UltraLog Project Updates


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Tuesday 28 March 2006

Scale Validation

Scale files were sent to the three validators last week. Above is an image of an enlarged printout of the scales being tested for accuracy by Otto Van Poelje's
Coordinatograph machine.


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Tuesday 21 March 2006

Scale Design

The iamges above show the practically complete scale design. Only the constants scale will be added to in the coming weeks. Please note: the quality of the .JPG images above is markedly lower than the quality of the source AutoCAD files.

The scales were designed using a purpose built software application and the AutoCAD software. The original .DWG files will be sent to the three auditors in a few days for validation as planned.

Fund Handling

Gary Flom, a moderator of the ISRG list who also runs the Swap Sheet Online project of the Oughtred Society, has kindly volunteered to handle all applications, receipts and payments. He has done so on two previous ISRG projects and will not be charging for his services. I will be passing to him all emails expressing intention to purchase received by me.

Production Tests

A subset of scales was sent to a British company operating in Hong Kong for CNC engraving and rasin filling tests. We are expecting to receive first samples in a week or so.


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Monday 6 March 2006

Scale Design

The image above shows an inspection of a draft .PDF file generated from Delphi produced alphanumeric data. PDF is used only as an aid to development - the scales are being brought to their final shape in AutoCAD, in a parallel process. Intensive programming effort during the last seven days resulted in a core scale design, including all graduations, numbers, scale designators and separating lines which is nearing completion. Gauge marks, constants and self documenting symbols will go in next. We expect to be ready for audit in 3 weeks.

Design Audit

Although we carefully validate everything we do, I have approached several persons well familiar with slide rule design who were recommended to me and asked them to audit the design when completed and validate it for completion and correctness. I am very pleased that so far three of them have agreed to assist in this important task.


Discussions are ongoing with several manufacturers here and abroad. It is beginning to look like a job that will suit a shop specialising in rapid prototyping using CNC and I am following this line as well.


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