Making Skins #74 - Brisbane Australia

[darren salyer]

Very cool.

[Regnar]

I like it. Just a suggestion. Get ride of all the hardware and make some of your own wooden knobs. I think it would make it really slick. Something like this just a little more sexy.

[jehayes]

Very nice, Ross. Thanks for sharing.

[Surfcnc]

Hi All

Russell - Hope the Instructables guy never gets to see how fast the MM cuts these.
I made some 38mm x 18mm 5 point M6 knobs.
Great suggestion.

38mm 5 pt Knob Cropped.jpg

Thanks
Ross

[Regnar]

Ross they turned out great. I always try and make a few with the scrap areas on some of the projects. Before I moved I had a whole 5 gallon bucket filled with them.

[Surfcnc]

Got that date right - 1926. The car has wooden spoked wheels !!

An interesting challenge as the original part was cast bronze that was then chrome plated.
It might look like the writing in the middle of the part is a bit funny but in fact it is an exact duplicate of the original to maintain the vintage look.

Huge Mess
Huge Mess.jpg

Final Cuts and Bevels Done
Chev Emblem.jpg

Final Part
Finished 1926 Chev Part.jpg

Lastly I have been working away on my air blower and wanted to pass along my eureka moment.
A 0.9mm screw in MIG tip and 6mm pneumatic tube are made for each other.
Once more I use a trapped wire along the tube to direct it to where I want.

Mig Tip as a Nozzle.jpg

I will post a link to a Youtube video of my machine cutting the lettering out and the deburring toolpath at the end once it is finished.

Regards
Ross

[sailfl]

Ross,

Nice job on the sailfish. Where did you get you vector or did you hand draw it?

I like the combination of the wood and Aluminum. Gives me some ideas.

[Surfcnc]

Hi Nils

I got the "basic" outline of a few fish off the web as a guideline to what a sailfish looked like.
After that my basic fish shape was heavily modified to give the end shape. Drawn at my normal pace .. slow.
All the alloy parts were then added to the basic shape where they seemed to fit best.

Regards
Ross

[Surfcnc]

Here is my YouTube video for the Chev part.

http://www.youtube.com/watch?v=uutPNGo-npI

Nice and Fast.

Regards
Ross

[KenC]

Brilliant work!
I like the way you line everything with plastic sheet, make cleaning the metal chips bearable.
BTW, what plastic sheet do you use? Will you be reusing them?

[Surfcnc]

Hi Ken

We refer to it as builders plastic, it is available in 0.1mm or 0.2mm any thickness is fine.
The whole mess is bundled up and thrown away as everything is also soaked with oil I use for lubricating the cutter.
As I say I like tidy.

Regards
Ross

[Surfcnc]

The two parts I made got installed today so the owner showed me his part of the handiwork.
He is very happy with how it all turned out and I was even more impressed with his efforts on his vintage car.

Back Guard Kick Plate.jpg

Regards
Ross

[Surfcnc]

My recent double sided machining experiment involved a few little "mistakes" along the way.

http://www.youtube.com/watch?v=sZLtq3W1JnA

What can I say other than "sparks came out !!"

Regards
Ross

[smreish]

...you should see how many fly when you hit and cut through a g-clamp. Trust me, I know!

[danilom]

was that a screw? I also twice started the drilling toolpath again after the screws were in holes, luckily estop button was close.
Bit 1 : screw top 0

[Surfcnc]

Hi Guys

The bit survived unhurt, one was a screw and the other a 4mm index pin.
Though I might have some company when it came to hitting stuff

Regards
Ross

[jessyjames]

Boy I needed that.. Brought a smile to my face and the memories of me doing the same thing before twice. Choose your vectors wisely is what I have learned and sometimes forget too

[Red_boards]

I decided that wooden dowels were less painful to hit than steel ones. I now center the object and hold it in place around the edges (but I've still crashed into the wood at the edges - not good at over 100mm/s!). A laser light mounted on a wall is a good way to check center line.

[KenC]

I had my fair share of chew up clamps & shattered bits.
Vacuum hold down eliminated (almost nearly) all these expensive & embarrassing moments ...
BUT with pieces too small for vacuum hold down, I just double side tape the part on a bigget piece of fomica laminated MDF & place the clamps (on the laminated fomica) light years away from any possible tool path

I had never nail my work piece on the spoil board, anticipated broken nails & most of all don't trust myself to nail at the right places all the time...

Better safe than sorry


##PS, I still get sparks when I surface my spoilboard cum vacuum grid board. I never seem to get the board hold down screw deep enough to clear the surfacing bit ... Mind you 4" surfacing bit is the most expensive bit I have in my tool box...

[Surfcnc]

Hi All

I have been drawing away and reading about the belt reduction drives for a while now.
My double sided machining experiments also had this project in mind.
I was in fact getting my head around how the MM might double sided machine out some Acetal bearing cups for my own variation of the 4:1 gearboxes.
Finally got around to ordering the pulleys so I suppose that makes me 1/2 committed to making the drives for my machine.

My design is completed in terms of the plates but is still a work in progress with respect to how wide apart the plates need to be.
Once the gears arrive that should become a little clearer.

My criteria for the design were.
1. simple but accurate bolt together design
2. laser cut 6mm mild steel motor and swing plates
3. MM machined acetal bearing cup that uses the same bearing as the grinding skate.
4. sneak as many complex curves into the design as possible
5. use the typical XL pulleys in most other designs

X and Y Assembly

Drive Cropped.jpg

Z Assembley

IMG_3494.jpg

Front View of Universal Motor Plate

IMG_3495.jpg

I might still need to loose the big hole for the stepper motor to move the shaft outboard for fitment.
Previously I drew up some alloy drive plates but they needed lots of tapping.
The steel solution using the 4 tabs was in the end a lot simpler.

Regards
Ross

[KenC]

That is a good looking belt reduction.
Looks like you have everything figured out

"4. sneak as many complex curves into the design as possible ..."
This is my favorite point...

[MetalHead]

So now get a mill bit and see if you can cut them out of steel on your table.

For sure could cut them out of aluminium.

I agree about loosing the steppermotor hole.

I am going to start a tech thread on pullies becuase I have a question and do not want to hijack your thread

[Surfcnc]

Hi Mike

Hijack away, its the wild west in my thread.
A question for you, I have looked at your site http://www.cvsupply.com/servlet/the-...-Plates/Detail and it does not say what is the reduction.
Maybe put a note on your site for the easily confused like myself.

The pulleys look great by the way as there is no need for them to be all alloy.

I have recently done far worse than trying to mill 6mm mild steel.
I set up a pinion and using a HSS bit then later in a separate experiment a carbide bit, milled 14mm holes twice through 30mm of steel.
The HSS bit deflected and the hole was conical, 1mm out over the 30mm.
The carbide bit being stiffer was more accurate but unfortunately not good enough for nicely rounded hole.
The internal walls on the bore were however beautifully polished using .5mm DOC.

Using a 2 flute 6mm carbide mill at 1500 RPM and constantly wetting with oil, I believe the Mechmate would get the job done eventually. In the end buying from you or having your own design laser cut is just quicker !!

Regards
Ross

[Surfcnc]

All the 1926 Chev kick plates are now on the car.
Here is the pic I promised.
The car looks like it has its Sunday best on now.

1926 Chev in Driveway.jpg

Regards
Ross

[Alan_c]

Beautiful! nice work.

[Surfcnc]

The pulleys and new pinions arrived today.
So I shot down to the local machine shop and asked the owner how much to machine the pulley bores out and do some pinions for me.
It was a simple formula he gave me apparently it was expensive as he had to use a 4 jaw chuck.
His final figure - $35 AUD that not in total ...each.

This happened not long after.

IMG_3505.jpg

Not at all impressed with being asked to pay $490 AUD to machine $300 AUD worth of parts, the Mechmate was tasked with making its own upgrade.
Just did some final axis calibration, drilled 4 holes in each pulley and screwed them directly to the machine.
Somehow I managed to snatch a victory from the jaws of a defeat.

Once the videos upload to Youtube i will post the links.
The actual machining video is a bit slow so please don't watch it all.

Regards
Ross

[KenC]

I reckon the machine shop guy is engouraging you to play with your MM more

BTW, I'll do the same if I were you... BUT luckily I have more than a dozen machine shops just within a stone throw... literally

[danilom]

And some of us even bought a small lathe to help in future upgrades

[David Bryant]

Did you find the center with a touch probe?

[Surfcnc]

Hi All

Yes David the probe finds the exact center by just touching the extreme inside edges of the hole on both the x and y axis then halving those distances.
The routine runs twice, once fast and then a second pass slower for more accuracy.
The probing facility is built into Gerry's 2010 Screenset for Mach3 along with a range of edge finding functions.
The probe tip I use is the shank (no flutes remaining) of a 4mm end mill.

Here are the videos

Center Finding
http://www.youtube.com/watch?v=En76h4c8ans

Boring 72 Tooth Timing Pulley
http://www.youtube.com/watch?v=mqfCwb65sIQ

Finishing Pass
http://www.youtube.com/watch?v=EfScbUfUPwA

Danilo - If I bought a lathe then i would be compelled to CNC convert it .
Nearly did buy one just to bore these pulleys but the machine rescued of my wallet just in time.

The fit is of course not metal lathe quality but still perfectly adequate for the purpose.
I am let wondering now how well the machine will bore with the new belt reductions in place.
Any comments from belt reduction owners would be appreciated.
Presumably the cut may be a little better but other factors like slop, flex etc in the machine will also determine the absolute accuracy achievable.

Regards
Ross