Tap & Die Testing

[cleven 4]

(This test was simply to be able to use a die to create male threads, I was having issues with tapping both male and female, and this is how I was able to get repeatable sucess. I printed at 0.1 layer with a 1mm wall thickness. PLA)

 

Since many threads are difficult to print I decided to test out a cheap tap die set. This allows for more complex printings and assemblies using either plastic or metal screws. Also have approximately a 1mm wall thickness if possible. Note that a 0.8mm thickness also functioned.

 

Set the print Diameter to 0.5mm under the desired Major Diameter. Then set the Drill size to 0.5mm larger than set.

 

These sizes allow for an easy cut and a 20% infill can be used. Any size under or over resulted in the plastic shearing. It can also be difficult to mount the die onto the OD. Place chamfers to assist in inserting and mounting tap and dies.

 

The threads worked well, no issues. Works very well! I bought a cheap tap and die set and it worked well for plastic.

 

STL file I used found here, an M10x1.5 was used.

 

[Titus 170]

Though I like the idea, I'm afraid that you simply loose to much strength due to your wall thickness being cut away :(

 

[chrisr 18]

Though I like the idea, I'm afraid that you simply loose to much strength due to your wall thickness being cut away :(

 

Print it solid ?

 

[mastory 44]

If a hole is to be tapped, I print the hole diameter to match the suggested tap drill for that size thread, and make sure I have adequate wall thickness to have material left after the thread is cut. For added strength, you can use a metal thread insert such as Helicoil or many other types.

 

[cleven 4]

Yes normally, and when I machine plastic I use helicoils but that isn't printed there are tolerance issues with printing. Otherwise you would just take the proper tap size drill and drill it out to be perfect. When you use the select the exact sizes I was having shear issues with the smaller bit sizes. Reducing the size of cut allows for ease of cut and extrusion of the plastic which ends up nearly matching the required size as he material plasticky deformed to fill the tap. .

 

If a hole is to be tapped, I print the hole diameter to match the suggested tap drill for that size thread, and make sure I have adequate wall thickness to have material left after the thread is cut. For added strength, you can use a metal thread insert such as Helicoil or many other types.

 

[cleven 4]

When printing it solid it isn't a problem to use standard size. But if you want to add threads in a large model printing it solid can take a while and isn't always needed.

 

Print it solid ?

 

[cleven 4]

This test was simply to be able to use a die to create male threads, I was having issues with tapping both male and female, and this is how I was able to get repeatable sucess. I printed at 0.1 layer with a 1mm wall thickness. PLA.

Each machine may yield different results. As mine was beat to crap by the Postal Service here in the USA I cannot say if someone else will be able to obtain better results. It is up to them to test.

I found this gave very nice results on the 10mm, sizes should be modified as tap/die size changes. It is up to you to figure out what works.

I also said a cheap tap and die set this makes it available to all. If i wanted I would have jumped in the machine shop and grabbed a few of my sharp high strength taps or machined the male threads a threading machine or lathe

 

[ultiarjan 1,223]

or you use a trick to get 100% infill locally, and then drill out the correct hole you need for tapping.

the trick;

http://umforum.ultimaker.com/index.php?/topic/7095-useful-cura-trick-sparse-solid-infill/

I tried tapping in a printed hole a few times, it did work but you need to be carefull not to be to quick as the PLA will get to hot while tapping.

 

[cleven 4]

The main reason for upsizing the was for the die insert. Im not too concerned with the female thread. That can be done with either size. Just reducing the hole eliminates possible shear. But give it a go to try and thread with a die on a small thin plastic printed part and you can then see the issue

 

or you use a trick to get 100% infill locally, and then drill out the correct hole you need for tapping.

 

the trick;

http://umforum.ultimaker.com/index.php?/topic/7095-useful-cura-trick-sparse-solid-infill/

 

I tried tapping in a printed hole a few times, it did work but you need to be carefull not to be to quick as the PLA will get to hot while tapping.

 

[aviphysics 9]

What about modeling the parts with threads and then chasing the threads with a tap and die afterwards?

However, to me, the biggest issue seems like the problem of most threads that you can get taps and dies for are not optimized for plastic.

 

[cleven 4]

It would work, but it can use up a lot of cpu/memory to have a lot of threads on most cad programs, Especially in larger models and assemblies. Seems why they just fake represent threads in their program settings.

For softer materials I think there is different tolerances for taps etc but it works if you take your time wih nominal sizes.

 

What about modeling the parts with threads and then chasing the threads with a tap and die afterwards?

 

However, to me, the biggest issue seems like the problem of most threads that you can get taps and dies for are not optimized for plastic.

 

[bigmouse 6]

I did some tests on tapping PLA and ABS, PLA wasn't very good! Ok it's possible to do if you frequently remove the tap and clear off the PLA swarf which build up in the form of long threads wrapped around the tap, if not cleared it will chew its way through removing any trace of the thread your trying to form! And its hard to remove this PLA swarf.

ABS Is good for tapping, although I allow a bit of oversize drilling! According to the charts M3 requires a 2.5mm drill but this 83% engagement totally unneccesary and unrealistic for plastics, I used a 2.6mm drill giving about 62% engagment.

Haven't tried male threading but probably the same idea applies!

 

and a follow up

 

 

[cleven 4]

I increased and decreased by about 0.5mm on a 10m thread.

Was able to do male and female with out having much of an issue.

The male thread is more difficult but you really need to design thread reliefs in place.

 

I did some tests on tapping PLA and ABS, PLA wasn't very good! Ok it's possible to do if you frequently remove the tap and clear off the PLA swarf which build up in the form of long threads wrapped around the tap, if not cleared it will chew its way through removing any trace of the thread your trying to form! And its hard to remove this PLA swarf.

ABS Is good for tapping, although I allow a bit of oversize drilling! According to the charts M3 requires a 2.5mm drill but this 83% engagement totally unneccesary and unrealistic for plastics, I used a 2.6mm drill giving about 62% engagment.

Haven't tried male threading but probably the same idea applies!

 

 

 

and a follow up

 

 

 

[chrisr 18]

When printing it solid it isn't a problem to use standard size. But if you want to add threads in a large model printing it solid can take a while and isn't always needed.

 

But it will work, yes? Or if applicable...re-think the construction of your part and split it so that where you need holes tapped just those parts are printed solid? When I bought my isolation miller to make my own pcbs (LPKF Protomat C60) I had to think through my layouts with a view to the process of the machine in mind.

Alongside my UM2 that's my other very favourite machine ;-)

 

[cleven 4]

I only did some initial testing. Mostly I don't use fine threads. I usually make a custom stub acme for what I need. I tend to just glue for my models and it gives a good representation.

 

But it will work, yes? Or if applicable...re-think the construction of your part and split it so that where you need holes tapped just those parts are printed solid? When I bought my isolation miller to make my own pcbs (LPKF Protomat C60) I had to think through my layouts with a view to the process of the machine in mind.

 

Alongside my UM2 that's my other very favourite machine ;-)