Blue Plastic Nuts For Wood Self Fabricated

[Pawel66]

We have fabricated some of the blue plastic nuts for dash wood holding. I think they are ok - at least I am quite happy with the result.
Mrfatboy prepared an excellent file for 3D printing based on wwheeler's drawing and a sample/picture of original from Joe and Alfred. So what I had to do is just to print and thread them.

The nut has 5mm orifice not threaded down to 4.5mm form the knurled top. Then the orifice diameter narrows to 4mm for M5x0.8mm threading. That is how the 3D file was made by mrfatboy - as it should have been. I just found it useful to drill a bit the 5mm part again with a drill bit, to widen it slightly.

Getting tightness right on a screw after threading needed experimenting - not to have them too tight and rip off the studs from the wood and not too lose so that they do not unscrew themselves on their own. I tried leaving part of the orifice at the coned end not threaded (like in the modern self-locking nuts) but then the nut was far too tight.

So I followed Alfred's advise on using the 3 staged taps. When I went through all 3 stages - the nut was too lose. When I stopped at stage 2 (intermediate) the tightness was just about right in my opinion, so that is where I left it. Best is to do some trials on your prints and studs if you want to fabricate these nuts.

Thanks everyone for help!

[wwheeler]

Good news! Looks really nice. The color looks pretty close to me. Sure, other plastic nuts may work. But you will feel much better when driving your car knowing that you have the correct nuts holding down the wood.

The other option for the 3 stage tap system are taps meant for plastic. I know McMaster sells one that “ejects” the material forward so that it doesn’t get run back through the threads. Supposedly creates tighter threads. https://www.mcmaster.com/2673A74/

Pawell, have you tried using a wrench on the nut? I think it was a 9mm wrench that was required. I wanted to check how the fit was.

The next question is....how can we get our hands on these?

[Pawel66]

Wallace, yes, mrfatboy prompted me to check it - 9mm socket/spanner fit nicely.

[mrfatboy]

I will put the 3D file in the tech manual later today. You can just download it and print them yourself.

[wwheeler]

Thanks!

[mrfatboy]

The 3D file (.stl) of the Blue nut has been uploaded to the Tech Manual.

https://www.sl113.org/wiki/Restricted/TemplatesDecals

[wwheeler]

To help us (me really) that are Hi tech challenged, What do I need to send to a 3D printer? The file in the tech manual is a .stl. I have that copied and is that what I send?

If I go to menu and click on "save as", it gives me options of a image, 3D image and then a video.

Thanks!

[mrfatboy]

Yes. Just download the file and send to printer.

I don’t think it matters what file type you select but make sure you get “Blue Nut.stl”

I have not actually done it but maybe Pawel can share his experience and let us know some details.

I think there are some online companies that print also. Check around for pricing.

[mrfatboy]

I just downloaded the file to my iPhone and viewed it with this free app.   Just search for “free stl viewer”. I’m sure there are similar apps for Android.

Once loaded in the app you can zoom and spin the nut around its axis.

Try it

https://apps.apple.com/us/app/stl-simple-viewer/id1493598400

[Pawel66]

As mrfatboy says, just download it, save it as .stl (would be probably a 3D image suggestion, just make sure the file is .stl type).

Find a 3D printer near your place in Google, or not necessarily near your place. Send them an e-mail or call them asking if they can print for you in blue colour. Send them the file you saved by e-mail and ask to ship the nuts to you. If they are near your place, you can go to them and check what they printed.

So: download, save as .stl file type, send by e-mail to the printer. That is all.

Print more than you need, just in case.

[col320ce]

This is fantastic...

[wwheeler]

Ok thanks. I feel empowered!

[wwheeler]

I contacted a local 3D printer and he produced one as a prototype. See attached. Pawell, how do you think the texture compares with what you made? Not sure it is going to get much better, but I can see. What material did your guy use?

I am thinking that I might get more than I need and can sell the remainder to other US members here if there is any interest. The nut is not threaded, but I can do that and send it on. I do not have a finalized price but possibly $2/each plus US shipping. To ship outside the US would be cost prohibitive.

Thanks. 

[mrfatboy]

I have seen several videos on how different printers work and even using acetone gas to smooth out the texture in one instance. That seems more of a hack than anything but it sorta worked.

I think it comes down to the quality and type of the printer used. I saw a resin 3D printer that had amazing detail. Again, I know next to nothing about 3D printing. 🤪

[mrfatboy]

Wallace,

Does your blue nut have a slight arch at the top of each side of the hex nut? I can’t see it in your picture but I see it in Pawel’s. Maybe just a bad angle of picture.

[wwheeler]

I looked on his 3d sketch and no it doesn't. Good catch! I will see about getting that fixed.

Thanks.

[wwheeler]

I just figured out how it happened. My printer added a hex on top of the nut in place of the circle. The hex allowed the distance from the point along the angle to be the same as the distance to the flat. Therefore no arch. To get the arch there has to be a circle on top just slightly larger than the bore. Hopefully he can fix that.

[mrfatboy]

Why did he even change the file? I thought he just prints what’s given to him. Again, I’m note familiar with the printing steps.

[wwheeler]

He said that the file had some glitch and he had to "fix" it. My guess is substituting the hex instead of the circle was the fix. But I am checking. I went back and looked at the print I gave you and I left off the angle dimension on the top. Not sure if that had anything to do with it. I am even further away from CAD and 3D printing than you, so I am no judge. Hopefully he can get it right.

[mrfatboy]

Your drawing didn’t have the arch. I added it after I saw a real one that Alfred brought over.

I don’t know about glitch. Pawel’ printing worked.  I think there is a”software” factor🤷‍♂️

[Pawel66]

Attaching pictures again - mine do have the arch. The texture is, I think somewhat similar. The cost here was ca $1.7 per piece.

[wwheeler]

Your drawing didn’t have the arch. I added it after I saw a real one that Alfred brought over.

I don’t know about glitch. Pawel’ printing worked.  I think there is a”software” factor🤷‍♂️

I left that feature off because it would have been too difficult for me to calculate. But if you have the circle on top and the flat angle going down, the arch appears automatically by geometry because of the different distances to the edges. That took me a while to get. My 3D printer changed the circle to a hex which allowed the flat as opposed to the arch. Hopefully I will find out why today.

[mrfatboy]

What software are you using? I have seen several free ones out there that people seem to like. However, I can’t remember their names. I’m sure you can google for the list.

[wwheeler]

I sent the company the STL file, "Blue Nut", and they took it from there. The drawing he sent back says Autodesk fusion 360. That is about the extent of my techie ability.

[olhughes]

I do 3d printing and the .stl file must be sliced to create a .gcode file that the printer understands. I have 2 printers and each uses a different .gcode file. when I first sliced the .stl file it told me that there were errors with the file and if ignored and printed anyway I ended up with a nut without a center hole. pulling it into a different drawing file then slicing I get a hole from the top down just shy of the base. Waiting on the blue filament so I can print them in the correct color. Once I print, I will probably print a bunch so if others need them...