jschuber

I put this 30 gallon double drum heater together in about 1982 and I don't see any signs of it rusting through or doing anything bad. The garage is 26' x 26' with a 11' ceiling and I can get most any temp I want in there. I ran it up to 110 for 6-8 hrs to sort of post cure my wings but I'd not do that again. The walls felt hot! They probably should have at 110 but I was really nervous about it. The 55 gal drums are monsters and good for heating cattle barns, I'd think. For more even heating, I have a 20" box fan on low to circulate the heat. Using the double drum really improves the efficiency and lowers the stack temp. I run the triple wall stainless chimney at 400F when staring the first fire and warming the place. After that initial demand, the chimney temp for maintenance runs about 250 on a zero day - depends on insulation & leaks. I'd not make a habit of running pine as the resin accumulates and you have to clean the chimney out to prevent a chimney fire. 400f temps seem to keep the resin hot enough that it leaves the chimney before it is cool enough to deposit on the chimney ID. If you are not familiar with running a wood stove you might want to read up on all that before spending money on something that you do have to fiddle with occasionally. It isn't like natural gas where you set it and forget it. There is VERY little ash to ever clean out. I used to clean it out every summer and there was maybe 2-3 5 gal buckets of fine ash by then. It is good to leave at least 1" of ash in the bottom as it insulates the drum from the heat , they say?? Pic is in my dirty area and I'm starting to contour a cowl mod. - very dusty & dirty!

The main gear strut shimmy you refer to is generally caused by the disc not being perpendicular to the centerline of the main gear axle. As Marc noted, a warped disc is the frequent culprit. The shimmy is caused by uneven pulsating braking, even when consistent pedal pressure is applied. The brake pads make intermittent contact with the pads, thus producing the pulsation. If the caliper is stationary and the disc wobbles back and forth between the pads, brake friction will be intermittent. Each time the brake "grabs", the wheel's axle is pulled slightly aft. Since the brake pad is located at a moment away from the center of the main gear strut, the wheels are rapidly "steered" away from the desired toe-in position into a toe-out position. As the wheel and disc continue rotation, the brake pressure reduces and the axles snap back to toe-in alignment. That toe-out tends to spread the gear strut slightly and on a pulsating frequency. The wheel/tires end up moving in and out as well as having a pulsating brake action. A lot is going on in multiple directions and not much is good. If this severe oscilating and pulsating action is allowed to continue for an extended period, it can cause damage to a landing gear mount that was not very robust to begin with. Remember, most of the Long-EZs, VariEzes and Cozys are operated above the original design weights. (See previous post on landing gear attachment upgrades). It would seem that to avoid main gear vibration no run out can be allowed on the brake disc. However, there is frequently more to the situation than that. I toured the Cleveland Wheel & Brake factory near Cleveland, OH some years ago and talked to one of the assembly inspectors about disc run out and that, what seemed, an excessive amount was frequently found on Cleveland parts. I was amazed when he showed me the allowable runout spec. I don't recall it now but I thought it was blacksmith wide at the time. The inspector said the frequent problem for brake pulsation on flexible landing gear struts, like our glass one or the RV tubular ones, is not caused by just disc run out. In fact some run out is expected during heating from high energy stops. The culprit is sticky torque pins. The calipers MUST be free to move around on the pins and follow the rotating brake disc as it wobbles back & forth applying consistent friction on the disc. The reason the pins stick is they are dirty. Even slight brake dust mixed with ANY wet lube (anti-seize, oil, grease, etc) will attract the dirt and make a sticky substance that slows or even blocks the caliper's abiity to move rapidly and freely on the pins. That lack of caliper/pad freedom to move is what causes the pulsation and brake shudder. The harder one brakes, the more severe the shudder becomes since the brake friction is higher. In some cases the prake pads get broken in pieces also due to the tensile loads. The fix is to be absolutely positive that the brake pins are perfectly free to move with the slightest pressure. They should literally rattle when you cross the floor to ramp bump going in or out of the hangar. The torque pins and holes should be smooth, CLEAN and DRY, lubricated with a dry lubricant like Spray Silicone Lubricant. Do NOT USE ANY GREASE OR OIL PRODUCTS. Obviously one MUST not get any silicone lubricant on pads or disc. Some folks insist on attaching solid metal brake lines to the Cleveland calipers. That frequently reduces the ability of the caliper to move freely. If you must connect the caliper directly to metal lines, put a large loop in the small diameter line to allow movement or install a flex line between the metal supply line and the caliper. Happy smooth stopping, Terry Schubert Central States Association Newsletter Editor & Publisher Long-EZ N9TS 4000+ hours

The VariEze, Long-EZ, original Cozy and Cosy Classic used a landing gear bow attached to the fuselage though extruded angles and bolts. That system has proven to be marginal in the long run due to over loading. Certain changes, especially for new construction, are smart to include. The original design was probably adequate for the original designed empty weights, but I know of no VariEzes/Long-EZ that were built to Burt Rutan's original design weight. Several mods will help transfer the landing gear load to the fuselage structure. If you are too far along to do them all, do what you can, as some help is better than none. You'll be limiting the number of weak spots. I'll list them in construction order. Back when building the fuselage sides, consider substituting a hard wood (oak-maple) for the spruce when making the LWX & LWY hard points. The soft spruce easily crushes when heavy landing gear loads hit the soft spruce/AN-4-16A joints. The crushed spruce causes loss of clamping force and starts the gear movement process. Loose extrusions also allow bending of the AN-6-80A mounting bolt. Once bent, the main wheel geometry gets misaligned and when that long bolt gets bent, it is EXTREMELY difficlult to remove. Look at the attached pic, flox donut2 Plans call for AN 960 washers to be used under the heads of the 16 AN-4 bolts extrusion mounting bolts. They have proven to be too small to adequately spread the bolt loads to the soft spruce hard points. It would be far better to use wide area washers (AN-970) so as to spread the compression loads. They are used only under the bolt heads. If you have a project, it is wise to replace those washers if the fuselage has not been painted. You will have to remove the bolts and do a local glass repair over the bolt head area. If the 16 extrusion mount nuts were over tightened and the spruce hard points crushed, you may have to use shorter bolts to get proper clamp up length. Note how the AN-4 bolts in the pic all show excessive threaded area. Typically there will be only a few threads exposed. That excessive thread area is probably due to over tightening during construction. This pictured project is being buit with a serious landing gear flaw and will probably result in early landing attachment problems. These are quite difficult to fix on a flying airplane. Look for that thread clue when buying a project or even a finished airplane. The aluminum extrusions were originally constructed with no bushing to transfer the long 3/8" diameter 80A bolt loads to the extrusion. The softer aluminum extrusion's bolt hole soon gets hammered out of round allowing strut movement . That can be noted by aluminum dust around the bolt/extrusin joints. The fix, which was later accomplished on most extrusions, is to install a flanged bushing in the extrusion. That spreads the load on the extrusion holes and allows longer life. The strut is attached to the landing gear tab & extrusions via the 5/8" diameter LMGA assembly. Be sure to assemble it and the 80A bolt with anti seize product. Steel bolts and steel bushings in a hidden potentially damp area will soon grow fast and will be a nightmare to remove or even tighten later. The LMGA assembly is attached to the strut with a drilled hole process and flox. That is a failure area which can be easily eliminated by inserting a flox donut between the strut tabs and the extrusion face. Note the large space between the inside of the extrustion and the outer faces of the strut tabs. see flox donut2 Any sharp impact from landing load or hitting a chuck hole can crack the LMGA assembly loose from the strut tabs and start a sliding process that gets worse with time. The fix is to grease the steel parts area so you can get it apart at a later day and construct a flox donut to fill that void between the tab & extrusion. The donut is loaded in compression and not a structural member so don't panic about trying to get the cleanest extrusion or tab face when installing the donut. It is a sloppy process. I lay out a piece of Saran Wrap about 2" wide and 6-8" long and put a blob of flox in the center about 1" wide and 2" long. Then lift both ends of the Saran up with the flox touching the bolt & bushings and sort of pat the Saran around the bolt so as to form a hard donut that will spread the impact from tab to extrusion faces. This will help prevent the landing strut shock from breaking the LMGA assembly loose from the strut tabs. These changes are easy and fast during construction. If not caught then, they have proven to be airplane grounding and major repair issues later. Terry Schubert CSA Newsletter Editor/Publisher Long-EZ N9TS, 4000+ hours with NO gear problems This post has been promoted to an article