My Crazy E11 Adventure

[QuartZ]

Alright, I've got some more progress to share. In my last post I was preparing to drill some small holes to help position some of the detail parts that get mounted to the receiver tube. What I didn't think about is that I should probably model those part first, measure them to make sure they are accurate AND work together with the receiver tube and muzzle assembly printed parts before drilling into the aluminum tube. So, I started with the front sight guard. I measured off my real part again, and was able to come up with the following in Fusion 360:

 

 

It doesn't have the knurling, I still gotta try to create that pattern and use it on some of these parts. I don't think my printer will handle that fidelity, but I learn something in the process I'm sure. Ok, so once I had that piece looking pretty good, I went back to the muzzle parts and checked how they aligned to each other. Here's one view:

 

And here' the reverse view.

 

Things looked good so I ran off a print of the front sight guard. When it was done I was able to double check where I was drilling this little hole and then I went for it. I made it a bit too big, but when I mount the part here it will get filled in anyway so I'm not worried.

 

Below you can see what it looks like with the guard part sitting in place temporarily. I haven't used any adhesive to mount this yet, the little locating pin and hole allow it to stay put like this.

 

I just have to do the front flash guard piece and then I can drill that little hole as well. That will wrap up the front end of the receiver. I'm currently working on a model for those little "C" shaped guards right now.

 

See you soon,

-Dana

[Thrawn's guard]

Very impressive work Dana and great attention to detail. I love what you have done so far and will be following your progress with great interest.

[QuartZ]

Thanks for the kind words Chris. Your E11 build thread is pretty epic! Thanks to everyone cheering me on...let's get back to some more parts.

 

I managed to complete the 3D work for the flash guards. It's a deceptively simple little piece. Really the shape of this has curves from all sides and I also wanted it to feature a curved profile on the bottom that matches the 38.1mm tube. So here's the final model:

 

I printed it out and drilled that tiny little hole that the pin fits in (again I went a bit larger than needed here). Here's a photo I snapped with all of the parts I've made for the muzzle end roughly in place:

 

It's starting to look pretty good (despite all of the printed parts being in desperate need of sanding/filling) I finally recognize that signature Sterling muzzle area. I think the bayonet lug on the other side will be next. How it mounts seems odd (I don't know too much about it yet) but since it impacts the front end of the receiver tube I may as well look into it and get this area all wrapped up.

 

-Dana

[themaninthesuitcase[Admin]]

Nice work. I did some flash guards for my doopy Doo build and they are deceptively hard to get right. You've done an excellent job on these.

[QuartZ]

I think half the fun of this build for me is really getting to know all of the parts to a degree that makes me really appreciate the design and craftsmanship behind the Sterling SMG. It's such a simple open-bolt design but there's so much beauty in the execution. On to the progress. Today I sat down for a bit and worked on the bayonet lug as I had mentioned in my previous post. This is another really complex piece. Nothing is a normal shape and much of it was created with careful measurements and a good number of splines were used to get arcs I wanted: 

 

I'm pretty happy with it and I think it's time for a test print so that I can refine the model if necessary after examining a physical part. Time to fire up the printer!

 

-Dana

[QuartZ]

Snapped a shot of the bayonet lug test print: 

 

I already spotted 3 differences that I'd like to correct. The shape of the rear/top curved feature is too wide on mine and too flat at the rear. The front/top triangular cut needs to be widened a bit. And you can't see it in this picture, but the front face/profile needed some tuning (very minor). I think after that I'll add the under side post that's missing and figure out what I want to do for the weird piece that goes inside the receiver featuring holes that match the outside. Anyway, new bayonet lug test print in going on the printer...

 

-Dana

[QuartZ]

I forgot to post this yesterday, but here's where I ended up on the lug model. I resolved all of the concerns I had with the earlier version. Here it is from a different angle:

 

And here is a new print for comparison. It's hard to compare exactly due to it sitting above the tube OD and not in the tube as the real one is mounted. But hopefully you can see how close it is (if you disregard the 3D print layer stepping):

 

-Dana

[QuartZ]

Back with another quick update. I was able to quickly bang out the folding stock pivot and associated rivet-like retaining posts. These were pretty simple compared to some of the previous parts. I'm definitely not complaining! Here's the main part that is normally soldered to the receiver tube:

 

 

 

And here's the model of the "rivet" which features the through hole that allows that thin metal pin to keep it from backing out. 2 of these are obviously needed to hold the folding stock in:

 

 

I'm moving on again, I think the rear sight would be fun to do next. Gotta finish everything that mounts to the receiver tube first. Getting closer....I think!

 

-Dana

[QuartZ]

OK, I got a little bit of desk time today so I worked on that rear sight. Most of the measurements were straight forward, and reference images of the disassembled parts on this site helped answer some design questions. So, here's how my model for the outer part turned out:

 

 

I chose to chamfer the sides of the notches on the rear curved edge because they really don't look like 90 degree edges on my part, research on other examples also seemed to indicate the edges are kinda beveled or something. Anyway, it's one operation in the history stack, so I can easily remove it if I don't like the way the print looks. I'll try and pop out more of the rear sight parts tonight.

 

Enjoy!

-Dana

[themaninthesuitcase[Admin]]

I'm really enjoying this build. Havign the real parts to measure up is really giving you great results.

[QuartZ]

I'm glad you're enjoying it. Thanks for your continued interest and support Chris! I couldn't agree more about having the real Sterling parts to use as reference. It helps tremendously but it also puts more responsibility on me to get it right given I have them (I really am trying to the best of my ability to create good 3D models for this project).

 

Ok, so I did get around to more of the rear sight pieces. Below you can see the aperture with the 2 peep holes. This one was really interesting and featured some tricky details. Of note, from the hole that the aperture part pivots (used to select which hole you want to look through) the two "sides" are not equal in height. As you toggle back and forth, you'll find one lower than the other. Almost tripped me up

 

 

And here is the spacer that gets used on either side of the aperture and rear sight guard (requires 2):

 

Finally, I wanted to post a picture of how all of those parts go together in the assembly:

 

So, parts wise, there's 2 parts I haven't created yet, luckily these are pretty simple. There's a small flat spring piece that is bent into an upside-down "U" under the aperture that creates a detent functionality. And of course the pin/rivet part that goes through the whole rear sight to allow the parts to pivot hasn't been modeled. I'm not sure how I want to do these pieces yet since they aren't ideal as plastic... I think I'll do them anyway in an effort to eventually have all of the pieces of the entire Sterling completed.

 

That's all for now!

-Dana

[themaninthesuitcase[Admin]]

For the pin I'd find the closest available aluminium or brass rod to cut to size. I'd assume it's an Imperial size so eBay would probably provide.

 

Some of the parts on this are tiny, begging to be SLA printed to ensure the detail remains.

[QuartZ]

SLA/DLP printers are great. We have one at work and it's really nice for small detailed objects (like most of these I'm making). The resin is a bit expensive, so I think my method of PLA printing and iterating makes sense for now. Although I am tempted to run the final set of parts I've designed on a nice printer to avoid the cleanup... I might still kick it "old school". Who knows.

 

Speaking of prints, here's the main part of the rear sight I printed to compare with the real part:

 

It looks pretty good. I might tweak one dimension.

 

-Dana

[themaninthesuitcase[Admin]]

Yeah SLA isn't great for itterating, unless you're loaded!  Though theres a new WanHao DLP machine that might make the machine affordable at least.

 

I'l be lookign at running at least some parts as a more detailed material, even SLS might be better for some but clean up is a pain.  I did some of my E-11 parts in SLS and painting is awkward.

[QuartZ]

I haven't been posting in this thread for almost a year! Well, I took a break from the blaster work and I've been working on the armor. Well, that's not entirely true. Before I took that break, I did create this 3D file for the receiver tube. Why? Well I'm going to look into getting a batch of them laser cut out of aluminum. I think that this version is really accurate (it's my third iteration from the ground up). It was very time consuming to pull all of the measurements from my Sterling parts. In fact, I now have 2 sets of demised Sterling parts so that I could compare dimensions across 2 samples to make sure I was getting this as close as possible:

 

 

 

There's a few of my other bits mounted on there for reference just so I could check how some key parts lined up. Oh, and I'll probably have to close up the magazine feed hole (seen in the second image) if I want to have these laser cut. I don't want to be accused of producing a functioning machine gun receiver. There's a few more bits to tweak, then I'll start talking to some shops. Any how, no idea how long that will take, I just wanted to post this since I forgot.

 

And, there's something else I worked on more recently...

-Dana

[QuartZ]

Tonight, I whipped up a version of the M19 scope found on several blasters. I did it for a reason unrelated to the E-11, but I think it's used on some of those as well (my Hyperfirm seems to have one on it). Anyway, it was fun to create. I still need to add the text on the lens ring area. Oh, and I haven't tried printing it yet. Here's some angles:

 

 

 

Most of the hole locations are just setup as impressions to be used post printing for getting proper drill placement. Some have countersink chamfers too (like the front 3 screws). I also left lips for lenses. The main body is hollow, it's built out of multiple pieces that fit together. Getting sleepy here... and I'm sure once I go to print one I'll find some things I want to improve. All in all, I'm happy with what I could bang out tonight.

 

Enjoy,

-Dana

[themaninthesuitcase[Admin]]

Looks like you're making great progress.  I like how you plan to use real hardware, always bugs me when people model in screws when real ones aren't that expensive.

[QuartZ]

Thanks, I think real hardware is good if it's readily available and inexpensive. I think I'm going to go back and tweak a few things before I print this. Mostly how the lens rings are designed. I think I got a few things wrong.

 

-Dana

[wirekat]

Great work Dana,

I ordered up a couple of aluminum tubes and not unlike you have started collecting parts and mods.

I 3D printed one a while back but the files were wonky so I have a few pieces to re-print.

Waiting on a Doopydoo as well.

Will you be selling parts? Sharing stl's?

 

Thanks,

Kevin