PVC Pipe Bracket

[kentd]

I have only had the machine for a couple of days.... and already kicking out some usable parts!

I needed a bracket to hold my furnace PVC exhaust pipe on the outside of the house..... so here is the bracket that I made on the M2 using PLA.

It is made to fit a 2 1/2" pipe on one end... and then it lays up against a 1 " pipe on the other end and gets tie strapped to the 1" pipe.

[Dale Reed]

kentd,

Nice job! I can see how the one semicircular part was printed (the shiny surface on top in the second picture gives it away). But the main shoe --- did that require some fair amount of support material? If so, you've done a masterful job of trimming it up. And if you've got several perimeters, which follow the curve of the pipe, this part will be very strong in just the right directions.

As you've obviously discovered, having an M2 makes creating custom parts for a job into a fun and rewarding experience, instead of hacksawing something together out of steel strap and angle iron and three trips to the home center and one to the pharmacy for bandages and disinfectant for the cuts from the sawed-off metal.

Welcome to the fun!
Dale

[kentd]

Thanks Dale...

Yes, you are correct... this piece did require a lot of support material.

I also had the software create a raft under the whole piece to help hold all of my support material in place.

I ran this whole print with my cooling fan turned OFF.

I tried the print it with the fans on but the fans kept loosening up my support material.

I've actually found that I've had my best luck running the prints with the cooling fans turned OFF for the whole print.

Here is a screenshot showing the support material placement.

Take Care...

Kent

[jsc]

What are you using for CAD? That's a very impressive "first part". You have some experience, I take it.

With PLA, you should (generally) keep the fan on in order to help cooling. Helps with exterior overhangs and reduces heat induced warping. If you're having trouble with support adhesion, you can start investigating which of several methods will become your favorite; see the "M2 tips" thread in the tips forum. They all have their partisans, I'm partial to glue stick. My experience was that my first few prints turned out great, then I started having first layer adhesion problems. The only cure is to keep the glass meticulously clean, or rely on chemical adhesives.

I've read that PLA isn't the most suitable material for outdoor use, although I've also read of some people's experience that contradicts that. It appears to have good UV resistance, but is sensitive to heat, so if it gets very warm where you are you may see it degrade over time. It is also considered biodegradable, although that is mainly in an industrial composting machine context.

One suggestion on designing for 3D printing: if you split your print into two parts so that the main beam inserted partially into a recess on the left clamp like a mortise and tenon, you could rotate the right part by 90 degrees on the X axis and print the whole thing almost entirely without supports. Saves on filament, and supported surfaces never come out as nice as the others. (You would solvent bond or glue the mortise into the tenon, like in joinery.) I've found that a .2mm clearance on all sides gives an easy fit, a .1mm clearance a very tight fit.

[kentd]

Thanks for all of the great suggestions.

Temperature may be an issue for me..... I live in North Dakota.... and the temps get down to Minus -40f in the winter.... so I'm guessing the PLA will get brittle.
I will probably make a rubber mold and use this as my original to create a mold to pour a material that is able to hold up to the low temps.

I am using Rhino 5.0 for my cad software. I've used it for years and it's rock solid with a ton of features.

[jimc]

Me too on rhino. Been using it about a year and a half. I love it. Its such a great modeling software. I turned on a few other members here to it as well.

[jsc]

Coincidentally, I just received this weekend my Smooth-On starter kit, for making RTV silicone molds and urethane resin parts. Looking at the tech sheet, it looks like the flexural and tensile strength is under what is reported elsewhere on the web for 3D printed ABS, although those numbers are probably for 100% infill parts. Curious if you have any experience with what casting resins are good for high strength parts.

[jimc]

jin, i have casted things in the past with silicone and urethane, epoxy and polyester resins. i have painted literally tractor trailer loads of urethane sculptures for casinos in the past. all were smooth on brand urethane.....i believe, or polytek. i can say that it is quite strong, probably equal to abs BUT its not the kind of material that takes constant pressure. for example the pvc bracket posted by the op. if that were a urethane casting you could walk up and whack the pipe with a hammer or hit the bracket with something no problem but hang just 5-10lbs off the end of the pipe and in a matter of a couple few days the bracket would be bent....no sure if that helps you or not. epoxy casting resins are the same way. extremely strong in one way but not another. polyesters are opposite. very rigid and wont take impact but stiff. sorta like the way pla is. of course with all these there are exceptions to the rule and there are different formulations of everything. thats just a general guide.

[kentd]

I agree 100% with everything Jim said about casting materials.

I have found that the smallest thing can cause all kinds of problems when you are casting resins. For example if your room temp is not warm enough your resins won't cure properly.
So my advise is to read the directions and follow them to a Tea as far as temps.

I use an electric turkey roaster with water underneath the pan to cure my parts. So in other words I pour water in the bottom part of the roaster and then lay my pan in. The water helps keep the temperature constant without any hotspots.
I run my temp very low.... ( around 100 to 123 ) and it really speeds up the curing process.

I have also ran into all kinds of problems in the winter months when I have materials shipped to me.... the UPS / Fedex trucks are not heated in the back so it really effects the quality of the material.

But once you get the hang of pouring castings it's a lot of fun and you can make some great pieces.

Do you have a vacuum chamber for degassing the materials?

[kentd]

Here is a fishing rod holder I made using poured resin material.

I made my original parts on a 3d printer, and then made molds from those for reproducing the parts.

I used Smooth-on Task3 materials for these since it has to stand up in the hot sun and so far I haven't ran into problems with the parts sagging from the hot sun.

All of the rubber parts on the rod holder I made using an injection molder I have in my basement.