Making Skins #74 - Brisbane Australia

[silverdog]

well .... the maker faire was a success for the organization .... their successfull target was to sell 20.000 tickets .... they sold 35.000 !!! both saturday and sunday they stopped selling tickets around 4 pm because the building was full ... there were a lot of cnc (most 3d printers) (and roland was close to us) but none was of the MM dimensions.
Something like 7 years passed from the beginning of Gerald's project, I begin my journey in the cnc world 3 years ago and IMHO there is still not a better project than this around ....

[Surfcnc]

Hi Everyone

I had my machine up on rollers ready to wheel out the door to its new owner.
In the end it was all taking far too long and getting more complicated by the second (from my perspective anyway).
Most said I should have just taken their money and left them to their own devices.
Despite this advice I really wanted my machine to get used and not languish in storage.
My call, probably wrong as usual but it is still my Mechmate for the time being.

The majority of people who wanted the machine had not done sufficient work in order to understand even the basics.
Most saw nothing wrong with taking many hours of my time wanting a CNC lesson.
This extended to every component of the machine itself, the machine controller, various CAD, design and CAM applications they have "thought about" or "heard of".
They also wanted to cut designs but no one ever produced a single design or emailed a file or brought a piece material to cut it out of.
In the future I will direct my efforts only towards those who have made the time to understand what they are getting into, best for both of us that way.

I did however inadvertently offend someone who made a genuine approach,
Confusing John the scammer from Sydney with John the genuine also from Sydney.

I put the machine back down on the deck, raised it another 70mm as I am pretty tall and levelled it up again with a levelling laser.
After that I ran some tests on a 3D prototype for a friend and reminded myself how awesome the Mechmate can be in full flight.

Then I took it apart again.
2013-10-24_18-44-31_HDR.jpg

The move caused a few changes as they never quite go back exactly as they were the time before.
In order to make the transition easier next time, I re-levelled everything from the cross beams upwards.
I was also really close to the maximum inwards adjustment on the X rails so also went about making that easier as well.

I slotted the holes in the X rails.
Damn that slotting took some time !!
2013-10-24_16-06-34_HDR.jpg

Note: Slotting the rail allows the rack to also move further inward.
The pinions will need to be moved on the stepper motors to once again align fully with the rack.

Levelled the "Tops" of the X beams, this time NOT assuming the PFC was actually Parallel Flange Channel

This is not finalised but note how the straight edge reveals any inconsistency.
Using a laser with just one top as a datum was not accurate enough.
In the past I had used shims to correct any incoonsistency but this time I will correct the actual issue rather than the consequence.
The second shot reveals how I had over corrected a little while testing some shims to set the top flange straight.

2013-10-24_18-46-50_HDR.jpg
2013-10-24_18-46-27_HDR.jpg

All the things take time and any tiny changes will ultimately require re tramming the spindle.
For those wondering why all the effort, this is just all about how good the machine can be.
When it is time to put the rails back on, I have now tested most methods for getting them straight, and the taunt wire method seems to be the best I can get.
After breaking a "taunt wire" and having the 50kg weight free fall dangerously.
Had a much closer look at wire breaking stains after that.

PS - great to see the newer guys knocking stuff out on their machines.
Still reading most of what is posted and enjoy it when I see the work.

Regards
Ross

[racedirector]

Ross

Its good in a way that your machine is still yours, I have always considered your machine as one of the best. You have now made it even better and you should be very proud of what you have done. Go forth and produce some more awesome stuff with it.

Hell, if I had the dollars I would have been driving up from Sydney to make it my own.

Keep up the good work!

Cheers

[Surfcnc]

Thanks for the kind words Bruce.

Spent some more time this evening getting the tops of the PFC's spot on.
Took a tiny twist out of one beam's top flange and they are both looking very good now.
It amazes me how using a few thickness of a coke can can have such an impact on how everything lines up.

Also checked the gantry for flatness against the tops of the beams and it passed with flying colours.

A few crashes and a bit of work related stress relieving on the welds, seems to have caused the gantry to go out of square by 2-3 mm.
Rather than pack the rollers my next move will be to fix one side of the gantry to one X beam and load up the free side with a ratchet clamp.
It is worth noting that with the proximity sensors off, the machine will easily correct these few mm when driven slowly onto the hard stops.

Basically you load up the gantry progressively and have it spring back to a marked point around 3mm or so from where it started.
I will try to take a pic of the set up as it could be quite useful for other builders who might need a bit of a correction in the squareness of the gantry.

Cheers
Ross

[racedirector]

Ross

I forgot to ask.... why did you have to slot the X rails? I assume that once you have a gantry built (becoming a solid unit) then the X rails can only be in one position for it to all roll smoothly and straight. I don't quite understand why you were running out of adjustment with the rails.....

Cheers

[Surfcnc]

Bruce

By correcting the X beams this had the effect of widening the distance between the rails (tipping the top of the beam outwards).
The rails were already at their maximum adjustment for the holes as per the original plans and the gantry was now too narrow.
I chose to slot the rails as this gave me a far wider range of adjustment than just drilling ever larger holes.
If you do your calculations right you should not have this problem, but changing things after the fact often challenges ones creativity !!

Quick Gantry Correction
I lie, nothing I do is ever quick.

Bolt a piece of timber to one side of the gantry
IMG_20131026_104427.jpg

Remove the rails and clamp the gantry to the X beam on one side
IMG_20131026_110244.jpg

IMG_20131026_110258.jpg

Attach a ratchet strap onto the free side and flex it back to the desired position
IMG_20131026_110743.jpg

The machine itself just happened to be the strongest thing I had laying around to act as a straightening rack
To finish up I sanded down the tops of the beams with a straight edge spanning between them and painted them again.
Now recoating the rails with some new black enamel so that will take quite a few days to dry.

Regards
Ross

[racedirector]

Aha, thank you for the explanation, if my analytic skills had been working I would have figured that out before asking the question I have had a couple of mini dramas with my build already so am primed for more along the way!

Looks like you are making great progress to get your beast as accurate as possible. I vote for not selling it at all after this round of maintenance - ha!

Cheers

[Mrayhursh]

I really like the way you mounted your electrical cabinets. I am going to mount mine similar. Good luck on the built it looks like you have the finish line in sight.

[Surfcnc]

Hurshy - Number 74 is already cutting, it just "looks" like it is being built.
Many have asked me if it has ever been used because I like to keep it so clean.
Looking back on my thread will reveal it has momentarily had some dust on it !

The control boxes also swing up, the feature is not often used but can save the back or legs.

Ross

[Surfcnc]

Gerald's method of cutting two sheets and flipping one, takes no prisoners when it comes to accuracy.
I am now well beyond any reasonable way to measure any variation.
Can no longer even 'feel" any difference in the flipped 6mm MDF sheets.
This tells me it is a perfect square as well as the measurements also confirming the sheet is square.

Squared Sheets.jpg

Despite getting the squaring right, the test also revealed that the rails are still not 100% straight.
In two places I can feel a slight variation along the long edges.
For most practical purposes the rails are now straight enough.

It would be nice to just jump in and make something as it has been a while now.
For the moment though another go with the taunt wire to try to eliminate the last bit of variation might be worth it in the longer term.

Ross

[darren salyer]

WOW. That's a whole new level of accuracy...

[Surfcnc]

Cheers Darren - Despite the international rules of manliness stating one must never read the instructions, occasionally it helps

Ross

[pblackburn]

It is good to see others strive for near perfection. As always, thanks for the information Ross.

[Mrayhursh]

I have worked in both engineering and data processing departments. Seems that the jokers that wrote the manuals and directions for products were always in my group. They never new the product and never got their hands dirty. So of course they new how to explain how to use the product. Read an IBM manual and see if you can understand what they are trying to tell you. Sometimes it is better to take a friend for lunch and ask him. I have asked a couple of vendors associated with the mechmate to explain how their product works. I sent one three emails and he never did explain it. He was the author of the instruction manual. Sometimes it helps to have a friend to help you over the hurdles.

[Surfcnc]

The single biggest problem with instructions is not knowing what you don't know.
After you know everything then they make perfect sense.
My first ever reading of a breakout board manual immediately springs to mind.

The gantry squaring instructions are very good and don't fall into this category of unintelligible instructions.
I know this as even I understood them.
Unfortunately they are not a magic wand that can be waved over a poorly aligned machine that makes all problems disappear.

PS My machine still needs the x axis pinions adjusted but have now trammed the spindle in and glued on a new spoilboard.
It "mowed the grass" (leveled the new spoilboard) in fine form.
Cut myself a test sign for a mate and all went well.
Great to be making something again.

cheers
Ross

[Mrayhursh]

I am very interested to hear how you resolve this issue with the x axis. good luck.
Edison said it best magic wand = sweat.

[Surfcnc]

Hi All

I am nearly finished my my machine updates (again) and decided to document cutting some UHMWPE plastic washers.
These are similar to the 40mm x M10 washers the motor swing plates pivot on but go on the outside of the plate on my machine.

On the left downcut spiral 2 flute carbide.
On the right upcut spiral 2 flute carbide - hmm fuzzy

Image00003.jpg

Putting together a you tube video of the actual cutting and will post the link when it is ready.
It is pretty easy to tell what was the best cutter to use.

Ross

[racedirector]

Enjoying your journey Ross and taking notes the whole way. These lessons are a good grounding in getting a machine as as good as one can get. I will be interested in seeing new things coming out of your machine in the near future.

BTW, where did you get the UHMWPE to cut those? I will be needing some of those in the near future and may as well use my current machine to do it.

Cheers

[Surfcnc]

YouTube video of the upcut vs downcut carbide bits.
http://www.youtube.com/watch?v=kZiR5RUR0Dk

Ross

[Surfcnc]

Bruce

Dotmar, Industrial Plastics and E-Plas here in Brisbane.
I have PTFE or "Teflon" on the inner join and UHMWPE on the outside, both 40mm.
Teflon sheet is more expensive and has a silkier feel by comparison.

Ross

[racedirector]

Excellent, thanks Ross. Will look those companies up to see if any have Sydney branches.

[Surfcnc]

I had a piece of timber 184 x 19 x 600 mm left over from a project and set the machine to cutting a small indexable wooden clamp.

IMG_0044.jpg

IMG_0047.jpg

Fitted Out.jpg

Ross

[Mrayhursh]

I need to make a couple of these. Great idea

[Surfcnc]

Out of $12 of stock I was able to make seven of these gifts.
They are used as a cable tidy to stop loose cables falling off a table.
The original that I saw made on a Youtube video just cut the bottom part out.
Thought that a bit of 2 sided machining could make it do double duty as a coaster.

The index pins were two 1/2 inch dowels drilled directly through the stock into the spoilboard.
Two of them were stained darker brown with a very exotic and expensive woodworkers colouring agent (liquid shoe polish)

IMG_0001.jpg

IMG_0002.jpg

Still needing a sand and a few more coats.
I am making a Youtube video of the steps, it is fairly long at around 15 mins.
Will post a link when it is ready.

Ross

[Surfcnc]

http://youtu.be/8adiSMs7sME

Ross

[zumergido]

omg.. that machine is fantastic. look like a commercial and expensive one. no like mine,

[lonestaral]

And it looks clean, unlike mine.

[Surfcnc]

You guys probably spend more time doing and less time cleaning.
All that hammer tone paint on industrial equipment the world over is no accident, it is really easy to clean!

Ross

[pblackburn]

Fernando and Al,

I work industrial maintenance (electo-mechanical technician). I will tell you that any machine likes to be clean. A clean machine will treat you well for years. Just like a clean work area is a safe work area. I just got done rebuilding a Bridgeport J2 Mill because one the machinists blew a chip with an air gun into an area where a chip should not be....the spindle housing and the casing. I just spent 8 hours with Scotch-Brite pads and a gallon of WD-40 cleaning this machine back to like new appearance. So the total downtime of this mill was more than 100 hours. There is no excuse for being dirty. It only takes a few minutes if you do it everyday but can take days if you do not. In the end, the machine suffers, you suffer or maybe even one of you employees or friends suffers. It is an accident waiting to happen.

Ross is very thorough with everything he does. I would not expect anything else but a clean and neat work area.

Take heed to this post and not offense as it is meant to open your eyes and not make them squint and blood vessels pop.

[lonestaral]

"In Penny Lane there is a fireman with an hourglass
And in his pocket is a portrait of the Queen.
He likes to keep his fire engine clean
It's a clean machine"

Penny Lane by The Beatles.

I quite agree with keeping things clean.
My machine will be a lot cleaner when I get a dust extractor sorted.

If anybody wants me I will be wallowing in the mud hole with my pet water buffalo.