Just use Thread Forming Tap!

[skom25 603]

Hi,

Before I start my new build, I decided to buy Thread Forming Tap. I was not sure if I have to, because I read many times that you can just use regular screw and not waste money, on really overpriced tool from Tamiya. I like to try new tools first, before I use them during build. I found few parts in spares which will not be used.

I am QA guy, so decided to extend my test and compare Thread Forming Tap vs Regular Screw. I had two exactly the same parts and made thread using both methods.

Conclusion:

Making thread is easier with Tap but it not huge difference. No big deal.

However, result is totally different. If you make thread with screw and try to screw new one, you will feel that it goes quite harsh. It is also bit hard to find that "start" point, when you rotate screw counterclockwise. It just feels like using screw in already threaded hole, which all of us did many times.

Thread made by tool is totally different. It really feels like screwing into aluminium parts. "Start" point is easily noticeable and screw goes really smooth. Event after I tightened screw really hard to stretch threads a bit, removed and screwed again, it still felt better than thread made with regular screw.

You can say that it is autosuggestion. No, I did blind test at the end. Both parts were exactly the same. I just mixed them and tried again. Difference described above was clearly visible.

One thing worth to mention: I did test on hard plastic. I am not sure about result on that very soft parts from cheap kits.

Second thing to mention: In XV-01 which I bought, you can find information in manual, to thread holes first. So it is not like doing "Voodoo" on kit without reason.

Summary:

If you buy cheap kit with self tapping screws, this tool is probably not for you. Of course, it it possible to use regular screws but soft plastic is not the best for machine screws.

If you buy medium or high end model which has machine screws in kit, just buy Thread Forming Tap. Yes, it is expensive but still in price of one Hop Up or even less in many cases.

Good tools are the basis of comfortable work and high end result. I learned this in cycling at it seems, that it works the same for RC.

 

[toyolien 3971]

I use the thread forming tool for carbon reinforced parts. It's a great too. However, I only use it for 3/4 of the depth needed, and let the screw cut the other 1/4 of the thread.

[echobase 1]

@skom25 Thank you for all your explorations into building techniques. How do you ensure the thread forming tool is properly aligned with the work piece?

[skom25 603]

Just by an eye. Put tip of Tap into hole and check if it is straight. Start really slow. If you see that it is not straight, do not remove it, just correct position.

You will not damage part, because it will be only 1 or 2 threads at start. If you go quite straight on that moment, hole will hold tap and you do not have to worry.

Tip of the tap is bit smaller than threads, so you have some kind of "driver" before you start make first thread.

My tip is to try at some unused parts. It sounds like serious job but in fact, it is easier than with regular screws and screwdriver.

[JimBear 262]

Tagging along here ... but can I use a "standard" (non-JIS, DIN?) M3 tap? I mean, the thread is going to be slightly different, but does it matter?

I had difficulties using the self-tapping screws on the Rising Fighter build - seriously hard plastic in the bathtub chassis, so going forward I was thinking of getting a tap.

[BuggyDad 2990]

1 hour ago, JimBear said:

Tagging along here ... but can I use a "standard" (non-JIS, DIN?) M3 tap? I mean, the thread is going to be slightly different, but does it matter?

I had difficulties using the self-tapping screws on the Rising Fighter build - seriously hard plastic in the bathtub chassis, so going forward I was thinking of getting a tap.

Generally regarded as not as good because it takes away some material where the rolling tap doesn't. However I would say that if you have a decent depth of hole to thread into and want to use this for the first few threads to make sure the screw starts well, with the screw doing the rest, then it would be useful and not really disadvantageous. 

A key benefit of a tap IMO (regardless of type) is that it really defines the starting thread, so on repeated reassembly you're more likely to keep using the same thread and therefore keep the hole in good condition. I can't prove this is true though. I could be wrong. I just find that on some plastics the old "reverse it til it bumps down a thread" method is hard to gauge and a bit more definition to it would be nice (I'm guilty of not always using the tap). If my theory is true, then only the first thread of a tap will help there. 

[skom25 603]

1 hour ago, JimBear said:

Tagging along here ... but can I use a "standard" (non-JIS, DIN?) M3 tap? I mean, the thread is going to be slightly different, but does it matter?

I had difficulties using the self-tapping screws on the Rising Fighter build - seriously hard plastic in the bathtub chassis, so going forward I was thinking of getting a tap.

It is forming M3x0,5 tap. If you use it, Tamiya screws will fit.

I believe JIS is standard of socket, not thread.

[Elbowloh 668]

Using one for the first time on my M05 pro, as seller included a full set of titanium machine screws.

 

[Pylon80 1308]

On 11/21/2023 at 8:54 AM, Elbowloh said:

Using one for the first time on my M05 pro, as seller included a full set of titanium machine screws.

 

That's great! Just don't do like me, use plenty of grease. I have ruined a brand new hard lower deck back when I first got the tap. Without grease, heat built up very quickly and melted the plastic in the holes 😐