Experimental Plug Track: 3D-printed, CNC-milled, laser-cut

[Steve_Cornford]

Hi Martin,
Just wondered how you are getting on with your L1 chair problem?
I believe you ruled out a horizontal drain hole.
I was wondering whether some sort of centrifuge system for accelerated draining of resin off the build plate would work.
A bit like those spinning turntables in a bucket for young childrens paint effects.

I assume any attempt at vacuuming the resin from the bottom of the slot would be madness?

Steve

 

[Martin Wynne]

Just wondered how you are getting on with your L1 chair problem?

@Steve_Cornford

Hi Steve,

My plan at present is to run the pin at an angle instead of vertical:

The trick is to find an angle which leaves enough of the plug behind it to have some strength for bash-fitting without deforming the slot, while not reducing too much the effect of the key clipping under the rail head. The above is 5 degrees, which works ok, but does pull out rather too easily. It would probably need a smear of superglue. Currently looking at 3 degrees.

I also have to think about not reducing the socket wall too much where two L1 chairs are side by side. Which is why there is rather more base overhang on the left above than I would like. Fortunately the L1 base is not as thin and delicate at the edge as the S1.

If, big if, the loose jaws were the only option available for the special chairs, some other possibilities come to mind. For example, where there are several chairs close together, they could be combined into a single plug-in item, with several slots for loose jaws. This would make a non-interchangeable component for a specific template of course, but we are likely to have that condition for some of the crossing chairs anyway.

Plenty to think about and keep plugging away at (!).

cheers,

Martin.

 

[Steve_Cornford]

Hi Martin,
Your mention of non-interchangeable component led me to wonder that if in the real world all the different types of chair are actually (for a given chair) interchangeable, instead of exporting an .STL file for a set of chairs for the current set of background templates it would be possible to have a function to provide .STL files for a standard raft of a given interchangeable chair?
That way you could perfect the design of a given inter-changeable chair in turbocad for instance which could include features too complex for on the fly geberation from Templot, for example a horizontal drain hole in the L1 chair that would allow the chair plug to reaitn its strength.
But I suppose this idea drifts away from the concept of export directly from the Templot templates.

How big are the resin molecules I wonder?
I have discovered that IPA molecules are larger than water molecules by attempting to filter my waste IPA through coffee filter paper, instead had to revert to using a used elegoo resin filter.

Steve

 

[Martin Wynne]

That way you could perfect the design of a given inter-changeable chair in turbocad for instance which could include features too complex for on the fly generation from Templot,

@Steve_Cornford

Hi Steve,

Some time ago I looked at trying to integrate some TurboCAD designs into the Templot export. It was a nightmare of different DXF versions, mm-inch conversions not working properly for blocks, and other issues. It also shot the file size through the roof.

The problem, if it is a problem, is that I am still using the very same DXF export functions which I wrote in the last century. To incorporate the modern 3D modelling stuff would involve a re-write of all that old code. It is far more complex nowadays than it was then, and would involve a significant learning curve for me. I was hoping to get the Plug Track done in my lifetime!

The alternative would be to develop rafts of plug track components entirely in TurboCAD. It is certainly doable, and some folks might want to do that. Don't forget all the on-the-fly options such as accomodating different rail sections, tweaks to the key thickness, and tweaking the track gauge -- and usable for any model scale.

I do want Plug Track to be usable for any Templot user without needing a CAD package or any CAD skills, so I think my current course of doing everything in Templot is the best way forward. It is time-consuming, but not actually difficult. Using TurboCAD would be the exact opposite for me.

cheers,

Martin.

 

[Steve_Cornford]

Martin,
The wider of the square tip reverse action plastic jawed tweezers are just right for holding 4mm S1 chairs in for threading purposes so thanks for putting me on to these.

Steve

 

[Martin Wynne]

.
So they are!

He said, hastily reassembling the pair that some fool had dismantled.

Martin.

 

[Martin Wynne]

I did warm the resin in a basin of hot water and gave it a good shake before filling the VAT.

@Steve_Cornford

Hi Steve,

Chilly in the 3D printing den tonight, so I wondered about warming the resin.

As you say, it is easy enough if it is in the bottle, but not so easy when it's in the tank. It occurred to me that the build plate is quite a chunky piece of metal, so if it was hot when dunked in the resin, it would nicely warm the resin.

So I pre-heated the build plate in boiling water from the kettle, and wiped it dry. And quickly started the print while it was still hot.

Seems to have worked well.

None of this practical stuff is ever in the instruction book.

cheers,

Martin.

 

[Martin Wynne]

.
I now have the loose-jaw L1 chairs working fine:

I couldn't get less than 5 degrees, and still retain enough bash-fit strength in the plug, or still provide some minimal additional support so that they print properly.

But spot the very slight design change?

There is now a very short vertical section to the slot and pin through the base of the chair. It hardly seems enough to make a difference. But it has done -- it causes some slight friction in inserting the pin, and causes the key to snap nicely under the rail head. And not easy to pull out without a tool, just like the other chairs.

important p.s. When I release the next program update with these L1 chairs, they won't match any existing timbering bricks you have made. The plugs and sockets are not in the same position relative to the rail gauge-face. They will require new bricks. See my previous note about making enough of the old L1 chairs for your needs before updating -- or at least, creating the required files to print them later. Alternatively, if you have made the L1 chairs but not yet the bricks, create the files for the bricks before updating. Or discard the the old L1 chairs and make new chairs and bricks. This applies for both loose-jaw L1 chairs and solid L1 chairs.

Usual cruel close-up. All the chairs on this test piece are loose-jaw. They don't need to be, because they are all separate L1 and S1 chairs, so could be solid slide-on chairs. It will be optional. (FDM timbers from the Neptune printer. EM.)

The best thing about loose jaws I'm finding?

Not having to thread them on the rail, or sort them into the correct order first is great -- you can just drop them in their sockets as you cut them from the raft. Then a quick tap with a pin hammer, using a cocktail-stick punch on the rail seat, and they are home.

But the best part is not having to fiddle about filing a lead-in on the rail ends, or trim the rails after sliding the chairs on. You can just touch the cut rail end against the sanding disc, getting a nice flat prototypical square end, and drop it on the chairs. Some blobs of Blu-tack between the timbers keep it upright while you get the first couple of loose jaws in.

Having square flat rail ends, not only looks prototypical where they are exposed. It also means we can have very close isolation gaps of only a few thou, which will hardly notice. With a smear of epoxy on the rail end to ensure isolation long-term. And some prototypical-looking fishplated joints -- 3D-printed fishplates applied from the side with a thin rear tab which fits between the rail ends. With randomised fish-nut rotations, of course.

cheers,

Martin.

 

[Martin Wynne]

.
And now the loose-jaw option for the switch block chairs (4-screw):

The right-hand part will also be used for the check rail chairs.

If the entire switch is done with loose jaws, these two-part chairs could be combined as a single chair. But I will leave that option for now.

cheers,

Martin.

 

[Charles Orr]

Hi Martin,
I've been marking exam papers for the past few weeks.

Can't wait to try all this out.

Cheers

Charles

 

[Martin Wynne]

Can't wait to try all this out.

@Charles Orr

Hi Charles,

Then you will be able to mark it out of 10.

I'm keen to get what I've done so far released soon, so that I can get some feedback. But there are so many unfinished loose ends I'm fearful it will cause a lot of confusion.

cheers,

Martin.

 

[Charles Orr]

@Charles Orr

Hi Charles,

Then you will be able to mark it out of 10.

I'm keen to get what I've done so far released soon, so that I can get some feedback. But there are so many unfinished loose ends I'm fearful it will cause a lot of confusion.

cheers,

Martin.

Hi Martin,
I think the work you have done/are doing deserves a great deal more than 10/10 😊
Cheers
Charles

 

[Martin Wynne]

Hi Martin,
Just watched the Neptune 3 Pro unbox & setup video.
Seems to be fairly straightforward to assemble.
Having handled the sample FDM printed bases you sent me I am sorely tempted to go the FDM route rather than outsourced laser cut ply & cork bed.
I must resist!
Steve

@Steve_Cornford

Hi Steve,

Just noticed the Neptune3 is now marked "Best Seller" and the delivery is now in January. Presumably the first delivery has sold out -- even though it hasn't arrived yet:

https://www.3djake.uk/elegoo/neptune-3-pro

That's an Austrian web site. The UK delivery to Amazon may still show up on there in December.

It seems there are no manual levelling screws. If using a rigid glass bed for the timbering bricks (as I do on the Neptune 2S), it could be levelled using packing shims of paper, card or kitchen foil under the clips.

cheers,

Martin.

 

[Steve_Cornford]

Hi Martin,
I wonder when it will appear on Amazon?
I assume that for our purposes the auto bed levelling is irrelevant and adding a glass build plate is the way to go?
Steve

 

[Martin Wynne]

Hi Martin,
I wonder when it will appear on Amazon?
I assume that for our purposes the auto bed levelling is irrelevant and adding a glass build plate is the way to go?
Steve

@Steve_Cornford

Hi Steve,

Elegoo's web site says Dec 29th estimated in the UK. They use Amazon for UK distribution:

https://www.elegoo.com/en-gb/products/elegoo-neptune-3-pro-fdm-3d-printer-225x225x280mm

I have never used so-called "auto bed levelling" so I can't make a proper reply. However, it is no such thing. Nothing gets levelled. It simply compensates for any out-of-level or unevenness on the bed by adjusting the nozzle up and down while creating the first layer.

Which therefore varies in thickness, and would be useless as a timbering base. Or maybe not, as I say I haven't tried it -- anyone?

But whatever, I couldn't get on with the flexible tinplate magnetic bed with a rough surface. It might be great for a Toby Jug. But I can't see it being much use for anything requiring accurate dimensions.

https://www.tobyjugmuseum.com

I much prefer a rigid glass plate, which works great. For the timbering bricks I use a thin film of PVP adhesive. Just a few dabs from the glue-stick, then smear it out with a damp sponge to a thin film. The timbering bricks stick quite firmly all over, without any warping. Then a wash under the tap with a nailbrush releases the brick from the glass. If you want to sand the timber tops, you can do that while it is still on the glass plate, the glue holding it firmly enough. But it needs to be PVP glue, and not ordinary children's glue stick. I use this stuff:

https://www.amazon.co.uk/gp/product/B08ZRXNH8D

Manual levelling is easy -- just print a bead around the perimeter of the work area. Measure its thickness at each corner, and adjust the screws, or add sufficient packing, to reduce the other 3 corners to the same thickness as the thinnest.

I can post a gcode file to do that. In fact I use it as a nozzle priming run at the start of each print. You can pull it off the bed as soon as the main print has started, to check the corners. If something has gone wrong and they are not all equal, you can stop the print before going any further. I have got it repeatable to +/- half a thou, even after removing and replacing the glass plate, which I find remarkable. I have marked the glass plate with a permanent felt-tip marker so that I always use it the same way round, and same way up. (The BIBO glass plate has a tiny chip out of one corner, which I use as the marker.)

I have to write all this stuff, and a lot more, on the Companion as soon as the plug track gets properly started. (Someone else will have to write the laser-cutting stuff.)

cheers,

Martin.

 

[Steve_Cornford]

Elegoo now showing as Neptune 3 Pro sold out for UK!

 

[Martin Wynne]

Elegoo now showing as Neptune 3 Pro sold out for UK!

@Steve_Cornford

Hi Steve,

This printer is available this week. 28% off if you order in the next 4 hours!

https://www.amazon.co.uk/MINGDA-Magician-auto-leveling-high-performance-230x230x260mm/dp/B09KC2Y56N

Dual Z drive. Glass bed. Direct drive extruder.

Reviews here:

https://the3dprinterbee.com/mingda-magician-x-review/

https://www.tomshardware.com/reviews/mangda-magician-x-3d-printer

I know nothing about it.

cheers,

Martin.

 

[AndyB]

I much prefer a rigid glass plate, which works great. For the timbering bricks I use a thin film of PVP adhesive. Just a couple of dabs from the glue-stick, then smear it out with a damp sponge to a thin film. The timbering bricks stick quite firmly all over, without any warping. Then a wash under the tap with a nailbrush releases the brick from the glass. If you want to sand the timber tops, you can do that while it is still on the glass plate, the glue holding it firmly enough. But it needs to be PVP glue, and not ordinary children's glue stick. I use this stuff:

https://www.amazon.co.uk/gp/product/B08ZRXNH8D

Manual levelling is easy -- just print a bead around the perimeter of the work area. Measure its thickness at each corner, and adjust the screws, or add sufficient packing, to reduce the other 3 corners to the same thickness as the thinnest.

Hi Martin,

Yes, much better to get the bed level and not rely on "self leveling". I have a heated glass plate on my printer too. It was supported on four springs with adjustable tension screws until I turned it into a tripod arrangement. That seemed to help a lot. I believe the four support version was actually bending the glass just enough to create problems.

Cheers,
Andy

 

[Martin Wynne]

@AndyB

Hi Andy,

Yes, the BIBO uses a tripod system, with only one central adjuster at the rear. It's a bit fiddly to get at because the wires for the bed heater and thermistor are in the way.

For the replacement glass bed on the Neptune I'm using 3 clips, two at the front and one at the back. In theory I should be using some packing under them to clear any undulations in the base plate. In practice it seems to be working fine.

Checking the base plate with a straight edge, it is concave, quite a bit lower at the centre than at the corners. I have no way of knowing if that is the plate itself or the plastic magnetic sheet.

When finished and cooling the glass gets suction-stuck to the magnetic sheet. I have cut away a small corner of the sheet, just enough to insert a screwdriver to release the glass.

cheers,

Martin.

 

[ralphrobertson]

I will be on the demo stand at the Manchester show on the 10th and 11th of December. If anyone is interested in seeing what I have been up to with my card laser cut sleepers and 3D printed chairs I can bring some along to show. I can also have some of Martin's individual key and jaw samples which you can look at too.

If you are planning on coming please let me know and I will make sure I put this in my bag for bringing otherwise I am demonstrating model buildings made with a laser cutter.

More details of where and when here Manchester Exhibition

Ralph

Edited for typo! Edited again to get the dates right! It is Saturday AND Sunday.