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Sienci
16-03-2016, 12:15 AM
Hey guys, my name is Andy! I'm a mechanical engineering student who's passionate about CNC machines

Over the last couple of years, I've had the chance to use some really intense CNC machines, from huge cutters for 4 inch steel plate to little Shapeokos. I fell in love with CNCing and decide to build my own.

After designing a simple and effective design from the ground up, I realized that this machine might be something I could share with everyone else.

For the last couple of months, I have been designing and prototyping what will be the world's most affordable CNC machine. You can check out our site here at www.sienci.com.

I just wanted to share this project with you guys and get your feedback. What do you want in a desktop CNC machine? What do you dislike about current CNC machines? What would you do with your machine? And most importantly: Would you buy it?

I would love your comments and feedback!

Thanks,

Andy Lee

Clive S
16-03-2016, 08:05 AM
I would love your comments and feedback Andy welcome to the forum and I wish you well with your venture, But you can hardly call that a CNC machine it is more like a toy for icing cakes. If you look at the video of the Z axis it is wobbling al over what do you expect to cut with it.:satellite:

lucan07
16-03-2016, 08:38 AM
Take a look at http://www.vicious1.com/ same intention and that one will cut aluminium badly soft woods and plastics quite well, as Clive says a cutter will just bounce off the item without sufficient rigidity in the design.

goldtop
16-03-2016, 09:30 AM
Hi Andy, just a quick word from someone who might be your typical customer:

I decided to add a CNC machine to replace some work I currently do manually (pillar drill, etc) and to hopefully give me more options - you know all that sexy 3D carved stuff that looks like so much fun. :) I thought I'd be spending a few hundred, but the more I read, the more I realised that it was always going to be a machine in the thousands of $$. Simply to get speeds and rigidity for working with materials that aren't really that challenging.

Speaking as a newbie, I'd say that I'm surprised that your calculations showed that those single flat rails are strong enough. Surely they will bend against the direction of the cutting bit's movement?

It's a tough crowd here, expect some bruises and no-BS arguments from some, but their heart is in the right place. Treat it as a reality check and a way of getting a better product.

Perhaps you can keep your material/speed/etc specs so simple that you can find a market. I wish you well. One last thing: as you're doing this as a business, I don't think the target price given on your Website is high enough for you to put food on your table.

Good luck. :)

komatias
16-03-2016, 09:33 AM
Andy,

Welcome aboard. The ideas you implement are interesting but again you need to specify your target market. I can see you doing well on kickstarter actually. Especially with the 3D printing crowd.

There is a huge "maker" movement in the US and Canada that are looking to make craft type stuff. Anything more and you start needing serious machines and not toys.

Not being dismissive of your machine here, just trying to help:

Your machine will perform "OK" when cutting light, small jobs with the drawback of being loud and slow. In the real world time is money so for me, along with the others above, your machine is cute but a toy.

If you want to lightly engrave plastic, cigarette cases or route PCB's then I think you may have a winner if you can make it for less than $200 and include your own software that has bells and whistles like the lightforge laser machine and that stupid pancake printer.

Either way, should you wish to sell it in Europe, make sure you use ROSHH materials and read about CE marking it.

Best regards

George

Ger21
16-03-2016, 11:28 AM
What do you dislike about current CNC machines?

Most machine available for less than $5000 are not very good. Being the most affordable will generally mean that it will be the worst CNC. A good CNC needs to be strong, rigid, fast, and powerful. Cheap machines are usually none of these.




And most importantly: Would you buy it?


Absolutely not.

The people that would buy your machine wouldn't be found on a CNC forum, as they would know that it's basically just a toy, and not really usable for any real work.

magicniner
16-03-2016, 11:34 AM
That looks like a great thing for people with no CNC experience to play with, it could prove a great DIY tool for very light work and some model making, and a cheaper option to the disposable Chinese machines which many buy to learn with only to find they need much more mass and rigidity.

- Nick

Sienci
16-03-2016, 02:17 PM
Andy welcome to the forum and I wish you well with your venture, But you can hardly call that a CNC machine it is more like a toy for icing cakes. If you look at the video of the Z axis it is wobbling al over what do you expect to cut with it.:satellite:

Hey maybe there's people out there who need to ice their cakes!

Yup, I did notice the wobbling, which is partly due to the threaded rod I threw in being bent and the v wheels needing to be tightened. You can read more about it in the post.

Thanks!

Sienci
16-03-2016, 02:23 PM
Hi Goldtop,

Yes, CNC machines can be pretty finicky and expensive quick, but at least you can sit back and relax while they do the work. ;)

I did do some quick FEA on the rail, and found that it's actually fairly stiff for my purposes. Here's the test if you want to look at it. I'm thinking of using larger rails in the next few iterations that are going make this machine even more ridgid, since the material cost per food is only around 1 or 2 dollars per foot.

17949

JAZZCNC
16-03-2016, 10:11 PM
I just want to say thank you for making the video of Z axis.? . . . . I haven't laughed so much since Grandad unbolted wrong Chandlier. . :hysterical:

Edit: Thought I better explain for our younger and Overseas visitors who haven't seen Only fools horses.


https://www.youtube.com/watch?v=LFuYIi5-igc

komatias
16-03-2016, 10:17 PM
was wondering when you would chime in Jazz

JAZZCNC
16-03-2016, 10:53 PM
was wondering when you would chime in Jazz

Well whats to say other than it's funny.? . . . Maybe not so funny if you'd bought it.:sorrow:

Clive S
16-03-2016, 11:37 PM
I haven't laughed so much since Grandad unbolted wrong Chandlier. . :hysterical: your beginning to show your age now, I saw it first time round.:nightmare:

magicniner
17-03-2016, 12:07 AM
Is the F in FEA really an abbreviation of Finite, or does it mean something else here?
Is this Mechanical Under-Engineering at it's finitest?
I still think it's a great idea for learning on foam and possibly balsa, if it's significantly cheaper than other inadequately engineered desktop CNC machines it will be less loss when it's passed on cheap or scrapped in favour of something almost competent,

- Nick

;-)

dodgygeeza
17-03-2016, 07:02 AM
lol, when a 5mm bent screw causes the whole axis to wobble then there is something wrong with the design. Most 3d printers i have seen are more rigid than this.

routercnc
17-03-2016, 07:12 AM
Sienci - In case it did not make it over there . . .
https://www.youtube.com/watch?v=LFuYIi5-igc

magicniner
17-03-2016, 09:56 AM
lol, when a 5mm bent screw causes the whole axis to wobble then there is something wrong with the design. Most 3d printers i have seen are more rigid than this.

He's done Finite Element Analysis on a computer which tells him it's all good so you must be wrong and I must be wrong for agreeing with you. :hysterical:

Robin Hewitt
17-03-2016, 11:02 AM
lol, when a 5mm bent screw causes the whole axis to wobble then there is something wrong with the design. Most 3d printers i have seen are more rigid than this.

What you are seeing is a motor bolted rigidly to the end of a shaft and being allowed to wobble. Much easier than messing with universal joints or isolating it with toothed belts. I have been suggesting it for years so it must be clever :suspicion:

cropwell
17-03-2016, 12:07 PM
Well whats to say other than it's funny.? . . . Maybe not so funny if you'd bought it.:sorrow:


You're on quicksand there Jazz - I bought a MD machine :hororr: (but I've learned a lot since !!!)

magicniner
17-03-2016, 12:48 PM
What you are seeing is a motor bolted rigidly to the end of a shaft and being allowed to wobble. Much easier than messing with universal joints or isolating it with toothed belts. I have been suggesting it for years so it must be clever :suspicion:

See what a formal engineering education and Finite Element Analysis can do for you?
Sweet Felicity Arkwright it would seem!
There but for the grace of god.............:tennis:

Robin Hewitt
17-03-2016, 02:02 PM
See what a formal engineering education and Finite Element Analysis can do for you?
Sweet Felicity Arkwright it would seem!

Note to self: Takka takka takka :chargrined:

JAZZCNC
17-03-2016, 02:58 PM
What you are seeing is a motor bolted rigidly to the end of a shaft and being allowed to wobble. Much easier than messing with universal joints or isolating it with toothed belts. I have been suggesting it for years so it must be clever :suspicion:

Ye real cleaver.!!! . . The Drives will love dealing with all the resonance banging thru that motor...:miserable:

cropwell
17-03-2016, 05:08 PM
Here's one from a few years ago - at a Pneumatics Suppliers Counter in Nottingham.

Me: Can I have one of those XYZ-123/B, like the one that's on the shelf over there.
Jobsworth: I'll just look it up on the computer. Sorry mate we haven't got any, computer says zero stock.
Me: What about that one there!
Jobsworth: If the computer says we 'aven't got any, we aven't got any.

Cheers,
Rob

magicniner
17-03-2016, 05:30 PM
Jobsworth: If the computer says we 'aven't got any, we aven't got any

I bet he was an engineering graduate just waiting for that big design contract to drop in his lap ;-)

Robin Hewitt
17-03-2016, 07:45 PM
Ye real cleaver.!!! . . The Drives will love dealing with all the resonance banging thru that motor...:miserable:

Oooh! I love it when you get cross, can I call you Mr Spanky? :anonymous:

JAZZCNC
17-03-2016, 08:38 PM
Oooh! I love it when you get cross, can I call you Mr Spanky? :anonymous:

Robin you can call me Miss Piggy if it makes you feel better and I could never be cross with you sweet heart. .:couple_inlove:

komatias
17-03-2016, 09:57 PM
I bet he was an engineering graduate just waiting for that big design contract to drop in his lap ;-)

Not all of us graduates are waiting for contracts whatever the sun and mirror lead you to beleive

routercnc
17-03-2016, 09:58 PM
This thread has gone a bit weird!

Back to the OP post#1 If you set yourself a design brief to 'Develop and then market a very affordable CNC machine' then I do think it has some merits. High performance CNC machines (DIY and industrial) have 2 vital characteristics. They are very stiff, and they have precision mechanical and electrical components. Together this allows them to cut harder materials properly, and with good levels of accuracy.

However, to fulfill your brief you must wind back the budget and therefore these 2 vital characteristics must suffer. You are therefore left with no option but to build a machine which can only cut soft things, and with a modest level of accuracy. But this is not the end of the project as I would say there is a huge market for craft work, balsa cutting, maybe drag knife vinyl cutting.

The challenge is to come up with something cheap, robust, does not need constant maintenance, and delivers. I'm not sure this has been done for the price you are aiming for, but that should not stop you trying. Some aspects of your current design are interesting, but some need more work.

For info the FEA analysis looks like you clamped each end of the beam then loaded the rail normal to the surface with 30 N. You got 0.03mm deflection on the rail which is reasonable for that beam on it's own - but remember your beam end conditions are not infinitely rigid, the V-bearings and brackets and gantry will flex, as will the Z axis, and the tool (dremel type I assume?) will along with the cutting bit which will have to be small. Backlash in the threaded rod will allow the tool to vibrate as so on. Push the Z axis with a set of scales and measure the deflection with a DTI. This will give you the true machine stiffness and it will be quite low. This is where the challenge lies to come up with something simple and cheap that still works.

Boyan Silyavski
18-03-2016, 05:58 AM
This is where the challenge lies to come up with something simple and cheap that still works.

There ain't no such thing as a free lunch.

I agree with Dean, even if i did not want to at first, this video made me laugh.


People don't want to understand basic concepts:

-"A machine is a tool containing one or more parts that uses energy to perform an intended action" , what we see there is a toy, cause its and will be unable to perform that intended action. So lets call them "toys" if their purpose is for the people to play a bit with them.

-V bearings are not meant for that. The only way a V bearing to work properly for that purpose is an additional arm with say 608 bearing which eliminates the v bearing play.
V bearings simply are not made to take forces in that direction.


-I have seen machines made from roller bearings 608, capable of milling aluminum, i dont say that they are good, just that better than V bearing machine.

-How can sb build a machine not understanding the base concept that box section is stronger than plate?



So in short IMO that toy can do nothing, don't lie to yourself/and others/.The way is designed it can not even move reliably a laser diode. You are making nothing new. Instead watch, read, learn and try to make something real.

Sienci
29-07-2016, 08:55 PM
Hi everyone, it's been a while since I've been here, but I'm happy to say that my team and I have radically changed the design for our desktop CNC machine with many of the thoughts and comments that you gave us several months ago!

If you have any other feedback please let me know!


https://www.youtube.com/watch?v=7QukwNML1kk

JAZZCNC
29-07-2016, 09:39 PM
Well Sadly you need to sack the team.!! . . . . My head starts shaking around 1:45 and by 1:50 my ribs are hurting Maybe a career in Comedy is better choice.?

Boyan Silyavski
29-07-2016, 10:01 PM
The biggest problem i see with all this is that there will be people /Americans/ dumb enough to make your Kickstarter campaign succeed. And please straighten that screw cause i have vertigo from watching it.

Clive S
29-07-2016, 11:04 PM
Speechless:hysterical:

Robin Hewitt
30-07-2016, 10:43 AM
Steady on chaps, we have all seen worse and he has not created a monster that will require a Hiab and skip to get it to the landfill site.
Some claims were made but we all had to start somewhere.
Confidence is that feeling you get just before you understand the problem.
Experience is that thing you get just after you needed it most.
The test piece may look like a dog chew but it is a beginning and can be improved on.
You must expect a bit of banter when you teach Granny how to suck eggs, isn't English a colourful language and I think it is time for my meds :encouragement:

magicniner
30-07-2016, 04:08 PM
Steady on chaps, we have all seen worse and he has not created a monster that will require a Hiab and skip to get it to the landfill site.

You're right, at least it can be slung into landfill by hand, from a distance, in a dim light, but so far that's the only viable destination.
I've seen better from plywood, angle section and skateboard bearings, either some innovation or good engineering is required there's nothing new and no innovation so far!

- Nick

JAZZCNC
30-07-2016, 06:24 PM
Steady on chaps,

Come on Robin for me that was steady has it gets.!. . . . And most land fills have limits they accept. .:hysterical:

routercnc
30-07-2016, 09:59 PM
Hi Andy,

The problem you have with posting that sort of information on this site is that regular members have been there, done that, and moved to more capable machines. Or with the advice of experienced members have jumped straight to the more capable machines.

Here are a selection (hope I've got the names right):

Work in progress from Chaz-
18952

Clive's machine:
18953

Dave's machine:
18954

Eddy's machine:
18955
and control box:
18956

One of many from Jazzcnc (Dean):
18957
and a smaller type
18958

Jonathan's machine for Sasha:
18959

Matt's machine:
18960

Neil's machine:
18961

A different Neil's machine under construction:
18962

Another member's machine:
18963

My current machine:
18964

Some members have started on the chinese machines you see on e-bay and got fed up with them and moved on to making things like the above.

On the whole these were built in garages with modest levels of tooling. Some were made without access to a lathe or milling machine (routed using templates etc.). Crucially, they were built using the hard won experience of other forum members following constructive design critique.

They are all very capable machines and much better than something bought for what they cost to make.

So perhaps a different approach would be to present the target price for the machine you are developing, and ask for suggestions on design improvements from the wealth of experience here.

Clive S
30-07-2016, 11:24 PM
Wow! Its nice to see all these machines in one place and what has been achieved by ordinary people with collective help and advise from other forum members.
It would be nice to put them in a gallery so it could be added to like Wal's beautiful machine and no doubt plenty more.

JAZZCNC
30-07-2016, 11:33 PM
That one post from Neil should Kill this Thread dead in it's track. . . Go away and try harder comes to mind.!! . .:thumbdown:

routercnc
31-07-2016, 03:59 PM
Wow! Its nice to see all these machines in one place and what has been achieved by ordinary people with collective help and advise from other forum members.
It would be nice to put them in a gallery so it could be added to like Wal's beautiful machine and no doubt plenty more.

Didn't mean to miss any out and Wals is just as deserving along with Boyans epic creations and many others

I was thinking the same thing about a central collection

How about a sticky at the top of the diy build logs where each person can send in one photo (ok maybe a handful) plus a link to the build log. No chit chat allowed just a long list of finished builds. That would provide a menu for new users to look through to see if one looks just what they were thinking of. Any thoughts Lee?


Instead of pointing new users to the build logs (which they have to them wade through) we can point them to the menu of pictures

Clive S
31-07-2016, 04:51 PM
Instead of pointing new users to the build logs (which they have to them wade through) we can point them to the menu of pictures Good Idea +one

mekanik
01-08-2016, 09:34 AM
Sounds good to me

magicniner
01-08-2016, 09:52 AM
An index of completed builds with a representative photo for each is a brilliant idea!

njhussey
01-08-2016, 09:49 PM
I can't put my router in the new thread as its not finished....will be waiting for a while yet for it to be complete I reckon 😉

Clive S
01-08-2016, 10:56 PM
I can't put my router in the new thread as its not finished....will be waiting for a while yet for it to be complete I reckon Neil as you well know they are never finished so put it in the new thread and then edit whenever.:applouse:

Boyan Silyavski
01-08-2016, 11:00 PM
Neil as you well know they are never finished so put it in the new thread and then edit whenever.:applouse:

You are absolutely right

JoeHarris
01-08-2016, 11:25 PM
Steady on chaps, we have all seen worse and he has not created a monster that will require a Hiab and skip to get it to the landfill site.
Some claims were made but we all had to start somewhere.
Confidence is that feeling you get just before you understand the problem.
Experience is that thing you get just after you needed it most.
The test piece may look like a dog chew but it is a beginning and can be improved on.
You must expect a bit of banter when you teach Granny how to suck eggs, isn't English a colourful language and I think it is time for my meds :encouragement:

Love this post.

And like the index idea a lot - I tried to make my own a while back but for some reason all the hyperlinks changed and no longer work.