Milling problems

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atrueresistance
Posts: 151
Joined: Thu Feb 07, 2013 6:20 pm

Milling problems

Post by atrueresistance » Fri Sep 13, 2013 4:06 am

I recently got my shapeoko back in action after having a short take out the arduino. I am getting ready to cut my first item out of aluminum.http://i.imgur.com/Wugwxhr.png

Since this is bigger 12"x12" and thinner, accuracy is something I'm looking for. I decided to mill a cedar shake to make sure I had a square level surface as far as the machine is concerned to mount the aluminum. http://i.imgur.com/2q91m9u.png

The problem is on one side of the cedar shake level cut does not cut correctly. http://imgur.com/a/ha7rq

I would like to clear this up before I try to engrave aluminum. Where would I start to fix this issue?
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Improbable Construct
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Re: Milling problems

Post by Improbable Construct » Fri Sep 13, 2013 5:13 am

What speed are you running and what is your acceleration?
Looks like you are cutting too fast.
It also looks like you have some flex in your X/Z axis.
Shapeoko #Classified some of the bolts may be original parts.
Shapeoko 1 # ???? Stainless plates, still in the box.
Shapeoko 2 # 3926 not stock
Shapeoko 3 # 0003
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atrueresistance
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Re: Milling problems

Post by atrueresistance » Fri Sep 13, 2013 1:04 pm

I do not know... probably stock? All milling parameters I tried to get in this screenshot http://i.imgur.com/2q91m9u.png

The settings were:
Depth Increment .03
Target Depth -0.825
Cut Feedrate 30
Plunge Feedrate 10
Tool Diameter .125

I'm guessing the flex is created based on the big dewalt and I can't do anything until the new plates come out?

https://www.inventables.com/technologie ... -end-plate
https://www.inventables.com/technologie ... otor-mount

I just find it weird that only one side ended up out of skew and not both.
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Improbable Construct
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Re: Milling problems

Post by Improbable Construct » Fri Sep 13, 2013 6:52 pm

atrueresistance wrote:
I just find it weird that only one side ended up out of skew and not both.
You have a couple of forces at work here.
The bit is alternately being pulled and pushed through the material.
With a very strong gantry with no flex at all it wouldn't matter but with the shapeoko the flex causes some weird things to happen.
When the gantry is moving in Y+ it is pulling the bit when it is moving Y- it is pushing the bit.
This is caused by flex in the X to Z transition.
Strange cuts along the X axis can also be attributed to this.
If the bit is pushed into the material there is not much flex but when the bit has been pulled into the material it can bounce and flex away from the material.

You can drill the stock plates to accommodate the double X makerslide rails. It makes a world of difference.
At the minimum I would flip the stock setup so that the wheels are closer to the Z axis.
Shapeoko #Classified some of the bolts may be original parts.
Shapeoko 1 # ???? Stainless plates, still in the box.
Shapeoko 2 # 3926 not stock
Shapeoko 3 # 0003
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http://ImprobableConstruct.com
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cvoinescu
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Re: Milling problems

Post by cvoinescu » Fri Sep 13, 2013 7:38 pm

Improbable Construct wrote:At the minimum I would flip the stock setup so that the wheels are closer to the Z axis.
I'd go as far as to say that Edward should make that change in the stock instructions. It's a small improvement, but I see no downside to it, and the BOM stays exactly the same.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

jkanzaki
Posts: 166
Joined: Sat May 05, 2012 3:00 am

Re: Milling problems

Post by jkanzaki » Fri Sep 13, 2013 7:52 pm

I agree, I wish there is a kit to begin with all these upgrade so i don't have to get them afterward. :(

like change everything to metal space, dual x rail, dual y motor, all the good stuff, acme z axis to make a delux kit or something

I think alot of us who built would eventually we have to dish out these money for these upgrade anyway. :P
Shapeoko 1 - dissassemble
Shapeoko 2 - 1 x 1m expansion TinyG, superPid, Dw660, Aluminum extrusion bed, Nema 23, acme, Z axis upgrade, Dual Y
Shapeoko 3 - 0051 Stock Dw611, SuperPid, limit switch, 9mm belt

Improbable Construct
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Re: Milling problems

Post by Improbable Construct » Fri Sep 13, 2013 8:49 pm

jkanzaki wrote:I agree, I wish there is a kit to begin with all these upgrade so i don't have to get them afterward. :(

like change everything to metal space, dual x rail, dual y motor, all the good stuff, acme z axis to make a delux kit or something

I think alot of us who built would eventually we have to dish out these money for these upgrade anyway. :P

I feel it is important to build and run the stock machine.
The shapeoko is a capable machine but many of its design choices were to bring the price down below $300.00.
As such building and upgrading really teach you what you are doing and how everything works.
There is a lot of trial and error, but in the end what you gain in knowledge cant be bought.
My shapeoko has been through 5 major upgrades/rebuilds. Not the most cost effective way to do it but what I learned was well worth the money.
Shapeoko #Classified some of the bolts may be original parts.
Shapeoko 1 # ???? Stainless plates, still in the box.
Shapeoko 2 # 3926 not stock
Shapeoko 3 # 0003
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calica
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Re: Milling problems

Post by calica » Fri Sep 13, 2013 9:23 pm

Dual Y should be default. Mine was completely useless without it. I got racking on the sharpie hello world unless the eccentric nuts were very loose. I already had spare stepper and a 4 axis board so the upgrade was cheap and painless for me.

Flipping X is a free upgrade. I haven't done it (just going to go dual X and see no point in rebuilding it twice. Going to extend axis at same time). The docs are on the Wiki so no reason the community can't do it.

atrueresistance
Posts: 151
Joined: Thu Feb 07, 2013 6:20 pm

Re: Milling problems

Post by atrueresistance » Fri Sep 13, 2013 10:18 pm

Is this what you are referring to flipping it? http://imgur.com/nevQqz1 I'm re-running the same program to see if the results change.

*ninja update* It is about halfway through the first pass. It looks to be doing the same thing even after flipping it. I'll comment and post pictures once the first pass is though. Would it help to post a video?
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jkanzaki
Posts: 166
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Re: Milling problems

Post by jkanzaki » Fri Sep 13, 2013 10:40 pm

Improbable Construct wrote:
jkanzaki wrote:I agree, I wish there is a kit to begin with all these upgrade so i don't have to get them afterward. :(

like change everything to metal space, dual x rail, dual y motor, all the good stuff, acme z axis to make a delux kit or something

I think alot of us who built would eventually we have to dish out these money for these upgrade anyway. :P

I feel it is important to build and run the stock machine.
The shapeoko is a capable machine but many of its design choices were to bring the price down below $300.00.
As such building and upgrading really teach you what you are doing and how everything works.
There is a lot of trial and error, but in the end what you gain in knowledge cant be bought.
My shapeoko has been through 5 major upgrades/rebuilds. Not the most cost effective way to do it but what I learned was well worth the money.

I got my machine last year , probably one of first or second batch, but never got around to finish the stock. Now coming back from the forum seeing so many problem encounter with wobbly Z axis, and lack of precision on the stock makes me want to upgrade right away. Spend some money (hundreds of dollars :P) Do it right the first time right? I do really appreciate the amount of help and feedback, I love this forum.

I do agree with you about the learning process, it is invaluable.
:)
Shapeoko 1 - dissassemble
Shapeoko 2 - 1 x 1m expansion TinyG, superPid, Dw660, Aluminum extrusion bed, Nema 23, acme, Z axis upgrade, Dual Y
Shapeoko 3 - 0051 Stock Dw611, SuperPid, limit switch, 9mm belt

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