Wednesday, June 25, 2014

A Discussion on iGaging Scales and Wildhorse Innovations DROs

NOTE: Nothing in this post is intended to imply that iGaging scales will work with the DRO-350. At the present time only the DRO-375 and DRO-550 support iGaging scales. Use of iGaging scales with the DRO-550 requires modifications to the PC Board, which if done incorrectly can render the board inoperable.

Model Engineers Digital Workshop in England has produced a daughter-board which is purported to allow the use of iGaging scales with the DRO-350. However, Wildhorse Innovations has not tested this implementation and cannot guaranty or support it. We can however, provide the parts necessary to implement this modification, eliminating the need to pay postage from England. Please email Wildhorse Innovations for additional information.

For several years, iGaging has garnered an increasing market share in the DRO scale marketplace. This is a well earned success as they have brought truly competitive pricing to the DRO marketplace.

What does this mean for Wildhorse Innovations customers?

This writer believes that, although there are some negatives, the use of iGaging scales will be a net win for all people using them.

The technology behind the iGaging scales is not new. It is, in essence, a rehash of the technology used in most "Chinese" scales, calipers and other measuring tools.  As such, the iGaging scales offer little in the way of improved accuracy and/or reliability. "Glass" (quadrature) scales are still far superior to the "Chinese" scales when it comes to accuracy. However, glass scales are far from kind to the pocket book.  For most of the "home hobby" users, as well as many applications in "commercial" machine shops, the accuracy of the Chinese scale is sufficient.

I should note here that in most applications, Chinese scales can provide an accuracy better than +- 0.001 inch and under the worst conditions will seldom fall below +- 0.002".

So where does the advantage of iGaging scales lie? In two areas, price and value.

You may ask, what is the difference between price and value? In this instance, the price advantage rests in the absolute, out of pocket, expense for a scale of a given size. Consider a 12" scale. A 12" iGaging scale from Amazon costs $36.95, which includes shipping. A similar 12" scale from (discount_machine on eBay) costs $55.00 (including shipping). A 12" scale from Little Machine Shop is $85.00 plus shipping.

The value advantage comes in the form of the remote display that is included in the price of all iGaging scales. While not a full featured DRO head, this display adds value to an already competitive price.

For those of you wanting to pair a set of scales with a DRO head such as the DRO-350, or ShumaTech's DRO-550, scale cost is just one part of the overall cost. There are three elements required to integrate a DRO scale and DRO head into a full featured DRO system.

1. The scale.
2. A cable to connect the scale to the DRO head.
3. A matching cable inside the DRO head to carry the scale's signals to the "brains" of the DRO system.

I will use the ShumaTech DRO-550, and the Internal Cable Kit from Wildhorse Innovations as a platform from which to draw comparative costs.

The Chinese scale comes without any cable to connect the scale to the DRO head. The only US source for these cable is Little Machine Shop. These cables are currently (June, 2014) on sale for $17.95 plus shipping. So to integrate a 12" scale from requires;

1.  12" scale - $55.00
2.  Cable - $17.95
3.  Shipping (cable) - $6.00
TOTAL - $78.95

(In this case, the internal matching cable is included at no additional charge in the Wildhorse Innovations cable kit.)

Now to the iGaging scale. Should be simple, right. WRONG... For all of its advantages, iGaging chose a wildly expensive connector for its cables, a SEALED Mini-USB connector. Why they chose a sealed connector, I have no idea. Perhaps they were envisioning these inexpensive scales being used in hash environments.

Whatever the reason, we have to live with it.

The mating, panel mount, connector for the iGaging cable is the Bulgin PX0446. As you can see from the pricing on the Mouser site, this connector is relatively expensive.

For this reason, Wildhorse Innovations must charge extra for kits requiring this connector. The current price is $9.00 per connector.

OK, lets compare the complete iGaging setup to the Chinese model shown above.

1.  12" scale - $36.95.
2.  Cable (included with iGaging scale.
3.  Internal cable - $9.00
4.  Shipping (included with other costs)
TOTAL - $45.95

So even with the expensive internal connector, the final figures show a savings of  $33.00, and that's on just one scale. The potential savings for a 3 axis DRO system can be over $100.00.

The bottom line is that no matter how distasteful the cost of the iGaging connector, it's a big savings when it all comes together. And hopefully someday there will be alternatives to the sealed Mini-USB connector which will bring the price down even further.

Now go make some chips.