ISO Metric 30 X 2 threads 3-D test printed ??

[keld.soerensens]

I have huge problems with the printed bolt and nut NOT fitting together !

I can make the threads in Fusion 360 and I can see by section analysis that it takes care of some cleanrance between nut and bolt, but when printed I can't even get i started !

It seems like I have to have a little more clearance - can I change that somewhere ?

My printer is printed within +/- 0,1 mm

[HughesTooling]

What I normally do is create the thread in a sleeve, scale in 2 axis (non uniform scale.) to increase the diameter then extrude the external finished shape.

Mark

[HughesTooling]

Another option is Press\Pull on the faces of the thread but you'd probably need to press pull the 2 angled faces then the 2 diameters. You'll probably need different offsets for the diameter.

[keld.soerensens]

THX for the quick answer !

In my workshop I managed to file/scratch and fidle so the bolt started, but after half or a whole turn the thread binded way too much so I had to un-screw the bolt again ... I think this tells that I need more CLEARENCE, right ?

Do I really have to use a "best-practice" like allways scale, let's say, the female part up a little like you do ?

(I think I have to 'cut' out a sleeve and scale it like you do and then combine it inthe original body again, or ?)

It should be solved with a 'clearence parameter' in Fusion 360 instead, right ?

[TheCADWhisperer]

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

There is one little issue that I want to check for.

[keld.soerensens]

THX !

I have tried to solve the problem by adding a chamfer BEFORE I do the threads - but oh, it gets even worse !

I've made a little test here WITHOUT the chamfer and here it is !

[HughesTooling · Accepted solution]

Here's a quick screencast, shows 2d scale of thread and adding chamfers. You'll need to experiment a bit with the scale to get a fit you're happy with. The chamfers are easier to add if you switch to cosmetic threads, add the chamfer the switch back to modeled threads. File's attached.

Mark

[keld.soerensens]

Oh My, it looks like a long and tedious process - thx anyway !

BTW: It's much better with speak added 😉 !

[keld.soerensens]

>> TheCADWhisperer
Did you find a better solution than HughesTooling - I think it's a little slow if you have many different thread sizes, right ?

[HughesTooling]

2 choices if you want a quick way of printing threads that work first time. One spend 100k or more on a good printer!😉

Or make a custom thread XML file that produces oversize female and under size male threads. Info here on custom thread XML files. Also an add in here to help manage updating the files after Fusion updates.

Mark

[keld.soerensens]

Hi again !

Easy, easy now ... I'm glad you found a quick solution and I will try it today - thx - for future use I too have to extact the essense of the method so I can use it quick without too much problems.

I still think the best 'solution' would be a paremeter for 'cleance' in Fusion360 ... the I can contunie to use my cheap chineese printer 😉 

[HughesTooling]

Are you printing metric or imperial threads and how many different sizes? I'd guess you will want to use standard screws\bolts so you'll only need oversize female threads?

Mark

[keld.soerensens]

I use metric threds for 99.9% and right now I have a series of projects for underwater use so I have to print both male and female in PETG - way to expensive to use stainless steel.

Too I have to make some special through holes in the bolt for rubber pipes to go through.

[HughesTooling]

To get you started I've attached a XML file with a standard pitch M10 and M20x2. I've added 0.1mm to the minor, major and pitch diameters. You can just copy over from the standard metric thread XML for other threads. I've only included female threads as you're more likely to need to fit to standard bolts\screws.

Original metric XML file on the right.

This shows the size difference using your sample file. You'll need to experiment to find how much oversize you need.

Mark

[keld.soerensens]

Wav ... thx, I'll have to study that for more details !

I must admit that 'the manual' method you showed in the video is rather simple and quick - the essense I think is:

separate the thread part scale it a little smaller and combine the bodies again ... but it's hard to find out from all the moving around ... a little speak would have helped - but I got it now ... I think !

THX again !