could download it and burn it to a disk and snail mail it to you.

Sean

[bill.young]

Hey guys,

For those of you that are going to be at the user group in San Mateo next weekend, Kirk and Connie Kelsey who are Alibre experts and do files and designs for several ShopBotters will be there and will talk about Alibre and show some of the ways they use it.

Bill

[butch]

Sean
I did. They dropped a CD in the mail for me. I have it up and running, and have went through some of the tutorials.
Thanks for your offer.
Butch

[gundog]

I have been cutting my first parts pictured above. I have cut 2 batches of 60 parts each. I am not getting a good profile finish on the part. I am using an UP cut spiral O flute .5" Onsrud 52-704 bit recommended by Onsrud. I am getting chatter marks on the finish. The first batch I cut .375" deep @ 1.5" a second. The second batch I slowed it down to 1" a second same depth of cut and the finish was the same.

I do not have vacuum I screwed down the UHMW to 3/4" plywood and clamped that to the table with heavy duty C clamps. The material size was 48" x 30" and I used 10 screws around the perimeter.

I plan on slowing the feed rate some more on the next batch maybe to .5" a second. Should I also take a shallower cut?

My machine is a new PRS standard with a Milwaukee 3.5 HP router. Am I asking too much of this setup? Will I have to upgrade to a spindle and Alpha series equipment to get a better finish?

Any suggestions would be appreciated.
Thanks Mike

[cnc_works]

Chatter free cuts in plastic are my holy grail, and I know many others share the search. Can you post pix of the marks you are experiencing? Are the chatter marks worst at 45deg to the X and Y axis?

Slowing down your cut beyond 1.5ips is unlikely to improve the chatter especially with a .5" bit, but there is often a speed/feed combo that will optimize the surface quality...finding the right resonance combination as well as chip size. I think your depth of cut is conservative. Have you tried a clean-up pass of .01" to .05"?

But be prepared for an uphill battle on this one!

Donn

[beacon14]

But be prepared for an uphill battle on this one

Especially without vacuum holddown, I'm sorry to say. All those clamps are holding the perimeter down real well but the rest of the sheet can vibrate quite a bit during machining. A spindle would probably help but the vacuum would be first in my opinion.

[gundog]

Here are some pictures. I will try a finish pass and see how that works. I do plan on vacuum I guess I need to get started on that. I did leave a skin on these parts if that maters and then cut them out with a laminate trimmer.
Mike

http://img.photobucket.com/albums/v292/millnut/DSC04660.jpg

http://img.photobucket.com/albums/v292/millnut/DSC04659.jpg

[wayne_walker]

Michael,

I cut alot of 3/8" ABS and I will do a rough cut in two or three passes (very conservative) and with a final pass at full depth. (2 flute - straight bit)

I have a vac with with a PC router. I cut at 10,000 RPM at 2.5 ips and use air to cool the bit so it does not melt back and blow the chips away.

Depending on the size of the part, I sometimes leave a skin. My finished parts need a profile on them so I do run the parts on a pin router.

Wayne