Pill box help

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Rinus
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Pill box help

Post by Rinus »

I have bought the Pill Box files and downloaded machinist and own Vcarve Desktop. I have opened the bottom file and I'm watching the movie. What is driving me crazy are those numbers I have to put in. I hope someone can help me out with this because I'm thinking of selling it all because I can't get it to work.

This is what I would like to know. I have a 3 mm end mill and a ball nose with these info, cutting diameter 1/16, shank 1/4, cutting length 1 1/2 and overall length 3 inch, 2 flutes and 3.6 degree. It's nice and small at the tip so it should do a fine finish I think.

Now I have problems because I don't have a clue how to put it in the tool library and what numbers to use for the pill box. I sent 2 screenshots how it's now. The roughing is about 11 minutes but the finish is 1 hr and 6 minutes. That should be lower I guess or not?

Please help me out what I need to do. Tears are closer to me than a smile. 😢
Attachments
roughing.jpg
finish.jpg

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Adrian
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Re: Pill box help

Post by Adrian »

3D jobs do take a very long time. If anything it's likely to take far longer as the default time estimate uses a scale factor of 1 whereas a 3D job is typically more like a scale factor of 3 plus.

Spindle speed, feed rate, plunge rate and pass depth are all down to the combination of what your machine can handle and what the material is. The manufacturer of the bit you're using should provide the optimal figures and then you have to adjust those for what your machine is capable of. My machine is capable of cutting far deeper and faster than yours is for instance.

It's part of the learning curve I'm afraid. You just have to experiment with simple cuts etc to learn and understand the capabilities of your machine. Someone with a similar machine would be able to give you ballpark figures but there is always going to be differences that you really need to learn to get the best out of your machine long term.

Rinus
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Re: Pill box help

Post by Rinus »

Can you please take a look if the numbers are right with this ball nose bit? Im losing it now.
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toolbase.jpg

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Adrian
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Re: Pill box help

Post by Adrian »

Stepover would usually be between 8 and 10%. A basic rule of thumb for pass depth is no more than the diameter of the bit but that can vary a lot depending on the type of cut and the machine. For a 3D finishing pass the pass depth is ignored anyway.

For RPM, feed rate and plunge rate I have no idea as I don't know what your machine can do and what material you're using.

What sort of settings do you use on other jobs? As long as you don't go faster than what you've done before you should be ok as 3D finishing cuts are very lightly loaded compared to profile cuts for example.

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scottp55
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Re: Pill box help

Post by scottp55 »

.25" shank, and a .0625" tip sounds like you should be entering that as a TBN(Tapered Ball Nose).
You'll need to get the correct side angle from the bit supplier.
.7" for an initial Plunge sounds a little deep for my hardwood tastes.

Don't let it get to you! You should have seen me trying to set up from scratch with Zero experience! :)
I've learned my lesson well. You can't please everyone,so you have to please yourself
R.N.

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Re: Pill box help

Post by Bob Reda »

you are really confusing me (which don't take much) you are using inches and in the same set up mm. So I don't know exactly what you are using. You are saying your plunge rate is 90mm sec which is pretty high, at the same time running at 20 inch per minute, which I think is pretty slow. and your plunge rate is .7 inches per pass, which you will break a lot of bits. I going to let you know what I do which is not saying you should do it. My speed is 190 inches per minute, my plunge is 100 inches per minute and my spindle speed is 12,000 rpm. I never change those. Now if I was doing aluminum or something to that nature I would take a look. But I've down alot of different hardwoods, softwoods, plastic, foam with those settings. How to put the tool in the data base. there are a lot of different videos on that. But you do need to know the tip size of the bit you have. You sound like you have a tapered ball nose, you will need to know the tip size to enter the size into the doc,and then you will know the angle on the side to enter that info. You should be able to get that from where you got the bit. Normally, I set my pass depth to 1/2 the bit diameter. So if its a 1/4 inch bit I set the pass depth at .125, don't know the type of machine you have or the router you are using to help with the speed and things

Bob
Last edited by Bob Reda on Mon Aug 17, 2020 7:10 pm, edited 1 time in total.

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Re: Pill box help

Post by Rcnewcomb »

Rinus,
Rather than taking pictures of your screen with your phone, please use the Windows Snipping Tool. The files will be smaller and the image quality will be better.

Taking a Screenshot
You can easily take a screenshot in Windows using the Snipping tool which comes with Windows.
  • Load the snipping tool and click the NEW button.
  • Click and drag the mouse from the top left corner of the area you wish to copy, and drag to the bottom right corner of the area you wish to copy.
  • When the mouse button is released, the Snipping tool will copy the screen and you can then Save the new image to a PNG picture file.
How do I upload files or photos to the forum?


- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop

Rinus
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Re: Pill box help

Post by Rinus »

Rcnewcomb wrote:
Mon Aug 17, 2020 7:10 pm
Rinus,
Rather than taking pictures of your screen with your phone, please use the Windows Snipping Tool. The files will be smaller and the image quality will be better.

Thanks. Just changed to Windows and did not knew this.

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Re: Pill box help

Post by Rinus »

I have watched a few movies and i think i got it with that database. About speeds and feeds i will have a way to go.

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Re: Pill box help

Post by adze_cnc »

scottp55 wrote:
Mon Aug 17, 2020 1:22 pm
.25" shank, and a .0625" tip sounds like you should be entering that as a TBN(Tapered Ball Nose).
Scott,

The first post does mention “3.6 degree” so I suspect that you are correct that this is indeed a tapered ball-nose bit being incorrectly entered as a striaght end-mill.

Steven

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scottp55
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Re: Pill box help

Post by scottp55 »

Steven,
I think that info was just for the Tapered Ball Nose.
Hope you're doing well!

Rinus,
Not familiar with your machine...
Don't know if you have a router or a spindle...
And unfamiliar with your machines software, But :)

I'd highly recommend using some scrap and doing some test cuts to find your particular "Sweet Spot"
https://www.precisebits.com/tutorials/c ... speeds.htm

IF you start out conservative with cut depth 1/2Diameter for a Pass Depth, you'll rarely break a tool.
When I first started Dialing in my bits for best finish in hardwoods,
I also started with conservative feeds and speeds with a shallow pockets.
I have a VFD I can easily reach, so I can adjust RPM on the fly....
If you have a router, can you in your software,adjust your Move speed on the fly?

I'd start at a safe(slow) Move speed of 1 Inch Per Second....then start a 1/2Diameter small Pocket.
I'd let it run a few lines and stop the cut.
FIRST...after spindle stopped I'd touch the end of the bit....It should be room temp,or Slightly warm.
IF it was hot, I'd lower the RPM (or raise Feed rate with a router)
and cut a few lines more, until the bit was cool to touch.
THEN I'd Proportionally increase Feed AND Speed, and check that the same way...
Until finish of the cut started to degrade....Then back off both Feed and Speed about 10%.
That was my "Sweet Spot" for that bit, in THAT material.

Use the same material most of your work will be in.
Pockets are good for testing Sweet Spot,pass depths,stepover,etc.....
as when one shallow pocket is done, You can duplicate the toolpath, make it deeper, and rinse repeat.

You want Chips, NOT dust(even if chips are very small with small tools).
Listen to your machine,watch for excessive vibration, and always bit temperature.
Once you find you're sweetspot...you can cut all day with a cool bit and a good finish :)

Very good way to learn your machine and it's limits!
Hope any of this helps you!
scott
I've learned my lesson well. You can't please everyone,so you have to please yourself
R.N.

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scottp55
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Re: Pill box help

Post by scottp55 »

Oh,
For 3D work, as a general rule of thumb, X,Y Move speed should be about the same as your Z Plunge.
The limiting factor is the Z Plunge rate.....You want a nice smooth motion in all 3 axis.
A lot of machines state the Maximum speed for the axis, and is often overrated for smaller cuts.
Try an air cut of a 3D at about 1/3-1/2 maximum Z Plunge stated for a starting point....
See if machine is moving smoothly with low vibration, no clunks,straining,losing position.
Vibration in the cutter head Is transferred to the cut!

IF you want to practice 3D with your 1/16"TBN, maybe take a Dished model from clipart models,
reduce size by 50%(they're designed generally to be cut at size imported with an 1/8" BN,
so 1/16"TBN will give approximately the same detail at 50% size), add a Zero Plane and use a raster cut.
May want to experiment with stepover at this time for cut quality with various stepovers(6,8,10,12%)
and compare just to understand the difference stepover makes?

Just my own personal experience and opinion....everyone does things a shade differently:)
I've learned my lesson well. You can't please everyone,so you have to please yourself
R.N.

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Re: Pill box help

Post by Jozua »

Rinus wrote:
Tue Aug 18, 2020 8:43 am
About speeds and feeds i will have a way to go.
When I started in 2009, I also did not know anything about a CNC machine let alone what spindle speeds, feed rates or cutting depth to use.
I only use Onsrud end mills, (but that is irrelevant) so I used their chip load calculator to determine cutting depth, spindle speed and feed rate based on their recommended chip load.
For that matter, any chip load calculator will help you to determine these numbers OR you can go the Trail and Error method to find out the hard way by breaking end mills one after another until you reached the “sweet spot” for your machine.
I started at the bottom numbers of the recommended chip loads and worked my way up the more I got used to my machine’s capability.
Stay the course…sometimes the learning curve is steep but you will get there. All of us stared at the bottom.
Example of A chip load calculator.
https://www.cutter-shop.com/information ... chart.html
I hope this helps
Joz

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