ANH Motorised stunt Saber experiments (& blades) Part 1

Pine has prominent growth rings this doesn't. It most looks like balsa but is denser & harder to mark hence I'm thinking Obechi but as I've not knowingly seen that I'm hoping someone will be able to identify this.

Snooker cues would be straight so there would be no wobbling problems. Jon has also said he doesn't remember the use of cues.
I did ask Jon a few more questions in the past, especially about the different blades that were used on the sabers. He kept replying that there was a bunch uf people working on those effects sabers, and they used whatever they thought was suitable for the job. Jon himself worked with round, untapered balsa poles which were painted black and partially covered with reflective tape.

He does not remember what went wrong with the original Vader hilt (now commonly known as the „Barbican“ Vader lightsaber hilt). I vaguely remember hearing him say that they unsuccessfully tried to hide the power cables on Vaders arm during the duel, so they went with a static blade for Vader.
 
I am pretty sure there was a large carpenters workshop situated at EMI Elstree during production of ANH, so for the FX technicians walking over and asking for some tapered wooden sticks made of different types of wood doesn‘t sound like a problem for me.
 
Got the Bunker BtB set up sorted. The beech dowel is about 2/10ths mm over 16mm so I had to reduce it slightly to fit through the exact 16mm bearing bore ( it's now loose in the stuffer driveshaft :sick:). If you're wondering what I'm doing at the end I'm removing the motor retaining screw so the internals are a friction fit.


Works quite well - for a while. A bit better than the stud set up but not as good as the stuffer. And there's a flaw, after some moderate waving about the grub screws holding the blade to the snub driveshaft work loose. It does this every time. I'll put some flats on the blade stub for a second test but this is an interesting result & another problem that they had on ANH ? Not had this with any of the other arrangements.
(When I slip out the bearing near the end you can still see all it's still intact as you can see the motor in the access hole also moves forward.)

 
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Tried flat spots on the blade stud under the screw positions. Short vid shows better than I can explain but screws still undo but because they are now recessed in the stud it doesn't fall off. It did stand up to somewhat more vigorous strokes. Remember, though, that this is about the harshest test of a warped untapered beech dowel.


I tried fitting the second bearing instead of the spacer but got the same result. We'll see how this set up does with tapered stuff once i get some made.
 
More videos - Yea!

This is the last different set up I can think of & is the same general arrangement as Kurtyboy used (but with dif components). This is with the blade fitting directly onto the gearbox shaft without an intermediary driveshaft (hole was drilled with No25 drill, app 3.8mm, to 4mm Gbox shaft). First up is blade insertion to core with motor & bearing already fixed. This worked really well & I was able to give a decent thrash about (looks less impressive in the video). The motor still stalls at a very abrupt halt to a swing but otherwise felt good and lively & the best option yet. I think this due to the absence of inertia from the relatively large chunk of metal driveshaft. Note this is a new beech dowel & not that used previously. It's a little straighter.


Next is with a front load, friction fit motor. Worked just as well but at the end I noticed the dowel was further forward than when I started you can see me push it back in.


I wasn't sure if this was the dowel slipping off the shaft or the whole innards moving so I did a 3rd test with captive motor.


Bad news - the dowel is slowly coming off the shaft & is noticeably not such a tight fit as when I started, That said it's better than the Bunker snub shaft version & is better than any other driveshaft type (beech dowel) in as much as I can swing it with more vigour with minimal slow down. The slipping is annoying but not terminal, at least short term. It also may not work with Balsa or Obechi which I think may not grip so well, I'll have to try it.
A lighter stuffer DShaft would probably improve that set up but not look like that Alec G photo anymore.
 
My final batch of trial motors. Left to right; JGA25-310 400rpm for comparison ; CHR-GM25-370 supposedly 1000rpm at 6V ; JGA25-370 rated 620rpm at 6V ; big red one for a chenglong RC tank app. 50mm long 28mm diam no gearbox. The gearbox on the black 1000rpm is noticeably longer than the usual 9.68;1 I've had so far & motor has exposed armature bushes. Black & red bought from Banggood, 620 from fleabay. As usual as soon as I buy one from fleabay they put the price up £2.

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Here again showing the 620rpm 370 has a different motor from my other 370, has crimp 'vents' like the red one. Lined up to compare motor length.
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I was hoping I could put a gearbox from one of my 310 motors on the red one (it has screw holes to take one) but the gear on the red one is too big.
I'll try & sort that out sometime but not as part of these tests. Shame as it looks like a much more powerful unit than the 370's & is closer to Jon Bunker's remembered Marklin one.
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I've just tested the 1000 & 620 for RPM (at the 5.8V I'm using for the normal 370 motor). The black 1000 clocked 981rpm & the 620 was 570rpm (near perfect). I swapped out the 1000's gearbox for a 9.68;1 from a 310 set up. It ran at 900rpm so is clearly a much faster motor. The '620' is running the same as my other JGA25-370 even though there is that casing difference.
 
The time has come for me to start seriously thinking about ‘skinning up’ these cores. To that end I decided to review my dimensioned drawing against the available pictures. This is has been on my mind since Kurtyboy did a quick CAD mock up & overlay & informed me some of my placements were out – specifically the switch & glass eye placements.

Scaling looks to be a art as much as a science so what I present here has to be view as an interpretation & not a canon. Just as any scaling should be. (Just to be clear ; I am no newcomer to scaling & have learned many wrinkles & sidesteps for when the going gets tough & some of these photo’s are tough.)
This is why I’m doing this long-ish post to show you how I arrived at the values I have.

In all cases I was drawing with a pencil directly onto my laptop’s (Matt) screen & using a fine division ruler to measure. I enlarged the image as big as would completely fit in the window them put a mark on the edges of the distance to be measured then measured. Id did this several times for each image taking tube then clamp as base factors &, in most cases, an inside & outside of a blurred edge as well as a best guess one. The sets of measures below have been selected from these as they show similarly & are from between extremes of scaled values. As each picture was taken in a different manner & may be a picture of a picture (eg I’ve been told the hut scene one was a picture taken of 50” plasma screen) I could think of no other way to compensate for this across them.

I haven't included the promo picture of the black nose stunt. There is too much perspective, it’s actually quite blurry when enlarged & the buttons are angled too much in profile for me to place their centers with any certainty.
(note; for those not familiar – a scale factor 1 is life size more than 1 means the image I’m using is larger than life less means smaller.)

PDF of my latest drawing is attached at end of post. [Having seen all the fancy CAD schematics on the RPF, & remembering a late friend saying how easy it is, I downloaded FreeCAD (unaided!) to redo this. 1 1/2hrs later I’d succeeded… in drawing a rectangle! I then remembered why I’d given up with CAD programs in the past. I’ll stick (again) with 3D modeling in my head & a sketch (literally most often) on the back of an envelope. ]


Key: ..................................................... Drawing value

A = front of tube to top button center – 2” [50.8mm]
B = front of tube to base of cut off – 1 3/8” [35mm]
C = base of cut off to center of glass eye – 1 1/2” [38.1mm]
D = base of tube (pommel) to center of switch hole – 3” [76.2mm]
E = base of tube to center of wires hole – 1” [25.4mm]

Ref 1:
This is the best resolution picture I have which is why I started here. Unfortunately it only shows the front of the hilt. Because of the good resolution and lack of perspective this scaled quite consistently every way I tried it – these are ‘mid-range’ ones that are closest to the others. (The minimum I had for the red button was exactly 50.8mm.)
Scale measure is the tube diam.

[Thumbs are example photo's of my screen showing, if you look very carefully, the thin pencil lines I use to measure.]

REF01.jpg
Scale01.JPG


A; 51.5mm
B; 35.3mm
C; 38.1mm [scale]
D; -
E; -

Blade diam; 16.2mm

Ref 2;
This looks like a decent picture but I could not get it scaled consistently. If scaled from the tube diam the clamp length was wrong – if I used the tube diam at the front it wouldn’t give correct tube diam at the clamp. They differ considerably from the others. I give the results but have little faith in them, there is just too much perspective & distortion from the photo reproduction processes. [ a photo of a print from ?]
Note; This is the view Kurtyboy overlayed to that shown my switch position as short. From direct measure it can be seen that the pommel to switch center is exactly 3 times the distance of the pommel to wire hole center.

REF02.jpg


Scale02.JPG


A; 49.48mm
B; -
C; -
D; 81mm
E; 27mm

Ref 3;
The classic hut shot. Shows everything but the switch position. Intermediate to difficult to scale as I have to enlarge a lot which gives a blurrier image than is good. Scaled using tube diam.

REF03.jpg
Scale03a.JPG


A: 51.3mm
B: 35.4mm
C: 38 mm [scale]
D: -
E: 25.7mm

Ref 4:
Forgotten where I borrowed this from. It does appear in Seth’s Saber bible. There is perspective here so I scaled for the red button from the tube diam between this button & the front. For the grip section I scaled from the clamp box length.

REF04.png
Scale04.JPG


A: 51.2mm
B: -
C: -
D: 76.5mm
E: 25.5mm


From these I drew up the PDF schematic. It’s sort of irrelevant if my switch position is short or not for my build as I can’t move it forward without altering the core sleeve &/or motor position & driveshaft lengths, which I’m not going to do esp. in view of the above. I would also point out that I originally chose the core sleeve at 5” because this was the longest whole number of inches that would fit without the 310 motor hitting the switch base. Once the 370 motor is substituted same switch base is pretty much a depth stop for the whole core.

For me the whole thing looks to be made according to the most convenient & easily read imperial measures that get somewhere close rather than slavish copying of dim’s from an actual graflex. (In my 1st drawing I used a measurement for the red button taken from my repro Graflex, which now looks like it was a mistake to do.)

Due to the position of the infamous grub screw at the front I’m guessing this is for bearing retention & that in this instance they seem to be using an NK roller bearing 19 – 20mm long (3/4” = 19.1mm , so screw is 1/2 way at app 10mm on black nose promo shot – no hight involved so I can get this center reasonably well)
I’m using NK’s 16mm long which puts the groove 8mm back from the B-C angle.
 

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I'm curious as to your results with the glass eye and button. I was under the impression they protruded inside, which would get in the way of the motor and bearings! Or they were cut, ground and glued on... Seems stupid though.

This was one way I was sure the "pipe" stunt was a new, updated version of this. Similar emitter bevel but ... those graflex parts
 
If you look on my PDF drawing (which is 1:1 for all components) the base of the red button thread is just short of the bearing pocket, even after being inlet the depth of the outer tube. The glass eye threads just break through, or nearly so, the core sleeve so all that's needed here is clip off the coil spring.

I'm basing this off the Roman's repro buttons I'll be using. I don't have an early Graflex red button but presume it's the same thread inc. depth. I also don't know exactly what bearing was used but looking at the promo pic (which is the only one I know of that shows even a half decent look down the front end) it was no bigger OD than what I have used.

They may well have glued them in or just gone for a push fit rather than spend time tapping threads. The whole impression I'm getting out of this is speed was King & corner cutting mandatory. I'll be tapping threads as I think I'll need to repeatedly dissemble them & push fit in Alley will soon wear out.

For those who don't know the pic.
1.jpg
 
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MAN, i just walked past that PDF, sorry haha

Very interesting. I see the filler around the main insert you've been making. Headed to work atm, will read more in depth later.
 
Updated PDF general arrangement with cross section. PDF layout template - though I had problems getting my printer to print this properly so I did a cropped version too.

Edit < new better template with MK2 bevel profile now available in post #119 bottom of pg 6 >
 

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As mentioned I tried to print my template (a dozen or more times) before I got one decent one which printed about 100.5% even though it was set at 100%. It then dawned on me they wouldn't have used a template (as they'd have to draw it - takes too long & no photocopiers then) & all you need is an upper & lower datum line to measure along / from. This can be scribed directly on the Ally or onto masking tape. I'll use the one I went to so much trouble to print for the MK1b skin up as that's in stainless steel. I'll directly mark up the MK2b skin job.
 
Update:

Here's the outer tube wrapped in the good template prior to center punching at the hole positions.

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I pre-drilled the taping hole for the front grub screw in the core sleeve then lined it up with the tap hole I'd drilled in the outer tube before tapping. I usually would like to drill both holes in situ but there was no good way to stop the core sleeve moving while doing it that way. The grub screw bottoms into the groove in the front bearing. Here I'm holding the core in place with my finger while tapping the threads & the result.

035.JPG 036.JPG 037.JPG

Hole for the wires & switch were next. With the switch in position the core & motor rest against it with the grub screw lined up exactly depth wise. I couldn't have done that better if I tried (esp if you see how I fared later...)

038.JPG

039.JPG


Witness marks for where to cut the angle & center punch for the glass eye.
040.JPG

Center drilled & starting to pilot hole for the glass eye on my mill/drill. (Grub screw is fitted to keep the core from moving inside while work & is why I did this first.)
041.JPG 042.JPG

Opening up the hole with 1/2" slot mill. This is where things started to go wrong. I did the drilling with a chuck mounted in the milling collet & feeding with the quill working on the drilling lever. I forgot to lock off the quill when I took the chuck out & mounted the milling cutter in the collet & I had a good deal of vibration lowering into the stainless tubing using the milling z-axis turn wheel. Result is the cutter didn't follow the pilot hole & cut off center by about 3mm - oops (as I'm using a milling cutter & it can do this.) I did the pilot hole to line everything up for the milling and because slot mills don't cut that well in the center (end mills not at all).
043.JPG

I noticed & locked the quill when changed to the 15mm end mill to make the final tapping size hole but failed to notice I was now off center, so didn't make any adjustment when I still could. Having milled the final taping diam.
044.JPG

Tapping the hole - using a spanner to turn the head while holding down with the drill lever, again, unlocked quill (ie. as in drilling). This was tricky as I'm using a plug tap ground down to absolute minimum start taper & trying to start in a strong radius & in stainless steel which tough stuff. Got there in the end though.
045.JPG

But things got worse again. I took the hilt out of the milling vice to de-bur the outside of the threaded hole & then decided to run the tap in again by hand to freshen it up . Tapping into a radiused surface is tricky & I cross threaded & chewed up nearly all the thread I needed for the glass eye. To the point I ended up having to recess into the outer tube to allow me to seat the glass eye deeper. Not what I'd intended. I also had spend some time removing the threaded part on the outer tube with a file as it was no longer in sinc with that in the Ally & tidy the threaded part in the core. (conveniently forgot to photo that mess.)

Note the big scar on the core from the hole where internal burs on the inside of the outer tube meant I had knock the core out with drift! What a pigs ear!
046.JPG


Not quite as bad with the core fitted & glass eye in place (note vestige of coil spring needed to keep the glass lens in place).
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048.JPG


Even though the glass eye projects into the core now it's still well clear of the moving parts.
049.JPG

It's not too bad overall, I've about 1 1/2 turns of thread holding the glass eye in & can screw it in firmly but definitely nothing to be proud of as it's still quite noticeable end on.
050.JPG


& I've got it all to do again for the red button - with a shallow blind hole... :sick:
 
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How have I only just seen this thread? This is fantastic! Added to my watch list :)
 
Thanks DP. Just in time to see me screw up an ally tube.

Here I am measuring out 1 3/16" when I should have been doing 1 3/8".
051.JPG

Doing a bit better with the holes for the switch & wires.
053.JPG 054.JPG

But not on the off set for the switch. Not sure quite how I'm getting so much wrong other than I'm trying to replicate the speed it would be done in a prop dept, not using a center drill 1st that sort of thing.
055.JPG 056.JPG

Fortunately (as I don't have a 10mm drill for the switch hole) I'd used a 9mm drill, so I could enlarge just one side with a dremel & small sanding drum.
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Then there's the grub screw hole I drilled in the wrong place as I didn't check my measuring (speed remember). Compare to my revised positioned.
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Luckily I can fix this. Chamfered the hole edge inside & out with a little ball stone on my 'dremel'.
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Turned a little ally plug about twice as long as the wall thickness which I then squished in place with Mole grips. A bit 1 1/4" bar wedged inside as a dolly & planished the outside with the pien of a small ball pien hammer. Dressed with files. Couldn't get the inside as neat as I could only squish with the mole grips but it's good enough.
060.JPG 061.JPG

I'm just going to have to be more diligent & quit the 'authentic' speeding. Using the set square to mark out wasn't a good idea but I found using a strip of paper with marks for the circumference & diameter useful. A wider strip with marks for the button positions would be better & quite quick to do & re-usuable,

I only discovered my grub screw measuring mistake when trial fitting the switch & the core with motor & finding there was an unexpected gap between the motor & switch - also that one terminal of the motor was close to hitting the switch. Which got me thinking. Is this why the real grub screw was offset, if they did use a core like mine & fitted like I'm doing with grub screw position pre-drilled before fitting to tube & with a fixed motor, they found they'd have to offset because of the motor terminal...

but that's a lot of 'ifs'.
 
That's an impressive patch up. It's cool that you're not just recreating the prop, you're retreading the steps. Love stuff like this :)
 
I find doing the step tracing. in conjunction with the making, leads places I otherwise would not think of. Such as a new trial for a Mk3 coreless version to test a method reproducing the look of the black nose promo saber front 'bearing' face which my current exposed roller bearing / ball race types don't quite match.
 
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Nice work - I'm sorry things went so wrong, but it honestly looks like you're saving the day.

A couple years ago I tried drilling and tapping one of these stunts for the red button (an empty tube, so basically the prop without any innards) and then realized the round surface wouldn't leave more than two threads, and thats why Graflex pulled shoulders to get a flat surface.

Keep up the good work!
 
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