Rivet templates

[Ironwing]

Peter

 

The grooves and half circles along the edge is a great idea and will make alignments and visibility much, much better.

 

Geoff

Edited April 14, 2016 by Ironwing

[Ironwing]

All

 

I want to weigh in a bit more about this. Ive been battling rivets for far too long. Im embarrassed to admit it. For something that looked like it would be a milk run, its turned out to be a nightmare.

 

Making straight lines isnt a problem. Making parallel lines isnt a problem. Intersections have been the item that have caused the problem. Some are thru and some are dead end. All total, there are twenty eight of them on one tail plane surface. It isnt the fault of the intersection. Its my fault for being unable to hold sufficient tolerance in rivet placement.

 

There is a good deal of cross talk between rivets. That is, rivet placement in X are often times dependent upon rivet placement in Y. This can occur or a very short span, or over the entire surface, side to side or front to back. Some lines intersect three or four times with other lines. This is especially vexing, in that, unless they are perfectly aligned, you end up with an obvious mismatch.

 

Ive come close, but havent yet been successful in producing skins that are acceptable. Admittedly, sometimes Ive just put something where it shouldnt be, mostly from loss of focus on my part. There are several hundred (appx) rivets per skin and after a bit, it gets hard to concentrate. Still, its hard to hold tolerance with induced error feed that I cant seem to overcome.

 

I think Peters tool might be a solution...time will tell. Ive only just glazed over this, There are other variables that I think have an impact. If anyone wants to talk about it, leave a reply.

 

Geoff

[Rainer Hoffmann]

Geoff, this is exactly my experience as well. Intersections of rivet lines are the major problem. I don't think that Peter's template will really solve this particular problem, as you have to start somewere and hope, that the intersections will end up right. They probably will in some cases but not all.

 

Fortunately, on checking the rivet patterns on the wings of the Viggen, I noticed, that the intersections of the rivet lines are pretty random on the real thing. So I decided that I'll be happy if I can achieve straight lines of rivets. I just won't worry about the occasional mismatched intersection. But that's just me and if it worries you, then perhaps you'll find a solution.

 

Now, if you find that solution then I want to kow, of course

 

Cheers

Rainer

[Ironwing]

Rainer,

 

I think your problems are more difficult than mine due to size. One thirty-second is only half the size of one-eighteenth or there abouts and it dwarfs twenty-fourth scale as well.

 

Ive tried Peter's tool, but rather than trying to use the etched holes, I used the edge since thee is a small grove at each line division that the beading tool fits into.  I tried using the etched holes. They work just fine, but I couldnt  get proper alignment with existing rivets since they were hidden under the body of the template. This problem would be eliminated if the edge had V shaped groves or half circles. Peter's idea is a good one for sure. It just needs a bit of tweaking.

 

Im using a twelve inch steel rule to make straight lines, and am able to get very fine control of where each rivet goes but it isnt perfect, and this is where the problem resides. The thickness of the steel rule becomes an impact variable. That is, because the beading tool is conical, the thicker the straight edge being used, the higher up on the beading tool the edge makes contact, and as a result, it pushes the tip of the tool farther away from the tool edge. I dont know if your using a beading tool so I mention this in passing. Also, and this helps greatly, I use a magnifying lens. Its either four or six X, and allows much better alignment between the tool and the metal edge. I doubt i could come close without it. Again, Peters tool would be a great help if the groves were along the edge of the tool. Unfortunately, alignment will always be a problem.

 

The real problem, as you know, has been intersections. Making a single dead end intersection isnt a problem. In my case, each rivet line intersects with three to five other lines so Im dealing with both thru and dead end intersections in one line. Rivet spacing is absurdly critical, especially for  the center rivet at the intersecting point. I cant speak for thirty-second scale, but for eighteenth scale, the slightest bit of misalignment becomes obviously visible. For me, this is unacceptable. The rivet pattern on the Mustangs tail planes is much different than what manufacturers have given us over time. Even Tamiya, for all their quality, did it wrong. My agenda is different than Tamiya's,  but thats a different topic.

 

Anyway, heres what I do. your mileage may vary...

 

1. Scribe a baselines into the litho. This becomes the datum and the TE. Everything is perpendicular or parallel to it. Without moving the metal edge, next scribe in the the shape of the tail plane using a master template, made from litho, which was made to fit the H stab.

Do port and starboard on the line. Rotate the litho sheet 180 and repeat the process of scribing in another datum, parallel to the first and the tail plane shape.  This leaves you with four tail plane skins. NOTE: This done on a flat sheet not attached to the model on a piece of glass. This prevents the rivet from creating a bump on the other side so no rubbing out is needed. The litho is also not annealed since it will be going on a relatively flat surface and adds no difficulty punching in the rivets. It's also more resistant to surface damage in this state.

 

2. I set the straight edge position using and optical comparator to get the most accurate placement of the straight edge. One the straight edge is in position and tightly taped down, I punch in the first line of rivets (48) which run tightly along the TE. This forms the base line for everything else. Its gets tricky here. The rivet line, while continuous along the TE, ends at the dynamic balance clearance slot in the TE, and goes up (perp to the datum) along its edge. These rivets are added next...exactly six of them, per the NAA drawing. This forms the first right angle and is done on all four tail planes. There is also a rivet line on the other side of the cut out but this isnt added until the end rivets are punched in but before the lateral rivet lines are placed because the laterals have to end at the outboard end of the tail plane and match up with it. 

 

3.The second rivet line runs parallel to the rivet line along the TE and aligns with the first rivet forward of the TE rivet line where they intersect. Confused yet?

Since the tail planes are scribed next to each other, the second rivet line, is set up by aligning the straight edge to the first rivet forward on the port tail plane to its counterpart on the starboard. This is done to insure uniformity and to minimize induced error per unit measure by spreading it over as wide an area as possible. In my case, line spacing between rivets is 1.6 mm. 

 

4. Perpendicular lines (LE to TE) are then inked on using a felt tip marker. Theyre called "Sharpies" here in the States. I dont know what the Euro counterpart might be. Fortunately, the line width of the Sharpie is just about the same as the rivet diameter which helps with alignment but it isnt perfect. It also only gives a close approximation of where a rivet has to go. Final positioning has to be done by aligning the straight edge from the first rivet in a line to the rivet line's termination point. To do this, the tool has to be placed in the first rivet. The straight edge is taped down on one end. The tool is then placed in the last rivet in the line and the edge is brought up against the tool. The second end is then taped down. Test punches are then done at the ends (off the part) to insure alignment before the rivet line is punched in. This works well but once you get into the center of the part, where the toughest intersections are, test punches arent possible and that is where the question of intersection alignment becomes a problem. LE to TE intersections involve twelve dead end and ten thru intersections.

 

Im going to stop here. I dont know if any of this helped since it might not be relative to your situation. All I can say is you have to be beyond careful when setting things up and try not to lose focus. It gets intense. Be extremely deliberate in what you do, but even then, its easy to foul up. Take it from someone who has experienced failure on an epic scale.

 

If you want me to continue, I will.

 

Hope youre well...

 

Geoff

[Rainer Hoffmann]

Jeez, Geoff, I had to read this three times, but it starts to make sense...

 

Thanks a lot for this explanation. I guess, since every skin panel on an aircraft is different one has to figure out the best tactics for each and every panel separately.

 

So, yes please go on! I'm learning from everything!

 

Cheers

Rainer

[dodgem37]

'The thickness of the steel rule becomes an impact variable.'

I use brown paper tape.  The kind used to tape boxes together.  It has enough body to be sturdy.

 

'The real problem, as you know, has been intersections.'

Locate the intersection rivet first.  Then divide the space between intersections and then fill in the blanks.

 

'the line width of the Sharpie is just about the same as the rivet diameter which helps with alignment but it isn't perfect'

I would use a Micron 005:

https://www.google.com/search?q=micron+markers&espv=2&biw=1920&bih=955&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiQ68_8u5XMAhUCyT4KHUYtCRcQ_AUIBygC&dpr=1

The point is delicately thin.  Don't press the marker down onto the surface.  Let the weight of the marker be the pressure to draw the line.  Just drag the pen.  If you add pressure the nib will break off.  Believe me, that is a pisser.  Found at your local Art Supply store.  Draw vertical intersecting lines at all rivet locations.  Determine before hand the location of the rivet.  Centered, or in a quadrant.  I have found quadrants to be easier and harder for similar reasons.  Easier because you have 2 lines on which to locate the rivet.  Harder because you have 2 lines on which you must align the tool.

 

Just my take.  Others mileage may vary.  Good luck.

Sincerely,

Mark

 

 

[Ironwing]

Jeez, Geoff, I had to read this three times, but it starts to make sense...

 

Thanks a lot for this explanation. I guess, since every skin panel on an aircraft is different one has to figure out the best tactics for each and every panel separately.

 

So, yes please go on! I'm learning from everything!

 

Cheers

Rainer

Rainer

 

Glad youre still on board. I thought my last post might have killed you. Ive done some photos to help with explanations. Ill get them posted asap.

 

Best

 

Geoff

[Ironwing]

'The thickness of the steel rule becomes an impact variable.'

I use brown paper tape.  The kind used to tape boxes together.  It has enough body to be sturdy.

 

'The real problem, as you know, has been intersections.'

Locate the intersection rivet first.  Then divide the space between intersections and then fill in the blanks.

 

'the line width of the Sharpie is just about the same as the rivet diameter which helps with alignment but it isn't perfect'

I would use a Micron 005:

https://www.google.com/search?q=micron+markers&espv=2&biw=1920&bih=955&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiQ68_8u5XMAhUCyT4KHUYtCRcQ_AUIBygC&dpr=1

The point is delicately thin.  Don't press the marker down onto the surface.  Let the weight of the marker be the pressure to draw the line.  Just drag the pen.  If you add pressure the nib will break off.  Believe me, that is a pisser.  Found at your local Art Supply store.  Draw vertical intersecting lines at all rivet locations.  Determine before hand the location of the rivet.  Centered, or in a quadrant.  I have found quadrants to be easier and harder for similar reasons.  Easier because you have 2 lines on which to locate the rivet.  Harder because you have 2 lines on which you must align the tool.

 

Just my take.  Others mileage may vary.  Good luck.

Sincerely,

Mark

Hi Mark,

 

Im glad youre adding to the conversation...

 

"Thickness of the steel rule..."

 

I use the same steel straight edge for everything so this isnt a problem. I mention it in passing in case someone wants to try it. I do like the idea of the brown paper tape. Sounds quite doable. Im just unsure of edge durability and the ability of the paper to provide a solid detent for the tool. I depend on the steel rule to provide an edge that, without a doubt, provides solid uniformity of line. I think for someone with steadier hands, paper tape would be great.

 

"intersections..."

 

I, as you suggest, do punch in the center rivet of the intersection first, then fill between them. The rivet spacing is consistent and scales out to just about .0625" on center. All dimensional and placement data is from NAA dwg: 117-21002, H Stab. It does show variations in spacing. This is more than likely draftsman inconsistency since the notes indicate equal spacing. Locating the center rivet works well, but there is always some variation due to my inability to execute with repeatability.

 

"line width..."

 

I like those pens!! I must get some. Thanks for sharing that. The Sharpie Im using delivers a line of .020 max width with some variation but not so much that I can't live with it. The nice part of the line width, is that the rivet diameter is the same. Hence, if I can get the rivet, within the confines of the line width, Im pretty much assured that its in the right place as long as the steel edge is in the right place. Operator inconsistency is again the problem.

 

I know ill get this. I keep zeroing in on it. There is a specific way each line needs to go in due to the interdependence of one to another. I sincerely hope youll continue to contribute...

 

Best,

 

Geoff

 

[airscale]

hi chaps

 

good to see the dialogue continues..

 

When I get to this point I have a few thoughts - namely that I think there is some mileage in adjusting placement of rivet lines and intersections to best suit making it easy. Geoff, I worry that with so many castaway failures to achieve perfection on a totally flat linear panel, that you might get tied up in all sorts of knots when the tricky shapes come along and the poor P51 will be naked for much longer..

 

I have decided to compromise a bit and hope this shows how and why..

 

first the traditional method has lines starting at a set point - this means the intersections have a chance, but no guarantee of being correct..

 

 

..I am going to go for a baseline row from which all others will orientate..

 

 

..the first mapping comes from the baseline and will set the guideline for all other horizontal rows

 

 

..I will then place the horizontals as near to scale position as possible, but in a position where the intersections on any verticals will work..

 

 

..I can then throw down all the other verticals using the same rules - they will go where the intersection works - that means they can be a maximum of 0.5mm out in vertical placement and I can live with that..

 

 

..I have redesigned the tool to add in the notches meaning that with rows up to 18cm you can slide to best match the intersections... and I have added a few other features on the smaller 10cm one.. open to suggestions as to how to fill the blank space on the wider version..

 

so here at the top is the original 1/18 Spitfire based version, below that the revised Spitfire version, and below that is a 0.75 and 1mm spaced version for Rainer

 

 

any further design thoughts?

 

TTFN
Peter

[Rainer Hoffmann]

Peter, that's absofreakinglutely brilliant!

 

I'll think about how to fill the blank spaces. I guess I'll have some ideas.

 

Personalized tools, now that's something special! It can't get any better than this.

 

Cheers

Rainer

[Hubert Boillot]

Why don't you do a "T" or square-angle template for these pesky intersections ?

 

Or an articulated one for intersecting lines at angles other than right angles ?

 

The work looks great, in all its versions. Well done Peter and the collective minds who put their brains into this development !

 

Hubert

[Rainer Hoffmann]

Peter, those circular patterns with 6 and 8 holes are a brilliant idea! I just would prefer to have notches instead of holes, like so:

 

 

Pattern with 6 rivets/fasteners shown, pattern for 8 rivets/fasternes would be similar, of course.

 

Again, this would enable the use of different diameter beading tools and make the alignment easier.

 

Personally I don't need the patterns for the inspection doors because I do have several templates with different sizes.

 

If you could incorporate these ideas into your design I would be a very happy camper indeed!

 

Cheers

Rainer

[Youngtiger1]

Peter, great idea. I will like to request for a 1/32 and 1/48 as well. I have several Academy 1/48 CH-53E/MH-53E and that kit is missing rivets on it's fuselage. You can build it without it but now that I know and I can't just leave it as is. So, I will love a tool like yours for it as well.

 

Mike

[airscale]

evening folks..

 

 

Why don't you do a "T" or square-angle template for these pesky intersections ?

Hubert

 

 

that's a great idea Hubert I will have a think about it and how to do it..

 

 

Peter, those circular patterns with 6 and 8 holes are a brilliant idea! I just would prefer to have notches instead of holes, like so:

 

Cheers

Rainer

 

 

Hi Rainer - thank you - again, that solves the problem of different sized tools - nice one

 

 

Peter, great idea. I will like to request for a 1/32 and 1/48 as well. I have several Academy 1/48 CH-53E/MH-53E and that kit is missing rivets on it's fuselage. You can build it without it but now that I know and I can't just leave it as is. So, I will love a tool like yours for it as well.

Mike

 

Mike - I am thinking I might do a small run for those interested (though there are only two tools a 10cm one and a 16cm one) - I just need to figure out a covering cost and shipping - I won't do it from my website, anyone who is interested just add your name on here and I will PM at the end of this month to get details etc

 

here are Rainer & Geoff's

 

10cm..

 

 

16cm

 

 

I will do one for Rich as well as I am sure that his SBD needs some template love...

 

TTFN
Peter

[dodgem37]

Aircraft-specific riveting templates.  I think you've found a market.

 

Sincerely,

Mark