CAD 3D PRINTING MODEL MAKING

[timbologist]

I'm just at the stage of working out what you have to do to stop the prints from curling at the ends

Are you using PLA or ABS for your printing
Timbologist

[Bufferstop]

Currently PLA. I'm using a cheapo Da Vinci printer which doesn't have a heated bed. The only problem I'm having is getting the first layer to stay stuck down to it's very ends. Printing on a "raft" over comes it, to an extent, including your own sacrificial extensions in the design seems to be the most surefire way. I'm currently trying to print a chassis block for an 0-4-0 loco, combining it with an oversize footplate which I can trim down once printed looks to be the answer.

[timbologist]

I mainly use ABS when I have used PLA I used the blue painters tape, clean with metho and use a Pritt glue stick on the blue tape.
A lot of people use Aquanette hairspray with good success I think that is how you spell it. There is plenty of info on the net about PLA sticking problems.
I have found that not every idea works for everyone and you just have to experiment till you find what works for you. Each manufacturers filament is different and it is different between colours, so it can get out of hand sometimes. But because you are stuck with the printers own filament hopefully it will be act all the same.

When I design large items I always flat pack it so that printing heights are not to much.
I always have drama's with PLA so I stick to ABS easier to glue with Acetone, and I make my own fillers using ABS, Acetone, and baby powder. Depending on how hard I want it depends on how much ABS I put into it.
What is the print surface of the printer, does it have the yellow Kapton tape on it.
when all else fails go make a nice cup of tea

Timbologist

[timbologist]

Have done some more playing with the SLA printer, and as I mentioned before could not get it to print at better than 0.1mm in the Z. But in manual control I can move Z at 0.05mm ,0.025mm. Which means that it has been nobled somehow. Just need to manually play with the gcode around the layer changes.

As for the Red resin have got that all sorted now printing nicely, I know it's not red ,I painted it before I remembered to take the photo and this is 1:12 scale, the 00 scale is yet to come

The problem I was having the job would stick to the build plate the after x layers would get pulled of. the reason was my own doing. As with the original resin, the FEP had come of the bottom of the tray, so I tried clear packing tape and it worked. But the red resin seems to not want to release properly. So I have had to stick the FEP down with sticky tap, and all is good. Which goes to show all resins aren't the same,I am getting there.

Timbologist

red resin lamp

001.JPG (141.27 KiB) Viewed 3081 times

red resin lamp

002.JPG (139.85 KiB) Viewed 3081 times

[timbologist]

Never a dull moment checked the model with the verniers and we are oval 0.5mm larger in Y and 0.5mm smaller in X.
Being of Chinese origin the bit we need to adjust is the hardest bit to get to, you can see and touch them but can't get a screw driver to them. So we have to nearly pull the whole machine apart to get to the adjusting pots. And of course the pictures in the manual don't match up with what is physically there.
And the manual says adjust clockwise to reduce and anti clockwise to expand, but if of other type reverse direction.

will get back with results

Timbologist

[timbologist]

Things are plodding along here nicely.
One thing I have been having trouble with finding is people in the right positions for some of the things I want to do.
Then the other day came across some software called Makehuman http://www.makehuman.org/.
You model your own people either gender and in various ages, there are some poses inbuilt into the program and clothing.
You set up your base person, complete with armatures ( used for animation and posing ) and export and import into Blender, and move the person into the position you want. Then export it into your cad program to make suitable for 3D printing, or if you know how to use Blender you can do it there. ( i have tried to use Blender that many times and just give up ). May seem a lot of work but I get what I want and not what manufacturer's think I need.

Both Makehuman and Blender are open source, I have done one person as a play, but will do some poses that I need and will show the rersults.

Timbologist

[timbologist]

Hi all.

Thought it was about time I gave everybody's brain a bit more of a hammering so Will explain a bit about the new printers I have. And some of the differences and how some manufacturer's are blatantly trying to miss-lead the consumer.

So I have been busy achieving not much lately, but playing a fair bit with other types of 3Dprinting mainly SLA, DUP, and DLP printers. There are a number of other types SLS and SLM, which are at the moment only available in commercial versions. So I thought I would write some brain strain stuff on these types of printers.
So what do these groups of 3 letters stand for.

SLA stands for Stereolithography also known as stereolithography apparatus, optical fabrication, photo-solidification, or resin printing) is a form of 3-D printing technology used for creating models, prototypes, patterns, and production parts in a layer by layer fashion using photopolymerization, a process by which light causes chains of molecules to link, forming polymers. (from Wikipedia https://en.wikipedia.org/wiki/Stereolithography)

Selective laser melting (SLM) https://en.wikipedia.org/wiki/Selective_laser_melting

Selective Laser Sintering (SLS)https://en.wikipedia.org/wiki/Selective_laser_sintering

All these 3 types of 3D printer use a laser to cure the material being used. The industrial machines have a very fine and precise lasers better than 0.025mm that is X/Y resolution of 0.025mm whereas the home SLA printers generally have a laser that is about 0.13mm that is X/Y resolution of 0.130mm.
The SLA printers are limited to UV Photosensitive liquid resins, that are sensitive to UV light of about 405Nm.

The SLS and SLM are currently only commercial units, but manufactures are working on home use units. These use very fine powders that are UV Photosensitive again cured by fine UV lasers
cheers
Timbologist

[timbologist]

A lot has been happening in the 3D printing world, since my last post many months ago I have purchased a DLP/DUP printer A Wanhoa D7 DUP printer. This type of printer uses an LCD screen that shows a cross section of the model to be printed and a UV light is used as the light source. it functions the same as a slide projector. Each layer of the model is shown in sequence as the model is raised from the vat bottom a new image is projected to cure the next layer of the model. Attached are some of the models produced with the D7.
As can be seen from the photo's this machine produces some nice detail prints.

I think I need a lesson in taking good photo's

[timbologist]

I have been playing with the DLP printer making some double sided LINKA moulds and multi part brick pillar moulds. as can be seen the results are impressive. the moulds have a draft angle of 2 degrees to help them come out of the mould. I use Armorall as a release agent, and have not had any problems getting the parts out. I am getting a bit of flashing on the pillar mould as I have a bit of a mismatch on the mating surfaces for some reason.
Have other moulds that I will try multi-part printing as it appears to be a viable process, as I have the models already and just need to use boolean subtraction to create the mould halves.

DOUBLE SIDE B1-1 CAST

HALF DOUBLE SIDE B1-1 MOULD

DOUBLE SIDE B1-1 MOULD AND CAST

4 PART FENCE POST MOULD

CAST BRICK FENCE PILLAR

[timbologist]

The last couple of weeks i have got to the point I have started to want more people for the layout. But in my stock of people I have nothing suitable to cut to pieces and make what I want.
So I have started to play with some free software MakeHuman to make, rig and dress the people. then I use Blender to actually pose the people, where also I can import my STL models of various parts, i.e. stairs for people using them, wheelbarrows to have people pushing them, Pallbearers carrying a casket up the church stairs.
MakeHuman has a vast range of clothing and other assets that are included, and are downloadable through the program.
The resulting models I have been printing on my Wanhoa D7 DUP printer with some startling results in the detail.
First photo you can see the detail in the hands the actual fingers.
Some of the photo's i have not finished painting the people, but you can get an idea on what can be done with these programs and a resin printer.
I have so many other people to make that to add that look of activity to the layout.

people walking up stairs

pottery saggers

pottery saggers

pottery men with wheelbarrows

pottery men with wheelbarrows

[TimberSurf]

First impressions...very glossy, I like the wheelbarrow peeps, not sure about guys with turbans?
Should be cheap to make, as little resin!

[Mountain]

They are good indeed. The wheelbarrows I like. The mould idea.

[timbologist]

Should be cheap to make, as little resin!

I made 6 wheelbarrows at once resin cost was AU 11 cents this includes a raft that is scrap 1.33 ml time 4h 15m 48s approx
I made 6 men for the wheelbarrows at once resin cost was AU 17 cents this includes a raft that is scrap 1.99 ml, time 6h 1m 15s approx.
These were made with a resin that costs me about AU$ 86 including postage for 1 litre it looks expensive but when you use it for small models it is very cheap.

The actual machine running costs are higher than the material, but this can be reduced per item cost by filling up the build plate. As the time does not change, with an increase in area of the models, only the height. The time can be reduced by using different resins I am using the Monocure STANDARD resin. As seen below I can reduce the time by a fair amount by changing resins, ( I have several litres of standard resin I bought for the SLA printer, so have to use that first.

What are the best settings for the Monocure resin with the Wanhao Duplicator 7 printer?
Monocure RAPID: 7 second layers. 3 base layers at 40 seconds and 0.050mm resolution. (White, Clear, Black, Blue and Grey)
Monocure STANDARD: 20 second layers, 4 base at 90 seconds and 0.035 - 0.1mm resolution. (White, Clear, Blue, Red, Yellow, Grey, Black)
How is Monocure 3D RAPID resin different from the STANDARD formula?
Our Rapid Resin has been developed for low powered LED DLP type printers (like the Wanhao D7) so it can have faster layer curing times. The STANDARD resin will cure at layer speeds of 15-20 seconds, while the RAPID will cure at 5-8 Seconds depending on the layer thickness.

[timbologist]

Well thought it was about time to write some more here. As I have said I have 2 resin printers A CTC riverside and a Wanhoa D7.
So thought I would talk about the Good the Bad and the Ugly of these 2 printers.
The Wanhoa I had trouble with initially with it arriving non working from the factory but contacting the seller and then the Manufacturer things got sorted out pretty quick but the longest time is waiting for things to come from China. So all worked good for several weeks then had another failure the LCD stopped working. On investigation it was found to be a broken flat cable that went from the controller to the LCD, reason it broke was bad design of the parts location came out of the LCD and did a right angle turn in about 3 mm with no stress relief so snapped at the LCD edge. So again contact the supplier and the problem was resolved as quick as it takes for parts to come from China. so all is good with this printer at the moment just waiting for some resin that is better suited to this printer.
As for the Riverside that is a totally different story, can't complain about the support there is non, had many problems with this printer and have had to sort everything out myself, blown electronic components, dodgy firmware, mechanical failures etc. despite all this it is a good printer in what it can do when it is working.
This printer is a Chinese clone of the Formlabs Form 1, the original batches actually had the Formlabs firmware. But I think they got into trouble and put in there own that was not worth a knob of that stuff you get from a goats backside. It was just functional and the Cura slicer was hopeless for this printer as it was designed for FDM printers. Could only print at a layer height of 0.1mm which was ok for there resin which was clear and the Monocure clear resin, Everything else would not print.
So I actually got the Formlabs firmware and am now using Formlabs software to slice the models, works like a charm especially with the open form software which they released as open source because they no longer support the Form 1.

The mechanical failures are mainly to do with the vat which is considered to be a consumable, firstly the FEP sheet came of the base of the vat within a week, I actually managed to contact the seller and got a replacement VAT but that was the only time the seller responded to my emails.

Recently the base of both the Vats have developed a crazing pattern like a shattered windscreen in the perspex. I made my own replacement Vat and it went the same way. SO the next one I made I used 3mm toughened glass for the base and that works better that the perspex, as the laser is much cleaner as it goes through the glass compared to the perspex.

So if you are thinking about buying a resin printer get one that has good support, and good user reviews.
until next time have fun and sorry it was so long

[timbologist]

These Chinese printers are a pain in the butt. As I have said previously my Wanhao D7 has been nothing but trouble from the beginning, and just after my last post the D7 failed again.
I purchased this printer from an agent that is in Australia which has turned out to be a good thing. After the January failure I was unable to get any support from Wanhao directly they completely ignored my emails, So I had to keep going through the Australian agent who was getting annoyed ( being polite )
And when I did get a response from Wanhao it was the same questions that I had given answers to, they just did not read the emails I had sent.
After 3 months of this I think the Agent spat the dummy with Wanhao and Tuesday a Brand New latest version 1.5 Wanhao D7 arrived on my door step.
I let it sit there till today when I decide it was about time to see if this one works. Powered up ok, and my Raspberry Pi running NanoDLP picked it up and I could control it so all looked good. Until I tried to print something and it would not happen lights on nobody home.
So after a bit of head scratching and cursing I found I had to change the Firmware as it does not talk to NanoDLP properly. I had to do this with the first D7 which was version 1.2, so you would think that at version 1.5 they would have fixed the problem but no same crap different number.
Of course after replacing the firmware all works as it should, it is printing while I type this and about 2 hours into the print all is good

So anybody who is thinking about getting a printer direct from China I would advise against it, it may be cheaper but you have more chance of ending up with a boat anchor. "When the going gets tough the Chinese ignore you" I have a friend who bought an inverter direct from China work ok for about 16 hours before the smoke got out, After a couple of emails they now don't answer him.
At least if you go through a local physical person you have somewhere to go for warranty who is covered by your local laws.