SEN 2347 - the right screwdriver 21 Sept 2017

Table of contents SEN 2347


  1. JIS Screws
  2. Altimeter Data Processing
  3. URL Corrected
  4. Dukie’s Comment





JIS Screws … and more


From FB – Jim, Mike and Norm


Jim Parker


Learned about screw heads from you tube video about Honda 90 carb rebuild. Japanese use JIS head, looks like a Phillips. Identified by a single dot recess on the head. Explains why it's difficult to get torque on a JIS screw with an "American" Philips screw driver and they are buggered-up. Photo of Jim Bradley ' s Honda 90 carb that I've cleaned.

For my Mechanical friends, a link to an interesting article on the history of screws and many variations. Even have the Torq Set screws used in Hughes-Boeing Satellites. 


Mike Schwartz 

JIS means Japanese Industrial Standard.


Don DeLoac

Did not know about JIS. Thx Jim


Norm Furutani 

Bought this set:


Hozan JIS-4 JIS Screwdriver Set (NEW 3rd. Gen)

The D-530-75, D-540-100, D-550-100 and D-555-100…


. Looks like a Phillips, but does not "cam" out. First time you disassemble an OS engine or Jim's Honda carb and you will be sold!

Further discussion involving Whitworth Threads and Classic British Motor Bikes and Shotguns edited out


Altimeter Data Processing 


From:Tapio Linkosalo


Re: Altimeters, another option (next to PC and Android) to read data from

RAM-loggers and FD-A (aka HobbyKing logger) is the Altitude Analysis

software for Palm, which I have authored with Petri Kuikka. The software is

giftware (that is: use it for free, but at your own risk). We have had the

version 2.6. for download for quite some time, and after the FD-A was

introduced I added support also for that logger, but never had the time to

throughoutly test it. I added the version supporting FD-A to the web page,

so it can be downloaded, but with the warning that it is a test version



The software is developed with NsBasic, which has the limitation that

maximum data table size is 8000 entries. This used to be OK way back then,

but modern loggers record much larger data sets. In which case, you can get

only a fraction into Palm. There are some means to overcome this, as you

can define offset for the start of data storing, in other words you do not

need to store the data from the start of the dataset, but you can go to the

middle. Or split a large set to a number of smaller datasets.


Another thing to note is that for the loggers you need a RS-TTL converter

(such as MAX232-family chip) in the serial cable to read the data into

Palm. Straight cable does not work! The serial adapter of the RAM logger

can be used, or any RS<->TTL converter. I'm afraid those are not readily

available. USB dongles do not work. Another way to get past the adapter

issue is to use a Bluetooth adapter. The BT dongle that HK sells for FD-A

does work when using a Palm that has BT port.


Ah yes, the AA software can be found here:





Question from Editor … For use in Fly Offs does the analysis program have to the certified by the CIAM group along with or separately from the altimeter hardware ?


URL Corrected 


From:George Voss




Here is the correct website for Soaring Circuits.



Dukie’s Comment


From:Shailor, William


Factory F1C

Doug Galbreath's post regarding factory built F1C's has to be one of the most insightful comments I've read on SEN in a long time. What have we done to ourselves?

Bill Shailor