View Full Version : Crest part on a Cheap CNC

06-04-2003, 08:15 PM
HomeCNC emailed me the 4 tool paths that cut the crest on his home made machine. I wanted to see how a Cheap-CNC matched up. I think the part looks great! It took much longer on the Cheap-CNC but then again, it only gets around 12 IPM so that was to be expected.

The first two tool paths were roughing passes

28 minutes for the first
22 minutes for the second

The final two paths were finish passes.

Pass #3 with an 1/8" ball nose took 3 hrs 37 minutes
Pass #4 with a 1/16" ball nose tool 18 hrs 26 minutes!

I must agree with HomeCNC in that the 4th pass was not really needed as the detail after pass #3 was almost identical to the forth.

06-04-2003, 08:16 PM
To give you an idea of size, here is another photo with the machine

06-04-2003, 08:22 PM
Wow very nice, but boy that sure took a long time!

06-04-2003, 08:25 PM
Your telling me! I think it took HomeCNC around 8 hrs. The last pass is the killer as the cutter overlap is verrrrrryyyyyyy high. Fun to try, but definitely would not be a money maker for a living!

06-04-2003, 09:35 PM
Yes, I have refined the process and I now know the largest pass for each ball cutter that still looks good. Also I have determined that the size of the part will dictate the use of the 1/16 cutter. My second crest run was larger and I stopped with the 1/8 tool but passed the 1/16 tool over only the artwork in the middle. In the second crest I used a dragon instead of a griffen. The complete time to make the second crest was 10 hours and it was 9" X 14" and a much deeper relief than before. It looks great!

06-04-2003, 09:58 PM
Photo of the new one?!?

06-04-2003, 09:59 PM
Hang on I will take one!

06-04-2003, 10:05 PM
Here is the second go around with my machine.

06-04-2003, 11:49 PM
Now that looks sweet!

Are you using them for something or just playing? They would make great doors for a dart board set in an Irish Pub! Yes it has been a long day.

06-04-2003, 11:53 PM

What kind of wood is that?


06-05-2003, 12:20 AM
I am making them as demo cuts. My partner is taking them around to cabinet shops to see if we can drum up work.

The wood is African Ribbin Mahog. My friend works at a nice door shop and got some scrap for me to play with.

06-05-2003, 01:41 AM
Nice work gentlemen.

Laff Riot
06-05-2003, 09:26 AM
Hit up your local kitchen fabricators as well. They always use a lot of custom eye candy work in Corian and certain woods.
If someones about to drop 30k on a brand new kitchen 3k of custom trim or initials is nothing. The Corian is especially nice since you can surface fill and resand back to a gloss smooth finish.

- - - - -

Also - hit your local sign shops for thier cutout letter requirements.
I can lend you a hand on initial prices for various materials if this interests you. As a side note - the prev. metal letter job I mentioned, we calculated that they have about 9k of profit built into the job. Sometimes its nice to have a big settup :)

- - - - -

Dont forget your custom closet & storage manufacturers as well - they are always looking for signature add-ons to differentiate them from the other shops. The bonus is that they are usually already paying top dollar for everything else.

06-05-2003, 02:05 PM
Geez, 10 hours seems like an awfully long time to cut a relief. It seems like it'd be waful hard to make a living doing that. Seems that your machine could handle a pretty deep stepdown. How many passes in Z are you making per tool before reaching final depth? Did you try increasing the stepover until you started getting scalloping and then back it off a bit?

I'd much rather have a little scalloping and maybe a 1.5hr cut time and clean up with a cabinet scraper and sandpaper than wait 10 hrs for a finish pass. After all it is decorative and not a precision part that mates with another.

Assuming that $100 per hour on the mahine (Which is probably way cheap compared to most commercial CNC shops.) $1000 per relief is not going to attract many customers.

10 hrs is not bad for a one time precision mold. And in that case I'd want the most detail I could get. But 10 Hr panels would drive me crazy.

06-05-2003, 03:39 PM
Or, get OnecncXp and use the "REST machining" function to detect only those areas that need machining with a smaller cutter. Make time on the broad surfaces.

I know that might be a bit more than you would like to spend for software, but if you were serious about making the jobs profitable, it would certainly be something to consider. Just wanted you to know the options that are available.

06-05-2003, 06:31 PM
>>I'd much rather have a little scalloping and maybe a 1.5hr cut time and clean up with a cabinet scraper and sandpaper than wait 10 hrs for a finish pass. After all it is decorative and not a precision part that mates with another.

That thing is only about 8" tall. What can you do with a cabinet scraper on something that small?


06-05-2003, 09:17 PM
The speed problem is with the controller I am using. I am useing CNCPro until Mach 2 is ready. Also ArtCam is outputing many small point to point lines in the code and CNCPro is slowing down to process this data. It will only run at about 20 IPM but changes between 12-30 IPM while the finish cut is going. CNCPro only has a 2 line look ahead which does not help with a large program like this. I am hopeful that mach 2 will be able to look ahead much more and make a smoother and faster run of the part.

07-13-2003, 04:28 PM
What did you generate that part in originally anyway - I mean what software ?? I have some things I'd like to make for our boats that would be simular 3-d engraving, but 'outdoor' type fishing images ? Anything you may suggest would be appreciated.
By the way - my software I have is :

Auto Cad Light
Maxsurf (3-D NURB / B spline surface development)
Visual Mill Basic

Thanks guys -

HomeCNC - -By the way - your part looks great - 'cheap' CNC or not - VERY nice.....

07-14-2003, 01:52 PM
Ninewgt, The model came as a sample with Artcam pro. Since my post in early June I now have a small probe scanner for making models with. It is neer to impossible to create something like the crest by using the tools inside of the software. I can tell that the crest model was scanned as well.

My scanning size is 8" x 12" x 2.375". I had a request for a buck deer bust carving that was almost facing you so you can see the rack of the deer. I found a small deer at the local hunting store and scanned it. I then made some small mods and then sent it to the CNC router. It looked real good enlarged to about 10" X 18".

07-14-2003, 03:14 PM
What kind of Probe did you use? I've been contemplating a Microscribe arm digitizer for a couple of years now. I could use it for a lot of the 3D graphics work that I goof around with as well as the CNC stuff that I'm hooked on.

You can do some pretty cool stuff using greyscale images and the relief features in ArtCAM, I've goofed around with it a bit and it's a pretty impressive program. I really like the V-Bit carving feature.

I did some contouring and pocketing with it also before the demo expired on me and it's toolpaths seemed to be very nicely optimized for program generated toolpaths, at least they were better than the DeskCNC created toolpaths for the same parts. I've not tried any relief carving with it though. I don't think that it's possible any detailed 3d carving can not be incredibly bloated though, so I don't suspect that artcam is any worse than most.

Oh, and Pics of the Deer carving if you would please....

07-15-2003, 09:27 PM

07-15-2003, 09:35 PM
very nice.


07-15-2003, 09:56 PM
I really like the probe scanner I got. It's from Roland and is called the Picza 30. Very affordable for home use.

07-15-2003, 10:09 PM



07-15-2003, 10:27 PM
Looks real nice! Now, if you could just get somebody to pay you to make these...... :)

07-15-2003, 10:31 PM
Looks great,
But it kinda resembles a deer.:D :p :D :p


07-16-2003, 12:29 AM
Jeff nice carving. I have tried emailing you a couple of times and am not sure if this new system is working or not. If you get a chance email me so I can try a reply. I need info on some servo motors.




07-16-2003, 01:07 PM
Looks real nice! Now, if you could just get somebody to pay you to make these......

That is what I'm working on. :) The quote when to the customer....so I wait... :rolleyes:

02-20-2004, 02:30 PM
Hey, Jeff,

July 2003 is about where I walked in, and this 'deer' project of yours set the hook (I took the bait on your machine design).

I've been waiting for the other shoe to drop. Did you get a sale?

Done any more custom digitz?

Thanks! (If you've read my other post, you'll recognize I'm on a "What can I do with a CNC?" kick.)

P.S. This fellow (http://www.3dclipart.net) is asking $25/model. ~That~ might be what you could sell (I looked up the price of a Roland Picza. :( Sigh.)

02-20-2004, 04:39 PM
Well, No. I turned in to the door company a very good price because I wanted to get something out there. They then presented a price for a custom double door to this customer. I guess he did not want to pay for the custom door.

I have now put this carving work on the back burner. I need my time for designing and building my house on my 7.5 acre lot I got. I will however do carving in my house and then take photos for a website I will have.

I have other items that I just have not scanned yet. I went out and found many embossed greeting cards that would scan well. I also have wondered if people would pay for a scan or not.

02-20-2004, 05:09 PM
Originally posted by HomeCNC
I also have wondered if people would pay for a scan or not.

When I was a lad, I thought--briefly--that I wanted to invest in stamp collecting.

I went to a stamp show, and met that rare dealer who took pity on a poor boy and became quite candid.

"How do I know which ones are going to be worth a lot?" was my question.

He answered, "Look at me. Do you think I collect stamps? No. I'm a dealer for people like you. You decide: you want to collect because stamps are pretty? Or because you want to invest?"

"Well, to invest, I guess," I said. "Then," he said, "Sell everything you got, and buy the most Expensive Stamp You Can Afford, and put it in a lockbox for 50 years. Then sell it. BUT, if you ENJOY stamps, buy what you LIKE, and maybe you get lucky in 50 years, ONE of them is worth something. If NOT, you still have 50 years of stamps you LIKE!"

Long-winded way to say, "Maybe if you scan what you like, and then offer them for sale, you get SOMETHING back."

02-20-2004, 05:09 PM
Jeff, here is a link to someone who does similar work. I thought that their approach was interesting.


03-25-2004, 07:02 PM
I am building a simillar machine to yours how did you mount your porter- cable trim router?

03-25-2004, 10:49 PM
Hi All,
I posted some pictures of my 24-12 "Cheap CNC" machine that I did some mods to in the "Marv" folder if anyone is interested. I put some 1/2"-10, .200 lead acme screws in with some 214 oz/in steppers. Works wonderful. I can get up to about 90 ipm rapids but usually don't run it that fast, around 50 seems fast enough for me. I usually cut anywhere from 15 to 40 ipm with no problems.

I like the site upgrade too. Thanks for the great forum.


03-28-2004, 03:49 PM

Can you go into more details on the mods. I need to update my system as it is toooooooo slow.


03-28-2004, 04:33 PM
Hi Paul,
What kind of details do you need? I used the cheapest acme screws I could buy but now wish I had used some ball screws, not that much more expensive. As yet I have no antibacklash nuts, just the brass acme nuts only. Backlash is virtually unnoticable cutting wood and doing photos. The 1/4 inch all thread and delrin nuts were removed, holes enlarged to fit the acme equipment. I did use the roller blade bearings for support on the opposite ends of the motor except for the Z axis. I just used forstner bits to do the pockes for the bearings and holes for the shafts. Just centered everything as best I could. Worked out pretty well. I did have to use a two thickness of paper for shim on the acme nut flange for the Y axis to keep it from binding but that was about it. I got some different couplings for the motor as I had a friend turn down the ends of the acme to 3/8" but you could turn them to 1/4 without any problem I think and use the original couplings. It's really pretty straight forward and all the locations for the holes are already made with the original equipment. Just enlarge and install.

The motors bolt right into place, size 23. The one's I got have a double shaft so I put a knob on the Z and Y axis but have not had much use for them yet. I tried the 116 oz/in motors I had from Xylotex and they worked almost as well. I really like the mods, I usually set up my g-code to run at 15-20 ipm then using Turbocnc just increase or decrease the speed overide for what ever material I am cutting by as much as 300 % if needed.

More question?? Bring them on.


03-29-2004, 10:13 PM
Specifically what steppers and controller did you use? I am ready and raring to go on the mods!

03-30-2004, 11:10 AM
I am using Turbocnc 3.24, Xylotex 3 Axis board, and the motors are MSG from Camtronics, 210 oz/in hooked up bipolar parallel


03-30-2004, 12:06 PM
What about limit switches? I think I spotted some on your machine in one of the pictures.

03-30-2004, 02:53 PM
Yes they are there but I didn't have any shielded wire to use on them and couldn't get them to work right without it. Haven't had time to mess with it again. I have a couple wired for home switches on my other machine and they work good. They are the cheapies from Radio Shack. I just got a relay today to wire in for my spindle control which is more of a priority for me right now.


03-30-2004, 10:43 PM
Marv, have you tried the motors series wired? Are you running them parallel at 2.5a? If so, your probably getting no more than 150 oz-in of torque. Wired series at 2a should give you more torque. I'm just wondering because I have motors with similar current ratings and will be using a Xylotex. Thanks

03-31-2004, 12:38 AM
Yes, I know I'm not getting full torque. I did try them wired in series when I first installed them and could not tell a lot of difference. I may do it again since the machine has been run in now I may see more difference. They work pretty good like they are though.


03-31-2004, 12:41 AM
Just finished wiring up my spindle control using Tei Newman-Lehman's (teihardo.com) method. Works great and will be very nice with the enclosure. Thanks Tei.


04-04-2004, 11:54 AM
Artcam 6.008 will also do rest tool pathing.

05-19-2004, 07:23 PM
Now gentlemen 8 hours to make a design on a piece of wood well, over here in the uk there is a product called "Trend" who make a template for a home router ,that will carve a design by way of a conical cutter into door panels and drawer fronts and it takes about 10 mins to do.my bedroom doors i did with this template after they were varnished they looked great.
ttfn BAZ

05-19-2004, 07:25 PM
Got any pictures to show us??


05-20-2004, 02:20 PM
Now gentlemen 8 hours to make a design on a piece of wood well, over here in the uk there is a product called "Trend" who make a template for a home router ,that will carve a design by way of a conical cutter into door panels and drawer fronts and it takes about 10 mins to do.my bedroom doors i did with this template after they were varnished they looked great.

I also have this same setup. This is nothing like carving a 3D relief pattern. This is simple valley cuts into wood. I can do this on my CNC router without the pattern using a V cutter and it would take less than 5 min for the simple shapes you can get.