Thanks for your interest in the Kobra Hollowing System. At the present time all of the units under construction are spoken for, but Jerry and I will be starting another run soon. Below are links to two videos, on youtube.com, of our system in use. The first one is intended to help new owners assemble their units and start hollowing. The second video completes the project started in the first and explains the use of the laser to establish a uniform wall thickness which follows the outside contour changes.
The basic Kobra hollowing system consists of the four knuckles and a mounting post, the mounting ring and rectangular plate which sit directly on the lathe bed, and a clamping plate to lock it to the lathe. This last plate is machined specifically for your brand and model of lathe as no one plate would fit all lathes. The Kobra head is bored to accept 1” diameter boring bars, but smaller sized bars can be accommodated by the use of adapters. There is a maximum of 12 inches of travel each side of the post centerline, which means there are about 21 to 22 inches of easily usable overall travel in the unit. Each movable joint rotates 360 degrees on thrust bearings which are capable of supporting your Ford F-150 pick up truck but still allow the tool to move like a puck on an air hockey table. Each unit is shipped with a tool rest of our own design. It uses the banjo for support at one end and has another support at the other end with an adjustment to keep it parallel to the lathe bed.
We manufacture a case hardened tool rest, which is supported on both ends for safety and rigidity, to use with our 1” boring bar which is also hardened. This boring bar comes with three interchangeable tips. They present the tool at 0, 22, or 45 degrees to the bar centerline. The tips come with a square hole in them for you to insert a square tool bit into, and the bit is held in place with a setscrew. You may order the tips for use with either 3/16 or _ inch tool bits. The hard round boring bar riding on a hard round tool rest bar means that as time passes there will be no nicks or dings in the tool rest or bottom side of the boring bar which would impede the smooth movement of the tool over the rest. We are talking MINIMAL friction here. This hardened tool rest is available only as part of the optional upgrade package of rest, boring bar, and quick change tips. The price for this optional upgrade is listed below. Your hollowing rig will be shipped with a toolrest which is not hardened unless you order the hardened boring bar/toolrest option.
The laser system is very compact and is one of the cleanest on the market. It uses three AAA batteries to power an industrial laser. No more long unwieldy laser pointers to thread between the supports of your steady rest or to replace when the springs inside give out. The wiring is all contained within the laser bar and the built in battery box has the switch located on the bottom side to keep out debris and dust. It uses a “one knob tightens everything” design which is like the one first written up in the American Woodturner by Bruce Hoover. Bruce told me in person that ours was the best adaptation of the idea that he had ever seen.
Beginning in 2010 we are discontinuing the 4x7 Kobra mounting plate. The Kobra will only be available with the large mounting plate which will allow you to position the main support post in one of 5 positions: on center with your spindle, 3” either behind or in front of the lathe bed edge., and about 1” + or – both sides of the lathe spindle centerline. The mounting plate comes now with one socket for the main post. The old two socket plates were a manufacturing redundancy which added nothing to the versatility of the Kobra.
Also new for 2010 is our “Top Drop” mounting system. This allows the user to install or remove the Kobra without removing the tailstock from the lathe or having to reach under the bed to engage the clamping screws with the bed clamp. Another recent addition is an option of non-hardened 5/8” boring bars with quick change tips. This set comes with three bars of 7”, 10”, and 13” lengths and three tips. The tool bit is presented at the same 0, 22, and 45 degree angles as the larger tips. A _” diameter boring bar which is tapered at the working end for use with these smaller tips can be produced also.
Adapters to allow use of any smaller diameter bar in the 1-inch bar socket of the Kobra are available as options.
If you are a “snowbird” and have access to a Jet mini lathe while in the South, ask me about the Snowbird feature of the Kobra. We can fit the unit on this small lathe for your hollowing pleasure
Kobra Pricing
Basic Kobra with 5 position mounting plate and top drop clamp----$675
Hardened boring bar with three tips and hardened “goal post” support----$140
Laser System with batteries and mounting post----$140
Adapters for smaller sized boring bars----$45 each
We realize that this may be an inconvenience to some people, but we are no longer accepting credit cards as payment. Payment must be by check or money order.
If you have more questions we welcome the opportunity to answer them for you. You may contact us either by phone or E-mail. Again, we encourage you to go to the links below and watch our “baby” at work. Notice how vibration free deep hollowing can be.
Al Crandall
alkaron@indy.net
317-485-5129
Jerry Arnold
earlygrandpa@yahoo.com
765-534-4437
http://www.youtube.com/watch?v=iwcx-T6UnZ0
http://www.youtube.com/watch?v=8B8HG5tLM04
