Templot Club forums powered for Martin Wynne by XenForo :

TEMPLOT 3D PLUG TRACK - To get up to speed with this experimental project click here.   To watch an introductory video click here.   See the User Guide at Bexhill West.

  • The Plug Track functions are experimental and still being developed. Some of the earlier pages of this topic are now out-of-date.

    For an updated overview of this project see this topic.   For some practical modelling aspects of using Plug Track see Building 3D Track.

    The assumption is that you have your own machines on which to experiment, or helpful friends with machines. Please do not send Templot files to commercial laser cutting or 3D printing firms while this project is still experimental, because the results are unpredictable and possibly wasteful.

    Some pages of this and other topics include contributions from members who are creating and posting their own CAD designs for 3D printing and laser-cutting. Do not confuse them with Templot's own exported CAD files. All files derived from Templot are © Martin Wynne.
  • The Plug Track functions are experimental and still being developed.

    For an updated overview of this project see this topic.   For some practical modelling aspects of using Plug Track see Building 3D Track.

    The assumption is that you have your own machines on which to experiment, or helpful friends with machines. Please do not send Templot files to commercial laser cutting or 3D printing firms while this project is still experimental, because the results are unpredictable and possibly wasteful.

    Some pages of this and other topics include contributions from members who are creating and posting their own CAD designs for 3D printing and laser-cutting. Do not confuse them with Templot's own exported CAD files. All files derived from Templot are © Martin Wynne.

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

Quick reply >
Hi Martin,

example of increased label text height, I doubled it

20221031_140937.jpg


Meaning: 4mm, S1, plug width adj. 0_00
Ie default plug width.

I am using this convention as I try various negative adjustments to suit my experimental ply timbers, easier to keep track of them if labelled!

Thank you for pointing out the text depth parameter.
Steve
 
_______________
message ref: 5188
Meaning: 4mm, S1, plug width adj. 0_00
@Steve_Cornford

Hi Steve,

In the next update, a separate setting for text on rafts:

raft_text_height.png


It has to be kept low for the bricks so that it gets hidden under the ballast.

You are being far more methodical than me -- all I'm doing is to felt-tip the date and time on the back of the raft. :) Which I can then cross-reference to the relevant files.

cheers,

Martin.
 
_______________
message ref: 5193
.
I'm now in something of a quandary.

Whether to continue with the work I have done so far (not much) on split chairs for the check rails, like the switch block chairs. Or to swap to using the loose jaws for the check rails? For P4 I think it will have to be loose jaws, but for 00 and EM it could be either. But it would be a lot of work to have two different systems for both the chairs and the timbering bricks.

When it comes to the V-crossing, splitting the chairs involves 3 chair parts for the A and B timbers. Whereas loose outer jaws would be much simpler with a single chair and more chance of replicating the spacer blocks properly. And be more amenable to complex formations such as tandems. I haven't given much thought yet to K-crossings and slips, but I suspect loose jaws will be easier there too -- it is after all replicating prototype practice in principle.

Forming rail bends and trimming to length can be a trial and error process -- the rail can be tried and placed against the inner jaws as many times as you like before finally fixing it. Blu-Tack is handy for holding it in place for testing -- the inner jaws set the gauge.

What's making me hesitate is the thought that many folks might regard it as far too fiddly, and might have trouble printing the parts successfully. I thought myself that it was a silly idea and too fiddly for words. Until I tried it. It is actually working well and quite satisfying to do. Put the rail in place, and push in a loose jaw to lock it into the chair. You can feel a slight click as the key snaps into place below the rail head.

Decisions, decisions. But in the final analysis it is my hobby...

cheers,

Martin.
 
_______________
message ref: 5207
Hi Martin,
Just to clarify. For loose jaw check rail chairs would the process be:

1 Slide the stock rail part of the chair (with plug containing the slot for peg) onto the stock rail, together with other chairs required for stock rail.

2 Plug the stock rail into the timber bases, bash fit as before

3 Place the check rail into position on the check rail chairs

4 Plug in the loose jaw pegs so that they click in place below the check rail head.

or have I misunderstood the process?
 
_______________
message ref: 5209
Hi Martin,
Just to clarify. For loose jaw check rail chairs would the process be:

1 Slide the stock rail part of the chair (with plug containing the slot for peg) onto the stock rail, together with other chairs required for stock rail.

2 Plug the stock rail into the timber bases, bash fit as before

3 Place the check rail into position on the check rail chairs

4 Plug in the loose jaw pegs so that they click in place below the check rail head.

or have I misunderstood the process?
@Steve_Cornford

Hi Steve,

Yes, that's it. The check rail chair would be in one piece on one plug, entirely prototypical except for a vertical slot on the inside where the opposite jaw should be. Into which the missing jaw+key is inserted later, after dropping the pre-formed check rail in place.


inner_check.png


The check rail chairs would be threaded on the stock rail along with the S1 chairs and all bash-fitted into the base at the same time.

The check gauge is the most critical dimension in pointwork. So it will be important that the check rail is firmly secured against the middle part of the chair to set the check gauge. That might mean a drop of superglue is used behind the rail, or we might print a selection of loose jaws with keys of different thicknesses, so that you could choose ones that fit tight against the rail. Model rail sections do vary at times.

A point to bear in mind is that for any individual piece of rail it has to be all one or all the other. It won't be possible, or it would be very tricky, to combine bash-fit chairs and loose jaws on the same physical piece of rail*. Which means it will be necessary to have rail breaks in the prototype positions. So for example the closure rails would be bash-fit as far as the wing-rail front rail-joint. A separate wing rail with the knuckle bend would then be loose-jawed all the way to the end of the rail. I don't see that as a problem, just something to bear in mind.

*edit: but see: https://85a.uk/templot/club/index.p...3d-printed-cnc-milled-laser-cut.229/post-5225

Once we've got the print settings sorted, it would be possible to print a thousand loose jaws in one go on the build plate -- because they are all identical and Templot can create an STL with them all bunched up. At a cost of about 10p per thousand, so there's no need to go looking for the one which pinged out of the tweezers. :)

All this stuff is still waiting to be learned on the job. I'm sure there will be lots of tricks and tips to talk about once we get going.

I just need to make progress a bit more rapidly -- for example James is still waiting for some rail locators on the timbering brick to create a full track assembly jig for rivetted plywood or copper-clad.

cheers,

Martin.
 
_______________
message ref: 5210
Hi Martin,
I like the idea of a "standard" loose jaw part for multi-rail chairs.

You mentioned manually dipping the loose jaw raft vertically as an aid to cleaning uncured resin out of the slots.
To help this process along, would it be possible to design in a hole leading from the bottom of the slot out to the end or side of the plug as a drain hole to assist in this process?
After machine rinsing a gentle blast of air from a blower should see the slot clear of liquid before curing?

I assume there would be two classes of chai:
single rail chairs which have fixed jaws (S1, S1J, L1, M1 etc)
multiple rail chairs that would have loose jaws (CCL, CC, CCR, etc)

My intuition tells me that after one more boiled egg your quandary will be solved.

Steve
 
_______________
message ref: 5212
You mentioned manually dipping the loose jaw raft vertically as an aid to cleaning uncured resin out of the slots.
To help this process along, would it be possible to design in a hole leading from the bottom of the slot out to the end or side of the plug as a drain hole to assist in this process?
After machine rinsing a gentle blast of air from a blower should see the slot clear of liquid before curing?
@Steve_Cornford

Hi Steve,

From the start I had thought of a small release hole somewhere near the bottom of the slot. Originally because I thought trapped air might prevent the jaw sitting down flush. When there seemed to be a problem I even tried holding the jaw down for several seconds for any air to escape, but it made no difference. (There is a reasonable clearance on the pin at the sides of the slot, because the position of the jaw in the sideways direction is not critical. So air should be able to escape.)

I thought about a release hole again when washing the print. I was thinking it would have to be a hole in the side of the plug, because it would be blocked by the support pyramid at the bottom. But simply taking the slot right through the plug is by far the easiest to program, so maybe the support pyramids could have a groove across the top to clear the slot?

In the event, all the chairs I have tried seem fine, and the loose jaws sit fully home now that I have modified them. So maybe it's a solution to a problem which doesn't exist. On the other hand, it only takes one clogged slot in 50 to bring track assembly to a halt, so it is possibly worth looking at it anyway. Only a short halt, because it would be possible to shorten the pin and if necessary glue the loose jaw in place, in the event of finding a clogged slot.

Sometimes I think my problem is too much thinking and not enough getting on with it. :)

My intuition tells me that after one more boiled egg your quandary will be solved.

Hmm. It would be easier if I could be sure everyone will be able to print loose jaws and slots which fit together cleanly. I'm going to post the STL files here shortly so that everyone can if they want try them and report back. But if I'm going to add the through hole clearance as above, obviously I should do that first. And before then, a boiled egg awaits... :)

p.s. How did your 2.2 seconds trial work out?

cheers,

Martin.
 
_______________
message ref: 5213
Hi Martin,
I first changed the exposure time down from 2.5 seconds (the default when setting printer to Mars 2 Pro in Chitubox) to 2.2 seconds, but this made no discernable difference.
I then read the article you linked to, and then amended the Chitubox "advanced" settings from:-
1667393813606.png


by unticking [Image Blur} tickbox and setting Grey Level to 0 giving this:-
1667393900387.png


Now when printing a raft of 20 S1 Locators, I get most printed as 2.02mm with a few 2.01mm and 2.03mm, so this change which is consistent with your parameters now appears to give me similar results as yours, so for now I will stick with settings that match yours.

However it was an interesting article, and also the video that you linked to was also informative, but he does talk quickly and non-stop! A bit like one of my sister in-laws!


I would be happy to try out one of your loose jaw example .STL's when you are happy to release it into the wild.
Regards Steve
 
_______________
message ref: 5214
Now when printing a raft of 20 S1 Locators, I get most printed as 2.02mm with a few 2.01mm and 2.03mm, so this change which is consistent with your parameters now appears to give me similar results as yours, so for now I will stick with settings that match yours.
@Steve_Cornford

Hi Steve,

Thanks for reporting your results and confirming that the Image Blur function upsets the dimensions. It's a bit of a mystery why it is on by default if it does that.

If you are getting 2.02mm consistently for the 2.0mm plugs, you could correct that by reducing the shrinkage allowance. If you are still using the default 1.5% shrinkage for resin-printing exports, try changing it to 0.5%.

Your result has prompted me to check mine again. They are fiddly things to measure, but using my trusty Mitutoyo micrometer instead of a digital caliper I'm also now seeing 2.02mm (0.0795"). I'm going to change the shrinkage default in the program to 0.5%.

2.5 seconds (the default when setting printer to Mars 2 Pro in Chitubox)

I'm still using the version of Chitubox which came bundled with the printer, and the default in there is 2.0 seconds. This is also shown in the printer instruction book as the recommended setting. Is yours the same? I increased it by 10% to 2.2 seconds following some discussion on one of the web forums, although I can't remember which one.

I don't know why it was changed to 2.5 seconds, but it is probably a trade-off between accuracy and stronger prints with a longer exposure.

p.s. We now have a through slot in the plug:

slotted_plug_underside.png

So now to design a support pyramid which clears that.

Newsflash: curing the rafts on the build plate appears to have stopped them curling up so much.

cheers,

Martin.
 
_______________
message ref: 5217
Hi Martin,
As the printed manual had illegible LCD screen images so, i downloaded a PDF copy. The PDF copy has chitubox screen image showing 0.05mm layer height with 2 second exposure, but on first running Chitubox I opted to upgrade to the latest version & when I then selected Elegoo Mars 2 Pro as the printer the resin setting defaulted to 2.5 seconds. Later on I uninstalled the latest version, installed v1.8.1 then selected Elegoo Mars 2 Pro and the exposure was still defaulted to 2.5 seconds.
I have since amended that to 2.2 seconds to match your setting.

Blur
Dont know either but will review the homework you set me. I might understand it if I read it a second time!

Steve
 
_______________
message ref: 5218
@Steve_Cornford

Hi Steve,

Does your instruction book have this page:

elegoo_mars_ins.png


I agree the images are barely legible. For some reason the whole thing appears to have been printed at half of A5 size when it should have been A4.

It's probably time I upgraded Chitubox and the firmware to the later versions. But it is all working so well I'm loath to mess with it while I'm in the middle of Templot design changes.

The video seemed to suggest that 2.0 seconds gave better results, but having done all my testing at 2.2 seconds I'm going to stick with it for the present.

cheers,

Martin.
 
_______________
message ref: 5219
So now to design a support pyramid which clears that.

Looking something like this:

slotted_pyramid3.png


slotted_pyramid2.png


slotted_pyramid1.png


Which hopefully should allow a free flow of wash through the slot.

The top of the small pyramid section is very narrow, only 0.25mm (10 thou) wide in 4mm/ft scale, but it's necessary to prevent an "island" and ensure the plug prints properly.

I will do a trial print later and see how it looks.

cheers,

Martin.
 
_______________
message ref: 5222
It won't be possible, or it would be very tricky, to combine bash-fit chairs and loose jaws on the same physical piece of rail.

Which is nonsense of course -- it depends on the situation.

For example, it would be advantageous to have the P slide chairs with a loose jaw. The plain slide bases could then be bash-fitted in advance. The stock rails then being bash-fitted over the top of them without any fiddling about. The loose P bolted jaws could then be added one at a time, making it much easier to add a drop of superglue to each one if desired.

So that's next, a loose P jaw. :)

Martin.
 
_______________
message ref: 5225
.
Loose P jaw:

loose_p_jaw.png


Test print done and looking good (4mm/ft):

loose_p_jaws3.jpg


cheers,

Martin.
 
_______________
message ref: 5230
@Steve_Cornford

Hi Steve,

The improved washing of the pin slots has made a noticeable difference, so it was worth making the change. The pins were previously a bit tight in some cases, and now they are a loose fit in the slots -- a bit too loose in fact. I shall need to tweak the clearance settings.

A loose fit may not be a bad thing for the P slide chairs, leaving scope to add a drop of cyano superglue when fixing them, and fixing to the rail. On slide chairs there is no inner jaw to clip the rail against, so the loose jaws could pull out.

I'm now more confident that others will be able to replicate my results, so I've decided to proceed on the basis of loose jaws for the crossing chairs for all gauges. It's not really an option for the switch block chairs for which I have used split chairs, because in those the loose jaw would be between the rails, and too small and fiddly to fix. But maybe worth a try one day.

Before I make a final decision I have ordered some fresh resin for some more test prints. My existing resin is now 12 months past its labelled shelf life, but the results are fine. I have noticed some changes though -- instead of pouring out like smooth cream, it is more gloopy like lumpy custard. :) It is also taking longer to cure, the latest test prints were still quite soft after the first cure and needed to be done again.

cheers,

Martin.
 
_______________
message ref: 5231
I would be happy to try out one of your loose jaw example .STL's when you are happy to release it into the wild.
@Steve_Cornford

Hi Steve and all,

Below are the STL files from my latest test prints (4mm/ft scale).

These are for slotted S1 ordinary chairs and loose S1 jaws, and for slotted P slide chairs and loose P jaws. Don't get them muddled up -- the S1 jaws (the ones with a key) won't fit the P chairs.

S1 ordinary chairs won't normally need to be loose jawed, I'm just using them as a test of the process. But it will be handy to have a few loose-jawed S1 around the V-crossings.

I'm very interested to receive reports from anyone who would like to try printing the files. On the Mars2 Pro printer I recommend putting the rafts north-south across the build plate. Perhaps other printers will be similarly direction-sensitive for best results.

test_slots_ctb.png


If your printer has a choice of pre-set print qualities, choose the finest setting available. If your slicer software has anti-aliasing Image Blur functions, you will probably need to turn them off for the loose jaw pins to fit in the slots, like this:

index.php

All testing so far has been done with Elegoo ABS-like grey resin. Results from other resins would be interesting. (The standard resins may not be flexible enough for the loose jaw pins.)

When you first try using the loose jaws, you will think that here lies madness. :) But it is no more difficult than other fiddly tasks in 4mm scale, such as fitting locomotive handrail knobs, or applying wagon strapping. And remember the trade-off -- you don't have to thread the chairs on the rail. Which also means you don't need to chamfer the rail ends. The secret is to have the right tools, and you can soon get into the swing of it. It's quite satisfying when the jaw key snaps into place and locks the rail.

loose_p_jaws2.jpg


First-off you need good light, and close-up reading glasses or magnifying lamp or headband or whatever.

For bash-fiting the chairs you need wooden cocktail sticks. Lots of 'em. Snip off one end entirely, and trim back the other end to a suitable size for different jobs. Locate the slotted chair in the base, and then use the cocktail stick as a punch with a pin hammer to seat it home. It won't damage the chair.

For the loose jaws you need some fine-tipped tweezers, but not too fine. You need to grip the the loose jaw pin close to the end of the tweezers, otherwise the tweezers will catch on the rail. So slightly blunt-tipped tweezers are preferably, about 1/2mm (20 thou) wide at the tip. If you have cheap plastic tweezers you can trim or file the tip to whatever you want.

In practice I prefer cross-over locking tweezers (not the ones in the pic) which clamp the part. You then have both hands free to position it. I have found some on Amazon which have removable screw-on plastic tips -- which we could 3D print to be the exact profile needed to handle the loose jaws. They should be here tomorrow, I will report.

Break off the loose jaws from the raft with fingers and put them in a tin lid. Some will be facing the right way up for the tweezers. Use those first. Then shake the lid and repeat. Note that for the S1 jaws, each row on the raft is keyed in the opposite direction*.

For pushing the loose jaw down into position, I have made a pusher-downer tool out of a bent paper-clip. Or a cocktail stick would do. Or even a thumbnail.

index.php


Here are the STL files. Mesh repaired ready to slice:

https://85a.uk/templot/plug_track/test_s1_slots_fixed.stl

https://85a.uk/templot/plug_track/test_s1_jaws_fixed.stl

https://85a.uk/templot/plug_track/test_p_slots_fixed.stl

https://85a.uk/templot/plug_track/test_p_jaws_fixed.stl

p.s. the rafts for the loose jaws are just for testing the experimental process. For production they will be better bunched up to save wasting resin and get more on the build plate. When washing the prints, plunge the build plate up and down in the wash a few times, to ensure a good flow of wash through the vertical slots.

*Using loose jaws makes it much easier to correct any keying mistakes than when using the solid chairs. :) Just pull out the loose jaw and replace it. For example, at rail joints the adjacent keys should be driven towards the fishplate.

cheers,

Martin.
 
_______________
message ref: 5232
Hi Martin,
My 2nd bottle of abs like grey resin arrived today. I gave not used all the 1st bottle but thought best to get some more before price goes up!
Atip I read online was to shake the bottle well (your tip actually) then warm the resin up whilst still in bottle by placing in a basin of warm water before another gentle shake & then pouring into the tank.
Thanks for providing the sample files.
I assume the P slide chairs are for EM and OO-SF rather than P4 as so far your tests have all been EM?
Cheers Steve
 
_______________
message ref: 5233
@Steve_Cornford

Hi Steve,

Yes, for EM and 00-SF.

(And any other 4mm/ft scale using a 1.0mm flangeway, such as EM-18, 00-D0GAF)

cheers,

Martin.
 
_______________
message ref: 5235
Hi Martin,
Some feedback
I have successfully sliced and printed your sample files.
I have successfully managed to insert both types of loose jaw in their respective chair slots, and despite my intial trepidation having seen their minute size in the flesh, managed to do this albeit with the aid of magnification.
As far as the S1 chairs go (which are a test bed for check chairs say) it might be useful, as you have already suggested, to have the option of some thicker keys as you can "rock" the rail slightly compared with the fixed jaw S1 chairs

I share your belief that this is another step forward towards solving your multi-rail chair dilemma.
Regards Steve
ps at this rate you will have us printing chairs without screws and separate screws :)
 
_______________
message ref: 5239
@Steve_Cornford

Hi Steve,

Many thanks for the feedback. You have set my mind at rest -- other folks can successfully print the loose jaws, see them, and use them without going mad or changing to Gauge 1. :)

Having detached a pile of loose jaws, In practice in takes me about 15 seconds per jaw to pick up a jaw in a pair of cermic nosed tweezers (the type sold for vape users, not that I do) and insert into the slot and then press home. This with the aid of a cheap illuminated magnifying glass on a stand.

I think you might get a bit faster with practice. The thing to bear in mind is that you save the time spent threading the chairs on the rail. Then noticing that you have got one in the middle the wrong way round, and removing them again. Then the next time you notice that you have got them in the wrong order and do them a third time. Finally they have to be carefully spaced out along the rail on the paper template so that they will drop into the sockets. The loose jaws option avoids all that. I have a hunch that with a bit of practice it might actually be a bit faster.

As far as the S1 chairs go (which are a test bed for check chairs say) it might be useful, as you have already suggested, to have the option of some thicker keys as you can "rock" the rail slightly compared with the fixed jaw S1 chairs

I hear you. We already have this adjustment:

web_adjust.png


Which modifies the effective key thickness without needing to add a custom rail setting -- originally included to allow for slight variations in batches of rail. But it's a good idea to have some additional separate rail-fit settings for loose-jaws. I have now modified the slot clearance setting for the loose pins, which should push the loose jaws more firmly against the rail. In addition to that I have now added this:

loose_jaw_fit.png


Setting that positive will tighten the keys against the rail. Negative to loosen them. Only small amounts of the order of say 0.03mm (1 thou) should be entered at a time. The loose-jawed chairs do not have to be threaded onto or slide along the rail, so can reasonably be made a tighter fit on the rail. But not too tight -- they might stress-fracture over time.

This setting can be used to create batches of tighter keys, for example for use on the check rails if needed. But don't overdo it, it won't work: :)
loose_jaw_key_thicken.png



The tweezers arrived. They are these: https://www.amazon.co.uk/gp/product/B08MLB869C

4 for £8 was about 2 more than I needed, but I thought they might come in handy for other jobs.

Also available with stronger solder-proof ceramic tips: https://www.amazon.co.uk/gp/product/B08LG6B82W

I didn't go for those because the tips looked less fine, and being ceramic they wouldn't be so easy to reshape. That may have been the wrong decision -- how fine are tips on your ceramic tweezers?

The reviews of the plastic-tipped tweezers were distinctly iffy, and I can see why -- the finish isn't going to win any awards, and the plastic tips are so weak that they simply bend under load. And no good anywhere near a soldering iron -- my guess is they are ordinary polypropylene.

I went for them for two reasons -- the cross-over reverse locking action makes them so much easier to use, and the screw fixing means I can make all sorts of other clamps and holders to fit them.

The first thing I did was to insert a packing washer under the forward screws to improve the clamping force on the plastic tip. Which was a bit better but not much. But for this application the loose jaw pins are so tiny that we wouldn't want to clamp them with excessive force. I also used the flush-cutters to trim off just the radiused very end of the tips, leaving a square end which is more convenient to use.

With the result that they are working fine for this task, but it would still be worth looking at 3D printing some tips specifically for holding the loose pins.

If you haven't used reverse locking tweezers they take a bit of getting used to, but are a great work aid. Squeeze them to open them, and release them to grab the part. You can then put them down with the part held, leaving both hands free and much less tiring on the fingers:

locking_tweezers.jpg


For magnification I use a pair of cheap close-up reading glasses for modelling, 3.5 dioptre, which are enough for my eyes, and more convenient than having to get the work under a fixed magnifying glass or lamp. Available up to 4.0 dioptres from supermarkets and pharmacies (where you can try them), and also from Amazon (where you can't): https://www.amazon.co.uk/Suertree-Reading-Computer-Presbyopic-Eyelasses/dp/B08R57DZ6D (not sure why they think you need 3 pairs*). Everyone's eyes are different of course.

*You could put 2 on at once, giving you 8 dioptres, or even all 3... :)

Back to making the separate chair screws strong enough to self-tap into the timbers...

cheers,

Martin.
 
_______________
message ref: 5241
how fine are tips on your ceramic tweezers?
just over 0.35mm. ie can just insert the tip into micrometer screw gauge if set > 0.35mm.
They are too tough to file, but they seem to be just right for the loose jaws.
Each tip is held on by two nuts and bolts so are replaceable, similar to your plastic tipped reverse tweezers.
I have also got a pair of metal jawed reverse tweezers and these proved too large and too strong. the loose jaws tended to snap/shatter.
Steve
 
_______________
message ref: 5244
Hi Martin,

Another of my mad ideas!
As far as sliding ordinary S1 chairs onto rail for plain track, I have find it easier to slide them on whilst still on the raft, as I can place a flat piece of metal against side of chair to hold chair still.
Also by offsetting the second template on the raft so the two sets are staggered, the chairs are pretty well in the right place. For example:
20221106_163222.jpg
Then snip the supports, and repeat as necessary.

5 rafts of 20 chairs costed as 32p.

Having the two sets of interlaced chairs aligned does reduce the size of the raft, but 32p fo 100 chairs aligned to make life easy is worth the extra pennies.

Steve
 
_______________
message ref: 5248
.
The trouble with using experimental stuff is that it can bite you. :(

I have had to change the plug and socket sizes on the L1 bridge chairs. This means that bridge chairs printed from the next program update won't fit in timbering bases from the current update. If you have made some timbering bricks, you need to make a stock of L1 chairs for them from the current version. Likewise if you have made a stock of L1 chairs, you need to make the corresponding timbering bricks from the current version. You can make lots of L1 chairs using this option:

all_l1_chairs.png


You don't need to make them physically of course, you can export and save the relevant files for later (and don't get them muddled up with the new ones!).

The reason for the change is that I have been working on the loose jaws for the L1, which I knew would be tricky. We do need them for some positions within the crossings:

loose_l1_jaw.png


As you can see, the slot comes very close to the end of the plug, which I have needed to extend to accommodate it:

loose_l1_slot.png


That means a change of socket size too. The changes are not actually needed for the solid chairs of course, but we must keep the solid and loose-jawed chairs interchangeable otherwise we are doomed. :)

cheers,

Martin.
 
_______________
message ref: 5249
Hi Martin,

Another of my mad ideas!
As far as sliding ordinary S1 chairs onto rail for plain track, I have find it easier to slide them on whilst still on the raft, as I can place a flat piece of metal against side of chair to hold chair still.
Also by offsetting the second template on the raft so the two sets are staggered, the chairs are pretty well in the right place. For example:
View attachment 4500
Then snip the supports, and repeat as necessary.

5 rafts of 20 chairs costed as 32p.

Having the two sets of interlaced chairs aligned does reduce the size of the raft, but 32p fo 100 chairs aligned to make life easy is worth the extra pennies.

Steve
@Steve_Cornford

Hi Steve,

Here's a mad way to get 24 chairs on a raft only 57mm x 11mm, and still be able to thread them at roughly the right spacing:

dual_level_raft1.png


dual_level_raft.png


Do the tall ones first, trim their supports from the raft, do the short ones. :)

I haven't sliced it to see if the extra pyramid cost outweighs the saving in raft area. The tall ones could maybe go a bit lower. But even if there is no saving, you could get several more rafts on the build plate.

Unfortunately at present you need to export 2 files and merge them in a CAD program.

It's easy to change the pyramid height (I used 3mm and 6mm). For the tall ones I switched off the raft and set a Z-shift of 3mm.

In the next update I will add an option to set a pyramid height and Z-shift per template, so it can be exported in a single file.

cheers,

Martin.
 
_______________
message ref: 5251
_______________
message ref: 5252
Hi Martin, I guess your script replaced "T h r e a d" with "topic" :)

Pyramid height and z-shift per template! As long as you feel its not getting too complex?

If you can supply a copy of your merged file I could give it a try first to see how practical that format is.

I found it best to only part cure the rafts so that they verge towards rubbery rather than brittle to aid the clipping from the pyramid supports.

ABS-Like Resin
my first bottle arrived in white box with colour printing and had P08/02/2021 and E08/03/2023 printed on the bottle label, which I assume means P for Produced and E for Expiry.
Second bottle just arrive was in a smaller brown box with black printing and just had P04BB511 printed on the bottle label.

Both labels had the text "Production and expiration date are printed on the product label" printed in red at bottom of label!

Have you received your second bottle yet?

Steve
 
_______________
message ref: 5253
As long as you feel its not getting too complex?
@Steve_Cornford

Hi Steve,

Perish the thought! :)

I found it best to only part cure the rafts so that they verge towards rubbery rather than brittle to aid the clipping from the pyramid supports.

How many seconds for that? Do you final cure with them on the rail? I would think they need to be fully cured to allow for bash-fitting without damage?

My bottles of resin exactly the same as yours -- except mine had only 12 months of shelf life. Yours had 24 months! (American date format.) Which interestingly is where mine has got to now -- Prod Oct 2020, Exp Oct 2021.

And now we must decipher the expiry date from the label code. Anyone? Mine is P04BB033.

p.s. did you notice on the coloured resin box that they mixed up maroon and red? I wonder what's in the actual bottles. :) And whether shelf life varies with different colours.

It was interesting in the video that the guy was happy to mix resins from different suppliers. It makes you wonder if there is a secret recipe out there somewhere which would be perfect for plug track?

cheers,

Martin.
 
_______________
message ref: 5255
I suspect that Wayne has perfected that secret recipe already!

Perhaps the BB stands for Best Before?

I have sliced 7 of your 24 chair rafts to give a total resin cost of 39p

Printing (i hope) as I type.

Intermittent showers in Brighton :( Means more experimental time :)
 
_______________
message ref: 5256
@Steve_Cornford

Hi Steve,

A thought. If we painted the support pyramids before curing they would remain soft? A quick scoosh with car primer after washing and drying, with a mask over the chairs?

Best Before 033? :confused:

Intermittent showers in Brighton :( Means more experimental time :)

Same here. There will be some Templot users doing a rain dance.

Martin.
 
_______________
message ref: 5258
So how come your first label had 2 years?

And if it's one year, we have only got 5 months left.

I'm going to use up my old stuff on other jobs -- first off being some loose-jaw pin holders for the tweezers.

Perhaps I need a second tank so I can swap old and new easily? I already have a second build plate, and a second wash tub for the Mercury. At this rate I shall have a complete second machine soon. :)

cheers,

Martin.
 
_______________
message ref: 5261
More feedback,
Cured for 4 seconds, sliding rail into the taller chairs is about 25% harder than the lower chairs as the tall chairs flex sideways more as the rail slides through,. If cured for 3 secsonds or less the flex is more and this increases friction and then the jaws tend to ping off!
20221107_142800.jpg
4 second cure rafts tall chairs used.

I think I will try making a cardboard square toothed comb that slides in and sits on top of lower chairs but bears against sides of tall chairs to deter sideways flex.

20221107_143017.jpg
Side view showing sufficient gap between top of lower chairs a d underside of tall chairs.

Steve
 
_______________
message ref: 5262
Back
Top