Build Log: MrPilotRon

[mrpilotron]

Most of the regulars here are also familiar with me on the Facebook page, but I am going to move to this forum as a build log that's easier to navigate and has FAR fewer advertisements jamming up the good stuff.

I first visited Chris at his Minnesota shop in March of 2022. I visited a few more times when I was in the area between then and November 2023 when I placed my deposit and formalized my order. I have an "F3++" ordered: Not quite an F4, but adding a few extra options like bigger tires, Black Max brakes, coil-over tailwheel, Oratex, and eventually a custom engine mount for my non-standard engine. I am also subtracting a few items though so maybe it's not an F3 after all. I plan to build my own wings, I don't want it powder coated, and I'll build my own dashboard. There's a good chance I'll end up with a half-naked covering scheme too. I am considering some changes to the main landing gear, but that will probably come as a modification after I get it flying.

While I wait for my kit, I've already started on the wings. Part of the reason I want to do my own wings is I'm not happy with using the front spar as the leading edge. The shape just isn't quite right. My CNC router makes building my own wing ribs a trivial task and I've included a slightly longer chord and the full correct Riblett airfoil shape. In order to make sure the airfoil shape stays true to form, I'm also including a formed, vacuum-bagged fiberglass leading edge similar to the Kitfox Laker Leading Edge option that adds 1,100 bucks to them.

[mrpilotron]

Here are some small sections of wing I'm building to show the difference between the normal wing profile vs the exact Riblett airfoil.

The small leading edge protrusion shown above adds support behind the fiberglass skins that will be formed from the molds shown later.

The standard wing might also benefit from a formed leading edge that wraps directly against the tube. I'm building a model of each so I can see how they each work out. Once I decide which way to go for sure, I'll build the full span wings.

These sheets of Baltic Birch plywood aren't exactly cheap, but I can burn through a few iterations of the ribs until I get the details just right. Unfortunately, I got a little overzealous and cut out enough to do a whole wing set before I remembered that this is supposed to be a small proof-of-concept first. I might have just made a bunch of kindling, or I might be prepared for the full build. It depends on if I like the results of my test pieces.

I'm not really happy with the way these pack together. Getting these foam blocks perfectly aligned and held in place while the epoxy sets up is a bit more challenging than I expected.

I did eventually get them "close enough" and sanded them to blend the minor imperfections. Once I skinned the whole thing with a thin coat of lightweight filler (aka: microballoons), final sanding and blending becomes a lot easier. These molds are the first step in creating the final leading edge skins. Once these are perfectly smooth and glossy, I will cast a fiberglass mold of these blocks that will become the female mold that casts the leading edge sheets. It's a copy of a copy process, but apparently that's the normal way fiberglass parts are created so I'm elbows-deep into learning this whole method of producing parts.

[Badland-F5 Pilot]

Very interesting. I've got to run, but will post some questions for you later if you don't mind? I like the modification to the leading edge of the wing. I was considering something similar but more like a slat, but I like your design.

Thanks,
Todd

[mrpilotron]

I made a little more progress on my leading edge molds tonight. I figured out a better way to cut out the pink foam for stacking so they hold themselves perfectly aligned. By cutting 4 holes with 2 of them slightly bigger than the others, I can pull the plug from the bigger holes and slip them into the smaller holes to act as alignment dowels. I sized them to have about 0.008 inches interference so they press in with some friction. These stacks got glazed like the originals and tomorrow I'll glue them together to make solid 54-inch molds that will get just a bit more sanding and final shaping before I use them to create the female molds that will then create the final products. I decided to go with 54 inches so there's plenty of trim on the ends to make each panel span across 2 bays of the wing with the seams landing centered on a rib.

[LA F2 Flyer]

Following this with interest...As much interest as your furry inspector!

A few questions - perhaps I missed something in the description, but why make the leading edge protrusion a separate piece from the rest of the rib?

And how will the larger chord affect the ability to fold the wings?

[mrpilotron]

Those are great questions. The leading edge protrusion is cut as a separate piece partly for ease of assembly, partly for better sheet utilization on the CNC table, and partly because I'm not sure it's even needed with the stiffness of the fiberglass leading edge. I might end up leaving it out to save some weight.

The longer chord should have little to no impact on folding the wings because most of the extra length is forward of the front spar. This will have more of an affect on stuffing it into an enclosed trailer since the folded width will be wider. The center of lift will end up moving forward about 2 inches which will help offset the extra weight of the heavier engine so I can make W&B easier.

[LA F2 Flyer]

I actually wondered if the size of the table on the CNC was the reason for keeping the leading edge separate...I hadn't even considered utilization of the sheet of ply (which you mentioned was quite expensive)...makes perfect sense! My only concern would have been the risk of the leading edge separating from the spar, but the foam and fiberglass serves to mitigate that risk, from the look of things.

Keep those pics coming. I am envious of both the skill and the patience to take on a project like this, so for now I'll just follow along on yours. LOL

[mrpilotron]

After doing some initial dry-fitting, it looks like I may have made a bunch of expensive kindling. I am still planning to make the test pieces just to get real test data, but I'm seeing a few "opportunities for improvement" in the fitting and alignments. I could probably make it work as-is, but I want the finished product to be better.

Here's my photo dump from the night. Notice on the smaller wing profile how much leading edge shape is missing when the front spar is used as the leading edge. I know the wing still flies just fine, but Harry Riblett was famously quoted as saying the first 10% of the airfoil shape is the most critical. I think that alone is worth doing the fiberglass leading edge cuff, even if you only used the first 5 inches of it. Also notice how easily the fiberglass will lay across the spar where it can be bonded to the spar for a little extra stiffness.

This shows setting the test panel in front of the foam molds to get an idea of the wrap onto the spar and ribs.

The large panel fitment is where the problems show up. With this much hanging out the front, it's really easy to misjudge how far back it should be stretched. I can see accidentally making the wing a half inch wider or narrower by simply pressing back a little bit on the cuff while setting it up. For this reason, I believe the little rib extension on the front of the spar is going to be critical for positioning the cuff properly.

Setting the small and large ribs together shows that I may have miscalculated how far forward to slide the center of the wing. My previous comment about moving the center of lift forward might be just barely true with this much tail sticking out the back. If I re-cut the large ribs, I'll probably move the whole rib forward about 1.2 inches, which will make that leading edge rib segment even more critical.

It seems almost comical to use a tape measure to show dimensions that were cut with precision less than .005 inches, but this gets the idea across.

[mrpilotron]

It occurred to me that I've been showing a lot of "what" and "how" on this project, but perhaps I haven't explained the "why" very well. My goal here is two-fold:
1) Provide a (perhaps marginal) airfoil performance improvement plus a (perhaps more significant) strength-to-weight ratio improvement for the true Part 103 builds. I think this can be accomplished with a lower overall parts count, lower finished weight, and faster completion time. I expect that there will be a tangible improvement, but we won't know for certain until I get a set of wings built and put them to the test. This wing upgrade will be exactly the same size as the standard factory wings and if it proves successful might become a factory option. I'm trying hard to stay out of Chris's way so he can keep welding fuselages, but I'm also keeping him in the loop on my developments. The first prototype will be tested to Part 23 Normal Category limits (+ 3.8G) at standard max T.O. weight of 550 lbs. I am completely aware that I may be violating Farmer Rule #1: "If it ain't broke, don't fix it!" I am also mentally prepared to abandon this leg of the project if the testing shows the change to have no tangible benefit.

2) Provide an optional bigger wing upgrade that has 2 extra inches of chord added to the wing and a bit more fiberglass structure that will not only shape the airfoil but greatly increase the overall strength of the wing. This wing is targeting EAB builders like myself looking for absolute Beast-Mode STOL performance, faster cruise and Vne, and more weight carrying capacity. Empty weight is always a concern so I will sweat the ounces, BUT I also want this wing to pass Part 23 engineering standards for Standard Category limits at max T.O weight of 680 lbs. I'll do the tests and re-evaluate any points that fail. Due to the extra weight of a large fiberglass section in the leading edge, I have doubts that this can be accomplished with a finished weight of 254 lbs. I am considering provisions for optional wing tanks that hold a bit more than 5 gallons each. Since part of the reason for doing the bigger wing is increasing max gross weight, I will change the "C" leading edge cuff of the smaller wing to a "D" section that includes a vertical spar bonded between the upper and lower skin areas. I have no idea how to calculate the theoretical strength gain from the fiberglass spar, but the load testing results will definitely give us some valuable data points.

3) Depending on the results of (2) above, I may also go completely off the deep end and build another set of wings using Harry Riblett's GA30U-615 airfoil plus another 2 inches of chord to really maximize the low speed performance. That project will remain just an idea until I finish the testing of the first 2.

For those who aren't aware, a "limit" test tests the wing to the target G limit and cannot result in any permanent deforming or bending. The "ultimate" load test goes 1.5x higher and may result in permanent damage to the wing, but it cannot suffer a catastrophic failure.

I managed to get both of my leading edge molds all lined up and bonded together. There is about a 1/16 inch variation over the length of the structure that I'm trying to work out. I won't be happy unless it's really, REALLY precise when the final casting comes out. I'm also starting work on setting up a wing testing jig so we can have dependable test data from the load tests.

[13brv3]

Interesting project. I'll be following your development and testing. Kitfox used a leading edge strip that gave a better shape compared to the large front spar tube. I wonder how much effect that would have? It would of course add weight, which is the enemy of Part 103.
Rusty

[mrpilotron]

Rusty,
That Kitfox leading edge extrusion would be exactly the right answer for getting back the correct profile. It would also weigh a lot less than a fiberglass cuff. However, the other thing I'm hoping to accomplish with the cuff is elimination of the false ribs and the tube they rest on. There will be some amount of structural rigidity added, but that is just a bonus on the small wing since the aluminum tube already provides all the strength needed. It remains to be seen if I can pull this off without having a net gain in weight.

[Badland-F5 Pilot]

This all is really amazing guys. I'm really enjoying seeing this level of experimentation in improving the wing. Peer and I were looking into making some improvements by printing parts for our planes. Some ideas are still possible, others proved to be more difficult than expected. However, you all are going way beyond what I had ever considered as possible.

I'm really interested in the leading edge extrusion, it being easier to modify the existing wing configuration instead of designing and building an entire new front part of the wing. Though I would think the latter method would provide improvement in performance of the simpler leading edge extrusion, the added weight has me concerned, plus the complexity might make it more difficult for the average flyer to build. Could the leading edge extrusion be created out of common insulation foam like shown for the ribs? It would be easy enough to epoxy the foam on. The wrap of the Oratex or other material would (I would believe) adhere nicely? I'm looking for something similar to forward slats but without the mechanical and weight.

I really do appreciate the discussion and what all I'm learning from the posts. Please keep posting, this information is great.

Thanks,
Todd

[13brv3]

FWIW, I'm pretty sure you could buy the leading edge strips from Kitfox since they still support the model 4. I don't see them listed in their catalog, but you can't list everything. Since people with the earlier planes probably wanted to try these, I'd be surprised if some other company wasn't also making them.

As for foam, I'd bet that would work just fine, particularly if you covered it with a thin layer of fiberglass. I'd worry that the foam would be too soft and get dinged up a lot if you didn't have some coating on it. I'd bet you could also 3D print short interlocking sections to create the leading edge.

Rusty

[Badland-F5 Pilot]

FWIW, I'm pretty sure you could buy the leading edge strips from Kitfox since they still support the model 4. I don't see them listed in their catalog, but you can't list everything. Since people with the earlier planes probably wanted to try these, I'd be surprised if some other company wasn't also making them.

As for foam, I'd bet that would work just fine, particularly if you covered it with a thin layer of fiberglass. I'd worry that the foam would be too soft and get dinged up a lot if you didn't have some coating on it. I'd bet you could also 3D print short interlocking sections to create the leading edge.

Rusty

I'll have to check with Kitfox and see if the strips are still available. I didn't think much about the softness of the foam. I know it's pretty solid, but that's me pounding on it with my hand, not having something hit it at 60mph, so point well taken. A layer of fiberglass would be easy to apply and be very strong.

So, some added questions if you don't mind?

I've asked around and gotten some interesting answers to the following question. With the current wings, there are full ribs and partial ribs that support the wing covering material. This creates a wavy up and down flow of the material from the cockpit to the end of the wing.

Wing.jpg (3.92 KiB) Viewed 179 times

If I were to use the foam between the ribs (basically copy the ribs but with foam) so the material would be smooth over the top of the wing, would this add to performance or is there no noticeable difference between a smooth wing or a ribbed wing? Also, from what I've read about VG's, they are almost always a benefit, even on UL aircraft. Your thoughts?

Screenshot 2024-11-12 6.59.03 PM.png (131.37 KiB) Viewed 179 times

On some STOL aircraft, winglets have been added. Do you think winglets would be an advantage on a Badland aircraft?

Wouldn't winglets provide a little extra range by ensuring lift is not flowing from under the outter edge of the wing rolling over to the top?

Thanks for any advice, opinions you have.

Todd

[mrpilotron]

Todd, your questions are exactly what I'm hoping to answer with my testing. I'm going to need a test aircraft that can swap wings back and forth so we get real apples-to-apples tests to prove if the consistent smooth shape with correct leading edge profile is worth doing. VGs have been tested and proven so many time over that it's pointless to repeat that test. However, I'll do the wavy wing/smooth wing comparison without them so any performance difference isn't attributed to the VGs. Once that test is done, I'm 100% going to add the VGs. This will also help settle the argument that rib waves create a pseudo-VG effect due to the dips not being quite the right airfoil shape and changing the flow velocity compared to the rib peaks.

Packing foam ribs between the wood ribs might actually hurt performance because that stuff isn't as lightweight as you might expect. The pink stuff I'm using is a bit of pain to work with because it doesn't cut really clean and creates a mess of shredded bits that get everywhere. I even bought a $50 special carbide CNC bit specifically designed for foam cutting and it struggles to leave a good milled finish. I've added a LOT of epoxy mixed with lightweight filler powder to get the surface smooth and ready for paint/release agent for the molds.

I think if you were to make the leading edge profile out of foam, it would be best to use a hot wire cutter rather than the CNC cut plates like I'm doing for the molds. A 2-foot wide hot wire guided by CNC cut templates could work well to get usable sized pieces. Glue those to the tube, then skin over them with the same epoxy w/filler stuff I'm using for the molds and it would be near perfect shape with maybe a pound added.

Winglets will have to wait. I'll be shaking my last piggy bank to get 2 full sets of test wings built already. I know the Horton STOL tips on a C-172 make a notable difference, but we're talking about a plane that stalls close to our max cruise speed. I'm not convinced that you'd be able to measure the improvement between 24 vs 23 MPH stalls.

[13brv3]

For part 103 where ounces count, I can't imagine the droop tips being much of an option. I do think they'd improve performance at least to some extent, and would likely be worth having if you're going experimental.

As for the wing shape, I don't have any data, which is why I'll be interested to see how these tests go with Ron (assuming that's his name). If you make the rib the shape you want the wing to be, then obviously you're not getting that shape between the ribs. I've wondered if that's taken into consideration when designing the ribs for wings like this though. Maybe the rib is made a bit taller than ideal, then the shorter profile between the ribs averages out the shape? I'm sure a smooth accurate profile is better, though the wavy shape just looks right on some planes.

Rusty

[mrpilotron]

My perfectionism is starting to catch up. Or, is that properly called "ADHD Hyperfocus"? Anyway, I feel like zero progress was made because these still aren't perfectly straight and smooth. I think I'm going to glue some 120 grit sand paper to the edge of a 4-foot level and use that to knock down the high spots.

[Badland-F5 Pilot]

Todd, your questions are exactly what I'm hoping to answer with my testing. I'm going to need a test aircraft that can swap wings back and forth so we get real apples-to-apples tests to prove if the consistent smooth shape with correct leading edge profile is worth doing.

This is great. I had many give opinions, but none could actually tell me if the smoother surface was an advantage or not. Just looking at the two surfaces, though, there's got to be a difference in lift capability as well as flow of air over the wing. What I'm really hoping for is not necessarily any additional lift capability, but more performance with longer flight times because of less drag. Granted we are flying high drag aircraft, but that doesn't mean we can't optimize as much as possible.

VGs have been tested and proven so many time over that it's pointless to repeat that test. However, I'll do the wavy wing/smooth wing comparison without them so any performance difference isn't attributed to the VGs. Once that test is done, I'm 100% going to add the VGs. This will also help settle the argument that rib waves create a pseudo-VG effect due to the dips not being quite the right airfoil shape and changing the flow velocity compared to the rib peaks.

Great point, and I've also seen almost no issue in using VG's. Either they help a lot or they don't help much if any, but none that I've seen test claim any loss, though there may be a few.

Packing foam ribs between the wood ribs might actually hurt performance because that stuff isn't as lightweight as you might expect. The pink stuff I'm using is a bit of pain to work with because it doesn't cut really clean and creates a mess of shredded bits that get everywhere. I even bought a $50 special carbide CNC bit specifically designed for foam cutting and it struggles to leave a good milled finish. I've added a LOT of epoxy mixed with lightweight filler powder to get the surface smooth and ready for paint/release agent for the molds.

I think if you were to make the leading edge profile out of foam, it would be best to use a hot wire cutter rather than the CNC cut plates like I'm doing for the molds. A 2-foot wide hot wire guided by CNC cut templates could work well to get usable sized pieces. Glue those to the tube, then skin over them with the same epoxy w/filler stuff I'm using for the molds, and it would be near perfect shape with maybe a pound added.

I was watching a few Trent Palmer video's and ran across this one:
Which appears to be exactly what you're talking about, using the packing foam. I may have to give the guy that did the work for Trent a yell, and see if he's interested in doing the same for my F5. That would be an interesting project.

Winglets will have to wait. I'll be shaking my last piggy bank to get 2 full sets of test wings built already. I know the Horton STOL tips on a C-172 make a notable difference, but we're talking about a plane that stalls close to our max cruise speed. I'm not convinced that you'd be able to measure the improvement between 24 vs 23 MPH stalls.

So thinking more about Winglets, maybe fences would do the trick without having to add much weight?

Keep up the great work. I'm enjoying the heck out of learning from your project.

Thanks,
Todd

[Badland-F5 Pilot]

For part 103 where ounces count, I can't imagine the droop tips being much of an option. I do think they'd improve performance at least to some extent, and would likely be worth having if you're going experimental.

As for the wing shape, I don't have any data, which is why I'll be interested to see how these tests go with Ron (assuming that's his name). If you make the rib the shape you want the wing to be, then obviously you're not getting that shape between the ribs. I've wondered if that's taken into consideration when designing the ribs for wings like this though. Maybe the rib is made a bit taller than ideal, then the shorter profile between the ribs averages out the shape? I'm sure a smooth accurate profile is better, though the wavy shape just looks right on some planes.

Rusty

I had read your comment about the droop tips, and along with Ron's post came up with the idea of just a fence instead of a droop. That would help keep the lifting air flow where it needs to be, and as you mentioned, ounces counting, they would be much less weight than a full droop. Good question about the shorter profile. I just look at the ribbed wing and see airflow moving much faster in the lower part than on the ribs, and wonder, are we losing lift from that area? I know, I know, build a wind tunnel and test! Maybe someday. In the meantime, I'm also watching Ron's work closely. I don't understand it all, and he's keeping my attention!

Thanks,
Todd

[Badland-F5 Pilot]

My perfectionism is starting to catch up. Or, is that properly called "ADHD Hyperfocus"? Anyway, I feel like zero progress was made because these still aren't perfectly straight and smooth. I think I'm going to glue some 120 grit sand paper to the edge of a 4-foot level and use that to knock down the high spots.

That's still not far off of what I've seen fly on many Cessna's! Ok, so most of them are 30+ years old.

I suppose, though, the cat inspection is also critical?

Todd

[mrpilotron]

I just watched the Trent Palmer video. He was trying to add extra cuff to stretch the chord and in doing so he created a new flatter airfoil shape. The new shape was not a carefully engineered airfoil like the original Riblett, but was something that has a lower chance of performing well in the intended application. His flight testing proved that to be true. That's significantly different from what I'm attempting.

I want the shape to be EXACTLY what Harry designed so the airfoil works the best it can. Both my small and large wings will be the precise shape, just stretched to a slightly longer chord. That extra chord is properly matched with extra thickness to maintain the thickness ratio.

My working theory is the best way to get the whole airfoil to the correct shape is to eliminate the scallops between the ribs. My method for accomplishing that is a very thin, lightweight fiberglass sheet that spans the gaps between ribs and supports the fabric.

Ron

[Badland-F5 Pilot]

I just watched the Trent Palmer video. He was trying to add extra cuff to stretch the chord and in doing so he created a new flatter airfoil shape. The new shape was not a carefully engineered airfoil like the original Riblett, but was something that has a lower chance of performing well in the intended application. His flight testing proved that to be true. That's significantly different from what I'm attempting.

I want the shape to be EXACTLY what Harry designed so the airfoil works the best it can. Both my small and large wings will be the precise shape, just stretched to a slightly longer chord. That extra chord is properly matched with extra thickness to maintain the thickness ratio.

My working theory is the best way to get the whole airfoil to the correct shape is to eliminate the scallops between the ribs. My method for accomplishing that is a very thin, lightweight fiberglass sheet that spans the gaps between ribs and supports the fabric.

Ron

Yep, I included the video as a reference for the cutting of the foam more or less. As you point out, the addition on his wing didn't help. With the wing he had, any advantage the cuff would have had appears to have already been built into the wing. With our wings, the spar really doesn't have the best shape. This is where I think a properly designed foam cuff would help, or is my thinking wrong here?

What I liked was the hot wire cutting used to create the cuff. That's why I'm considering contacting the guy that did the cutting for Trent and seeing if there is the possibility to do the same for my wings. The question is, attach them to the wing before covering and hope they work, or wait until after covering. Then put them on and have an extra layer of material weight to have to account for? I'm leaning towards the latter. At least if they don't work as well as I would expect/hope, I can take them off without having to recover the wing again.

I see we're similar in that we both want every last inch of efficiency we can get. I'd like a wing that provides the maximum amount of lift along with the best performance for fuel economy. I know, those two don't always go together very well.

As you know, I'm very interested in how well your wings will eliminate the rib scallops. Though I've heard some not so flattering news about the Belite, the smooth wing surface the Belite had is the first ultralight I've seen to remove the scallops. I'm not sure how it was done. I wondered about the performance gain or loss, but also, it looks good, giving the plane a more refined look. I would give up the refined look if there was a performance loss without a compensating benefit.

Thanks,
Todd

[LA F2 Flyer]

Hey Todd, the pics you posted are actually not of the Belite UL...it looks more like the 2 place Chipper that James has been building.

[Badland-F5 Pilot]

Hey Todd, the pics you posted are actually not of the Belite UL...it looks more like the 2 place Chipper that James has been building.

You know, I didn't even notice that. It was listed in the magazine article as a Belite Chipper. So goes it, I got that one wrong. Oh well, the look is the same - smooth top wing. Here's a video of the Pro Cub Lite with the smooth wings.



Thanks,
Todd

[LA F2 Flyer]

Oh wow, I never noticed the smooth wings on the UL. It looks good. I also was always a fan of the rounded wingtips.

However, on the bright side our Hershey bar wings lend themselves nicely to fences or droops, as you mentioned.

(Is James still building ULs? I thought I had heard he was focusing exclusively on the Chipper, but that was some time back.)

[Badland-F5 Pilot]

Oh wow, I never noticed the smooth wings on the UL. It looks good. I also was always a fan of the rounded wingtips.

However, on the bright side our Hershey bar wings lend themselves nicely to fences or droops, as you mentioned.

(Is James still building ULs? I thought I had heard he was focusing exclusively on the Chipper, but that was some time back.)

I think using fences would be the way to go for sure and would work great on our planes. I like the smoother look of the droop, but for ease of install and also important - Cheap! the fence would be the way to go.

Yes, I think he was only doing the Chipper at that time. I recall something with Kitfox that he had an agreement with. The video is 10 years old, so yes, no more UL. It is a nice looking plane, but I don't believe he had the quality that Chris has. He doesn't seem to be producing planes anymore. His website goes to Radiant Technology. He appears to be the owner and develops some nice looking aviation instruments. The website doesn't show the complete instrument, just the face. The specifications don't list the weight, kind of strange. They appear to be something that would work well with ultralights if they have a lessor weight advantage. https://www.radiantinstruments.com/

Todd

[Dobie]

Todd: https://www.flyingmag.com/belite-aircra ... d-by-fire/

[Badland-F5 Pilot]

Todd: https://www.flyingmag.com/belite-aircra ... d-by-fire/

Yep I had read about that and because nothing was insured he didn't have the funds to rebuild. Then I heard that in 2023 he was thinking he could start small and build the company back up. I guess that was either just hear-say, rummer, or should I say "misinformation"

What do you think of the instruments he's making? I need to send off an email and find out what the weights are on several of them. Of course I will still have a few steam gauges. An electrical problem with nothing more than electronic instruments could quickly turn into a bad situation!

Todd