#2014F - the Birth, life and fall of a machine...

doorknob
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Re: #2014F - the Birth, life and fall of a machine...

Post by doorknob » Mon Sep 09, 2013 1:46 pm

Gadgetman! wrote:

Then I started on the Y-axis idler.
Methinks there's a problem with the holes as the eccentric spacers won't fit the holes.
Didn't fit on the Y-axis motor mount, or the X-axis plate, either.
No problem with the Z-axis plate, though.

Also, there's a problem with the M3 washers. 3 of them aren't M3 at all, so I only have one left after fitting the X and Y motors.
I finally got around to assembling my ShapeOko - it was shipped to me from Inventables on July 8, so my assumption is that mine is from the latest batch (batch 5?).

I also found that the holes for the eccentric spacers on the X- and Y-axis plates were too small, but the holes in the Z-axis plate were fine.

The too-small holes had a diameter that was less than 0.277", while the diameter of the eccentric shaft parts was about 0.279", a difference of a bit more than 0.002". I found that a size "K" drill bit with a nominal diameter of 0.281" opened up the holes well enough for a good fit.

(Yes, I know that you're in Europe, so your toolchest may not contain fractional inch tools, but that's what I mostly have in mine, with the odd exception. :) )

And I also found that several of the M3 washers were not as advertised, as the hole was too small to fit the motor mounting cap screws. I bought the dual-drive kit which came with some extra M3 washers, and so I was able to complete the motor mounting without the need to run to the hardware store (or attempting to enlarge the hole in the washers).

While I have not yet completed the assembly process, it looks like I will have a lot of extra parts left over (not that that's necessarily 'a bad thing'). Maybe I got someone else's (or maybe I have missed some critical assembly steps which are going to surprise me when I try to get things running).

My current challenge is to get the Z-axis drive screw locked into place with the M8 nuts - I'm going to try the modified approach that I saw in the wiki, with one nut above the bearing and the other one below it (but I may need to have two nuts below the bearing to keep all of the nuts in place). My current mystery, though, is to figure out where to get a super-thin 13mm open-ended wrench that I can fit between the bottom of the shaft coupler and the top of the bearing, to hold the M8 nut in place while I crank up the torque on the nut(s) below the bearing. I may need to make my own wrench out of some aluminum sheet just to get it done.

cvoinescu
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Re: #2014F - the Birth, life and fall of a machine...

Post by cvoinescu » Mon Sep 09, 2013 11:25 pm

I tightened the nuts with just the threaded rod, bearing and Z mount plate, before mounting the motor and attaching to the Z axis. That way, I had plenty of room, so I could simply use a vice for the lower nut and a 13 mm spanner for the upper nut. If you tighten the heck out of them, they won't come off, but you can use thread locking compound to be extra sure.

Your rod must be perpendicular to the bearing, or it'll wobble (and flex the whole Z axis). Ordinary M8 nuts aren't quite flat, nor tapped precisely square, so they don't self-align. I think it's mostly a matter of luck to get the rod perpendicular. I just tried half a dozen times until I was happy. The bearing has a little play that will absorb some wobble, but it's best not to rely too much on that. The threaded rod is slightly smaller than the inside diameter of the bearing, so I thought that wrapping some aluminum tape around it would help keep it centered. It turned out that it mostly got in the way, and I was more likely to get it nicely perpendicular without any tape. To test the alignment despite the play in the bearing, hold the assembly by the motor plate, rod horizontal. The long end will droop somewhat, so it won't be perpendicular, but that's fine. Gently rotate the rod by the short end, while watching the long end: it should not move up and down (it should droop the same).

By the way, this is still the part of the machine I'm the least happy with, but all solutions I could think of were too expensive; and having to try a dozen times to get the rod aligned is not that big of a deal, if it means it can be done with inexpensive stock components (you only do it once).
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

Gadgetman!
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Re: #2014F - the Birth, life and fall of a machine...

Post by Gadgetman! » Thu Sep 12, 2013 6:29 pm

doorknob wrote: I finally got around to assembling my ShapeOko - it was shipped to me from Inventables on July 8, so my assumption is that mine is from the latest batch (batch 5?).
It should have a serial on the outside of the box, somewhere.
If that ends with the letter 'F', then yeah, you have the latest batch.
(Yes, I know that you're in Europe, so your toolchest may not contain fractional inch tools, but that's what I mostly have in mine, with
the odd exception. :) )
You mean, tool-wall, right?
http://ic.pics.livejournal.com/anthony_ ... 5_1000.jpg
(I'll write about that in my other thread)
And no, there isn't a single drill-bit with weird fraction writings on it, there.
A couple of other tools, but that can't be helped.

/Rant/
I mean, if they only used 1/64", 2/64", 3/64" and so on, but nooo....
1/64", 1/32", 3/64", 1/16"... Whenever you see a kit with bits, sockets, spanners or whatever, you suddenly start wondering if they threw it together from leftovers of old kits...
/EndRant/
My current challenge is to get the Z-axis drive screw locked into place with the M8 nuts - I'm going to try the modified approach that I saw in the wiki, with one nut above the bearing and the other one below it (but I may need to have two nuts below the bearing to keep all of the nuts in place). My current mystery, though, is to figure out where to get a super-thin 13mm open-ended wrench that I can fit between the bottom of the shaft coupler and the top of the bearing, to hold the M8 nut in place while I crank up the torque on the nut(s) below the bearing. I may need to make my own wrench out of some aluminum sheet just to get it done.
Or you could assemble it in this order:
1. Install lower nut.
2. Drop bearing into place.
3. Install upper nut and tighten!
4. Thread onto Delrin nut on Z-plate.
5. Slide Z-axis slide into place and affix with M5 screws.
6. Mount coupler to M8 Rod.
7. Fiddle and swear profusely as you mount stepper on top.

You may need to remove a piece of the slide so that it doesn't conflict with the M8 nut, though.
(Haven't studied the alternative solution, so I may be wrong)

I don't like the stock mounting.
When you plunge the tool into the work material, the stepper will pull the spindle down. The nuts will put pressure on top of the bearing, and the bearing rests on the edge of the slide, so that seems to work.
But when it lifts, or is just left hanging, the weight of the spindle is actually suspended from the stepper motor axle.
That's what it looks like to me, at least.
What I would like to see is two thin pieces of steel, shaped like the Delrin plate, but with a slightly too small hole in the middle.
(1 - 2 mm smaller diameter.)
Then the bearing would be captive between the plates. The plates would be held together around the Delrin because of the M5 and M3 screws, and it wouldn't matter if you cut a little bit out of the slide to accommodate 2 nuts on each side, or possibly even NyLock nuts.
The Nylon spacers also needs to be replaced with metal spacers.

Looking at maybe moving the Y-axis belt to the outside. On a one-motor setup, that will buy about 1/2" travel on the X-axis. On a Dual-motor setup, the difference is a whopping 1".
Weird guy...
Shapeoko 2014F: 1000mm X/Y, 300W Quiet Cut spindle, Arduino Uno/G-shield and GRBL 0.9i
15x30 drag chains, custom spindle mount, 9mm belts, 8mm endplates, 6mm motor plates.

cvoinescu
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Re: #2014F - the Birth, life and fall of a machine...

Post by cvoinescu » Thu Sep 12, 2013 9:40 pm

Gadgetman! wrote:What I would like to see is two thin pieces of steel, shaped like the Delrin plate, but with a slightly too small hole in the middle.
(1 - 2 mm smaller diameter.)
Then the bearing would be captive between the plates. The plates would be held together around the Delrin because of the M5 and M3 screws, and it wouldn't matter if you cut a little bit out of the slide to accommodate 2 nuts on each side, or possibly even NyLock nuts.
This is very close to what you're describing (except it's a flanged bearing, which makes things simpler).
800px-EShapeOko_assembly_step_13_Z_motor.png
800px-EShapeOko_assembly_step_13_Z_motor.png (148.35 KiB) Viewed 1609 times
To avoid having to notch the rail, there's a shim in the next assembly step.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

Gadgetman!
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Re: #2014F - the Birth, life and fall of a machine...

Post by Gadgetman! » Fri Sep 13, 2013 6:22 am

Wasn't aware of the flanged bearing.

I'll be taking a long, hard look at those parts after the ShapeOko is finished and I can begin on the upgrades.
Weird guy...
Shapeoko 2014F: 1000mm X/Y, 300W Quiet Cut spindle, Arduino Uno/G-shield and GRBL 0.9i
15x30 drag chains, custom spindle mount, 9mm belts, 8mm endplates, 6mm motor plates.

Gadgetman!
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Re: #2014F - the Birth, life and fall of a machine...

Post by Gadgetman! » Wed Sep 18, 2013 8:21 pm

Got a slab(50 x 62cm) of 22mm chipboard to build the ShapeOko onto.

I mounted brackets for the front endplate and fastened it.
(I replaced the screws that came with the brackets with sligthly longer ones, though)

Then took my large set square (One arm 40cm, the other 60cm) and laid the short arm against the front endplate.
The long end should have touched the end of the rear endplate, but was approx 6mm of.
Then I checked the other end... That should of course also have been 6mm wrong...
Yeah, right... that was 3mm off.
And of course, when I checked the front plate properly, it's slightly bent. Hopefully it's just being tensioned by the other parts.

It does mean that I need to disassemble it and adjust the ends of the makerslides a bit.

I can't be certain how much the slides are of, or even the angles of the frame, though, as it's an old set square, and while it shouldn't be 'off', but I think it's time to get a new one, anyway...
(Dropped it a few times too many... It will no longer lie completely flat... )
I'll probably get a new small set square, too, and some better brackets.
Weird guy...
Shapeoko 2014F: 1000mm X/Y, 300W Quiet Cut spindle, Arduino Uno/G-shield and GRBL 0.9i
15x30 drag chains, custom spindle mount, 9mm belts, 8mm endplates, 6mm motor plates.

WillAdams
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Re: #2014F - the Birth, life and fall of a machine...

Post by WillAdams » Thu Sep 19, 2013 2:52 am

Check the square by placing it against a known straight edge, drawing / cutting the right angle, then flipping the square and repeating the angle --- error is half any deviation. Fix it by hammering on the inside or outside flat near the angle --- pound it to lay flat first though.

I prefer to check square by using a push rod to measure the diagonals.

The endplates can be trued up before assembly, failing that, you can force the machine into square when bolting it down so long as the Makerslide is cut accurately --- loosen the M5 schs as needed, bolt down, then re-tighten.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

Gadgetman!
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Re: #2014F - the Birth, life and fall of a machine...

Post by Gadgetman! » Thu Sep 19, 2013 4:51 am

The square is made of a single piece of 2mm thick metal sheet.
If it's out of true, hammering on it will only make it worse. And it's the one that I've usually used as a 'reference' straight edge.
Weird guy...
Shapeoko 2014F: 1000mm X/Y, 300W Quiet Cut spindle, Arduino Uno/G-shield and GRBL 0.9i
15x30 drag chains, custom spindle mount, 9mm belts, 8mm endplates, 6mm motor plates.

WillAdams
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Re: #2014F - the Birth, life and fall of a machine...

Post by WillAdams » Thu Sep 19, 2013 10:34 am

No if it's not square, one can hammer on it in the right place to fix it. See Fig. 9 on pg. 86 of Andy Rae's _Choosing and Using Hand Tools_ (pg. 84 has the procedure for how to check a reference square).

Accuracy has to start somewhere, and one of the most basic tools for it is a true square --- if your square isn't true, you can fix it as I described --- in the meanwhile:

- verify that your Makerslide lengths are consistent
- begin bolting the machine down
- check its squareness by measuring the diagonals (or using 3, 4 & 5 or the Pythagoream Theorem)
- adjust / repeat until it's square --- if you can't get it square check to see if your Makerslide was cut accurately
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

Gadgetman!
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Re: #2014F - the Birth, life and fall of a machine...

Post by Gadgetman! » Thu Sep 19, 2013 1:28 pm

My square is cut from a single piece of 2mm thick steel. The long arm is 2" wide and the short is 1.5" wide.
If there's any error in it, there's very little possibility to correct it.
(I know that it doesn't lie completely flat)

I will stop by a store and see if I can find a good one there, and also try to check the old one when I get home tonight.
(I need a smaller one, anyway.)
I will be checking the makerslides and everything else, also.
Weird guy...
Shapeoko 2014F: 1000mm X/Y, 300W Quiet Cut spindle, Arduino Uno/G-shield and GRBL 0.9i
15x30 drag chains, custom spindle mount, 9mm belts, 8mm endplates, 6mm motor plates.

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