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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 Some of the earlier pages of this topic are now out-of-date.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.

3D printers - messin' with resin

Quick reply >
Hi Jim,

I think the main problem with the fumes is not the likely ill effects, just the awfulness of the pong and its extreme pervasiveness.

I can't stand the pong of most solvents, including butanone and dichloromethane, so I try not to use them. The only reasonable ones for me are butyl acetate (Humbrol Poly) and acetone, so I tend to stick with those (sorry!) if I can. So when I got the Elegoo Mars I went for the one with a built-in extractor fan and carbon filter. It does seem to help, providing I keep the cover lid over the printer. The downside is the rather noisy fan, without which the printer would be near-silent. Of course it doesn't do anything for the smell of IPA being sloshed about, but that's not quite so bad and tends to dissipate more quickly.

The presence of the fan in the base of the printer also means that it's possible to feel a very slight vibration buzz in the base. I'm wondering if that has any effect on the printing process, beneficial or otherwise?

cheers,

Martin.
 
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Just a comment on 3D resin printer fumes. I've had a Phrozen Shuffle for over two years and recently added a Phrozen Sonic Mini 4K. When I originally got the Shuffle, I was aware of comments about fumes and started building a cabinet to house it with an exhaust fan routed outside. When the Shuffle arrived I hadn't appreciated that the door hinged upwards which wouldn't work with my cabinet, so I started printing with no provision for fume control and extraction and did not suffer any ill effects at all. The Sonic Mini is the same. It is actually housed in the cabinet built for the Shuffle but only to provide a stable temperature environment in winter months, otherwise no ill effects when it is used. I use Phrozen resins. So it might be worth trying to get up close and personal to a working 3D resin printer to see if any fumes affect you before buying one. If you are like me, fumes might not be a problem.

Jim
Hi Jim

I tend to agree with Martin - it's not the effects but the smell. In addition, any effects may be cumulative so wouldn't be noticed maybe until many years later. I have nowhere to escape from any smells in my flat, or for that matter smells coming up from downstairs! More than once I've had to sleep with one chemical smell or another (or cooking!) still lurking about. I don't have anywhere in my flat where I could set up near a window, so I think resin printing is a non-starter for me at home currently which is a real shame, given the affordability of printers now. Maybe when I move back into a house I'll have more space!

Unlike Martin, I quite like the smell of butanone but I'm very aware of it's dangers so try not to smell it!

Cheers,
Paul
 
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BTW in the US IPA commonly refers to India Pale Ale ☺

Same here, but Isopropyl alcohol or Isopropanol takes longer to write. :)

Old_Phipps_IPA_Claret_sharpened.jpg
 
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My favourite IPA is Palmers of Bridport, I nearly got caught out in the Pilchard on Burgh island, drinking it on an incoming tide, fortunately the staff give you about half an hour's notice of the tide covering the causeway, just enough to drink up and walk back without paddling.
 
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@Paul Boyd

Hi Paul,

Having both a FDM (filament) printer and SLA (resin) printer I wouldn't want to lose either of them.

The FDM is great for strong functional parts -- for hobbies such as model engineering, model aircraft, drones, spare parts for bikes and boats and lawnmowers. But also maybe a working gearbox in 0 gauge? unbreakable signal posts and telegraph poles? a large-scale lever frame? a turntable deck? point-motor brackets? or even the whole point-motor? all manner of modelmaking tools and jigs.

SLA is much better for fine detail on small-scale models, but unless you go high-end with expensive equipment and resins not so good for strength and working parts.

And when it comes to domestic user-friendliness there is no contest. You could easily have a FDM machine in the corner of a living room if using PLA polymer. The slight smell from hot PLA is actually quite pleasant -- it's made from sugar cane and non-toxic. When it's finished printing, that's it -- remove your new part.

Whereas an SLA printer is only for a workshop area (and preferably one of its own). The resin is toxic, smelly and unpleasant. The process is messy. When it's finished printing that's only the start. You then have to leave it dripping for 10-20 minutes or so (wafting the smell around in the process), before transferring it to a tub of IPA solvent (also smelly) for washing. Don't have any source of UV present (such as sunlight) until all liquid resin has been washed off. Intricate model parts will need careful brush washing in the IPA to remove all traces of liquid resin. At this stage the model is still soft and delicate, so needs careful handling. Finally it needs UV exposure to fully cure it and harden it. But the results are great!

The machine which is going to lose out to resin printing in this hobby in my view is the Cameo cutter. It's been a great disappointment. When I next need some signal box window frames, or a panelled coach side, I feel sure the resin printer would do a better job. Without the option to use it as a pen plotter, I think it would be in the bin by now. :)

cheers,

Martin.
Thanks, won't bother with a Cameo then as I already have an old Roland Pen Plotter than I haven't used in anger for quite some time, though I could if I wanted to.
 
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Thanks, won't bother with a Cameo then as I already have an old Roland Pen Plotter than I haven't used in anger for quite some time, though I could if I wanted to.
Hi Stephen,

I haven't binned the Cameo yet. :) I have a hunch it will be one of those gadgets which get left and forgotten at the back of the workshop for years. And then a job crops up for which it is the very thing.

Modellers do use it for cutting thin frets. But I think you have to regard thin as the operative word there for modelmaking -- up to about 10thou max. The deeper cutters are good for soft craft materials only -- just the job if you want to cut a fluffy bunny rabbit out of felt.

A 5 thou fret would be quite tricky to remove without damage from the build plate of a resin printer. It would probably need to stay on the plate until fully UV cured, and hope it's not stuck too firm. The Cameo might be an easier option.

There is a long topic on RMweb about using the Cameo for modelmaking. This post shows what happens if you try to go thicker and cut 20 thou plasticard:

https://www.rmweb.co.uk/community/i...-cameo-cutter/&do=findComment&comment=3956613

But combined with a normal printer, a Cameo might be just the thing. Print you own brick paper on 160gsm paper (7 thou thick), including archways, window openings, viaduct walls, ... and then cut them out on the Cameo. Make your own card kits, with resin-printed details.

Like most things it's horses for courses. And track-building isn't the course for this one.

cheers,

Martin.
 
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The Cameo is useful for cutting upto 20 thou plasticard, it won't cut all the way through, but once the cutter has done 4 passes, it's relatively easy to finish the job with a scalpel. Don't forget to add diagonals for apertures.
 
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The Cameo is useful for cutting upto 20 thou plasticard, it won't cut all the way through, but once the cutter has done 4 passes, it's relatively easy to finish the job with a scalpel. Don't forget to add diagonals for apertures.
@Phil O

Hi Phil,

Please can you post chapter and verse? Which blade do you use? Set for what depth? At what speed and force? Do you do all 4 passes at the same settings, or stop and adjust the blade depth or other settings for each pass?

How small an aperture can you snap out? I wanted to cut chair sockets 4mm x 2mm but there is no way it would score the outlines and diagonals cleanly, or in the right place, even with the overcut setting.

Does it need to be new plasticard? My stocks are several years old and getting a bit brittle. Does it need to be white plasticard? Most of my stock is black, which is tougher than white.

cheers,

Martin.
 
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Hi Martin,

I use the standard blade, set at the maximum depth and the speed set at around 3 or 4. You can set the machine to do a double pass, once it has completed the first two passes, just start it again, don't alter anything and definitely don't eject the sheet from the machine.

I have only used white, which I have had for around 20 years or so, I have not tried to cut apertures that small, so I can't say whether you can snap out pieces that small. I think, I would drill a couple of 1.5mm holes and clean up with a scalpel and files. What the machine does do is give you is an accurate outline to cut to with a sharp scalpel blade. I keep the blade sharp with an oilstone.
 
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Hi Martin,

I use the standard blade, set at the maximum depth and the speed set at around 3 or 4. You can set the machine to do a double pass, once it has completed the first two passes, just start it again, don't alter anything and definitely don't eject the sheet from the machine.

I have only used white, which I have had for around 20 years or so, I have not tried to cut apertures that small, so I can't say whether you can snap out pieces that small. I think, I would drill a couple of 1.5mm holes and clean up with a scalpel and files. What the machine does do is give you is an accurate outline to cut to with a sharp scalpel blade. I keep the blade sharp with an oilstone.
@Phil O

Thanks Phil.

I will have another go. The Cameo 4 can be set to do as many passes as you like, so that's not a problem.

But of course even 20 thou isn't much. I was hoping to cut 1.25mm (50 thou) card and mounting board, or similar. Given the availability of 2mm and 3mm blades I assumed that would be possible, but clearly it isn't, or at least not for precision shapes in solid material. They are for soft felt, foam and similar materials. The kraft blade is ideal for cheese slices. :)

But all is not lost, because I'm quite pleased with the pen plotter function and the ability to print long track plans up to 60ft long. Because of the buggy software it's quite a lot of faff to get it the correct size, but it is doable. For about half the price of any comparable CAD printer/plotter I can find. Given the prices charged by digital copy shops for prints of such a size, it should break even after a while. Silhouette have promised a fix to the bugs in the DXF import.

cheers,

Martin.
 
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I may have to unearth the engraving machine to see how it might do. If I remember correctly (which would be unusual) it wasn't too bad on wood but the small area is a problem. I suspect it might tend to melt Plasticard too but I never actually tried that.
 
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Hi Stephen,

I haven't binned the Cameo yet. :) I have a hunch it will be one of those gadgets which get left and forgotten at the back of the workshop for years. And then a job crops up for which it is the very thing.

Modellers do use it for cutting thin frets. But I think you have to regard thin as the operative word there for modelmaking -- up to about 10thou max. The deeper cutters are good for soft craft materials only -- just the job if you want to cut a fluffy bunny rabbit out of felt.

A 5 thou fret would be quite tricky to remove without damage from the build plate of a resin printer. It would probably need to stay on the plate until fully UV cured, and hope it's not stuck too firm. The Cameo might be an easier option.

There is a long topic on RMweb about using the Cameo for modelmaking. This post shows what happens if you try to go thicker and cut 20 thou plasticard:

https://www.rmweb.co.uk/community/i...-cameo-cutter/&do=findComment&comment=3956613

But combined with a normal printer, a Cameo might be just the thing. Print you own brick paper on 160gsm paper (7 thou thick), including archways, window openings, viaduct walls, ... and then cut them out on the Cameo. Make your own card kits, with resin-printed details.

Like most things it's horses for courses. And track-building isn't the course for this one.

cheers,

Martin.
Interesting, I did consider trying to use my ancient pen plotter to mark out some designs on copperclad but swiftly realised that the pen lift would not clear the normal 1.6mm thickness. Now if I could subsitute a cutter for one of the pens, I might be able to utilise it this way if I ever have a need.

Though I would have to make sure the cutter didn't touch the static hold base.

Getting an HPGL driver might be the problem as I understand XP was the last OS catered for, but not to worry I have an old XP laptop, little used these days and if I ever needed to could even build a separate XP machine from the pile of obsolete bits I have accumulated over the years. In fact I even built a Windows 95 machine fairly recently but not used it in anger. Why I hear you ask?

Certain members of the family expressed a desire to re-visit some really old games that aren't playable on the more recent OSs. (it has a real Voodoo 3 video card in it)
 
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@AndyB

If you moved the clip socket inwards a little, or stretched the top of it, it could grip the very edge of the rail foot. It would barely notice in the small scales:

andy_fb_idea.png


cheers,

Martin.
 
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@AndyB

If you moved the clip socket inwards a little, or stretched the top of it, it could grip the very edge of the rail foot. It would barely notice in the small scales:

View attachment 1771

cheers,

Martin.

Thanks Martin.

Yes I think that should work. I doubt if printed Pandrol clips are up to the task in 00 although I did wonder if I might try real metal clips. I might have another solution too ;)

I just noticed I left a piece out of that screenshot. There's supposed to be a ramped section between the clip holders that partially obscures the holes. Presumably it's a stop to prevent the clips being driven in too far. It should look something like this:

Screenshot (24).png


I discovered that the clip holes actually run "uphill" towards the center of the plate. I think that's to stop the clips working out of the holes. Any tendency to do that should increase the tension in the clip. (I didn't bother tilting the holes in the model.)

As drawn the clip is in its fully relaxed state. I need to revise it and flatten it out a bit to represent it in a working position.

Cheers,
Andy
 
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Thickness of the resin bases that I used for Check Chair testing is 2.89mm to 2.90mm, rather than target 3.2mm
The base without chairs was 66 layers x 0.05mm per layer
1689162566611.png

Chitubox displays it as 3.250 on 66th layer.
So no, have not got to bottom of this.
Steve
 
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Perhaps we need a different Z shrinkage setting from X-Y ?

Martin.
 
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Could it be that when resin printing our layers which we expect to be 0.05mm are in fact less than 0.05mm, rather than there being lost layers?
How can we test for lost layers?
@Steve_Cornford

Hi Steve,

The physical movement of the head can't be any other than 0.05mm if it's based on the stepper motor and screw pitch. It would be possible for severe suction to cause the stepper to jump a few steps, but with the mechanical advantage of the screw that would need a lot of force on the build plate. It would probably wreck the part and the FEP.

The most likely explanation is incorrect shrinkage figures, or getting the plate too close with the levelling. Or both.

I think I'm fairly close with my levelling -- 1.0mm raft is 0.96mm thick. So all down to shrinkage? Off to measure the tweezer tips.

cheers,

Martin.
 
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For some strange reason, when I was purchasing the abs-like resin earlier today I actually read some of the reviews posted.
One of them mentioned having to increase the later cure time I order to achieve a 0.05mm layer.
Perhaps that is so.ethingvto try in a controlled experiment?
Steve
 
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For some strange reason, when I was purchasing the abs-like resin earlier today I actually read some of the reviews posted.
One of them mentioned having to increase the layer cure time I order to achieve a 0.05mm layer.
Perhaps that is something to try in a controlled experiment?
Steve
@Steve_Cornford

Hi Steve,

I have been so focused on the programming and chair design recently that I have taken my eye off some of this practical stuff.

We are clearly way off with the resin shrinkage. Measuring some rafts and other parts I have made, I think we may be over doing the shrinkage a bit on X and Y, about 0.1% may be closer. Some parts seem to have actually expanded on X-Y, i.e. negative shrinkage.

But on Z the parts are shrinking by around 6% or 7% -- way more than the 0.25% we set.

That's a massive difference between X-Y shrinkage and Z shrinkage. I don't know enough about the internal structure of the cured resin to know what is going on here. It would be helpful to know the actual size of the uncured resin on the build plate, but of course it's too soft to measure with any accuracy. But I might try next time, after washing.

I don't know if a longer exposure per layer would increase the density and resist some of the shrinkage. But I believe increased exposure also reduces the effective resolution as light bleeds across from one pixel to the next. For our purposes this would affect the fit of the chairs on the rail, and fine detail such as the square heads on the chair screws might be lost.

It can't be the case that insufficient exposure reduces the layer thickness while actually on the machine, otherwise it wouldn't be able to print -- raising the plate 10mm off the FEP while the part is only 9mm thick would obviously not work for printing further layers on it. The size change must come later in the process in the washing or curing or ageing.

Some careful experiments needed here. The actual chair parts are printing well, so we don't want to change the machine settings too much -- for example increasing the component density to resist shrinking might reduce flexibility and make the chairs more brittle.

In the meantime you might try changing the Z shrinkage to around 6% and see what happens?

cheers,

Martin.
 
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Hi Steve/Martin,
just been reading your posts with interest.
so I feel I should make a comment on the resin printing accuracy piece.
background.
I have been finding reproducing prints of chairs I did 3 or 4 months ago which came out great, are not being replicated with prints I did in the last few days.
At first I though it was the ago of the resin, until somebody at the shop mentioned print temp.
Here in NZ its gone cold now, whilst I am still printing in the house, I need a lot of windows open for the smell issue, ergo its at least 8 degrees colder then printing 4 months ago which now = a lot of print failures :(
Anyway after much research on google, its looking as thought very constant resin temp is critical for consistency of finished product.

Its also documented, as the resin temp changes even slightly the layer exposure time is affected. On this basis I am of the opinion shrinkage will also be heavily impacted by resin temp.
The most interesting thing is, best temp seems to be at about 25 to 27 degrees. In order to hold that as a constant, a resin vat heater compete with thermal controller or a heated area also with thermal controller around the resin vat is required.

For the Mars 2, Elegoo actually sell or at least did sell, a heater vat modular. For my Mars 3 not so good, however there are threads to some good DIY heater module ideas. I have ordered all the parts required and will report back on progress once I have everything sorted out.
in the mean time I would suggest if at all possible whist doing print testing accurate resin temps should also be recorded as this could be a key input to constant and accurate chair manufacture.
phil
ps yes it is the middle of the night here, just can't sleep :)
 
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@Phil G

Hi Phil,

A trick I was doing in the cold weather was to pour boiling water over the build plate just before printing. Quickly wipe it dry, install it on the machine, and start printing. As it gets dunked in the resin, the heat is transferred to the resin.

It's all a bit uncontrolled and low-tech, but the results were fine.

For a bit more tech, this controller device is currently on Prime Day offer from Amazon:

https://www.amazon.co.uk/dp/B01AWA2PTG

inkbird.jpg


No electrical knowledge needed. Attach a small heater of some kind to the printer. Drill a hole in the printer cover for the heat sensor, plug it all together and switch on. Set the required temperature. Wait for it to be at a stable internal temperature for half an hour or so.



Or make your own heater to fit inside the cover:




cheers,

Martin.
 
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Fan heaters tend to stir up dust, so you may prefer to point some other small heater at the printer, such as an infra-red radiant heater or lamp.

In the meantime, I have ordered one of these:

https://www.amazon.co.uk/gp/product/B086HDKGWX

To wrap round the Mars printer. 25W isn't going to do a lot, but if switched on an hour or so before starting printing it would probably warm up enough to print ok. A slow warm-up is preferable to rapid heating to ensure the resin is up to temperature. We shall see -- although not for a few months, it's a funny thing to order in July. :)

Martin.
 
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Martin - congratulations on achieving your fully chaired point - and it looks very nice, and I am looking forward to learning how to create a print!

Just on the issue of z-scaling, I have an Elegoo Saturn 2, and on the Saturn Facebook page, a chap (who is a real-life precision engineer) did a fair bit of investigation as he required highly precise parts off the build plate and he discovered what he calls "initial layer compression" due to a degree of backlash / hysteresis in the z-axis. This is not an issue except for the first few layers where the high forces involved in squeezing out the resin against the FEP causes inconsistencies to appear. Because the effect is non-linear and non-repeatable, he was never able to exactly calibrate his z-axis shrinkage. Nor could he get any z-axis precision. His solution was to make and fit a collar to the ball screw after which precision was restored.

Linking to Facebook is a mystery to me, but this link might get you close if anyone wants to follow his experimentation. His solution is easy enough for anyone with a lathe.

https://www.facebook.com/groups/elegoosaturn/posts/1285076838743427/

Although we are not looking for extreme precision in the first few layers, he makes the point that any attempt to calculate z shrinkage by printing something not very tall then measuring it, will fall foul of this issue as the thickness of the first few layers will vary 'randomly'. Since we are only interested in the first few millimeters, it might be significant.

Howard
 
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Since we are only interested in the first few millimetres, it might be significant.
@JFS

Hi Howard,

Welcome (back?) to Templot Club. :)

Many thanks for the link, I found the topic on Facebook and your replies.

I have a Mars2 printer, so maybe a different Elegoo design from the Saturn. I can't detect any backlash in the Z-screw by hand. What I can detect is the Z-column flexing forward and back under load at its fixing in the printer base. Which would have the same effect as backlash under a heavy suction load.

It certainly explains the difficulty we have had in measuring Z-shrinkage. We have also found that using very large raft areas causes suction problems. It is better to use several smaller rafts with gaps between them. I have a rule-of-thumb figure of 1500 sq.mm as a max for a single raft.

Actually, most of us are not bothered with the first 6mm or so. For the chairs the raft thickness, support pyramids, and chair plug depth are not at all critical. All we ask is that printing proceeds accurately after that to create the actual chairs.

Those making resin-printed timber bases are bothered of course, but only to the extent of matching today's timber thickness with yesterday's -- the exact thickness is not important, only repeatability.

However, resin-printed timbers are not really part of the plug track project. Most home machines are too small to make a usable-sized timbering base in 4mm/ft scale, and there are problems with shrinkage and curling for large flat objects.

Mostly users currently printing resin timbers are making test pieces while dithering between getting an FDM printer or a laser cutter. :)

Or a desktop CNC miller/engraver. I'm still intending to develop that option further, although I realise it's probably not for everyone:

index.php


cheers,

Martin.
 
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In the meantime, I have ordered one of these:

https://www.amazon.co.uk/gp/product/B086HDKGWX

To wrap round the Mars printer. 25W isn't going to do a lot, but if switched on an hour or so before starting printing it would probably warm up enough to print ok. A slow warm-up is preferable to rapid heating to ensure the resin is up to temperature. We shall see -- although not for a few months, it's a funny thing to order in July. :)

Martin.

A report. Daft time of year to do it. :)

https://www.amazon.co.uk/gp/product/B086HDKGWX

I didn't expect 25W to do much, but it does just enough for an unheated indoor room in winter. For a garden shed with frost on the windows, maybe not.

mars_heater_belt.jpg


I found an elastic bungee cord just the right length to pull tight round the Mars printer case. Then slipped the heater belt under it. The ribbed belt worked just fine to locate under the elastic cord. The belt was a couple of inches too long, so I cut through the hole in the end tab to release the mains cable, and overlapped the ends.

I put a digital thermometer inside and switched on. Left it an hour.

The temperature went up from 22.5 degC to 27.5 degC and rising. i.e. a lift of 5 degC above ambient in an hour.

The resin label says its recommended working temperature is 20-25degC. So in winter if the ambient temperature is around say 11-12degC, maybe from a small room heater -- if the belt is switched on a couple of hours before use it would get about 10degC above ambient to the working temperature for the resin.

So a useful printer heater with minimal installation to warm up the resin on winter evenings. But no good in full arctic conditions.

p.s. the parcel tape in the pic is holding the rubber seal on the Mars lid -- it's not part of the heater.

cheers,

Martin.
 
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