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A few years back, I invested in a few of the 3d printed guides that were on the market at that time. I liked the way they were designed, and the price was good enough. My experience with them however, left me a lot disappointed in the overall quality of the printing, and the reliability was terrible. I soon gave up on the "stacked plastic" guides. Enter 2018: I get my own printer, i observe the much changed quality of 3d printers and the printing media itself. So, Just for fun, i look on the freebee sights for a guide to print. I came across this one.
https://www.thingiverse.com/thing:1050424
At first glance, I noticed something that had been missing on the original printed guides i had used. That being the way the guide was printed! This one is printed standing on its nose, and is built upward. The seams of the layered plastic are now running in a totally different direction, and are not subject to the loads put on a guide during hard racing. The mounting stem passes from top to bottom of the blade in a continuing line. I printed off a few of these to try, and was amazed at the strength they have. I was able to mangle one up with pliars, but not able to actually break it anywhere. I use a LOT of guides in all my build scales, and usually just use the slotting plus guides that have worked so well for me. The problem is, that i out build my inventory quite often, and have to wait on the next order. These printed guides have a nice rounded front that allows free movement under the nose of my midgets, while still using either the Ferrells, or grub screws (my personal choice), It takes about 15 minutes to print one off on my ender 3 three, using the 01 setting. So, I now have guides available to me whenever the need arises. And wont have to wait for the next order to come in! well, except for brass, and oh, braid, and well i still need pinions sometimes, and then there are those...........
Anyway, here some shots of the new guides.

Nice! I haven't printed those up yet, but good to know they work well. Orientation of the print definitely plays a major role in part failure, as does material. PETG is stronger, and might even work in the original orientation that failed. Also, printer set up and maintenance can affect quality of layer adhesion. With proper adhesion, a thicker layer is actually a stronger part, because the weak part will always be the layer bond, so less layers means less points of failure.

Yup. I took that one, lengthened the post, deepened the blade....and I print them 6 at a time for our club.

I guess I could upload it.....

Yes please.

Now this is a part I can get motivated about.

Thank you Bob for guiding me :)

Very nice. Instead of waiting for the brass, you could start to play with designing and printing your own chassis.

Bob,
Those look really good, thanks for the post and link. What material are you using? Or did I miss that somewhere in the text :?:

Peter

Woot! Thanks for sharing!

chappyman66: please explain Thingiverse.

WB2:. It's a website where people post files that can be used with 3D printers. The link i posted above is the file for the guide flag that I modified to have the deeper blade and taller shaft.
File sharing, if you will.

Well, Turns out my theory on 3D guides is still valid. I thought that standing them on their nose to print was a fix. Not so much. I put one on a fresh Midget build, to try them out. Not a heavy car by any means, but solid with the brass chassis. It made about 125 laps of hard racing (alone) and then gave up in turn three. Could be that I am using PLA instead of ABS? Don't know, could be that my grub screws used to hold the wire in place, put to much strain on the seams? again, don't know. Might be from tail out driving causing the guide to slam the locks? Don't Know. As you can see by the pic, it was a clean break along the printed lines. My settings were on .1, with solid fill, if that matters. I am not ready to give up on printed guides just yet, as they are handy to have when I need them. But more research will have to be done to completely comfortable using them on my favorite cars.

Bob...
I managed to break one like this, by slamming it into a wall (my fault, 22k motor on my short track). I cracked one with grub screws. I have broken a post by cutting it off too short and then using the mounting screw (the post is not hollow all the way down). They were all PLA.

A couple things come to mind. Brass chassis are much heavier which creates a different stress than the plastic chassis. And yes, I suspect the brass shoulder of the guide tongue could whack the edge of the guide, looking at your picture.

I did think that printing temp makes a difference....5-10 degrees hotter can make a better part in some cases because of better layer adhesion. But if you go too far you get strings which are bad too. And material does make a difference...but the PLA has been great for all of our plastic cars.

Just my .02.

No need for thinner layers for that kind of part, really.
You might try PETG. It's much more resilient than PLA, and is just about as easy to print. Costs about the same, too, especially with Amazon selling a 5 pack of their Basics filament for just over $60. Yep, about $12 per 1Kg spool. They're doing the same with their PLA 5 pack at a little over $50. You get Black, White, Gray, Blue, and Red, but it's a fantastic deal on good filament (I've used both their PLA and their PETG). Looks like they have the same deal going on their ABS.

Looking at where the flag split, it looks like it split at one of the layers. With this thought you may want to try increasing the extrusion temperature by 5 degrees centigrade. I've had issues with the solidoodle printer that I had due to the variation in the temperature. Your printer should be a closer tolerant on the temperature setting than what my original printer had.
Once I getting back into a condition where I could go out to my laboritory (Manwan) I'll try one of my prints of a flag that I had modeled up and printed out using the IC3D Nylon filament that was printed out on the low side of the temperature scale for the filament. It was printed out at 245c but the suggested temps are 245c-260c.