3D printers - messin' with resin

[KHC1]

Well I have made a new resolution. This afternoon I have struggled with a V crossing with getting jaws to go in. As such I need to print another V crossing and heal for my B7. What I will do now is print the chairs and jaws separately. I think that I was being a little timid on the wash when jaws and chairs are on the same build plate. By separating the chairs and jaws I can do a more vigorous wash of the chairs and not worry about the jaws.

Keith

 

[Martin Wynne]

@KHC1

Hi Keith,

I think perhaps these warm conditions are leading to over-exposure.

It is 29degsC in my 3D printing den this evening. I have just started a print at 1.2 seconds exposure to see what happens.

Martin.

 

[Martin Wynne]

@KHC1

Hi Keith,

I think perhaps these warm conditions are leading to over-exposure.

It is 29degsC in my 3D printing den this evening. I have just started a print at 1.2 seconds exposure to see what happens.

Martin.

And the result is -- it's ok, but...

Printed with 1.2 seconds exposure with the resin at 29degsC, resin AnyCubic ABS-Like V2 water-wash:

All the chairs printed ok, including the chair screws with square heads. 90 S1 chairs and 90 L1 chairs, loose jaw.

But on 4 of the 90 L1 the support pyramids are not fully formed.

All the loose jaw pins are very loose-fitting and fall out easily if the chair is turned over. They do not grip the rail properly. If this exposure setting is adopted, it would be necessary to tweak the rail-fit settings.

The loose jaws are very fragile and do not break off consistently in the intended place.

On balance I think that this exposure is too low, and possibly in these warm conditions 1.35 seconds might be about right. Alkaid printers may be inconsistent on UV lamp power, and yours may differ.

What it does demonstrate is that the temperature and exposure timing has a big effect on the size of small pins and slots, probably more so than tweaking the pin clearance dimensions.

The rafts have significant elephant's foot and some distortion at the corners, suggesting that the bottom layer exposure needs to be reduced in the same proportion at these temperatures -- say 20 seconds.

Martin.

 

[KHC1]

Thanks Martin. I am going to hold off printing for a couple of days. I will change to chairs only rafts and jaws only. I t maybe also that i was exposing the prints to sunlight and may well just use day light. So away from the front of the house to a window cill at the back. My garage does have a lower temperature so will stay at 35 seconds but will play if its a problem. Wasting a few rafts at the end of the day is just a few pence. I went through similar problems when i started using my FDM printer. It is all about gaining confidence and your advice and from others on here is always very well received.

keith

 

[Hayfield]

Over the past couple of days I have come to the same conclusion. Wait till it cools down a bit

 

[Martin Wynne]

Over the past couple of days I have come to the same conclusion. Wait till it cools down a bit

@Hayfield

Hi John,

The V2 resin bottle actually says: Suggested temperature 25 - 30degC. Suggested exposure 1.1 - 1.5 seconds.

So my suggested setting of 1.35 seconds at 29degC is on the mark. The problem is to use that setting consistently all year round would require a heated printer. When working at lower temperatures the exposure needs to be longer, and that's reflected in the settings I have posted over recent months.

I have rigged up a simple heater on my Mars printer using an Inkbird controller and beer-brewing 25W belt heater. It works well if switched on a couple of hours before needed (and it's not the very depths of winter):

I have obtained the same parts for the Alkaid, but not fitted them yet. It's not so easy with the angled base unit, I need to print some clip thingies.

More info: https://85a.uk/templot/club/index.php?posts/7161

Martin.

 

[Hayfield]

Are you going to use beer soluble resin ?

Thanks for the info, I was wondering how the professional printing firms cope, I guess both with heating and air conditioning

 

[KHC1]

John some of the larger more expensive printers are now coming fitted with heaters as standard.

Keith

 

[John S]

Are you going to use beer soluble resin ?

Presumably also washing with IPA.

John from 33820 St Ciers sur Gironde

 

[Penrhos1920]

I've coughed up and bought a heater that fits inside the printer. It's set to run at 28degC which is about as hot as Teesside ever gets. I calibrated the exposure time after I'd had the heater running for 30 minutes and now get consistant prints. Chitu resin heater

 

[KHC1]

I have been following the thread about Templot 5 and the issue I am causing. SORRY…………… However it does raise an issue for me. I have been producing rafts as per Jameses video where he extended the checkrail chair to the end of the turnout and produce from the last timber a raft of chairs. But is there a difference between checkrail chairs. I see that you refer to them as CCL and CCR are these different by introducing a flare to the checkrail. So do I need to change my rafts to accommodate the three different types.

Keith

 

[Steve_Cornford]

Hi Keith,
You are not causing an issue, merely providing the impetus to get a feature added that will be useful in the future.

Without knowing why you are extending your check rails it will be difficult to answer.

The standard check rails (without any extending or heaving being performed) have just 3 types.
Viewing from outside a particular stock rail, the on on the left hand end is a CCL, the one on the right hand end is a CCR, all the others in between are CC.

Zoom in on the end chair then perform an extend slowly. You will see the End chair change through diffenet iterations as you extend, to cater for that part of the flare over the timber.

Why are you extending?

Steve

 

[KHC1]

Thanks Steve I was just following the video about creating chair rafts. In that video James showed a way of extending the chairs along the length of the two stock rails. Then once done the turn outside blanked or reduced in length to the last timber. Then using the shift multi create a raft. However this means only one type of check rail chair. I will go back and create a new raft that covers the v crossing and check rail and reduce gauge and build a raft on that basis.

Keith

 

[Martin Wynne]

Why are you extending?

@Steve_Cornford @KHC1

Hi Steve, Keith,

Steve, Keith is using the store and shift multi function to create a raft of check rail chairs.

Keith, change the hand of the template before doing shift and multi to create the opposite of CCL or CCR. There is no problem with the actual chairs -- the issue is what to put on the labels. But I've got it fixed now.

You can't do shift and multi from a V-crossing, it works only on the first few timbers, up to the first P slide chair.

cheers,

Martin.

 

[Martin Wynne]

before doing shift and multi to create the opposite of CCL or CCR

p.s. Keith,

Multi is not working with CCL or CCR for some reason. Store and shift manually to create a raft of CCL or CCR. Something else to get fixed -- the CCL and CCR have been a pain in the proverbial from start to finish.

 

[Paul Boyd]

.
Glad you have your own resin printer?

https://3dprintingindustry.com/news/shapeways-bankrupt-5m-rescue-bid-rejected-231387/

"On July 2, 2024, after considering all strategic alternatives, Shapeways Holdings, Inc. (the “Company”) ceased operations and filed a voluntary petition for relief (the “Bankruptcy Filing”) under the provisions of Chapter 7 of Title 11 of the United States Code, 11 U.S.C. §101 et seq. (the “Bankruptcy Code”). The Bankruptcy Filing was filed in the United States Bankruptcy Court for the District of Delaware (the “Bankruptcy Court”). Each of the Company’s subsidiaries also ceased operations and filed voluntary petitions for bankruptcy relief."

Martin.

An update on this - as hoped, the Dutch side was profitable and is in the process of being resurrected as Manuevo. This press release explains it, and also why they can't use the Shapeways name.

 

[Martin Wynne]

@Hayfield

Hi John,

The V2 resin bottle actually says: Suggested temperature 25 - 30degC. Suggested exposure 1.1 - 1.5 seconds.

So my suggested setting of 1.35 seconds at 29degC is on the mark. The problem is to use that setting consistently all year round would require a heated printer. When working at lower temperatures the exposure needs to be longer, and that's reflected in the settings I have posted over recent months.

I have rigged up a simple heater on my Mars printer using an Inkbird controller and beer-brewing 25W belt heater. It works well if switched on a couple of hours before needed (and it's not the very depths of winter):

I have obtained the same parts for the Alkaid, but not fitted them yet. It's not so easy with the angled base unit, I need to print some clip thingies.

More info: https://85a.uk/templot/club/index.php?posts/7161

Martin.

I've coughed up and bought a heater that fits inside the printer. It's set to run at 28degC which is about as hot as Teesside ever gets. I calibrated the exposure time after I'd had the heater running for 30 minutes and now get consistent prints. Chitu resin heater

@Penrhos1920 @James Walters @Hayfield @gavin

After a lot of measuring chairs, I have come to the conclusion that temperature control is essential for consistent results. Fitting the same heater to the Alkaid as the Mars is tricky because of the shape of the casing. Also at 25 watts and fitted externally it is barely enough for the coldest nights.

So a birthday Amazon token has been put to good use -- I have followed Richard's lead and just received one of these:

https://www.amazon.co.uk/dp/B0C3VS2T9Q

It fits in the Alkaid ok with careful positioning. The chunky sealing strip makes the cover a bit cumbersome, I shall probably discard it and file a cable notch in the cover instead. I've temporarily put the temperature sensor from the Mars in with it and left the two on for an hour to see how the readings compare. Currently showing a difference of only 0.5degC which is fine and suggests I could use identical print settings on both printers (which I do anyway) if they are both set to the same temperature. The heater's sensor is presumably in the air intake at the back of it.

It also has a timer, so you can set it to switch off when the print will finish.

It makes a bit of a mockery of the Alkaid being the low-price option, but worth it if it gives consistent results through the winter months.

Martin.

 

[Hayfield]

I will await your report on how its doing, I thought the issue is its too hot at the moment? Can see the benefit during the colder months

 

[Martin Wynne]

I will await your report on how its doing, I thought the issue is its too hot at the moment? Can see the benefit during the colder months

@Hayfield

Hi John,

It's not too hot. The water-wash resin is suggested for use in the range 25degC to 30degC and we very rarely go above that in this country (for now, anyway). But we do go below.

The issue we were having is that you need to know what the actual temperature is, and change the printer settings accordingly. If we make a file for use at 20degC and then use it at 30degC, it is going to be over-exposed and the chairs will be too chunky. Having a heater which you can set means you can create files in Chitubox knowing what the printer temperature will be and make the print settings in the file accordingly.

cheers,

Martin.

 

[Phil G]

Hi Guys,
I found the importance of consistent heating about 12 to 18 months ago, and posted as such on this forum. At the time it was not overly accepted as being that important, although Martin did purchase a band heater for his Mars 2.

After much trial and playing around in the intervening time. I found its not so much the exact temperature that matters, but that the exposure time and the temp need to match. As that is where the correlation exists.
I personally have found 23C to 24C is a very good temp to aim for, partly because here in NZ 24 C can easily be a summer time evening temp (I can't print in the summer day time) the UV is way to harsh even for the cover. clearly the heater can also get to this temp in winter. I then used the cones of calibration to determine the best exposure time. Which on my set up is just about 1.8 seconds.

I would not say that is always the correct exposure for 24 degrees because both the machine and the resin used make a difference. even two machines of the same brand machines can be slightly different.
So its very important you find your own sweet spot using the cones. I can tell you time spent dialing in your machine/ resin combination using the cones, is the best return on time you will ever spend with a resin printer.
cheers
Phil.