Plastic Nuts for Wood From Mercedes Dealers

[wwheeler]

Ok sorry. I didn’t see sedan in your description. That makes sense. Thanks for the clarification.

[Pawel66]

Wallace and I have already had a discussion regarding the threading and came to the same conclusion.   I will be making two versions. One version with M5 threads and the other with a hole that you can tap yourself.

You would definitely need a high quality 3D printer for the threaded version to work. We will just have to see.

No hole at all - trouble to make a centered hole. Any hole - can be drilled to proper diameter for the thread to be made.

Again, the drawing should be in high resolution. I am happy to test print.

[mrfatboy]

Here is my first attempt at creating the nut in 3D. I'm just a beginner at CAD drawing and some of the geometry was difficult to replicate.

Special thanks goes out to Wallace, 66andblue, and ja17 for sketches and providing a nut for analysis.   

I do not have a 3D printer and who knows how this will turn out. 

The original nut has a 5 mm hole at the bottom(unthreaded) that goes up 4.5mm. Then the rest of the hole is 5mm threaded.  Instead of trying to make 5mm threads I just reduced down to 4mm. Someone can just tap or force make the threads with a 5mm bolt.  We will just have to see how it works.

I will send Pawel the 3D file to test print. When everything checks out and we are happy with it I can post the file in the tech manual for others to print.

Cross your fingers

[Pawel66]

Great!

We make the threads not with the bolt, but with the thread maker (do not know the English name), you can buy (most likely) M5x0.75mm everywhere.

I will just probably need to work out the resolution dispute with the printing house.

Got your file on mail, thank you. I will take it with the printing guy.

[Benzgirl]

Better deal at Niemoller for sure but then shipping cost must be high....

[Garry]

Better deal at Niemoller for sure but then shipping cost must be high....

It is probably cheaper to get from Germany as the US postage has skyrocketed in price recently and is certainly quicker as next to nothing is getting into or out of the USA at the moment due to Covid flight restrictions.

[Pawel66]

I think they sell the same type of nuts at Niemoeller as they sell in SLS. It is a really cheap looking one...

[wwheeler]

The tool you need is called a tap and will cut threads into the ID of the nut. You need a 5mm - .80 tap. BTW, a die is the tool used to make threads on the OD.

The specs call for the ID hole to be 4.2mm to make correct 5mm threads. So you will need to drill the 4mm hole to 4.2mm or just try it the way it is. Cutting threads in plastic is different than in metal, so who knows what will work the best.

Don’t use a regular screw to cut threads and won’t work well. They do make special thread cutting screws but only create so-so quality threads. You will want the threads in the nut to be smooth so that you do not dislodge the studs in the wood.

[mrfatboy]

Inside the nut the threads start out to be 5mm and toward the top they get smaller slightly for a interference fit.  I measured a 4mm hole at the top in the sample nut I had. If necessary I can enlarge the upper part of the hole to 4.2nm

I would be surprised if I got this perfect on the first try so I will wait Pawel’s comments for version 2 if necessary.

[wwheeler]

I would leave it as is for now. Who knows what the hole diameter will need to be in the end. It is more close enough for now.

Nice job on the CAD. I did that some when it came out years ago. But I found that I spent more time figuring out how to get the program to do what I wanted and less time actually creating the part.

[66andBlue]

Great!
We make the threads not with the bolt, but with the thread maker (do not know the English name), you can buy (most likely) M5x0.75mm everywhere.
I will just probably need to work out the resolution dispute with the printing house.
Got your file on mail, thank you. I will take it with the printing guy.

Pawel,
to tap hard plastic it will help if you don't use only the final dimension thread cutter but go in stages, coarse to final. Unfortunately, few sets include this feature. And if the taps are tapered then you can stop and not go all the way through to the largest diameter. As Wallace wrote, it should be a M5x0.8mm, not M5x0.75mm.
I have found this one very convenient. Even Joe A. likes it. 

[Pawel66]

Alfred, yes, thank you I was thinking of cutting the thread in stages. I do not think I will have an issue finding any of the cutters here, some of them I probably have in the garage.

I am not sure about the 0.75 or 0.8mm thread. I believe what you are saying that it is originally 0.8mm, but some of us may have the studs replaced and if anybody did it, they did it with standard M5 bolts. I am not sure what is the most common standard - 0.75 or 0.8. Anyhow if the "raw" nuts are produced, anybody can thread them as they need.

Thank you for your kind attention and the tip!

[mrfatboy]

If anybody is interested I have attached a photo how I started the CAD drawing.  First, I drew it out as a 2D shape looking down on it.  From there, I just push/pulled the geometry to make the basic nut.

Once I got the basic shape I had to do a lot of detail work.  As Wallace said, it can become frustrating to get the App to do what you want.    I had to start over many times.  You really need to think the whole project through before you even start.

I used Google Sketchup.

[DaveB]

you are a super-tinkerer!

[wwheeler]

Alfred,

I have never seen a tap set like that. That makes prefect sense because the standard taps usually create threads that are a bit too loose. You can get adjustable dies, but never seen a way to make better internal threads. I know they have the tapered, plug and bottoming taps with different ends. Very interesting.

[Pawel66]

Alfred and Wallace were right as for the M5 thread cutter (not a surprise, actually). The standard is M5x0.8mm.

Example of the set under the link, can be Google translated.

https://allegro.pl/oferta/gwintownik-gwintowniki-m5-m6-m8-m10-uchwyt-zestaw-6280691090

[wwheeler]

I can't seem to find these in the US and also with inch sized taps. Maybe just in Europe and metric?

[Pawel66]

We have fabricated the 3D printed nuts - description is under separate thread "Blue Plastic Nuts For Wood Self Fabricated".