Nylon Spacers

As you know, the kits shipped so far had the 23.81 mm (15/16″) nylon spacers replaced with 19.05 mm (3/4″) spacers plus three 1.58 mm (1/16″) washers to make up the correct length.  The 23.81 mm spacers are due to arrive tomorrow, and I will post them to the eShapeOko owners, in case they want to mount their Y motors the right way.

I’m still looking for ideas for belt clamps, by the way.  I’m not very satisfied with the zip ties.  The clamps need to be fairly cheap to have made, or very easy for us to make them ourselves.

Assembly Instructions

A few people have received their eShapeOko kits today (yay!). The assembly instructions, sadly, aren’t quite ready yet. I have just finished the single-X instructions, and I’m working on the dual-X, but that won’t be done tonight. Only a few steps are different, so it shouldn’t take more than a couple of hours tomorrow.

After that’s done, I need to set up the wiki so that I can create accounts for the owners and anyone who wants to contribute. Until I figure out how to keep spam at bay, you will have to contact me to get an account, though.

Kits Shipping Today

Sorry for the lack of updates.

The spindle mounts arrived, and they are good. They are ugly and a little heavier than the ones in the Inventables kit, but they do their job. They are mild steel, not aluminium or stainless steel, so they will need to be painted or at least greased a little, or they’ll rust (not right away, but eventually). I’m still looking for a better solution (especially given how long these took to make…).

We have a small pile of boxes (with kits in them!) waiting to be shipped. We’re in the process of printing postage labels. You will get individual emails with the tracking numbers later tonight.

For the second lot, which was waiting for the toothed belt pulleys, I have mixed news. The pulleys were supposed to arrive this week, but when I called the supplier, they said that their supplier did not have any in stock. They are manufacturing some, but they’ll take about three more weeks. The good news is that I have that box of crappy Chinese pulleys, and I’m going to use the best of those to complete the second lot of kits. When the good pulleys arrive, we’ll send them to you, free of charge, to replace the temporary ones. This way, you can play with your machine right away, and when you get the good pulleys, you’ll have three extras (useful, for example, as Christmas tree ornaments).

MakerSlide Production On Track

Here’s a piece of good news.  The first lot of eShapeOko kits includes American-made MakerSlide, brought to the UK at great expense.  (For those familiar with the assembly issues of ShapeOko Inventables batch 3, don’t worry: our plates have holes large enough to work with the MakerSlide tolerances.)  As you know, Harry Raley bravely endeavoured to produce MakerSlide in the UK, and launched this successful Ulule campaign.  He had an extrusion die made, which arrived at the aluminium extrusion company yesterday, and they did a test run earlier today.  The resulting samples are on their way to us.  So we’re on schedule on this front.

We have a new shipment of V-wheels coming, and they will be here before the MakerSlide, so that’s also on track.  The laser-cut parts we have already (except for the spindle mount, of which we have no news…).  Everything else is already in stock, or on its way to us, so hopefully there will be no delays with the November shipments.

Also, thank you for all the useful suggestions we received about the belt clamps.  Keep them coming.  Lots of good ideas (some of which we had thought of, some new and intriguing).  We can produce absolutely marvelous belt clamps, I assure you; the difficulty is in staying this side of £20 for one…

Spindle Mount Delayed

The laser cutting company now says that they will get the machined parts tomorrow, and we should have them Monday or Tuesday. I’m taking that with a grain of salt. I will send an update to everyone who bought the kit by email later today, just in case they don’t obsessively check this space. I am very sorry for this unexpected delay.

The longer nylon spacers for the Y motors are on backorder, so the first few kits will ship with 19.05 mm (3/4″) spacers plus three 1.58 mm (1/16″) washers each to achieve the correct 23.8 mm (15/16″) length. The washers work perfectly well, they are just not as nice as a single spacer of the ideal size.

Clean Room Build

I did a clean room build of the eShapeOko (using the spindle mounts from my ShapeOko, because ours haven’t arrived yet). The bad news is that I found several problems. The good news is that I got a working machine in the end, and it’s very nice. All problems are fixable, and they won’t delay the kits more than a few days. Here’s a list. The asterisks mark what we will do for the kits already ordered:

  • BOM error: a belt tensioner (ES-LBT) is missing from the dual-Y upgrade BOM.  Fix*: add a belt tensioner.
  • Model error leading to assembly problem: the screws for the X motor are too long. Temporary fix: added some washers.  Permanent fix*: supply M3 x 6 mm screws instead of 8 mm.
  • Model error leading to assembly problem: the spacers for the Y motors are too short.  Longer spacers allow motors with shafts shorter than 20 mm to work on Y, and make the assembly easier.  Temporary fix: added three 1.58 mm (1/16″) nylon washers on each screw.  Permanent fix*: replace 19.05 mm (3/4″) nylon spacers with 23.81 mm (15/16″) spacers.
  • Model error leading to assembly problem: the screws for the Z motor are too long.  The next shortest screw available is too short.  Fix*: two 1.58 mm (1/16″) nylon washers on each screw.  This was a problem with my ShapeOko kit too, but it’s more pronounced with the eShapeOko because our Z motor mount is slightly thinner.
  • Laser cutting error: the central hole in the Z motor mount plate is ever so slightly too small — should have been 22.00 mm minimum, it is actually 21.96 mm.  The bearings are 21.98 mm diameter, so they don’t fit.  Temporary fix*: enlarged the hole slightly.  Permanent fix: change the drawings to call for a larger hole, because the tolerances specified were ignored by the fabricator.
  • Laser cutting error: some of the 7.14 mm holes for the eccentric spacers are slightly oval, measuring about 7.14 x 7.11 mm.  The diameter of the eccentric spacers varies a little too: some fit (barely), some don’t.  Temporary fix*: reamed all eccentric spacer holes to the proper diameter (9/32″).  Permanent fix: change the drawings to call for a slightly larger hole.
  • Part design and quality problem: the belt clamps aren’t very good.  They are soft, hard to tighten well, and unless tightened very well, they slip.  Zip ties work better and are easier to fit.  Fix*: use zip ties instead of belt clamps.  A toothed belt clip would be ideal, but they are very expensive off the shelf.  We’re looking for a way to make a cheap one.
  • Assembly difficulty: the Z leadscrew wobbles if the locking washer is used.  Fix*: discard the locking washer; tighten the nuts directly against the inner ring of the Z bearing.  No wobble!

As you can see, there’s some reaming and minor Dremeling to do, and new screws and spacers (and zip ties) to order.  It’s very likely that everything will be here this week, so that we can pack the kits over the weekend and ship them out on Monday.

The good things: except for the missing belt tensioner, the BOM was otherwise accurate; every single washer found its place, and nothing was missing. The machine looks good, works well and seems sturdy.  It’s not terribly difficult to assemble and adjust.  The belt tensioners are sweet.  Everyone ordered the dual Y drive; the next largest source of unwanted movement is the X V-wheels, where the dual X rail will help (I have yet to do a clean room build for the dual X option).  The Z axis is very solid, and the good quality allthread helps a lot.

Complete tool list:

  • 4 mm Allen key (for the M5 screws)
  • 2.5 mm Allen key (for the M3 screws)
  • 2 mm Allen key (for the flexible coupler grub screws)
  • 1.5 mm Allen key (for the MXL pulley grub screws)
  • 8 mm spanner (for the M5 nuts and the eccentric spacers); an adjustable wrench can be used, but it needs to be narrow enough to fit on the eccentric spacers.  An open-ended and ring “combination spanner”, like this one, is best
  • two 13 mm spanners (for the M8 nuts); adjustable wrenches will do, or a vice and one spanner/wrench (there are only two M8 nuts to tigthen, but they need to be tight)
  • M5 tap and tap handle (for the MakerSlide and belt tensioners — both are aluminium)
  • tapping fluid (or almost any kind of oil, including WD40 and mineral oil from the pharmacy. Boots Baby Sensitive Oil is better than WD40 and doesn’t smell)
  • small open container (e.g. a ramekin) for the tapping oil (if needed)
  • plastic brush to clean the tap (old toothbrush or nail brush)
  • sandpaper for metal (200 to 400 grit), a piece the size of a business card (to deburr the MakerSlide ends)
  • permanent marker (to mark the eccentric spacers)
  • set square (to align the X rail)
  • adhesive aluminium foil (a tiny amount is needed to help center the Z leadscrew in the coupler) — will be included in the kit
  • scissors (for the belt and aluminium foil)
  • small diagonal cutters (for the zip ties)

Laser Parts Arrived

Laser-cut parts for eShapeOko

The laser-cut parts arrived today.  They are very good!  Cosmetically, they don’t look much, but the precision is excellent.  The hole for the eccentric spacer is the only one with a tight tolerance.  I’ve measured a few of them, and they are all 7.14 mm, according to my calipers (the nominal dimension is 7.14 mm).  The eccentric spacers fit very snugly.  The other holes are cut to very good tolerances too, much better than the quoted ±0.1 mm.

Detail of laser-cut stainless steel motor plateAs you can see, there are no “nubs” or other cutting problems (this is the bottom side; the other side is even cleaner).  The only minor problem is the occasional splash mark, but that’s just ugly — or a reminder of the science-fiction-like technology used to produce these parts: that is molten stainless steel splashed there, while being cut by an ultra-fine, computer-guided lightsaber.

The aluminium parts have a continuous burr around the cut on one side, and I am going to try to remove that before they get to you (because it’s embarrassing).  Before you ask, the round cutout is off-center by design.

We’re still waiting for the very last item, the spindle mounts, due “early next week”.