Russrep Obi parts: Issues with Accuracy

[Excelsior]

I'm creating this thread in order to bring up some issues that I've noticed regarding the accuracy of Russ' recently completed Obi ANH grenade replica run. My purpose is solely for discussing how to improve these parts. I've used some pictures that belong to others for the sake of comparison--I apologize if they are yours, and if you wish to have them taken down, PM and I will do so.

The first thing that seems off to my eye is the profile of the windvane sleeve. Here is a comparison that I did to show what I'm seeing:

The other issues with the grenade involve the chamfering around where the frag body meets the brass neck, in addition to the thickness of the frag body in this area. Here are several pictures again highlighting what looks off to me (from left to right--an original grenade, the chronicles Obi saber, and Russ' replica):

I think the Chen grenade (thanks to Franz Bolo for the pic) was closer in this aspect, though the edge of the steel still seems a tad too thick to me:

The only other things I'd like to mention while I'm at it are:
-On Russ' balance pipe replica from last year, the chamfering around the small holes on the top is missing--here's an old pic of an original:

Hopefully Russ can rectify this in his next run, and perhaps allow the rest of us who so wish to send our old ones back to have the chamfering done. It's a minor detail, but that's what this saber is all about, after all! Additionally, it would be nice if Russ could offer some kind of bead-blasting option for the emitters as well.

-For the windvane sleeve, I think it would be nice to see perhaps a bit of research into the possibility that nomenclature was present. Although our reference photos don't really show it, I think there's a strong possibility that it was on the original prop. A nice option would be to somehow have this etched on (stamping would likely be too expensive), although I'm sure that most would not care/want this detail present on their replica. I've attached a picture of an original grenade--*EDIT: from inert-ord.net--that seems to have the correct windvane sleeve profile, and I think that this could be used to get an idea of the placement of the lettering:

 

[Serafino]

The last picture is from the inert-ord site. We do have permission to use his images, but only so long as they are credited.

 

[franz bolo]

Hey, that's my old grenade! :lol

FB

 

[Excelsior]

lol sorry! I hope you don't mind me using it--I'll credit your name to it in the post. This is what happens when you accumulate pictures for personal reference--after a while you have no idea where you got them from.

Hey, that's my old grenade! :lol



FB

 

[Serafino]

Seo, although I have been assuming that a visible chamfer is present on all balance pipes, it has come to my attention that I have been forgetting one example which has so little chamfer that it is not noticed by the naked eye, and that's the one which I believe was shown to the machinist for Russ' project.

So because the chamfer can't be defined in the photo we have of the original prop, and since originals are anywhere from apparently nothing to very obvious, the only way to figure out how much of one there should be is to take photos of one of Russ' at the same angle and distance and compare via overlays and all the usual (for me, anyway) tedious research process. If the apparent hole size is bigger or inconsistent, then this would be some evidence for a chamfer of a given size, which could then be included on the next run.

If anyone's got time to rigorously match the perspective and angle (and hopefully similar lighting) in a photo I'll be happy to do some comparisons. I just don't have time to set up for the photo right now.

FWIW back when I did the research for the Obee1 emitter I ended up with about the same hole size as on the originals, which tells me there wasn't enough chamfer on the prop to make me think the holes were larger than their main diameters.

I am all for taking a careful look at this to make sure we've got the right idea. But I'm beginning to think it's going to be one of those details which remain a personal judgment since it is not clear in the reference. Maybe we will end up with some tutorials for putting a custom chamfer on one's own BP at home.

I'll be back to this thread in about a day.

 

[Howard]

I'll address these issues today - when I get the time (I have the kids home on Easter holiday).

For the time being, all I can say is that it's important to concentrate on the prop photographs, rather than the various and varied dims of several examples of grenades and balance pipes when speaking of accuracy.

 

[scarf man]

for the time being, all i can say is that it's important to concentrate on the prop photographs, rather than the various and varied dims of several examples of grenades and balance pipes when speaking of accuracy.

qft

 

[Howard]

To address these points:


The windvane sleeve.

On the replica it measures 7.5mm.*
I've looked at this time and time again, holding the replica infront of the hi-res shot in Photoshop, moving the replica backwards and forwards with one eye closed, tilting the replica so the angle drops slightly away, with the windvane sitting on the topmost thread.
If it is a little short, then it's in the region of 0.4mm - 0.6mm.*


The frag body top edge.

This is 1.2 to 1.3mm on the replica.
For my money, this is a difficult call. It could be in the area Seo points to in his comparison is damaged - I'd go as far as to say it's almost a certainty, considering the condition of the prop grenade in general - which would perhaps 'squash' this area in the picture of the prop and cause the highlight we can see.
Okay - the other real grenade points to a thinner measurement here - but we must remember none of these grenades are identical. All exhibit different characteristics throughout their dims, so taking one as a benchmark is problematic and far from being a good example of how the replica should be.

Balance pipe hole chamfer.

As Andres pointed out, my original BP was used to produce the replica.
My BP does not feature a chamfer on the holes. However, it was agreed the holes on my BP are slightly larger than seen on the prop, and this was factored into the blueprints for the replica as the hole size was reduced a little to match the prop.
Now, if a chamfer is added to the hole size it will make the holes appear larger, once the replica is photographed to match the pic of the prop above.
For the record, the blueprints which were drawn up for this replica do not feature a chamfer.

From the only picture we have it's very difficult to say if the prop's holes feature a chamfer.
Once again, using other original balance pipes as an example as to how the prop should or would have appeared is problematic - as just because the average feature a chamfer in no way whatsoever proves the prop featured a chamfer.
Is it a deliberate chamfer, or wear caused by the components usage? Chris's BP looks very worn in the pic above.

Looking at the picture of the prop again, I'm convinced the prop holes do not have a chamfer.

Windvane sleeve nomenclature.

IIRC, there were more than one factory producing these grenades? Therefore, which factory produced the prop grenade?
This is obviously impossible to determine from the reference we have.
We could guess, but that's all it would be.
We could have etched the nomenclature into the replica as per the Parks replica, and this possibility was discussed at some point during the process of development, but we decided against it, as there's no clearly deciding evidence of it on the prop.
If it had been added, we'd have members building an AFBB saber having to sand and polish out the nomenclature, and undoubtedly members building a weathered version doing the same.
It seemed pointless to add this at an extra cost when ultimately the majority would have had to remove it themselves.
Oh, my BP also has nomenclature, but we decided to omit this also, as it's not identical to the prop as it's an assembly reference number.

*All dims are within tolerance as per the blueprints.

 

[Excelsior]

I appreciate your taking the time to look into this Howard. I do not have the capability of doing extremely in-depth analysis and scaling of these pictures, and I respect what you say. Regarding the windvane sleeve--the discrepancy still seems blatant to me. You say around half a mm; to my eye it looks more along the lines of a full mm (but again, I'm only going by what I can see--perhaps someone else can do a proper comparison). I understand the angle of the sleeve is extreme in the picture of Russ' grenade above, but even by looking at the sleeve in person it does not seem to match with the chronicles pic. The difference may be slight, but it is noticeable to me.

Concerning the frag body edge--you're right in that we cannot rely 100% on pictures of other original grenades because they all varied so much. However, I chose this particular picture of an original because it seems to match up to my eye exactly with the chronicles prop for this particular detail. Though it cannot be considered canon, I still think it may give a good idea of what the prop grenade was more like.

Concerning the balance pipe hole chamfers, I think there's a good chance they were present on the original. I've attached a photo with green boxes surrounding areas that look to me like highlights on the edges of the chamfering.

And about the nomenclature on the windvane sleeve: I completely understand why you left this detail out on the replica, and--you may be surprised to read--I totally agree with that decision. Perhaps I wasn't clear enough--I know full well that most collectors would rather not have this detail present on their grenades, but personally I would, and perhaps there may be others out there who feel the same. My call was only that more research be conducted on this detail. Most grenades had the nomenclature, I believe, so based simply on that there's a good chance that it was also on the prop. How many different grenade factories were there? And each inscribed its own insignia? I thought that they all simply said "Cotton Powder Co. etc." Of course, the argument that this is all speculation is perfectly valid. I'm not expecting this detail be added on the next run or anything, but it would be nice if we could figure out what the original 'possibly/probably' had based on comparisons with pictures of other similar grenades and, dare I say, the high-res chronicle pics--if anything can be discerned from them--and then see if someone has the capability to etch the pieces on a case by case basis.

 

[Howard]

Many thanks, Sean.

Regarding the chamfering.
What you're seeing as chamfering is actually the light catching the inside edge of the holes at the 3 O'Clock position, 7 O'Clock and the 10 O'clock positions. These features pointed me toward the theory that the ring of holes sat on a slope, which later turned out to be the case when the BP was found.
I don't know what's going on with the hole between 9 and 10 O'clock - this could be a bright area caused by a dent.

Regarding the windvane sleeve - if I get time (it won't be today, unfortunately) this week, I'll set up a comparision shot to see where we are regarding the measurement. Saying this, when comparing the replica to the Chronicles picture it's surprising how far back you must tilt the replica to match the angle of this shot.

 

[Excelsior]

bump--it's been a couple weeks, anyone have any other thoughts?

 

[Jedi-72]

I've got my Russ parts and I love them. No complaints at all. There can never be a "definitve" forensically indentical replica of the greande because the grenades varied so much from one to the next, and from maker to maker, and who knows exactly which one was used in the film. People have built replicas using real grenades, and they still differ from the screen used one. It's like trying to copy a signature. Every time you sign your name, it looks the same but varies greatly in the details. The same is true of this grenade. I need no further refinement. This IS my Obi saber.

 

[TazVader]

Yup same with me. I love mine and the fact Russ and co have got this far with all the "Possibles" made as definite as they are able quite a feat in my book.

Well done guys and for those who aren't happy I am sure Russ is happy to talk and deal ect ect he is after all a STANDUP GUY. I sure don't understand how he's been able to keep track of all the parts, option ect ect. A few mistakes ect are bound to happen.

Looking forward to seeing this sucker completed. All I need is a pommel lol

Regards
TAZ

 

[TridCloudwalker]

Chiming in as well to say that I love my parts. I've never seen better looking ones, and when it comes to the unidentified parts like the cone and the spacer, I love his finished interpretation.

 

[Jedi-72]

I would re-title this thread, and remove the, "issues with accuracy" bit, especially since you're basing your observations on photos as opposed to a physical piece in your possession. It implies that the piece is inaccurate when that just is not the case. There was no "standard" grenade. Each was unique in its' own way...just like little snowflakes. Make a replica "accurate" to a given grenade, and then somebody who has an original that differs in some way, as they do and as can even be seen in your pics of two originals, and someone cries, "that's not accurate". Russ NAILED this about as much as one could hope for, and with a level of detail and accuracy superior to ANYTHING that's been done before. Short of buying an original grenade, which I ain't about to spring for and which would still wind up being "inaccurate" compared to the screen used one anyway...short of that, THIS is IT. This is the one. This is what you want folks.