I'm new at 3D printing, and am trying to learn supporting techniques and placement. I figure we can use this thread to bounce ideas regarding supports to a model off each other. This is not just my thread, so by all means, jump in! To start us off, here's a model I want to print. Open top bathtub gon in N scale. My questions: Will the supports under the bathtub overhang be a problem to remove? What about the one in between the brake wheel stand and under the tub spars? Am I orienting and supporting this model most effectively? I'll need to add a hole or two in the tub base to prevent suction.
I'd think about cutting it so you are only printing about 1/4 of the length and use it as a test to see or just try the whole thing. Looks like you are jumping in the deep end with this as a first major print but what the heck it isn't going to cost you a fortune. I recently printed the little pump house I made with the roof on which required internal supports for the roof. There were so many that I gave up trying to remove them as they were hard to get at inside the small building. I went back to printing the roof separately and gluing it on. I could of left the internal ones but you would see them through the window. I designed and printed a partial store front the other day and had Cura add supports in the large windows. They turned out to be really easy to remove, just popped out with a little pressure on them. Other than that I haven't used supports so don't have much experience with them. I'll be interesting to see how easy it is to remove the car from all the bottom ones. At least you can get to them and they aren't inside something like they were with my building. My main cleanup tools are an Exacto knife and the nippers that are like what you cut rail with, Sumner
I have the Xuron rail cutters as well as their ultraflush cutters in my modeling toolbox. Favorite tools I've had for more years than 3D printing has been around, and quality made. I figure they're tailor made for removing supports. A bit of Xacto blade work to remove the nubs under the car won't be bad. The under/inside tub stuff is what is an unknown. If the inside tub supports are that much trouble, I figure I can delete the spars and add them after printing using styrene strip. I wonder if I need to raise the supports under the base and remove some of the density of supports to allow resin to drain and not congeal into a glob due to surface tension?
Great thread! Even though I've had my printer for a long time now, I'm not that prolific at printing. However, I have printed some gondolas before in N-Scale. I can tell you that those supports inside the tub will be an absolute nightmare to remove. You might consider adding the cross supports using styrene rod after the print? As for the end of the car, those supports for the lip should not be connecting to the bottom shelf. A neat trick is to add a support anywhere else (say the side of the car), and then move the connecting point and the base where you need it (in edit mode, select the part you want to move and drag it around). I also typically raise mt model by 8mm off the base plate. Also, in my gondola print, I had two holes at the bottom, just enough for the bolsters for the trucks. It didn't seem to be enough and I had warping walls.
This definitely supports (pun intended) my thoughts about the interior and the suction issues. 8mm height off the print plate or raft, check. Edit supports to connect from outside of car to overhangs/details, remove interior spars. Should I print it flat or angle it ?
Honestly, I'm not sure. I haven't had a lot of luck printing cars without some sort of warping (usually the corners or walls where they meet the bottom of the car). I suspect if you print as you have it now, you will get the walls caving inwards. I might try 45 degrees, but I'll let an expert answer!
@HemiAdda2d - If you can print it at an angle without scarring up too much of the model with support marks, I'd recommend it. Print at 45 degrees and layer heights that are multiples of your LCD panel's pixel widths. In your case with the Photon, 0.04725mm layer height will be perfect. You won't see any stepping on your planar features that are oriented at 45 degrees, and it will help mask dead pixel streaking as your equipment starts to age. @Stephane Savard - I've had those problems with warping at the corners. What I've done is given up being dainty with my supports in those areas. What I mean by that is my supports shoot straight up into the wall, no tapered point at contact, just a support rod going right up in there. I do place them on the inner edge/side of the wall so they're a little easier to remove without scarring the show side of the model. And sometimes I'll put up to three, one on the corner, and one on either side of that. I'm at work so I don't have a picture of this but hopefully the description is clear. Happy Printing! -Mike
I printed it flat, and the supports are marring the angled tub sides below the sill. The walls printed straight--the interior spars printed just fine without supports. I missed finding/removing a support the Chitubox system auto-placed in the stirrups. Future prints will not have that deformation from support removal. My handling during cleanup warped them. Hamfisted baggage handlers need not apply... The upward warping of the platform ends are what concerns me. Will printing on an angle cure that?
For the upwards warping, see SLSF's reply to me in post #7. It might be a good place to start! Still, looks really good for a first print. Do you have other pictures of the interior? I'd be curious to see how it printed from most angles. As I mentioned in an earlier post, I did try printing a gondola, and the walls warped all over the place. I'm curious to see the drain holes you made. As for the bottom of your print, I find most resins do "bloat" just like yours did. The top of the model (what prints last) has nice sharp details) and anything underneath (towards the build plate) is bloated to some extent. I've printed with Anycubic Green, Anycubic Grey, and Siraya Tech Fast grey so far. And honestly, the original Anycubic Green was the one resin that bloated the less on the bottom. I don't know what details you had on the bottom (you didn't show the screenshot of the underside of the 3D model file), but scrubing the print on a flat sheet of sand paper can flatten it out nicely. Edit: Also curious to know what resin did you use for this.
My supports are light, and basically what you see in the first post. Resin Elegoo black. I'll grab some photos of the interior tonight when I finish the last print.
That looks awesome! I'm jealous, you managed in only a few prints what I've struggled with so far! Would you mind showing some screenshots how you positioned your supports? I'm sure I can't be the only one thats very curious to see and learn from your prints
You know what they say... "If at first you do succeed, try to hide your astonishment!" I'll post a new one with the angled supports for the tub, but same as above. I wonder if doing less supports helps the upwards warping?
The supports directly under the tub were removed; I added angled supports that connect to the underside of the ribs. I was skeptical it would work, but it does and I'm definitely not complaining! The learning curve here is steep...
I’ve wondered whether Chitubox over does the supports, but I like the flexibility it gives for angled supports.
The supports under the body sre fine, and dense. I'm not going to lie on that. It looks like a fine toothed comb! The whole raft just unzips from the body just as nice as can be.
As I said to my students when I used to teach CAD if the technique you use works for you then that's the correct one to use, I agree that the support structure looks a bit dense but if it's giving good results then you are clearly doing something right
