Mechanical Parts Threading Help Quality  

settings

For threads, I have found that I have to shrink them a little more than expected on the male side of the insert (externally threaded part).  

Also, I use these settings in PS 2.3x

• 0.25mm z distance.
• 75% xy distance.
• 3mm support spacing.
• 4 interface layers. 
• 0.2mm interface layer spacing.

Most likely, the designer didn't make accommodations for FDM printing but just gave you what came out of SolidWorks. which is fine for CMC but not FDM.

I've done a fair bit of threads lately, here's what I do, and it usually works great:

I offset the thread faces on both, male and female by -0.1mm.

Then on the male side, I fillet the newly created edge by 0.1mm.

Prints fine with 0.2mm, no supports, and usually screws in like butter. But based on size etc your mileage may vary, and some additional adjustments may be necessary.

Screw tolerences depend on orientation as well as filament.

For vertical threads in good quality PLA 0.1mm radius is usually enough, cheap PLA may require 0.2mm.

Horizontal threads generally require double the tolerance.

PETG and nylon vary, I generally start at about double PLA values and print a couple of test screws for each new filament.

You *might* be able to rescue your part with fine abrasive but be aware that if one part is not printed you may cause damage...   Put toothpaste into the thread, repeatedly screw it as far as you feel safe to go and unscrew, wash away the paste and check the fit.  Repeat until it fits, or is ruined.

Cheerio,

Cheerio,

@dst

If this is the same model I just helped you with? both male and female threads are the same size. that doesn't work in the real world. you must have a decided tolerance as well as creating a relief. you should also consider a slight taper to the male thread section.

Good Luck

Swiss_Cheese

video

Posted by: @swiss_cheese

@dst

 

If this is the same model I just helped you with? both male and female threads are the same size. that doesn't work in the real world. you must have a decided tolerance as well as creating a relief. you should also consider a slight taper to the male thread section.

 

Good Luck

 

Swiss_Cheese

There is a good video on Youtube about this and it reduces the size of the male more than expected.  

Same model

Yes, I’m fact it’s is! Makes total sense. I’ll have to pass this along and see if we can make modifications. I wish I knew how to do it myself. I’ll have to learn some basics. 

Yes you do

It was not my intention to chastise you, I noticed this during the tuning of the lattice area of the model, but I felt it was best to let you experience this for yourself and learn the answer. and since we are at this point I'm going to suggest Twist Lock mechanisms for your product.

With that said take the time to learn about Threading, it's important, however not the answer for your plant support model.

Consider a design like this, for your locking mechanism.  Try to understand the reasons why.

Regards

Swiss_Cheese

Video thanks

@cwbullet, thanks for sharing the video   And feedback  

Posted by: @cwbullet

 

Posted by: @swiss_cheese

@dst

 

If this is the same model I just helped you with? both male and female threads are the same size. that doesn't work in the real world. you must have a decided tolerance as well as creating a relief. you should also consider a slight taper to the male thread section.

 

Good Luck

 

Swiss_Cheese

There is a good video on Youtube about this and it reduces the size of the male more than expected.  

 

I wish you luck, it's a large/ long learning curve, I have 30+ years & several 3D suites under my belt.

I'm sure if you continue to try hard you will succeed.

Regards

Swiss_Cheese

And succeed i

@Swiss_Cheese, I am so impressed!

Every bit helps  and makes me better and expands my knowledge. I'll take it a day and project at a time. 

Speaking of success. With all the notes taken and some minor adjustments to female parts. It spins line butter and perfect seal!

I'm sure if you continue to try hard you will succeed.

 

And succeed i

@Swiss_Cheese, I am so impressed!

Every bit helps  and makes me better and expands my knowledge. I'll take it a day and project at a time. 

Speaking of success. With all the notes taken and some minor adjustments to female parts. It spins line butter and perfect seal!

I'm sure if you continue to try hard you will succeed.

 

Design

I like that mechanism.  I might have to try it with a couple of my designs.  It is simple and holds well.  I need to figure a way to stop them from opening up back up.  I though about a design like this for avionics bays on rockets, but the parachute rotates and might open them up.  

Posted by: @swiss_cheese

It was not my intention to chastise you, I noticed this during the tuning of the lattice area of the model, but I felt it was best to let you experience this for yourself and learn the answer. and since we are at this point I'm going to suggest Twist Lock mechanisms for your product.

With that said take the time to learn about Threading, it's important, however not the answer for your plant support model.

 

Consider a design like this, for your locking mechanism.  Try to understand the reasons why.

 

Regards

 

Swiss_Cheese

 

@cwbullet

What direction does the parachute rotate? Set the twist-lock mechanism to the opposing direction of rotational force.

As well you can model in a type of snap-fit at the end of travel. 

Regards

Swiss_Cheese

Rotation

I was thinking the snap fit, but I might have over complicated things.  The clockwise rotation seems simple. 

Posted by: @swiss_cheese

@cwbullet

 

What direction does the parachute rotate? Set the twist-lock mechanism to the opposing direction of rotational force.

As well you can model in a type of snap-fit at the end of travel. 

 

Regards

 

Swiss_Cheese