SLA Wire locking bolts for large scale vehicles

[Schwarz-Brot]

This is a test post, but I think something meaningful is a good idea.

 

A while back on this thread by @Renek he showed a sketch of wire lock bolts he got printed for his Alfa Romeo Monza in 1:12. Some users voiced an interest in these studs, and I jumped at the opportunity to see what I could do. It was the first attempt at creating parts from scratch, not working from existing 3d files. With several active users we developed the design further - the users from a design perspective and me to optimize printing. For example the head of the screw was shrinked considerably to optimize the look. All of course with printability and stability of the part in view. Several testprints were done on the iterations. This way the orientation was optimized for cleaning up the printed parts and aid with painting. The hole size was adapted in several steps to find the best tradeoff regarding print quality, cleaing out and stability. The design itself is very simple, but the process showed all those involved - including me - what it takes to take an initial design and turn it into something that can be printed with repeatable results.

 

I guess we all learned quite a bit from it and I can only encourage all of you who start out with 3d designing and printing to start with such a "simple" design, maybe even go and try to repeat the process - the initial sketch and dimensions can be found in the thread linked above.

 

The discussion was held in private as this section didn't exist yet and it was not really clear how and where to show parts that were intended to be sold. I am most happy to see this makerspace area where such an discussion can be held in the open. I found it most educational. A shoutout goes to all involved: @Sloucher, @colin, @Bengalensis, @Renek, @Armchair Thank you, guys.

 

In the following testpost I'll show some pictures.

 

Test editing:

The bolts were made for the Italeri Alfa Romeo Monza Kit in 1:12. They should fit all cars of 1:12 and larger.

 

Edited July 26, 2020 by Schwarz-Brot
Added information, just to see if editing works. Edited Tags and title

[Schwarz-Brot]

So this is where the design started from. The dimensions are according to reneks sketch. The pontons are designed by hand to bind the bolts together in multiples for easy handling. They are needed in the printing process and are part of the support structure.

These bolts are nice to print as the support stem also acts as an integral part of the design - this is rarely the case but super nice because there are no suport marks to be cleaned off of the final part. The upright orientation without any angles also means there are no visible layers in the final part. The height of the head was lowered in later parts and the orientation of the holes was rotated 90° - thus allowing me to blow them out with compressed air before postcuring.

 

 

This was the next iteration in 3d CAD with the smaller head:

 

And after several iterations I ended up with these - the final parts after cleaning but before postcuring. At this stage they are still very soft and sometimes feel sticky. Postcuring hardens the resin further and afterwards the parts feel like regular casted resin.

 

 

I know at least @Sloucher put his bolts onto his model, showing the result. Maybe I can persuade him to post the picture here as well.

 

[Sloucher]

@Schwarz-Brot, it will be my pleasure 😀

 

Here are a few photographs of the incomplete build of my 8C, showing the wirelocking bolts:

 

 

  

 

They certainly added that missing element to the Italeri model. I just wish I'd been able to finish it!

[Pouln]

Now that you have a working design, you should be able without much effort to print them in Pocher scale 1:8. Right?

There might be interest in those from the Pocher builders that lurk in BM

[Schwarz-Brot]

Yes, I can rescale easily to 1:8 for Pocher and others. In that scale hex-bolts should work out just as fine if there is demand.

 

Downscaling is not possible as I am at the limit of a robust and repeatable design. I might do smaller ones with the hint of a hole to drill out manually, but to be honest, this is a task I wouldn't recommend doing. I think this is only doable repeatedly with a jig and watchmakers precision tools.

[Sloucher]

Actually @Schwarz-Brot and @Pouln, I would suggest that the current size and shape (square headed) is just fine for the 1:8 scale Pocher 8C Monza as I think they are slightly oversize for the 1:12 Italeri.

[Pouln]

2 hours ago, Sloucher said:

Actually @Schwarz-Brot and @Pouln, I would suggest that the current size and shape (square headed) is just fine for the 1:8 scale Pocher 8C Monza as I think they are slightly oversize for the 1:12 Italeri.

I see what you mean. Looking at the pics you included you may well be right.

[Abandoned Project]

 

Wow! Amazing work! Absolutely awesome. Really makes the model.