After many years of sitting in the corner watching my kids grow up, my 1951 170A project has been patiently waiting for me to return. Last one just graduated and the time has come. It has been time well spent.
Trying to get the interior and panel put in and noticed I don't have the braces from the firewall to the panel P/N0513000-6 (Fig 19-50) and the glovebox hinges, the part that attaches to the fixed panel. P/N 0413109(fig 35-35)
I'm sure I can build the braces if needed, but I don't know what they look like. The hinges might be a little nore difficult. Pictures and/or sources?
I know this is just the start of many more parts needed.
I was figuiring that is what the braces were, it's what I have seen on every other later Cessna I have ever worked on, but I thought I should ask anyway.
As far as the hinges go, yes, that would be great. I have absoluty nothing to go on there. My glovebox door and the hinge arms are in good shape, but I have nothing to put them into.
This took longer than I hoped but, here's a decent reproduction of the hinge on my glovebox
The hinge is bent up 90 degrees a the two parallel dotted lines and maybe 20 or 30 degrees at the single dotted line.
Sorry, I dont have a photo of a good one.
Hope this helps.
IMG_0735.jpg
I'll add that I was able to make a copy for my airplane based on this data.
It will be much easier to make two at once tho.
Admittedly, I'm not the sharpest knife in the drawer, but I started to draw that in CAD, and it appears to me there are some critical bits of information regarding the geometry of that hinge towards the top that is missing. Did you draw that and dimension it yourself, David, or is that drawing something you found?
I inked it myself based on the broken part and a set of calipers.
I didnt have a way to measure the angles accurately so I hoped the few data points would be enough to reproduce the part good enough.
Thinking back to when I made mine, I did cheat since I had the part to physically verify against.
The outer most crosshairs is the intersect of the two angles.
As you can see from the part, the top portions of the drawing are not exactly to scale. I fudged the drawing, figuring whoever made it would be hand shaping it anyway.
Is there a particular measurement that would help?
Let me preface this by saying that I'm incredibly lazy. I don't like to cut anything by hand as it will never be symmetrical and perfect, and having learned CAD for my previous job, as well as knowing people that can cut things by either CNC, laser, or waterjet, I take full advantage of being able to draw a part once and then replicate later, ad infinitum. This piece is very simple and a blank can be cut by some computer-controlled means and then bent by hand relatively easily. I also went to school in a rural part of a southern state and have yet to finish college, or take my checkride for my private, though I'm 27 and started logging hours at age 10. My family's 170 that we owned since I was an infant and for over 22 years has been the object of my affection since I have been old enough to remember, and once we move back to North Carolina, I will buy her back and pick up flying where I left off to go play with R/C airplanes. Being a '52 model with the original panel, it has but has not had a glovebox since we've owned it. I'm not sure when it was removed; the best I can tell is that it would have been in the mid-1970s after having reviewed the maintenance records from the FAA (obviously I don't currently have the logbooks) and seeing that's when it got an avionics upgrade. All of the gloveboxes I've found have not had the original hinges on them, so tackling this little drawing exercise is a personal interest of my pretentiousness.
Having said that, the problems that I am running into are related to the outer angles of the top portion. The bottom angled portion is simple enough to figure out; it goes from the center of the .020 hole to the cross hairs, but at that point, things begin to fall apart.
First, you have the dimension going from the centerline to the outermost cross hair as 0.75 and the entire dimension from crosshair to crosshair as 1.35. Either this is offset (doesn't seem like it based on the drawings), or something isn't adding up. Half of 1.35 is 0.675, not 0.75, so I'm not sure which is which. Drawn with the half dimension (0.75), it looks a lot more like the drawing you have.
Where it starts to come apart is where you have the dimension of 1.25 for the centerline of the 0.13 holes, and then the total dimensional height of 1.40. This is simply not enough room. Using your dimensioned drawing, the top radius protrudes down around 3/8 of the way into the bottom radius. Mathematically if the holes are to intersect at one point tangentially, the total height of the piece should be 1.445. However, there appears to be some distance between the to radii, so it would need to be taller than that.
Halfway through this post, I ended up importing your picture into AutoCAD, roughly tracing part of it, and then using it to solve for some of the things that were either not apparent, or incorrectly dimensioned, more or less to demonstrate where I was having issues. The only thing that was throwing everything off is the total height. I find it to be 1.45 versus the 1.4 labeled. Everything else fell into place pretty easily, actually. I can e-mail you a 100% scale PDF from the drawing that I made to cross-reference the hand drawing you made, and if all is correct, I can post that to the board, or pass along to Bruce to put in the MX Library documents.
I love doing stuff like this; I would draw every iteration of every airplane in CAD for the Association if I could. It pains me to see an airplane hacked together, so when someone takes the time to reproduce an original part, I jump on it. I'm simply taking the hard work you've done and putting it in a format that can be 100% reproduce able, perfectly, every time for the poor bastard out there like me who would like to have original parts to prevent cobbling together some haphazard bandaid.
My last drafting class was with pen and ink almost 25 years ago and I learned CAD on AutoCad 3.8
If you have access to a better way to document the piece (and it sounds like you do), I'd be more than willing to pass along the part.
I think it would be incredible to have accurate drawings made and possibly a bunch of blanks cut! I didnt even think about machines making these
If you're willing take on the task, I can mail you the part and would even be willing to pitch in for the cutting of a bunch for the club.
I'd like to have a few spares as well.
I really appreciate all the work you guys have put into the glovebox hinges. I never expected this kind of response. I too, would be interested in pitching in to have some made. Maybe I missed it somewhere, but what is it made of? I'm guessing a thin spring steel.
Thanks Bruce, but I have those pieces, they are aluminum and they are spot welded to my glovebox door, but they don't look like the part in the picture that David drew. I believe the parts we are talking about are attached to the forward flange on the panel with screws and receive the hinge half spot welded to the glovebox door.
With the picture that David drew, I can make the part. Prior to that, I had no idea what they looked like. It seems to me that there is some interest from some other members that might want some. If we had a good CAD file, they are a snap to make the blanks and I would be willing to persue that if the interest was there. I would also be willing to bet there is a bag of them in somebody's junk box somewhere.
There is a part of the hinge that is spot welded to the door and the other part that I made a semi scale drawing of.
The part I drew is in Figure 37 #37 PN 0413109
Talking with Ryan, the drawing isn't 100% correct however, it's close enough to make a few hinges by hand that will work well.
Ryan and I are playing email tag with some scans to make a 100% accurate drawing in order to make parts from.
