Herr engineering: Mini-Floats

Model Airplane News, Nov 2001 by Randolph, Randy

MODEL AIRPLANE NEWS PRODUCT REVIEW

A laser-cut kit for small models

I am lucky enough to belong to a club with a very nice 50-acre lake just off the north end of its concrete runway, so I've had lots of practice building and flying float- and seaplanes during the long, hot Texas summers. Since my primary interest is in small model airplanes, most were in the .049 to .061 size engine class. I have built floats from foam, balsa sheet, balsa blocks, plastic and even doped cardboard! If Herr Engineering had produced its Mini-Floats kit years ago, I would never have fooled with the things I cobbled up! The Mini-Floats look like the classic Edo type, work perfectly and are lightweight and easy and quick to build!

The Mini-Floats kit is simplicity itself with all of the laser-cut parts, sheet balsa, hardware and instructions packaged in a single plastic sleeve. The included hardware provides everything necessary to mount the floats on an airplane, with the exception of a length of Nyrod. The instructions are complete and explain how to mount the floats on just about any airplane that has conventional gear.

IN THE WORKSHOP

Following the instructions, I labeled the parts before removing them from their carrier. The construction of each float is of the egg-carton style; the top is pinned to the workbench, and the tabbed keel is glued to the slots in the top. The construction is completed when the bulkheads are fitted and glued into matching slots in the keel. I did this just as instructed and ended up with a straight, true, basic structure. While the tops were still pinned to the building board, I added the laser-cut sides as instructed and held them in place with pins until the glue had set.

The instructions then tell you to sand the bottom of the floats (which are actually facing you at this point) to remove any bumps that would get in the way of the sheeting. I thought it was easier to remove the floats from the building board to sand them and then return them to the board for the sheeting.

Sheeting the bottom section of the floats aft of the step was very easy; just be sure that there's a good joint at the step. I used aliphatic resin glue for this and held the sheet in place with pins 'and masking tape while it set. Before sheeting the forward section, I trimmed each sheet to fit the curve produced by the keel's downward (upward when the floats are upright) sweep to the tip. I then sprayed the sheets with water, allowed them to dry a bit and cemented them into place. The damp sheets were easy to form, and the job proceeded smoothly.

With the bottom sheeting complete, I sanded the sides and sheeting flush and squared off the front and back of each float. Then I glued the provided balsa blocks to the front of each float and allowed the glue to cure. I used a razor saw to trim the nose blocks to shape and 100-grit sandpaper to finish them, as shown in the instructions. It took less than 10 minutes to finish the sanding.

After I had established the position of the attachment fittings on each float, I feathered the edges of each ply mounting plate so that they would blend into the top sheeting when the covering was applied, then I cemented them in place to support the fittings. The last step before covering is to drill an 1/8-inch hole in the aft end of one float and glue the plastic water-rudder mount into place, then sand it flush with the top and bottom of the float.

I covered the floats with Transparent Clear Oracover to match the airplane for which the floats were intended-a Speed 400-- powered version of my old Nickel. The finished weight of the floats, including all hardware, was 4.5 ounces; not bad!

I installed a water rudder, as the instructions dictate, even though I didn't think one was really necessary on an airplane of this size. I was glad I did because the plane maneuvered much more quickly on water; this is handy in somewhat restricted areas.

ON THE WATER

How did they work? Just fine! The Nickel's takeoff run was fairly long because of the additional weight and the water drag. The model was up on the step in about 60 feet and airborne in, another 25 to 30. Touch-and-go's were really fun, and the floats performed very well, even in a light chop. Landings on grass are smooth and didn't cause any damage. This winter, I hope to try them on snow-if there is any this year!

Herr Engineering, 1431 Chaffee Dr., Ste. 3, Titusville, FL 32780; (407) 264-2488; www.iflyherr.com

Hobby Lobby Intl., 5614 Franklin Pike Cir., Brentwood, TN 37027; (615) 373-1444; fax (615) 377-6948; www.hobby-lobby.com.

Oracover; distributed by Hobby Lobby Intl.