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Thread: SCSI2SD 3D printed brackets


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Permlink Replies: 9 - Pages: 1 - Last Post: Apr 28, 2015 10:39 AM Last Post By: bbraun
bbraun


Posts: 493
Registered: 7/25/12
SCSI2SD 3D printed brackets
Posted: May 3, 2014 1:13 AM
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I recently got a Form1 3D printer, so thought I'd see if I could print the 3.5" adapter bracket for the SCSI2SD. The print area of the Form1 is too small to print the whole 3.5" bracket in one shot so I'm experimenting a bit with a modified design.

First, I broke the adapter into 2 parts, a right and left side. I figure this should be fine, since all the mounting is done on the sides, and it gets the printable size down to something that fits in the printable space of the Form1.
Second, the Form1 prints differently than extrusion based printers. It wants to print on supports, away from the base platform. This means both printing time and material gets used for support structures, which I wanted to minimize. It turned out, it was both faster and less material overall to fill in the frame structure of the bracket and have fewer supports.
Third, I shortened the bracket a bit, since anything outside the mounting holes really isn't totally necessary for operation of the bracket. This also got the bracket to fit within the X and Y axes of the printer, rather than needing to angle it vertically to fit within the print area.

Here are pictures of the model demonstrating the difference.
The original bracket:


One half of the modified bracket:


I first printed one the way recommended for the printer: up on supports. This ended up taking a lot longer and a lot more material for the supports. It worked ok, there was nothing particularly wrong with it, but then I tried printing directly onto the build platform of the printer. This isn't recommended for a number of reasons, including the cured area spilling over along the edges, some inaccuracy of the thickness of the curing at the build platform, and the aesthetics of curing on the build platform may not be as great. But, I figured I'd give it a shot, and I didn't really care about the aesthetics much for an adapter bracket.
It ended up working out fairly well, I think. The thickness of the bottom plate is not consistent, but it's all there which is what counts. It also printed both brackets in about 90 minutes, with a minimum of resin used, so I'm calling it a success in this case.

Here are some pictures of the SCSI2SD mounted in the brackets, and then mounted on a 3.5" drive sled from a Quadra 800:





Sorry for the poor photo quality. I'm a terrible photographer.
dougg3

Posts: 190
Registered: 8/13/12
Re: SCSI2SD 3D printed brackets
Posted: May 4, 2014 9:40 PM   in response to: bbraun in response to: bbraun
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That bracket looks awesome! Nice work. I never would have thought of splitting the bracket into two, but that looks like it works perfectly.
bbraun


Posts: 493
Registered: 7/25/12
Re: SCSI2SD 3D printed brackets
Posted: May 5, 2014 9:28 PM   in response to: dougg3 in response to: dougg3
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Thanks! I've been experimenting with the bracket a bit.
I've shortened the bracket a little bit, since excess beyond the holes doesn't seem to buy much, and I've increased the thickness of the bottom portion. The biggest problem I've run into has been removing the printed result from the build platform, without damaging it. When the model is built on supports, who cares about damaging the part that adheres to the build platform, but when building directly on the platform, it gets a little trickier. I've experimented with adding some cutouts along the bottom of the brackets, to try to just get less surface area and less adhesion to the build platform, but it doesn't seem to have worked well. Resin gets caught in the grooves I've made and then gets cured when doing the upper portion, so essentially the grooves bought nothing except along the edges, which was still somewhat helpful to have notches to help in the removal process.




I also tried printing a single solid bracket in the shortened form, but I ended up breaking it in the build platform removal process. I've been experimenting with other build platform removal techniques, so maybe I'll try again. It's all new, still so much to try.
bbraun


Posts: 493
Registered: 7/25/12
Re: SCSI2SD 3D printed brackets
Posted: May 14, 2014 8:51 PM   in response to: bbraun in response to: bbraun
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Attachment oldmounts.jpeg (611.3 K)
Attachment newmount.jpeg (786.3 K)
Attachment interference.jpeg (939.5 K)
I've been messing with this a little bit more.
I had wanted a solid "floor" on the mounting bracket for full protection from any shorts between the case and the scsi2sd, particularly for mounting in things like the II/IIx/IIfx, but I also wanted to be able to print directly on the build platform of the printer, since a full bracket used about 22ml of resin, while the supports alone used ~30ml of resin. Unfortunately, the formlabs resin material seemed pretty brittle when I was trying to remove the print from the base plate, and I ended up breaking the bracket in the removal process.

I recently got some new resin from makerjuice and was eager to try out the new resin on the bracket. Removal from the build platform went super smoothly, so no problems there. But when I went to mount the scsi2sd in the bracket, I found the bulked up support for the holes in the vertical walls interfered with the mounting on the scsi & power connector side of the scsi2sd:


Since the design hadn't really changed, I wondered why I hadn't noticed this before, so checked my old brackets:


The old material was sufficiently flexible and/or warped such that I hadn't noticed. You can see the vertical wall kind of bending out away from the scsi2sd so it "fits".

I updated the model to remove the bulking around those holes to allow the scsi2sd to sit flat, and I think it works much better:
techknight

Posts: 110
Registered: 10/13/12
Re: SCSI2SD 3D printed brackets
Posted: May 27, 2014 8:33 PM   in response to: bbraun in response to: bbraun
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I am not very good at CAD other than PCB versions, one of the biggest reasons why I never jumped on the booming 3D printer bandwagon.

Nice thing is, all kinds of custom replacement parts for our macs could be made ;-)
bbraun


Posts: 493
Registered: 7/25/12
Re: SCSI2SD 3D printed brackets
Posted: May 28, 2014 7:20 PM   in response to: techknight in response to: techknight
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I'm not at all into CAD either, but you might want to check out openscad, it's basically CAD for programmers. That's what the scsi2sd bracket is in.
techknight

Posts: 110
Registered: 10/13/12
Re: SCSI2SD 3D printed brackets
Posted: May 28, 2014 9:35 PM   in response to: bbraun in response to: bbraun
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That makes it even worse for me. LOL. Yea, I can write programs but only in BASIC or the atmel AVR ASM, and then there is the 6805 ASM.

I am no good in java, or C, or any of those style languages.
bbraun


Posts: 493
Registered: 7/25/12
Re: SCSI2SD 3D printed brackets
Posted: May 31, 2014 1:25 PM   in response to: bbraun in response to: bbraun
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Attachment full mount.stl (998.4 K)
The stl file.
fraveydank

Posts: 73
Registered: 4/23/15
Re: SCSI2SD 3D printed brackets
Posted: Apr 27, 2015 11:09 PM   in response to: bbraun in response to: bbraun
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Oh good, I was dreading having to come up with one of these myself. Do you know if it's likely to fit the new, shorter one for sale? I would assume yes, but I haven't bothered to check yet.

I'll have to give it a try on my Prusa i3 when I finally acquire a SCSI2SD.
bbraun


Posts: 493
Registered: 7/25/12
Re: SCSI2SD 3D printed brackets
Posted: Apr 28, 2015 10:39 AM   in response to: fraveydank in response to: fraveydank
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I'm not sure about the new shorter model, I haven't had any of those. There's some different designs to try for the different printing methods. I've got an SLA printer, so had some different requirements.

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