CNC by trial and error!

Having seen all the amazing results others have accomplished, most recently Deezle and Warhog, I purchased a cheap 3040 cnc.

After having gone through the entire process as a beginner I now realize there are MANY details that need to be worked out.

I used Lars' cad drawing to do a little test of hardware/software and came up with this.

I was actually impressed with the results. Crisp straight lines even on MDF scrap piece.

On Warhogs advice I have ordered some Rowmark and Cutters to experiment with.

Results to come.

Anybody that wants to share any tips or tricks would be greatly appreciated.

Thanks

ClayM

Looks good, just make sure you engrave on a surface that is flat, I would usually put down a piece of scrap and surface it so that I know I get en even depth when engraving.

Make sure your rowmark is also flat. If you are using an engraving bit that has some sort of V shape then changes in depth will show up as wider engraving which may or may not be a problem depending on how flat it is.

You dont have to go very deep at all with the rowmark, much less than you have for your test piece.

Yes! Great point metalnwood.

In my case i have T-slots in various places. My thoughts were to make a sacrificial board and attach that to the bed. Then use management tape ( as we call it, same as two faced like the managers at work ) to secure rowmark to flat surface. Sounds like a pain and i would like more advice on this.

Start with the basics!

Work holding.

Doesn't matter how good your tools are if you cant hold your work properly.

Thanks

ClayM

Your idea with the Dobbelt Sided tape is definately the way to go, it sounds like a pain in the ass, but it really isnt. There may be some leftovers from the tape on the panel you cut, because u cut through it, but thats easily cleaned up with natural spirits.

I would also recommend as metalnwood suggested, to Mount a plate of some sort to the machine, and then lvl it of with the cnc. so no matter what you place on top of that, its level to the cutter.

Keep in mind that if you want to use dobbelt sided tape, MFD table surface is NOT a good idea, since it can get Loose on longer cuts. Thats because its allways kinda dusty, no matter what you do.

I will recommend you order a piece of 8-10mm Acrylic, sized to the machines table, and fasten that, and then level it off. Dobbel sided tape Works great on Acrylic. And dont be afraid to use too much tape... its not that hard to get off Again... accually, the less tape you use, i find it harder to get off the machine Again. depending on the objects size of course.

Also the machine you bought, is accually ready for limit switches. Its just not mounted. So you can Mount limit switches, and connect them to the motherboard inside. Its pretty easy, because they are called limit on the PCB. Just a future upgrade maybe :)

Hope this helps

LynxDK

Regarding limit switches.

I think this is another priority. Are you saying I can wire in home switches to existing controller? or both home and limit?

I have already used incorrect home positions and slammed into the end of axis travel:(

Trying not to damage anything before I actually produce anything!

I'll pull the cover off and take some pics.

Thanks

ClayM

LynxDK

Regarding limit switches.

I think this is another priority. Are you saying I can wire in home switches to existing controller? or both home and limit?

I have already used incorrect home positions and slammed into the end of axis travel:(

Trying not to damage anything before I actually produce anything!

I'll pull the cover off and take some pics.

Thanks

ClayM

Yea sry, i meant home switches. one for each axis.

You wont really damage the machine by running over the edge, its made to jump when it does, but dont do it too much tho :) it definately dosnt sound good when it happens.

Its all part of the learning process, and everyone does that until they realize which side of the X and Y you need to place the drawing :)

Just to be clear, even tho you put homing switches in for X and Y, its not the 100% same place evey time you home it, and thats because its a cheap china model. but you can use it as a starting point every time, which saves you time.

I wont recommend using a homing switch for the Z axis, but there is an easy way to home that, when you have placed your object on the table and have homed the X and Y, you move the cutting bit just over the surface you wanna cut, without touching. then you place a piece of thin paper between that and the bit, and then you move the Z axis Down by 0,1mm at a time. while you do this, you move the paper back an fourth, and at the time you feel the bit touch the paper, you stop and press Z Home.

And now your set for cutting :)

Hope this was helpfull. Good luck :)

It would depend what kind of tape you use! I use a double sided tape often and I find the opposite, I have to be careful or I might not get my piece off.

The stuff I use has an acrylic based adhesive and is very thin, dont use and foam double sided tape.

Another option is to use the CNC to cut the top of a vacuum table. I have a vacuum pump that sucks through about 30mm of MDF and then sucks the work on to that. It takes a big pump to to that. Another option, much easier is to make a small table with a lot of holes that you attach a vacuum cleaner to, that will work equally well for the small size of your table. No fasteners required then.

Because you are not taking heavy cuts a basic vacuum setup like that should hold your work ok.

Here s a link to a guy to did the homing switches, and there is Pictures of the Motherboard too.

http://www.cnczone.com/forums/chinese-machines/178465-anyone-added-switches-yoocnc-3040t-control-box.html

MetalNwood

I problaly have less agressive tape i guess :)

But when i use small pieces of tape positioned around the piece, i sometime cant get it off too :)

But if i cover the Whole bottom of the piece with tape i have no problem getting it off... Sound funny, but thats the truth...

So i cover all of it allways, and no problems here... but Again.. might be the tape :)

Opened it up and found this header

Look correct?

If so that will be my next project!

I guess i can check in Mach3 if those pins give outputs.

Thanks LynxDK for the tip!

I thought i might have to get another parallel port card for more outputs.

Any other magic you know about these contollers?

ClayM

The chinese BOB's can be simple but I would be surprised if they didnt support limit switches. One port will support these but usually not have room for separate homing switches so software like mach3 has routines to share a limit switch as a homing switch.

Ask for the diagram of the BOB from the supplier and you will probably get something from them.

Thanks LynxDK for the link!

I think before i proceed with anymore cutting I will implement home switches!

Glad to know hardware has the capabilities ready to go.

I'm always amazed at the knowledge of all the hackers,makers,programmers or whatever we want to call ourselfs on this forum.

Necessity is the mother of all inventions!

ClayM

That looks right.

You should be able to see them Work in Mach3 without any problems.

Im afraid thats the only thing i know about those controllers... also know that some of them can have troubles with Stepping out of place when you fx cut circles for a long time, due to interference on the cables, but you might solve the problems by reducing the acceleration of X and Y axis.

Some changes the Power supply for the spindle to an external one, to get rid of it

But i hope you wont have those problems :)

Yes! Great point metalnwood.

 

In my case i have T-slots in various places. My thoughts were to make a sacrificial board and attach that to the bed. Then use management tape ( as we call it, same as two faced like the managers at work ) to secure rowmark to flat surface. Sounds like a pain and i would like more advice on this.

 

Start with the basics!

 

Work holding.

 

Doesn't matter how good your tools are if you cant hold your work properly.

 

Thanks

 

ClayM

This thing about a flat surface is only half the battle. Using the t-slots will hold the edges down but when you start removing material away from the edges the end mill will lift the material and cause all sorts of grief.

The best tape to use is

http://www.dickblick.com/products/scotch-removable-poster-tape/

I have tried so many tapes and this tape has been the very best... easy to apply, easy to remove and holding power for engraving is perfect. It works for .06" engraving plastic and .125 acrylic. No other clamps are necessary. Maybe some edge clamps to ensure it doesn't slide if its a small piece.

I buy huge amounts of it and that's all I ever use now. Don't try and reinvent the wheel. Try this stuff and you will not go back.

You need to cover the entire backside with it. Both surfaces must be clean. Sometimes your cutting tool will pick up some of it so you may need to use a small wood dowel and gently push against side of cutter to remove tape.

More to come when I get some time to post.

John

I now have the homing/limit switches working!

Fairly easy to do and setup and already saved me a couple times. I have found the z-axis usually causes me problems. I installed a Z+ home/limit.

When doing trial runs (spindle off. no cutter) im cautious about crashing into the table so I start a little high. but i always set the clearance height too high in the cam program (HSM). So when i start the cut with Z zero'ed at about an inch off the table I crash into Z+.

Simply a matter of getting used to all the parameters that need to be setup.

I should point out to everybody..

I have NO experience with CAD/CAM or G-code. Steep learning curve here!

Warhog,

If i want to do backlighting in the future will the rowmark work for this?

Thanks

Clay

Warhog,

 

If i want to do backlighting in the future will the rowmark work for this?

 

Thanks

 

Clay

Need I say more:smilewink:

This is the technique I use to achieve, what I consider to be, excellent back lighting. Here is a basic gauge face. This could just as well be a panel since it's all the same material and thickness. As you know, I use 0.0625" (1/16") thick engraving plastic for everything in the cockpit. But .0625" is too thick for LEDs to transmit sufficient light to illuminate the lettering. The solution...make it thinner...

SO how do you do that?

Its really easy. You flip it around and pocket out anywhere there is lettering that needs to be back lit. When I'm doing the g-code in CamBam, the last thing I do is mirror the panel or gauge and then I draw boxes around all the lettering. I then pick those boxes to be pocketed to a depth of 0.035". That is the perfect depth to get excellent light transmission through the plastic. And because the plastic is white on the back layer it helps to diffuse the LEDs so there are little to no hot spots.

Some might say that this is a pain in the ass to do but when you use CNC for everything, this is just a minor operation that takes just a few minutes to code and the actual cutting doesn't require exact registration when you flip the work piece. The cutting time is just a couple of minutes. The end result though is very nice and exactly what I wanted to have when the panel or gauge was sitting in place with the back light turned on.

I believe Anton also uses this method.

To achieve even better light diffusion I build into my panels a diffusion box and I mount common LED strips to the backside. They are intensely bright. Here is an example of one such panel.

These strip LEDs are intensely bright as I mentioned so I need to dim them a bit. And thats what this panel is for...

The console dial as well as all the other dimmers on this panel are actually 12v dimmers I bought on ebay for $2.00 each. http://www.ebay.com/itm/12V-8A-PIR-Sensor-LED-Light-Strip-Switch-Dimmer-Brightness-Adjustable-Controller/141714284675?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D33098%26meid%3D8f8472b800a8444393784ff3c392d680%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D331601522755

For that money (and free shipping):music_whistling: how can you go wrong :thumbup:.

I gutted them and used them for all the dimmers on the is panel. You can see three of them in this picture.

The pots are mounted inside and the three wires from them go to the respective circuit boards on the outside. From there I will have lighting rails to each are being controlled by this panel. It works really well. I am just ecstatic as to the control I know have over my cockpit lighting.

Sorry for rambling on like this but I wanted to give you a complete answer to your question.:smilewink:

John

I know you can get HSM xpress as a free version for hobby but it is a very hard way to do some of the basic stuff you are doing.

Are you using it integrated with inventor or solidworks?

metalnwood

Some advice on software would be great! currently using inventor with integrated hsm(my son has student version as he is taking cad design at school so he does some drawings for me) and mach3 for the cnc. We use solidworks at work and I have some experience with that but I cant afford to pay the $5000 or so dollars for a license or whatever the yearly rates the high end guys want. Tried sketchup as an alternative but after using solidworks and inventor I just could not get used to it.

On the cam side of things I have only used hsm. I am willing to try anything people suggest as an easier solution and welcome any thoughts on that. Obviously Warhog has excellent results with CamBam.

I realize building panels is pretty straight forward. Not really any assemblies needed I guess.

Can this be done with cheaper software with good results? How about Adobe Illustrator? Apparently ,my son claims, you can get it for $20 a month?

Warhog

Nice response to my question! I expected you to respond with a simple "yes, works well" or something like that. But no! You respond with every detail you possibly could. Thanks for that and thanks for taking the time once again. What is the material you are building the enclosures with? I agree with you on the results. Very consistent brightness. Looks Great!

Thanks

Clay

metalnwood

 

Some advice on software would be great! currently using inventor with integrated hsm(my son has student version as he is taking cad design at school so he does some drawings for me) and mach3 for the cnc. We use solidworks at work and I have some experience with that but I cant afford to pay the $5000 or so dollars for a license or whatever the yearly rates the high end guys want. Tried sketchup as an alternative but after using solidworks and inventor I just could not get used to it.

 

On the cam side of things I have only used hsm. I am willing to try anything people suggest as an easier solution and welcome any thoughts on that. Obviously Warhog has excellent results with CamBam.

 

I realize building panels is pretty straight forward. Not really any assemblies needed I guess.

 

Can this be done with cheaper software with good results? How about Adobe Illustrator? Apparently ,my son claims, you can get it for $20 a month?

 

Warhog

 

Nice response to my question! I expected you to respond with a simple "yes, works well" or something like that. But no! You respond with every detail you possibly could. Thanks for that and thanks for taking the time once again. What is the material you are building the enclosures with? I agree with you on the results. Very consistent brightness. Looks Great!

 

Thanks

 

Clay

Thanks Clay.

Acrylic face plates and styrene plastic for the housings.

Warhog

Do you have a Canadian supplier for Rowmark or buy out of the US?

Thanks

Clay

I would just Google them and see where their suppliers are located. I buy my material locally, which is outside of Toronto. They have it delivered in 2 days to me. I expect there will be a supplier close to you.

Google is you best friend for these kind of things.:)

The rowmark distributor for my area doesnt stock the rotary engraving line. so i have to wait for a stock order so its 2 weeks away.

Ordered cutters from 2Linc on warhogs recommedation. Great service! About a week away.

So while I'm waiting I am going to experiment with Mach3 some more.

The rowmark distributor for my area doesnt stock the rotary engraving line.

Your kidding??? WTF? There are lots of rotary engravers in operation. Laser may be the leader but it hasn't eliminated Rotary engravers yet.:( Where abouts are you located? Right in downtown Vancouver?

What did you order Clay and how much? Did you go through Synergy for the order?

While your waiting...

1. Have you run the setup routine to correct for x and y axis "measured vs actual distance" discrepancies yet?

2. Have you tried cutting a circle (hole) and measuring the diameter both horz and vert to ensure its a circle and not an ellipse?

3. One more thing, have you determined and corrected for backlash?

As far as limit switches go, I would only use them to ensure you don't crash into the sides of the machine. Home switch won't be needed as all you need to do is establish zero before you cut your work piece. I assume you are using Mach3? Do you know how to set zero before you cut?

What are you using for g-code?

I'll try and give some max cutting depths relative to material, feed and speed rates and anything else I can think of once I know what you setup is... as in PC, PC to controller connection type, controller type, motors and maybe post some pics of you setup as well. :thumbup:

Warhog

NO not dowtown Vancouver, but in the surrounding suburbs. I did go through Synergy since they are 10 minute drive from me. Did not have stock but were still VERY happy to take my small order. Ordered 2 2'x4' sheets of 222-412V. $56 ea.

One of my industrial plastics suppliers came up with some EnCore sheets. At the bottom of the sheet on a small tag was 402-222?? Strange. Anyway I now have test pieces I can cut.

For the price I couldn't help but buy one of these cheap chinese CNC's. Taig was at least double and just not in the budget.

Heres what I did to check calibration. Owner at work let me borrow a couple Mitutoyo dial indicators and mag bases. I clamped some steel flat bar to aluminum table first in X axis than Y. Using Mach3 checked indicated versus displayed. Over 2 inch stroke on both axis it was within half a thou after 10 or so manual jogs back and forth. I was surprised actually.

I did not check backlash! I don't know why because I deal with it everyday on old machinery. It does have ballscrews that seem to move very nice.

Z Zero i think i figured out. What i cant do is change x y. like rotating 90 degrees in the mill. Is this even possible?

Setup is

XP Pro - Inventor - HSM - Mach3 - Parallel Port - rest made in china - Nema 23 maybe?? 1.8 degree 2 amp. i think 36 volt. Sorry no idea on spindle motor rating but it has a decent ER11 collet chuck!

Thanks

Clay