Bearhawk Aircraft Bearhawk Tailwheels LLC Eric Newton's Builder Manuals Bearhawk Plans Bearhawk Store

Announcement

Collapse
No announcement yet.

LSA140 Build

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Regarding welding cheater lenses; A number of years back, I noticed that my welding skills were degrading. Strangely enough, I decided to replace the clear cover lenses and voila! I could see the weld process better and my welds improved. Imagine that. The cover plates were so messed up, I could barely see through them. Who'd have thought that would be a problem... At that point, I figured I'd try my reading glasses, under the helmet. The welds improved further! Now, don't get me wrong; I'm not a great welder, but I can hold my own, when I can see the puddle. No matter how great your equipment is, if you're not in a comfortable position and you can't see the weld, your welds aren't going to be optimal. My helmet doesn't use standard size lenses, so I can't put a cheater in it. But reading glasses, a notch or two above what I read with, work just great.
    Moral of the story; Don't sweat getting the perfect cheater lenses. Reading glasses work fine.

    Bill

    Comment


    • Great info Bill. I wear glasses for a slight astigmatism. This spring I ordered a pair of glasses from Zenni Optical for under $40 shipped. I use these for work and in the shop. I have been meaning to order another pair with some magnification. Some of those clusters keep your helmet a little far away to really see what is going on with the weld. I'd highly recommend getting set up right with your helmet/vision before welding an airframe. It is well worth the time and effort.

      Comment


      • Anybody tried these inside a welding helmet?

        https://www.walmart.com/ip/Hydrotac-...=1105544726399

        Comment


        • O[QUOTE=bergy;n25980]Anybody tried these inside a welding


          I use them in my helicopter flying helmet to see the gauges. For me personally, I don't think they would be terribly helpful in the welding helmet. Too small of an area.

          Comment


          • *Note: Deviation from plans. Changes to the LSA shown here have not been approved by the designer.

            Should be finished with the additional fuselage tubing to accommodate the gear modifications tomorrow. I'm welding some of the joints as I go for ease of access.

            Comment


            • Originally posted by Bdflies View Post
              Don't sweat getting the perfect cheater lenses. Reading glasses work fine.

              Bill
              Yep; I think this is a good idea, what I do as well... inside the helmet I use the full-sized reading glasses in the correct diopter, I've tried the smaller "look-over" glasses that are popular, but seemed like they were always in the wrong spot, so I use cheap, full-sized... although once the helmet is off, I'm immediately "blind" until I take the glasses off...

              Comment


              • Bcone1381
                Bcone1381 commented
                Editing a comment
                x2. When I am having a "welding day" I am going back and forth between my regular bi-focals and welding goggles with my strong reading "Welding" glasses. Its common to light the torch, put the goggles on, and get ready to resume welding only to think "Why can't I now see?"...shut everything down, take off the goggles to clean the lenses only to find that they are not the reading "welding" glasses rather my bifocals...another frustrating Alzheimer's moment.

            • Hey LSA140!

              Haven't seen you in a while. Whatcha been up to?

              Bill

              Comment


              • Bdflies Your Patrol is looking great! Thanks for checking in. I chose to hit pause on the LSA build around a year ago after encountering a couple concerns with the project. I'm just now revisiting the build and deciding how to proceed. A big thank you to bway for the excellent flight testing reports on the LSA. It's been good to get caught back up on the forum and see everyone's progress. More on this later.

                However, I've been busy in the shop as usual. The most recent project has been setting up a small CNC router and designing/building a set of skis for the RC plane.

                Happy new year!

                Last edited by lsa140; 01-01-2018, 12:56 AM.

                Comment


                • Thanks about the Patrol! I enjoyed every minute spent building and now enjoying flying it!
                  Very cool skis. I can see many possibilities with that router...
                  "couple concerns"?

                  Bill

                  Comment


                  • The router is just big enough to mill out a instrument panel for the LSA. It makes quick work of thin aluminum with the right bit/rpm/travel and leaves a very nice edge. I went to work at a local machine shop running a CNC lathe when I was 16 and have been fascinated with the tech since then.

                    Comment


                    • JimParker256
                      JimParker256 commented
                      Editing a comment
                      Is that one of those infamous "Bit Coins"? LOL (Just kidding, of course.)

                    • lsa140
                      lsa140 commented
                      Editing a comment
                      I wish! I could use a few of those.

                    • sbmurphey
                      sbmurphey commented
                      Editing a comment
                      LOL....If any one wants to participate in a Bearhawk build with bit coins, here is an address for my project

                      18mVfR9hR6rnw2XutCZR8FgqHKXBuyk94M

                  • I was disappointed to discover quite a few of the small parts I had fabricated developed surface rust over the last year despite being inside and dry. After some research I went by O'Reillys and found a can of Rust-Block from the same company that makes Evapo-Rust (great stuff). It is a non toxic indoor rust inhibitor that dries to a clear mat finish. The product can be rinsed off with warm water when you are ready to continue fabrication or paint. I tested it on one of my axles and expedited the dry time with a heat gun. It sprays out clear and dries to a non tacky surface.
                    Last edited by lsa140; 01-03-2018, 05:43 AM.

                    Comment


                    • I found a 3D model of a C-90 and imported it into Rhino. It has some dimensional error but will work for what I need. I'd like to design a nose bowl and carve out a mold on the CNC when the time comes. Cut a vac foot out of MDF and will build one out of HDP/acrylic once the design is dialed in. Tried milling some thick 6061 and it went better than expected. The finish isn't what you'd get with a milling machine/better tooling but it will work just fine for some axle/brake disc spacers.

                      https://grabcad.com/library/continental-c90
                      Last edited by lsa140; 01-04-2018, 07:40 AM.

                      Comment


                      • *Note: Deviation from plans. Changes to the LSA shown here have not been approved by the designer.

                        Working to wrap up a couple projects to make room for the fuselage coming down off the shop ceiling this week. I've taken some time in the evenings to dial in the extended gear design. It was interesting to run tubing load calculations on the stock LSA landing gear and cub gear. The rear tube on the Bearhawk gear carries a tremendous amount of compression when the gear is loaded. The shallow angle between the gear strut/landing gear leg on the Bearhawk loads the strut quite heavily when compared to cub type gear. This is evident when looking at the cub's small single tube external landing gear cabane vs the Bearhawk's much more heavily constructed internal truss that carries the gear strut loads.

                        I've opted to move the gear strut loads to an internal inverted pyramid truss centered on the axles. This drops the strut attach point down, increases the angle between the gear leg/strut, and allows a wider gear stance/additional gear travel. This also splits the compression loads evenly between the two gear leg tubes when loaded. The belly will be slightly deeper to accommodate the truss. It has taken a significant design effort to be comfortable with making these changes and I do not advocate or suggest doing so. In short, follow the plans! I have some specific and unique needs that warrant the time/effort.
                        Last edited by lsa140; 01-10-2018, 08:29 AM.

                        Comment


                        • jim.mclaughlin924
                          jim.mclaughlin924 commented
                          Editing a comment
                          I like your modification. It reduces the gear leg and strut loads, simplifies maintenance and opens up a congested area where the struts attach per plans. Are you going to go with a softer spring and increase the strut travel?

                        • lsa140
                          lsa140 commented
                          Editing a comment
                          Yes, to get comparable travel/rate to the stock gear I would need a slightly longer/softer spring because of the geometry change. Dayton and Danly both have a very extensive catalogs with detailed specs. I'd like to gain a little travel and have a larger margin before the travel bottoms out in an extreme drop. The big tires help as well.

                      • *Note: Deviation from plans. Changes to the LSA shown here have not been approved by the designer.

                        Spent some time this evening really digging into the spring specifications, gear geometry, and load calculations. I found this video of a Cessna 180 clearing some pylons and coming down hard on the gear! It looks like he tried to come in with power to slow his descent and the engine was loaded up from the slow approach. It's impressive the Cessna gear can handle a hit like that... I wonder what the gearboxes looked like afterwards.

                        Comment


                        • The fuselage descended from on high and landed in the rotisserie this afternoon. Unfortunately I found the tube in front of the spar had been damaged and needed to be replaced. I had one side of it fully welded so it took some creative slicing with the 2" cutoff wheel to extract the it. After some grinding and fitting the new piece is in place and it felt great to have the TIG torch in hand again.
                          Last edited by lsa140; 01-13-2018, 01:16 PM.

                          Comment

                          Working...
                          X