VST screws insanely tight

[99yam40]

what is the main difference between the Philips and JIS?
The filed off tip so that it does not bottom out in the screw socket?

[cpostis]

what is the main difference between the Philips and JIS?
The filed off tip so that it does not bottom out in the screw socket?

Here are a couple of diagrams for you to ponder:

[IMG]JIS SD by Charles Postis, on Flickr[/IMG]

[IMG]screws_JIS_phillips_screwdriver_angle by Charles Postis, on Flickr[/IMG]

[boscoe99]

I hate Phillips/JIS type of fasteners. What a pain in the arse. Give me a Torx or other type any day.

[cpostis]

I hate Phillips/JIS type of fasteners. What a pain in the arse. Give me a Torx or other type any day.

Here's a ballade just for you Boscoe

https://www.youtube.com/watch?v=oqMl5CRoFdk

My JIS screwdrivers fit nice and tight and stand up in these tiny VST screws. Like I said before, I have no problem with them. look for the "dot", use the right tool and be on your way!!!

[IMG]JIS Screw by Charles Postis, on Flickr[/IMG]

[boscoe99]

You try removing 150 or more Phillips/JIS screws from the leading edge of a P3 aircraft and then get back to me about how great those screws are. I know how to remove a Phillips or JIS screw. Do I want to deal with them? Not usually. When when there are so many better products available?

Is it just a coincidence that Torx and other types of similar fasteners are more commonly used today? Methinks not.

[cpostis]

You try removing 150 or more Phillips/JIS screws from the leading edge of a P3 aircraft and then get back to me about how great those screws are. I know how to remove a Phillips or JIS screw. Do I want to deal with them? Not usually. When when there are so many better products available?

Is it just a coincidence that Torx and other types of similar fasteners are more commonly used today? Methinks not.

Gees Boscoe, I agree with you!
Just saying I have not had a problem. Others may appreciate what I have posted to avoid problems with these JIS screws on their VSTs. My VST has ten of these tiny screws and cost about $4.00 a piece from Yamaha.

One thing I must say, IMO JIS screws are much better than Phillips if you use the proper tools.

My point is, find and use the proper JIS screwdriver for these screws, and you will have a much better chance of not having problems removing them or damaging them.

By the way, as I am sure you know, a P3 Orion is a marvel originally introduced to the US navy in the 60's. Still in use today by the US and other countries abroad.

[99yam40]

look for the "dot", use the right tool and be on your way!!!

Do all JIS screws have the dot?
How do you tell what the bits are if you cannot read makings on them

[pstephens46]

Dot or no dot, my new impact screwdriver got them loose. Little scary the first one. Head didn't disintegrate. Took 3 good whacks per screw. All good and idling in driveway looking for fuel leaks. VST gasket is kind of pitiful too...

[rodbolt17]

dunno who designed the hand impact driver but they need a medal.
worst part about some of those well maintained VST's is drilling out the broken screw.

[cpostis]

Dot or no dot, my new impact screwdriver got them loose. Little scary the first one. Head didn't disintegrate. Took 3 good whacks per screw. All good and idling in driveway looking for fuel leaks. VST gasket is kind of pitiful too...

Did your screws have the dot, or not? I noticed your VST screws have a different part # than mine and are about half price of m8ne as well.

[pstephens46]

I'll buy the champagne for the medal awards ceremony.

No dot Chuck. Weak screws. I did not crank them back down. No leaks so far.

The hp pump does not look rust resistant and I was thrilled the body was clean with no rust. Filter has very fine mesh. Blasted with cleaner and put it back in.
Not impressed with gasket but again no leaks as I reused it.

[cpostis]

I'll buy the champagne for the medal awards ceremony.

No dot Chuck. Weak screws. I did not crank them back down. No leaks so far.

The hp pump does not look rust resistant and I was thrilled the body was clean with no rust. Filter has very fine mesh. Blasted with cleaner and put it back in.
Not impressed with gasket but again no leaks as I reused it.

I wonder if depending on VST model, some screws are JIS, some are not. Mine defintely had the dot. My internal anode screws have the dot as well, and I used a hand impact on them sucsessively before I realized they were JIS.

[pstephens46]

Plus 100 on the hand driven impact hammer tool....

Just make sure it's supported WELL when you whack it...

Paid for itself many times well over 30 years with the same unit..


If it has a round head sticking out, a small vise grip may work as well.

Supported better than wife holding between knees...

[99yam40]

Did not get an answer to my last question so I looked on line to see about the dot.
found answers to several questions I had.
Just in case others are interested.

The JIS stands for Japanese Industrial Standard

"The JIS driver can be used on Phillips quite easily but not reciprically. Drivers are not easily available in North America, try your local RC Airplane hobby shop.
Most RC Helicopters use JIS screws to mount the propeller.
JIS-spec cross-head screws are generally marked with a single raised dot or an "X".

JIS always fit Phillip fasteners, but because of slight design differences, Phillips drivers may not fit JIS fasteners. (unless the tip is ground down a bit)."

So It does seems grinding a little off the tip of your Phillips driver, will make it fit better

[99yam40]

Supported better than wife holding between knees...

a little too much give going that way I believe