Peter Haas (films.peterjhaas.com) from NYC ordered a customized DSLR CAT Rig several months ago, and sent us these images and his positive feedback after using it on a long documentary shoot. Here's what he had to say: "I have to say, this is by far the most comfortable rig I've used - the weighting was spot on, and there where many times where it one could easily forget it was a DSLR rig and not an Aaton. At the price point that you're offering this thing, I think you could rack up a good amount of sales. The over-all size of the rig is great, the grip on the side of the camera feels like it's exactly in the right spot. The leather strap was really comfortable, and it made the longer verité shooting days a lot easier. A great thing we discovered: since our view finder came with the swivel HDMI cables we were able to run the cable through the X bar and tied it down with some plastic clasps. We also added some biker's grip to the handle (about $15 will buy a lot of grip tape) to make it a little more comfortable when doing some low-angle shooting. The Zacutto viewfinder mounted brilliantly to several of the mounts. We found that depending on the "style" of shooting we wanted to change where we mounted the eyepiece, so having a number of options really saved our bacon a couple of times in tight spaces. You might consider adding another mount, or quick-release plate to the bottom of the rig, one that would allow the user to slap the entire rig onto a tripod. We tended to put the camera on the lower mount, for the 7D especially it seemed to balance best; for the GH2 we would move it around depending on the lens we used. Brilliant job man, I plan on getting a blog post up about this next week. We're going to be attending a documentary convention in November and will definitely be showing off the rig as part of our gear package!" #dlsrcat

Tormach offers a power drawbar option for $1200. After already spending a chunk of change on the machine and other accessories, I found it hard to stomach to pay another $1200 for what amounted to be an air cylinder, air valve, and some machined steel plates and hardware. Also, I design machinery with pneumatic automation and have cylinders, valves, etc lying around just waiting to be used for a project like this. Tormach uses a 3 stage air cylinder with a bore diameter of 100mm. The part# of their air cylinder is CQ2B100x12-3, and it's made by a company in China called XINYIPC. These cylinders are a copy of the SMC CQ2 series cylinders. Basically, they've taken 3, 100mm bore by 12mm stroke air cylinders, and stacked them in series to multiply the force times 3. I considered a few different options of making a power drawbar that would work with the TTS tooling system. At first, I considered using an impact style drawbar, like is commonly used with Bridgeport style milling machines that use an R8 taper. This is a proven, effective, cheap method to change R8 tooling. I spoke to someone who had done this for their Tormach, and later switched over to Tormach's power drawbar solution, and said that theirs was by far better. The main problem he had was stripping the drawbar bolt, and he was spending too much time keeping the thing working. This could probably be resolved by improving the lead-in for engagement and only activating the impact wrench once properly engaged. The problem I was trying to figure out (without having the mill available to test the idea) is how to loosen the collet just enough to allow the TTS tool holder to slip in and out, without the impact driver completely unscrewing the collet from the drawbar. There needs to be something that limits the rotation. I may experiment with this later to see if I can find a solution. The second idea was to use an air cylinder that I already have that has a smaller diameter than what Tormach uses (100mm), but a longer throw, and use a lever to increase the applied force. Although not that difficult to build, it is still more complex than what Tormach has achieved using 3 stacked cylinders. Not yet having the mill at hand to take measurements, it was difficult to design something that I knew would fit. While waiting for the mill, I did a little research on CQ2B100 air cylinders. SMC, the original manufacture sells a 15mm stroke for about $230. Take that times 3, and add the time machining open the backs in order for the rod end to push the piston of the next cylinder, machining grooves for o-rings to seal between them, and you may as well pay up the $1200 for Tormach's solution. From China, the cylinders can be purchased individually for about $25 each. I spoke with a vendor, and they said that they could make a 3 stage version for $125. Although I was interested in trying to make my own from individual cylinders, I thought that having them make it may be better since they have more experience. Of course, shipping cost more at $130, but it's worth a try. Looking at this cross-section, it appears to me that it would not be difficult to machine a hole in the back of the cylinder, machine a groove for a seal, and sandwich the air cylinders together. 3 Stage Cylinder Arrives! And it's just what the engineer ordered! This is a nice-looking, hefty cylinder for the price. Matches my specs, now we need to make the rest of the parts. Machined Spindle Pully Nut A new spindle pully nut had to be made that has a flange that the cylinder mount could grab onto when the cylinder is compressing. This eliminates any force applied to the spindle bearings. Since these were steel parts, which I did not have a lot of experience machining, Helton did all the machining of these parts, and I assisted and learned. Replacing the Spindle Pulley Nut Eccentric mounting pin An eccentric mounting pin is used for fine tuning the position of the cylinder and cylinder mount such that it does not touch the spindle nut, and is concentric with the spindle. So, How Does the DIY Power Draw Bar Work? It works great, probably just like the one that Tormach sells. I wouldn't want to be without it, it's a huge time saver. However, the retention force is not good for end mills over 3/8 in, and this is a problem that has been discussed on many forums. At the recommended tension (2.5 turns of the drawbar after hand tight), it took about 95psi to release the tool. The pull-out was horrible with a 1/2inch tool. I would have to go back to the original drawbar, and hand tighten in order to use a 1/2inch end mill without any pull-out. I did a few things that greatly reduced (but not totally eliminated) the pullout. How did I reduce the pull-out? I have the release pressure set pretty high, in the 120psi range. This means tightening the drawbar more than 2.5 turns Ditched the Tormach TTS Collet, bought a Hardinge 3/4 R8 Collet, and ground the face down to allow clearance for the TTS Collets. This was a huge improvement in retention. Added an additional Bellville washer pair, so now there's a stack of 4 pairs. This increased the travel, allowing the collets to release easier under the high force. Always make sure that the TTS shanks are clean, dry, and free of lubricant. Keep the collet inner faces clean. Based on this experience, I don't believe that an Air Piston/Bellville washer power drawbar is the best design for the TTS-style tool holders. The Bellville washers allow the tool holder to be pulled out, even when providing the theoretically necessary retention force. Tightening a rigid drawbar to the correct torque provides much better retention. This leads me to believe that a torque-type power drawbar would be better. I may consider replacing this drawbar in the future with an impact-style power drawbar. The downside is that the hex at the top end of the drawbar tends to wear out.

The Giottos M621 Quick release provides a solid, adjustable attachment of the camera. It even has bubble levels. Compared to the Manfrotto quick release, The Giottos works better with DSLRs because the sliding plate is centered with the base. The Manfrotto has a ~5mm offset, which I believe is designed to work with video cameras. The Canon video camera that I use has the tripod mount screw offset from the center of the lens.

The DSLR Cat is designed to move the weight of the camera back and over the shoulder, thus making a more well balanced rig that requires less counterweight. The overall result is that the whole rig is lighter, and is less tiring to keep on the shoulder for long periods of time. The downside is that the screen on the DSLR is not visible, so an EVF or external monitor must be used. The handle of the DSLR Cat is modeled after the handle used by the Aaton cameras, which gives good control of the whole camera rig using only one hand. The other hand is free to control focus, zoom, settings, etc. The handle is 3D printed. The shoulder pad is made from comfortable leather. It's attached to the rig at the ends, and space is left between the leather and the rig, to suspend the rig over the shoulder, so that no hard surface is touching the top of the shoulder where the weight is bearing down. There are 2 levels at which the camera can be mounted. The lower level mounts the camera ahead of the shoulder, and leaves more room above the camera. The upper level mounts the camera directly above the shoulder. This is especially useful for zoom lenses, as it balances out the weight better. The DSLR Cat can also be used for other video cameras, like small handycams. The handcam is positioned further away, so that the flip out screen is visible. The top rail can be used to support a microphone, since most handycams don't have a full size hot shoe. #dlsrcat

We used the Fiber metal laser engraver to engrave the logo of our capoeria group, Maculele, and the members names on the back side. The metal was brass, cut and machined by Magrao.

Note: This tutorial shows how to make a shoulder pad using the DIY method. The shoulder pads on production KRIGs are made using more highly repeatable methods using laser cut foam and metal. Cut out a piece of aluminum 3in wide by 12in long. The aluminum must be thin enough to bend into a curve to fit the shape of your shoulder. Find a piece of thick foam that will make a suitable shoulder pad. Mark out the size of the foam using the aluminum piece, leaving a 1/4in extra border of foam around the aluminum. Bend the aluminum into a curve that approximately fits over your shoulder. Use 3M Super 77 spray adhesive to attach the foam to the aluminum. Spray the adhesive onto the aluminum, and quickly apply the foam. Press the foam onto the adhesive for a few minutes to ensure a strong bond. Mark the center, and then mark 2 drill holes 8mm to either side of the center mark. These are the screw holes for attachment of the shoulder pad to the rig. Drill out the holes, passing all the way through the foam. Careful not to tear the foam, as it may have a tendancy to wrap around the drill bit. Insert screws through the foam side, and place T nuts on the other side.

Changes from V1.0 Addition of industry standard 15mm rail adapter. Accessories that work with the 15mm diameter, 60mm spacing rails can now be attached to the rig. New hand grips. Using Mushroom style bike grips. These are comfortable, nonslip, and the mushroom cap rests on the top of your hand. Foam shoulder pad, comfy Handle and microphone support that goes above the camera Added counter weights. Aluminum bar stock for now, but need to find something better. Mounting for Zoom Mic, or other 1/4-20 threaded accessory using an angle bracket. Installed a Manfrotto 577, which was a royal pain, because the screw holes in the base are not lined up with the camera attachment screw on the quick release plate!!! The plate centerline is offset to the left from the base centerline by about 5mm. Very frustrating. Will order a Giottos MH621 next, because it costs less, and is centered. But, it's not plate compatible with the Manfrotto. In the video below we're testing the amount of weight and placement necessary for a balanced feel. The weight will eventually be closer to the shoulder, and lower.

Built a new KRIG using black anodized extrusion. This is going to be used with a Canon video camera that has a flipout style screen, so it does not need an extra offset bar to suppor the camera in front of the cameramans face as with a DSLR. The handle going over the camera will also support a boom mic. Changes from V1.2 It's black. 2 thumbscrews being used to hold on the counterweights. One thumbscrew clamps a small flat piece of aluminum in front of the weight to keep it from sliding too far onto the frame. The other thumbscrew threads into the end of the frame, and clamps the weight. Thumbscrews are from McMaster, part # 6390K51 Metric Phenolic Four-arm Knob, M5 X .8 Threaded Stud, 15 Mm Stud Length, 25mm Dia Added Handle/Mic Mount using two 150mm lengths of extrusion, and the adjustable side brackets.

The counterweight system is much improved in this version of the Krig. Readily available barbell weights with 1inch center holes slip perfectly over the 20mm t-slot extrusion. The tail of the rig is height adjustable. It can be raised to put the weight further back and increase the amount of counterweight. Or it can be lowered for greater stability, and shooting in tight quarters. The weights are held in place with a screw and t-nut used as the stopper, and a screw and washer in the end which clamps the weights against the stop screw. The offset camera rail option shown below allows the camera to be placed directly in front (or anywhere left to right) of the film maker. Don't need to crane your neck to the side anymore. It's a lot more ergonomic. Counterweights are now standard barbell weights with 1 inch center holes. Counterweights are position and height adjustable. 2 screws for the shoulder pad attachment instead of just one. Prevents the shoulder pad from twisting. Grips are Pyramid Black Ops BMX grips. Very nice, comfy, nonslip, and fit a larger hand. Seperate, offset rail for the camera. Positions a DSLR directly in front of the cameraman's line of site. Quick releases for the handles Laser engraved Logo and owner's name on the front. Changed to the Giottos MH621 Quick Release, which is much nicer and cheaper than the Manfrotto 577 Quick release. The Manfrotto 577 was also a pain to install, because the screw holes in the base are not lined up with the camera attachment screw on the quick release plate!!! The plate centerline is offset from the base centerline by about 5mm. The Giottos MH621 base and plate are perfectly aligned. Also the tighening thumbscrew is easier to use with a DSLR, because it only requires 1/2 turn to go from loose to tight.

These knife handle blanks were cut from 1/8 inch thick exotic hardwoods with the C02 laser for a woodworking customer in the Atlanta, GA area.

First build of the shoulder rig. Still missing several components, but just testing it out for size and feel. The camera mount also acts as a tripod mount.

This Eppendorf Easypet pipettor had several issues that were relatively easily resolved by opening it and cleaning the corrosion off some contacts. This video covers several common issues with these, and how to fix them.