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This is an archival page
  This page documents some of the process of development of the Chinhda cart. We have moved on in the cart development. For up to date information, visit the pages devoted to the Chinhda cart Version 3.
 
Sound Cart Project First Efforts
This page is continuously under construction. Check back regularly.

Scan to the bottom of the page to see the prototype that went to NAB.

Noodling around with a suspension system. This is not necessarily what the finished product will be like.
 We'll post photos and information about the development of the new cart as we have it available.
Mouse over to see the drawer opened
Technically, these drawers are more an update of the old cart than progress on the new one. However, the availability of the right components is very much part of the construction of the new cart.

We installed aluminum rack drawers available from the Starcase company. Each drawer weighed only 6 or 6.5 pounds and replaced a Mid-Atlantic drawer weighing almost 18 pounds. The new drawers are a nearly exact replacement. We were even able to use the foam insert fitted to the old drawer in the new one. We were impressed with the build quality; they slide open smoothly on well-engineered drawer glides. The drawers "notch" close with a friction latch and can also be locked. We would have preferred a more positive latch but the drawers seem to stay closed without the necessity of constantly locking them.

Link to the Starcase site.
We're using this drawing as a reference as we move forward. Some features will change as build the prototype and both possibilities and liabilities become more clear.

The Scale of 1"=4" refers to the original drawing, not this graphic reproduction. However, the proportions should still be approximately correct.
The partially completed prototype. It sort of looks like one of those "robots with personality" from a movie.

At this stage one can see the mounting arms for two recorder platforms. Chinhda has changed the orientation of the shock mounts, affixing them vertically in the arms. This permits one platform to be mounted in close proximity to a platform above or below. The platforms will slide out on a rail to give ready access to the gear for loading or attaching cables.

The panel with multiple holes above the handle is a patch bay. Some of the power and audio connections would be routed there for easy access.

The frame in this prototype is bolted together but most of the joints in the production model would be welded.

The mixer drawer would fit in the space below the handle and above the aluminum cross piece. The idea is that very deep mixers, like the Yamaha O1V or Mackie Onyx, can actually protrude slightly past the frame when the drawer is closed. Although the drawer might extend beyond the frame, the component continues to be protected by the handle and the wheels.
A closer shot of the frame arms supporting recorder platforms. The slide-out platforms would be affixed to the shock mounts (those red and black thingies) mounted in the arms. This orientation permits using the platforms very close together so the cart can accommodate considerable equipment without being too tall. These arms are clamped to tubular frame pieces and can be adjusted up and down. One can squeeze the height down to only slightly more than the height of the gear itself.

The tubular frame pieces on the top part of the cart can also accommodate antenna poles for the radio mikes.
The suspension system. The prototype has fairly small wheels but allowances were made to mount larger wheels. The bar running across between the castors is intended as a footrest as well as a frame member. The castors here are bolted to the frame because we are waiting on a parts delivery. In the production cart even the castors will be spring mounted.

A metal basket will be fitted to hold batteries and power supplies.
The mixer drawer is designed to fit mixing panels up to Yamaha O1V size. Here we see it in the open position with a Mackie mixer. This particular unit is not likely to be a popular choice for location mixing but it's approximately the size of the Yamaha or the Mackie Onyx and give us a feel for how everything fits together.

The keyboard drawer pulls out from under the mixer drawer. Alternate configurations are also possible
This view shows the mixer drawer in the closed postition. The black doughnut in the red metal frame is one of the Lord shock mounts.

The two knobs visible in the foreground (along with two knobs in the background) permit separating the upper frame (with the mixer and recorders) from the lower frame. We expect the implementation in the production model to be more elegant than in this prototype.
A new mixer drawer utilizing perforated aluminum with a narrow frame. This design revision yields considerable weight savings.

The vise clamps permit testing the sliding action of a recorder platform on drawer glides.
A pipe clamp sitting in the new mixer drawer. These clamps were used at an early stage of the prototype construction to mount platforms to the support columns. Chinhda has a new, proprietary clamp but he's asked me to ease off a bit on sharing development details. You'll have to wait until we have a complete cart to show to see how everything fits together.
The NAB Cart

This is the prototype cart taken to NAB and exhibited at the Cooper Sound booth. (With thanks to Andy Cooper and also to Peter Weibel)

It's fitted with three platforms: a mixer drawer (with pull-out keyboard sub-drawer), a recorder drawer, and a tilting utility platform. These may all be adjusted for position by loosening the clamp and sliding the platform up or down the frame poles. Any number of platforms may be attached, depending on equipment needs. All of the platforms are 18 inches wide. The mixer platform shown here is 24 inches deep to accommodate the big Yamaha 01V panel. The standard mixer platform will be 18 x 20, a bit smaller but still large enough for a Cooper 208 or the new Sonosax panel.

The black box visible in the lower frame area is a mounted rack drawer.

Cable and headset hooks are mounted to the recorder platform but can be attached wherever and individual owner prefers.

The upper superstructure can be detached from the base unit for use in insert cars or boats. It's also possible to disassemble the upper structure for shipping. The whole business can come down to three nested trays, two poles, and some hardware that could easily fit into a shipping case.

We are exploring having clip-on case lids for the base unit that would permit it to be shipped without crating.

A swing-out laptop platform is under development.
A closer shot of the backside of the cart showing the handle, the attachment brackets and the knobs that can be eased to slide the platforms to any desired position.

The ends of the handle will be fitted with rollers, probably in-line-skate rollers, for ease in maneuvering the cart into a station wagon or SUV. With brackets securing the equipment to the platforms, there is no necessity for the cart to ride upright. Lying it down permits transit in ordinary vehicles.

mouse over for a closer view
 This is a patch panel that Chinhda is making as an accessory for the cart. It is set up to handle both audio signals and power. Five individually fused XLR connections can supply either 12 volts or 24 volts from a single input. An LED readout provides a constant voltable monitor. There are also up to 16 audio inputs to facilitate making connections to the mixing panel.

This ratio of 5 power to 16 audio connections is entirely arbitrary. The client can specifiy how many of each should be fitted.

mouse over for a closer view
 We're trying to extend the versitility of the cart by providng for rack mount recorders. We have a DV-40 mounted up here. A number of mixers are beginning to use the Fostex 824 as a field recorder in preference to the PD-6 (or perhaps along with a PD-6). In any event there are a number of applications where it would be useful to have rack-mount gear above the base section of the cart and protected by the same shock mounts that protect other gear. The rack mounts are suspended below the shelf holding the Nagra V and benefit from the protection of the same shock mounts. However, the rack equipment is stationary; it doesn't move when the shelf holding the Nagra V is extended.

The backside of the patch panel is also visible here.

We've made some changes to the design since NAB and after some production experience. To see the production cart in its present state, go to:
Cart Update
To see some of the other articles on the Cart Project, use the "jump button:
© 2005 by Production Recording