Chroma - Lasercut Acrylic 4x5 Field Camera

Hi Steve. What material did you use for the inner/outer layers?
I used an old changing bag which had broken zips. It's the perfect light proof material.

The alcantara I'm using isn't holding the creases too well so is proving 'challenging'!
Mine needed weighing down with a couple of heavy books for quite a while until they learned what their new shape should be.


Steve.
 
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If any of the bellows don't work out Steve, I need a new gaiter for my gearstick.
 
Yes. And Hogwarts needs a new Sorting Hat!
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I can't even get the folds to stay in place long enough to get a book on them unfortunately. Even with an extra few pairs of hands I reckon it's a losing battle!

Really enjoying this thread, am about to embark on a couple of projects combining photography and electronics - that clip regarding rotary encoders will be particularly useful.

Not having any experience working with alcantara, I was wondering if making three or four folds and then clamping tightly with cauls might encourage a lasting crease? As it's a polyester/polyurethane composite, would applying heat (hairdryer or similar) help matters?
 
Thanks for the comment @RazorHoof, I'm glad you're enjoying the build thread and my electronics will help :0)

With regards to the alcantara, the main issue is that it doesn't really hold a crease very well, even when clamped, so it proved too difficult to get into the correct shape to weigh down. I tried using a bowl of boiling water to steam the material as well but that didn't give any improvement either. Having looking at the dark bag material more closely I think it will hold its' shape much more effectively although alcantara looks better!
 
It's been a bit quiet on the 4x5 front for me recently but it's still ticking along! I haven't built the bellows yet, I'm waiting for the body to be ready so I can build them around it. I have been refining the design a bit though to make it look a bit less 'industrial'! Mainly playing with some of the sizes and rounding the corners. As it stands, every part will be cut from one sheet of 6mm material. The first build will be made from MDF to test the alignment/sizes on something cheap. once I'm happy with it, I'll make another out of 6mm acrylic but as it's not a standard size it will have be ordered in so I want to know it's right before I do.

Render1 by Steve Lloyd, on Flickr

Render2 by Steve Lloyd, on Flickr

There are a few parts that might not work too well in 6mm material, particularly the lens board and brackets. I'm going to test them out first anyway and make a decision after that :0)

For reference, the rear standard is 30mm thick in total (layered from 6mm pieces that are essentially frames so won't be heavy). The front standard is 18mm thick (3 layers).

If anyone's interested, there's on online model available here that can be rotated/zoomed to see more detail.
 
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Wow, 2 updates in the same week is some kind of record! I've just spent a few hours slaving over a hot laser cutter and came home with a new tortoise sun shelter (don't ask!) and configuration settings for cutting 1/2/3mm rebates into MDF :0)

The pieces are going to get cut tomorrow but it will take a few hours to do all the rebates. I should have the completed pieces ready for the weekend though. Getting exciting now.
 
It's been a bit quiet on the 4x5 front for me recently but it's still ticking along! I haven't built the bellows yet, I'm waiting for the body to be ready so I can build them around it. I have been refining the design a bit though to make it look a bit less 'industrial'! Mainly playing with some of the sizes and rounding the corners. As it stands, every part will be cut from one sheet of 6mm material. The first build will be made from MDF to test the alignment/sizes on something cheap. once I'm happy with it, I'll make another out of 6mm acrylic but as it's not a standard size it will have be ordered in so I want to know it's right before I do.

Render1 by Steve Lloyd, on Flickr

Render2 by Steve Lloyd, on Flickr

There are a few parts that might not work too well in 6mm material, particularly the lens board and brackets. I'm going to test them out first anyway and make a decision after that :0)

For reference, the rear standard is 30mm thick in total (layered from 6mm pieces that are essentially frames so won't be heavy). The front standard is 18mm thick (3 layers).

If anyone's interested, there's on online model available here that can be rotated/zoomed to see more detail.
It's looking good Steve - definitely more than just functional in design!
 
It's looking good Steve - definitely more than just functional in design!

Thanks. I'm trying to make a balance between functionality, size and design without trying to copy existing large format cameras from the likes of Wista/Intrepid etc. Also, by using laminated parts cut from a single sheet it should keep the cost down too.
 
Thanks. I'm trying to make a balance between functionality, size and design without trying to copy existing large format cameras from the likes of Wista/Intrepid etc. Also, by using laminated parts cut from a single sheet it should keep the cost down too.

Nothing easy then?
 
Looking seriously good but does it have to be so "chunky" could you get away with thinner acrylic to cut the weight even more.
 
Looking seriously good but does it have to be so "chunky" could you get away with thinner acrylic to cut the weight even more.

Thanks Ashley. It's designed around 6mm sheet to be a happy medium between weight/strength and also give me enough depth to cut the various slots required to clip a standard 4x5 DDS holder (max 3mm deep). I've also factored in a 3mm rebate/rotating infill to allow me to rotate the back. I think I'll get a feel for the overall size once the MDF version has been cut and go from there.

Ideally, 4mm sheet would be easier to get hold of in Acrylic but I'm not 100% sure how strong it would be when the rebates are cut into it.
 
2 ply 6mm = 3 ply 4mm. Rather than cut slots, you could "simply" leave suitable gaps in one of the plies - no potentially weakened rebate slots.
 
2 ply 6mm = 3 ply 4mm. Rather than cut slots, you could "simply" leave suitable gaps in one of the plies - no potentially weakened rebate slots.

That's definitely a good call. After spending some time working out the power/speed to rebate the 6mm MDF I started thinking about using thinner layered pieces instead. With the current settings, the laser is cutting passes in 0.01mm intervals to ensure that the parts are smooth. As you can imagine, that's going to take quite a while to complete!

The rear standard has various 1/2/3mm rebates to contour around the DDS holder along with 3mm rebates to form the rotating section. Apart from that, the base has a 2mm rebate to drop in the focus rail but that should be pretty straightforward. I'll have a look at the design to see how easy it would be to just cut pieces from 1/2/3mm material instead.
 
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I've now split and redrawn some of the pieces so the majority can just be cut from two smaller sheets of 6mm & 3mm MDF. There's also one small piece of 2mm Acrylic that will need a 1mm rebate to be cut into it but it's much less work than the original design.
 
The updated pieces 'should' be getting cut today so I'm genuinely excited about how they will all come together. I'm expecting some re-work like any new design and may need to factor in some upright supports to strengthen the rear standard but I'm hoping that 27mm thickness slotted into a 12mm base should give it enough rigidity. Fingers crossed!
 
Steve, looking at post 89 I'm confused about whether the rear standard (?) is fixed to the bottom piece? If so, it won't be very portable, I guess.
 
Steve, looking at post 89 I'm confused about whether the rear standard (?) is fixed to the bottom piece? If so, it won't be very portable, I guess.

The rear standard slots into the base in one piece with the bellows attached. My plan is that this is a secure enough joint (its got staggered T-joints) to hold the back in place with friction. When it comes to putting it away, the rear standard/front standard will separate from the base as a single unit with the bellows between.
 
Just out of interest, what's the cost involved. Could you run these off in kit form once the process is ironed out.
 
Just out of interest, what's the cost involved. Could you run these off in kit form once the process is ironed out.

At the moment it's cost me £7.99 to pick up a sheet of 3mm MDF. Moving forwards, I have thought about a kit form build, a bit like the older Bulldog cameras. The main issue with costs will be the bellows as there's no cheap way of having them supplied by someone else because of the time involved making them.

I've already spoken to a few suppliers and they're averaging £60-£100 for a standard bellows. Intrepid make their own in-house which is the most sensible approach although there's much more work involved then. I've got a set of lasercut slats ready to go (thanks the Steve on here) and I think that could be the most cost effective way forward and basically laser cut all 3 layers.

Ignoring the bellows, all material for the main body should be less than £20 plus laser time and assembly.
 
You can get plenty of pre owned bellows off the bay for under £40 you just have to hope they're on good nick. A 5x4 for under 100 is pretty damn good though.
 
I reckon the actual material cost for a new bellows would be less than £20. The higher cost is the labour in assembling it and cutting the slats etc. If the slats and inner/outer material were laser cut it would make assembly much faster so it's something I'll look into once I've built my first complete camera.

The only issue I have is that I don't currently have any LF lenses to test the camera with so I may be looking for a willing volunteer to do some product testing :0)
 
Well, if you ever felt like making them in kit form, I'd have one! Sourcing my own bellows, glass and lens would be part of the fun :)

Thanks, I'll keep you in mind :0) When it's first cut it will be a pile of parts that will need to be glued/clamped to make the complete body. I'd guess that a 'kit' would have the main body ready assembled/glued rather than being a flat-pack!
 
Thanks, I'll keep you in mind :0) When it's first cut it will be a pile of parts that will need to be glued/clamped to make the complete body. I'd guess that a 'kit' would have the main body ready assembled/glued rather than being a flat-pack!

Glueing/clamping is also good! I had fun making the Lomography-style Konstructor and Recesky cameras... this would be a whole other level :p
 
I've been down to see my mate with the laser cutter tonight and have brought back the 3mm parts with me. I need to make a few updates to the models using a different programme that works better with the cutting software than Sketchup but other than that it's coming together nicely. The circles from Sketchup aren't 100% smooth (it draws circles using small straight edges) so will need a bit of sanding but are already rotating nicely :0)
 
I've been down to see my mate with the laser cutter tonight and have brought back the 3mm parts with me. I need to make a few updates to the models using a different programme that works better with the cutting software than Sketchup but other than that it's coming together nicely. The circles from Sketchup aren't 100% smooth (it draws circles using small straight edges) so will need a bit of sanding but are already rotating nicely :0)

Are Sketchup's pseudo circular straight edges tangential (ie outside) or connecting points on the circle (ie inside)? Could make a difference to the fit of parts. I'd be guessing the latter, inside the circle, so sockets will get bigger with sanding, and male parts smaller... could maybe leave things a bit loose?

(I'm really nervous about the potential for deliberate misinterpretation here!) ;)
 
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