Since we may be contracting 3rd party to make PCBs and supply parts for the CNC, I'd like to gauge how much real interest there is in buying one of these machines, when we're done.
Keep in mind that this is not a commitment, just think to yourself to see how serious you would be, and comment yay or nay.
Update June 8th, 20122:
Ok, just counting heads. So far it's 17 people. Let me know if I missed anyone.
My personal budget for this is $1000-$1200, so any higher, and I'm out, but of course would continue to do my best to get this done for everyone!
Here's a list of "yays" so far (again no commitment assumed):
Drive System Survey
Franco Scipioni has set up a survey to gauge interest in which system we want to have on the system.
Access the survey here:
Ok folks I added the survey link and my description of what the servo vs stepper system is up top of the discussion. Monroe, and RD, please correct or add any info you wish up there for everyone to see.
Here's the link again to the survey created by Franco:
Here are the poll results and responses as of today. It's quite interesting that its 50:50 at this point. For the most part, most of the reasons for choosing one or the other have to do with price, accuracy, power, and other reasons that have already been discussed, but there are some that are less obvious and It's cool to get these responses and see different perspectives. Unfortunately, it looks like this poll is inconclusive thus far :( If there are more responses I'll post them too :)
Poll Results as of 8/9/12 @ 3pm ET
Stepper Motors: 39.1% with 9 votes
Servos: 39.1% with 9 votes
Another Solution: 21.7% with 5 votes
1. Servo controller with a stepper motor (ex. QuickSilver Controls)
Reasoning: Best of both worlds... lower cost compared to straight up servos, yet with similar performance.
2. either ,but want encoders
Reasoning: want feed back in machine. repeatable positioning. dont want to have to find zero point if power is lost or machine overloads and trips circuits.
3. I'm too ignorant to have an opinion! (lol)
Reasoning:but if the cost difference is "not too much" I would prefer the higher quality option.
4. Servos with Positional Encoders
5. Depends on users needs
Reasoning:Either will work fine but depends on the user budget and what the user hopes to do with the machine. Build the mechanics of the machine first. Then determine the forces needed to move the parts. Then determine the forces needed to cut the desired materials.
Reasons for choosing Stepper Motors:
1. A printer can place a small dot of ink on a page with reproduced accuracy, using steppers and opto feedback (simple disc) and it is the cheapest, why use servo's?
2. Price. Just need upgrade ability to servos in the future.
3. Servos aren't precise enough to correctly control velocities of the various CNC axis
4. Lead time, it's off the shelf. Ultimately I want servos but I'd rather have a machine than wait years
5. I am doing light work with wood an aluminium.
Reasons for choosing Servos:
1. Quality over price
2. Much more Power
3. more power and precision, looking for pro grade CNC
5. Servo Feedback with encoders provides better reliability. Machining can be both accurate and precise allowing for more exact replication of models. In woodwork designs (and other projects), multiple products can be made with more certainty that they will all come out the same.
6. closed loop vs open loop. I know that this would be pricey..
7. more experience with them
The boards seem to be open source, but the code is not. We'll have to make our own code.
Fantastic! Thanks Monroe. Anxiously awaiting for a response!
The *initial code* for the Elm Chan board (pre UHU) is available - I downloaded it.
Looking over the history of this board, I believe the Elm Chan came first.
Then Uli (German developer) improved the code and made it a popular project.
Uli sells the programmed chip for 5 to 10 Euro, shipping included.
He has sold/shipped over 5,000 of the chips. The current version is 3.0
Invite him to join this group.
No biggie, we'll have fun programming it ourselves.
Elm Chan <-----Click there, scroll to the bottom of the page. 'Firmware' is what you are looking for. Note the original date of the page at the top in the header...
Hi Everyone, I'm In.
Happy to help in anyway I can.
I have a software background.
Hi All, new to the group and have just read the history. Sounds great.
I'm based is Aus so a little challenge but happy to help where I can as I have a long background in electronic construction and design from my defence days. Put me down as yes. Looking at the servo version for me I think.
I'm interested. Currently looking at building a cnc router for wood and Al in a 18 in by 36 in cutting area, but 24 by 36 would be ok too. I have a cnc mill, so can proto parts if necessary.
Is there a working spec somewhere with drawings? I use Alibre and draftsight for CAD.