Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful?

Harvey White

On 12/31/2020 7:32 PM, Larry McDavid wrote:
Why would using Chinese made boards require a different physical design?
money, simply money.

using SEEED studio as an example, a 113 mm by 246 mm board, HASL (roughly a complete inside of plugin, is 65 dollars for 10, 48 dollars for 5.  ENIG goes to 94 dollars/10 and 75 dollars for 5.

a 4 by 4 board, HASL, is $4.90 for 10.  same price for 5.

The board interface to the frame, 113mm by 52 mm, is roughly 23 dollars HASL lots of 10, 19.00 HASL lots of 5.

The main board can be done as a 100mm by 100 mm board,

The front panel board can be made within the 100 x 100 mm range.

So: HASL, 6.50  for the main board if full size.  otherwise 2.30 and 50 cents for board connector (can be used for different designs), and main board.... $2.80.

and if you don't get it exactly right the first time, the costs mount up.

This neglects the front panel board(s) which will fit within the 100 * 100 mm promotional price.


The author, Jared Cabot, used PCBWay, surely fab'd in China, and provided Gerber files for each of the four PWBs. Since several here want boards sets, the simple thing seems to be order them from PCBWay. Delivery timing is really not an issue and shipping cost for blank boards can't be that much... I will ask PCBWay for a quote.


On 12/31/2020 3:50 PM, Harvey White wrote:
Oshpark is very good, with 3 board per order for the price of 5 dollars per square inch.  I should point out that the board set I saw would be rather expensive.

Their boards are purple, and ENIG (gold plated)

The typical Chinese made boards may have a size limitation for lowest cost, and the lowest price will be for HASL (Hot Air Solder Leveled) boards.  On the other hand, a 100 mm square board can be had for 4.90, and that's for 10 of them.  Shipping with DHL is likely 20 to 25 dollars, but that price range covers 5 different boards, all 100 mm in size or less.

Using Chinese made boards will require a different physical design.


On 12/31/2020 6:33 PM, Michael W. Lynch via wrote:
Are there any US PCB  Houses that we could contact?  Or are they all in China?  I have never done boards before.  I would be willing to help out with the process.

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