Brand new Shopbotter

[angel and the bear]

Thanks to this forum and the fine folks in North Carolina my wife and I are new Shopbot owners, all of you guys got me excited about the potential the Shopbot would give us.

Attached is my first project, aluminum coins for myself and a buddy's business. Probably too ambitious for a first project but had a few weeks to play with software before Desktop arrived. Managed to cut too deep and fast on the outside profile cut and broke my first bit... :confused: (and not many bits available up here, so need to order more).

Comments and advice are always welcome.

[scottp55]

VERY nice for a first cut Barry!
Is metal what you'll be working mainly?
Which one did you break?
Welcome,
scott

[angel and the bear]

The coins in image are aluminum, broken bit is still in image if you look close, it was the 1/8 round over. Primarily we'll be doing wood products. Was just wanting to see how the Desktop handled metals.

BTW is your avatar an old Goldwing or Silverwing? We're Wingers when the weather allows (in AK).

[scottp55]

Pretty ambitious:) (still haven't cut metal yet, brass first to try)
Pointed round overs it seems like you have to run pretty much as if a shade above the tip is the diameter of the bit for feeds and speeds, pretty much a compromise for your material too.

SACRILEGE !!!!! :):)
Beemer '76 R75/6 LTD

Nervous the first time you pressed "Start" like I was?:)
You liking it? Is it like you thought it would be?
Learning curve is fairly quick, BUT just as soon as you think you've got it---
You pull a "Stupid Trick" !
Good time now to develop good habits and stick to them and get a routine down.
How do I know.........
scott

[angel and the bear]

Pretty ambitious:) (still haven't cut metal yet, brass first to try)
Nervous the first time you pressed "Start" like I was?:)
You liking it? Is it like you thought it would be?
Learning curve is fairly quick, BUT just as soon as you think you've got it---
You pull a "Stupid Trick" !
Good time now to develop good habits and stick to them and get a routine down.
How do I know.........
scott

Scared to death
LOVE IT! More than I expected!
I think more "stupid tricks" yet to be pulled here along with a lot of learning (but this forum has been invaluable for the learning piece) :)
Thanks!

[MogulTx]

You probably want to use an end mill with an upcut spiral to cut aluminum. I just worked some today using an Onsrud 63-712 ( 1/8") and 65-000 (1/16")

The original is shown with the replacement. They are the same size within 100ths of an inch. The size diff is an illusion. Original has some damage on the back side. New one is billet aluminum. Use SLOW speeds ( .5-.7 ips) and SHALLOW cuts ( I often cut as little as .007" deep, per pass) and ramp all cuts... use a very small cut 10-15% overlap...

And use 5052 or 6061 aluminum, whenever possible....

YMMV

Welcome to the ShopBot world. We hope you have an excellent time with your machine.

Monty

(oooops. File too big apparently. Will upload a smaller file when I can!)

[MogulTx]

Here is the milled aluminum handle....

PDF is not quite as clear as the picture. Will still try to load the photo...

[scottp55]

Nice Monty :)

[angel and the bear]

Thx for the advice, ordering in a few minutes. And nice work!

MGM, what RPM, pass depth, and speed do you usually use for the 1/16 bit?

[MogulTx]

For the 1/16" I am using 13500rpm and .40 ips and .25 z speed. For that one I am using .004 per pass and ramping over 40". ( it is a clearance cut- clearing the area for the letters. There is only a distance ramping option for clearance paths, as I recall....- ramping over a specific distance. So I chose 40", because I figured the total distance of any one area of any letter would be less than 40". Then I arbitrarily chose to use .008 depth of cut per layer and when I got to the clear area on the "b" in Rebel ( This is for an old AMC "Rebel" wagon... NOS Handles are hard to come by... and I have a CNC router.... )- the first 1/16" bit was unable to withstand the side load. I broke the bit at that point.... So I reprogrammed/reduced the depth of cut to .004 per pass and set the speed down from .55 to .40 IPS... No more bit issues.

Profile was cut out using the 1/8" bit. Slow ramps and slow speeds there, as well, but not nearly as slow..... ( .70 and .40 IIRC. Still at 13500. And .007 per pass, with ramps.
Used DS Tape to hold down and when the hole for the screw was cut, I used a deck screw there to further pinch the part to the table.... The shallow cuts and slow speeds allowed for very little force on the part ( so very little impetus to move around.)

As to cutting metals: I got some early advice from Brady on cutting metal. He is a great resource. Listen when he offers suggestions. Always use an upcut spiral for aluminum. Always ramp into your cut and make them shallow. ( 1/16" bits are not going to give you a supremely smooth cut. They are too thin and therefore deflect. But if that is the only thing that is going to cut the profile you want... slow things down within reason to get a good cut.... and be prepared to buy a bit or two. These are about $27 ea from Hartlauer. Not a regular stock item for them. (the # 65-000) - how many people are buying 1/16" bits, right???-

Anyway- back to coins and a new Bot! That sounds much more interesting!

(And thanks Scott. That is a big compliment coming from you!)

Monty

[scottp55]

Thanks for feeds/speeds Monty!
Need to start cutting something besides hardwoods to broaden out.
Yep, I Always listen closely to Brady(even though it usually takes me hours of Googling to understand half of it:)
Looking forward(nervously) to trying 360 Brass and Soapstone:)
(Still consider myself a Newbie who yaks too much!:)

[scottp55]

Oh, Barry,
If you haven't already joined the Vectric Forum, I'd Highly recommend it!
Every bit as helpful as this forum from the Vectric side of things. Nice people.
Nice to pose questions on something that's driving you up a wall because you KNOW it can be designed faster/easier/better.
http://forum.vectric.com/index.php?sid=a3cc396b1f3546faa7f6daed80c2912d

[angel and the bear]

Thanks MGM (Monty) and Scott for advice and encouragement!:D