eShapeOko #71 SWEDEN!

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selektha
Posts: 42
Joined: Tue Jul 02, 2013 2:05 pm

eShapeOko #71 SWEDEN!

Post by selektha » Thu Jul 11, 2013 9:31 am

So I received my eShapeOko in april but have not had the time to finish it until now, ordering the electronics I wanted took longer time than I plande but now it is finaly alive!
I still need to make some adjustments to it to get better precision but for my tests yesterday it is okay.
built.jpg
Finished HW build
built.jpg (127.32 KiB) Viewed 1866 times
Specification
eShapeOko batch #4
- dual Y
- Dual X rail
- Nema17
- TinyG v7

Test drawing, start and end points are not aligning right and pressure from the pen is not 100% even:
test.jpg
First working pencil test(earlier test was to much pressure on the pen and ripped the paper)
test.jpg (45.09 KiB) Viewed 1866 times
So next thing to do is leveling the machine better(I think its maximum 0.2-0.5mm to high on the right side(Z or Y I do not know) and to see if I am missing steps or the pen is flexing.
Will update with my progress.

Upgrades Im thinking of is:
- Upgraded Z lead screw
- Kress spindle (dremel today)
But that will be a later problem.

My goal with the machine is to be able to cut aluminium parts for my RC models.
Last edited by selektha on Sat Jul 13, 2013 8:40 pm, edited 1 time in total.

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
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Re: eShapeOko #xxxx SWEDEN!

Post by cvoinescu » Thu Jul 11, 2013 9:56 am

Congratulations on assembling your machine!

If you misplaced your serial number, or if I somehow forgot to put it in the box, PM or email me and I'll look it up.

Missed steps almost never return to to the right path -- after the missed steps, the remaining drawing would be shifted. You don't have missed steps there. What I see is flex or slop, most likely from the pen, but could also be V-wheels not tight enough, or the X belt too loose. It could also be the pen itself: in ordinary ballpoint pens, the tip can move around in the case. That could well be what caused the errors. The uneven pressure on the pen can be from an uneven surface (some pens are very sensitive to tiny variations, especially if mounted rigidly), or from the machine not being exactly parallel to the surface.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

selektha
Posts: 42
Joined: Tue Jul 02, 2013 2:05 pm

Re: eShapeOko #xxxx SWEDEN!

Post by selektha » Fri Jul 12, 2013 7:41 am

I am quite sure I have the serial at home but I have not had the time to find the original papers :) much more fun tinkering with the eShapeOko.

Regarding the backlash/flex/pencil issues I have, I cant seem to get rid of it, I have tried with a new pencil but I think it flexes to, will try a ordinary led pencil tonight if I can find the time to tinker with it(I have on-call(24/7) on work this week so there are a limited amount of time).
I have tightened the belts as much as I dare to but the result is consistent and my machine is really rigid, the only flex I can find if I pull the right side of the X and at the same time pushes on the left side of the X but that is the steel plates flexing and that should not effect anything as long as I have Dual Y right?

I have found one thing that can but should not be an issue, one of the bearings do not go as smooth as the others, but do not worry I have already bought a 10pack because when I received the kit on of the bearings where already broken :) so I will switch that as soon as I can confirm it is not the pencil flexing.

As soon as i get rid of the flex issue I will start measuring so the scale is correct then it is on to start creating parts :)

I have to also say that I love the TinyG drivercard, it gives us such great platform for customising our CNC machines into whatever we want.

Ohh one more thing, I have bought a set of limiting switches(I have not mounted them yet) and wondering what solution people have for using them on the Z axis?

Now back to work :)

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
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Re: eShapeOko #xxxx SWEDEN!

Post by cvoinescu » Fri Jul 12, 2013 12:40 pm

I don't know what you can do about the flex, you seem to be doing all the right things. One think I keep forgetting about is the paper: sometimes that's what moves around. :)

The TinyG is really nice! Shame I've been away so much, I didn't get to play with mine yet.

About the Z limit switches: there's a block I've designed that you can use to mount them. See attached files. It's designed to be 3-D printed, but I'm sure you can mill a similar one too.
eShapeOko Z limit switch (small).png
eShapeOko Z limit switch (small).png (30.44 KiB) Viewed 1804 times
Attachments
eShapeOko Z limit switch holder.zip
(75.3 KiB) Downloaded 79 times
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

selektha
Posts: 42
Joined: Tue Jul 02, 2013 2:05 pm

Re: eShapeOko #71 SWEDEN!

Post by selektha » Sat Jul 13, 2013 8:44 pm

Great, will se if my friend can 3D print that for me :)

I have updated with the serial now :) I still have the flex/backlash issue but its a little less now but I cant seem to get it anny better now, and everything is deadon square.
I will try to do some more calibration test and see if I can see the same error in those.

WillAdams
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Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: eShapeOko #71 SWEDEN!

Post by WillAdams » Sat Jul 13, 2013 10:45 pm

Your ``Hello world'' looks great --- as good as any I've seen --- I think you're ready to start cutting and I think you'll find your cuts are better than the drawing (end mills deflect less than pens and pencils).
Shapeoko 3XL #0006 w/ Carbide Compact Router w/0.125″ and ¼″ Carbide 3D precision collets

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