Turbo Pad Screws

[Teknix1]

Hi,

I recently purchased a TurboGrafx 16 system with controllers, I'm really happy with it, it's in a much better shape than I expected based on the auction images. I thought I'd still give it a little cleaning job just to get the last bits out. I always like to clean the controller insides to get those in tip top shape. To my surprise, the screws are all rusted. Not the system ones though, they're so rusted I'm afraid they might break off in a few years when I might want to reopen them again. So I'm now on the hunt to get replacement screws. I don't want to damage the plastic shell's threads so I want to get these exact same ones. My two controllers had different sizes. I don't beleive hardware stores would carry screws this small so I figure I would have to find them online. I don't know how to measure them or what numbers mean when looking at screw specifications  online.

Any help is appreciated, thank you.

Nic

PS: I would love to add photos of the screws in question but the site tells me the upload folder is full. They're about 160KB total...

[ClodBuster]

I'll have a look at the screws of my Turbo Duo and Coregrafx controllers tonight to see of their screw sizes match Tamiya's 3mm self tapping screws for plastic.

Also, that upload limit is intentional. Use an external hosting service for uploading pictures and embed them into your post afterwards.

[ClodBuster]

On my Turbo Duo controller, there are five screws:
Self tapping screw pan head 2mm x 8mm

The following screw set of ten pieces, suitable for two controllers, should have the same dimensions:
Tamiya 50573 2x8mm Tapping Screw (10 Pcs) MSRP $2.20
https://www.tamiyausa.com/items/radio-control-parts-70/r-c-glow-engine-spare-parts-66000/rc-2x8mm-tapping-screw-44002-50573

Do NOT use wood screws or machine screws.
When putting in the new screws, turn the screw driver anti-clockwise until they fall into the existing threads. Then gently turn clockwise until you feel resistance and stop turning,
Have fun getting your controllers sorted.

[Necromancer]

I don't know if you got 'em in your neck o' the woods, but Ace Hardware might have such screws.  They have a ton of little weird screws, bolts, nuts, and doohickeys that you buy by the piece.

[Teknix1]

That is awesome. I'll have to figure out which screws these are. I have two different controllers with different screws.

Here's an attemp to post them:



My apologies if this is not the right way to do this.

Nic

[Teknix1]

Doesn't look like I have an Ace Hardware in Ottawa, Canada unfortunately. I have been to other hardware stores but the never have anything this small. I'll try hobby stores as they carry Tamiya products, I hadn't thought of that.

Nic

[ClodBuster]

Trying a hobby shop is a good idea. They should have fitting screws available.

I measured mine using calipers. Thread diameter x screw length. The head doesn't count for length.
Unless you're using countersunk screws, where the head counts.
Japanese hardware is usually made in metric dimensions.

[Teknix1]

I don't why I hadn't thought of measuring them. I guess I was kind of hoping these would somehow be standard. So after much digging and measuring, here's what I figure these are:

Style:
Thread Rolling Screws (or sometimes simply called screws for plastic)
Self Tapping
Flat End
Pan Head

Small screws:
M2-0.75mm X 8mm
Head diameter: 3.2mm

Large screws:
M2.4-0.85mm X 8.5mm
Head diameter: 4.4mm

I'm not too concerned about the head diameter, but finding the right pitch is next to impossible, I don't know if these pitches were common back in 1990 but not anymore. Half the time they're not listed online, I figure if anything is going to damage the plastic, it woukd be getting the wrong pitch. Anyways, I get to go to a hobby shop at lunch today. I'll see if I can track the tamiya ones to compare.

Thanks for all the help!
Nic

[ClodBuster]

Thanks.

The head diameter may differ even visibly slightly from manufacturer to manufacturer, but shouldn't concern you too much.

The thread pitch is determined by the screw diameter type. A 2 mm self tapper for plastic will always have the same pitch, regardless of manufacturer or year.

Don't mix up M2 and 2 mm, like so many shops do unfortunately.
The "M" stands for ISO metric machine screw thread. Machine screws with their fine pitch are not meant for threading into plastic threads, they are only meant to screw into metal threads. Still, you CAN try machine screws at your own risk.

If you've got trouble finding suitable 2.4 mm screws (do these exist?), you might get away using 3 mm screws IF you slightly enlarge the plastic thread hole to something like, let's say, 2.5 mm, beforehand. A fine pin vise helps with carefully drilling into plastic. Also make sure the head will still fit.

I had to replace all the case screws on the bottom of my Turbo Duo with 3 mm Tamiya screws, since the previous owner already replaced the original screws with some others of the wrong type, and had stripped the holes due to repeated assembly. With the screws I chose, I was able to cure the problem.

[Keith Courage]

I want to mention that the screw holes for the controllers can take a little more length than what the original screws are. Meaning you could get away using a slightly longer screw than the original. just not a lot longer because it will go through the controller front.

also, if you can't seem to find any replacement screws at a hardware store, maybe try finding some old used electronics at a thrift store? I've used screws from a number of portable CD players and or tape players in the past to replace screws in PC engine controllers.

[Teknix1]

Oh, thanks for rectifying the M vs mm. Perhaps this will yield better results in my searches. I have seen 2.3mm online, perhaps those would be close enough. My caliper was alternating between 2.3 and 2.4 but was more often on 2.4.

[ClodBuster]

My calipers aren't digital anyway.

Regarding the "M" designation, what I meant is that I see shops on the web advertising their 2 mm tapping screws with "M2", even if you can clearly see from the product pictures that these aren't machine screws. Especially those shops that aren't familiar with metric sizes.

[Teknix1]

Had no luck at my local hobby store. They would have to order parts in and even then they wouldn't be to the exact specifications. So I searched and searched online and the only ones I could find where I thought they would be a close enough match were on eBay from China. I've decided to place an order and be patient. I'll check back here in a few months when I get them.

Thanks for all the help! I've discovered a great community on PC Engine FX in the process.

[ClodBuster]

You're welcome!