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Introduction

You should have a good understanding of how acrylic cement works at this point. We are now going to introduce the use of epoxy. The epoxy acts as a barrier to the water and allows wires to "pass through" the endcaps.

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  2. Cut just past the plunger stopping point and at the 2.0 mL mark.
    • Cut just past the plunger stopping point and at the 2.0 mL mark.

    • The cut on the left needs to be to the left of the end point of the syringe so it will have a place to seal underwater.

    Sorry which kind of syringe do you use? The diameter is too much different! the plexi hole is about 9,4 mm the syringe is 6,5mm, so it dance inside!

    SERGIO GIUSTI - Reply

    Are you using the syringe that came in a kit or are you building from scratch. The syringe that we use has an outside diameter of ~9.25mm so it is a nice fit with the acrylic parts. You can find the part number and a link in the Bill of Materials

    https://docs.google.com/spreadsheets/d/1...

    Link http://www.amazon.com/Luer-Lok-Disposabl...

    If this was built from a kit please email our support team (https://openrov.zendesk.com/hc/en-us/req...)

    -Brian G.

    OpenROV (Sofar) -

    Hi Brian sorry I didn't see the syringe! was hide by the other components in the bag. Now I find it thanks for help reply

    SERGIO GIUSTI - Reply

    Glad to hear that everything was in the kit. Have fun with the rest of your build :)

    OpenROV (Sofar) -

    is it a problem ,and how is it corrected if the order of disc is onto the seringe is: 3mm then 1.5mm then 6mm, being the 3mm piece is flush with the closed end of the seringe. Is there a way to separtate the disc once glued ? or do i have to purchus another set of acrylic pieces and start again ?

    James Milne - Reply

    Hi, there may be a typo. It is 0.2 mL mark, not the 2.0 mL mark. Well, of course, it is very clear in the picture though. Nvm.

    Jianxiao - Reply

  3. Save the plunger. You will need it later.
    • Save the plunger. You will need it later.

  4. Cut the syringe tube with a thin hacksaw blade.
    • Cut the syringe tube with a thin hacksaw blade.

    What is the point of cutting off this part of the syringe

    Dan Britton - Reply

    The syringe is a vent port for the air. If it was not there then when you put the endcaps on the air inside the tube would compress and cause the endcaps to want to pop off. With the syringe, after you put the endcaps on then you put the plunger in to keep water out during your dive and the pressure on the inside of the tube matches the pressure on the outside.

    -Brian G.

    OpenROV (Sofar) -

    It goes through the non-pass through end.

    david - Reply

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  6. Make sure to sand both ends.
    • Make sure to sand both ends.

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  8. Use a paper towel to clean out the inside.
    • Use a paper towel to clean out the inside.

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  11. The endcaps have a large surface area that needs to be cemented together.
    • The endcaps have a large surface area that needs to be cemented together.

    • The best method of cementing the endcap parts together is as follows:

    • Note: These pieces are for demonstration purposes only. While holding one side, place the needle of the applicator between the two surfaces to be cemented.

    • Add a liberal amount of cement. The goal is to have cement completely filling the gap between the surfaces. Any excess or spills will evaporate quickly or can be wiped away.

    • Apply slight pressure with both hands while the cement cures.

    • Add acrylic cement around the entire edge of the newly cemented parts to ensure that they are completely joined.

    • Clean any excess off with a paper towel or cloth.

    • When working with acrylic cement it is recommended that you wear gloves, safety glasses, and work in a ventilated area.

  12. You are not going to use this piece right now.
    • You are not going to use this piece right now.

    Caution! In my kit there were 2 white acrylic pieces, but there were also a couple of pieces of clear acrylic that were covered in white paper instead of the usual brown paper (piece 5, I think). Make sure you have removed the paper covers from these pieces.

    Sean Leary - Reply

    Yes, this. This comment should be elevated in BOLD & RED to the main instructions above, and maybe to step 14 & 15. My white covers were not paper. They were shiny white plastic easily mistaken for white acrylic. The material bonds but with wrinkles and air pockets that don’t look like they’ll hold water and they’ll be exposed to the water side of the ORing. Now I’m stopped dead until replacement parts.

    Ciel - Reply

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  15. The hole is on the left side of the rectangular opening
    • The hole is on the left side of the rectangular opening

  16. When working with acrylic cement it is recommended that you wear gloves, safety glasses, and work in a ventilated area.
    • When working with acrylic cement it is recommended that you wear gloves, safety glasses, and work in a ventilated area.

  17. Make sure the holes are lined up.
    • Make sure the holes are lined up.

    Is there a way to align the "slits" of the disc perfectly. Or is eyeballing enough?

    Maneesha Pandey - Reply

    Eyeballing is as close as you can is the easiest way. - Brian G.

    OpenROV (Sofar) -

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  19. Make sure the opening is to the right side.
    • Make sure the opening is to the right side.

  20. Make sure the opening is to the right side.
    • Make sure the opening is to the right side.

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  26. Closed side of syringe down and flush with 3mm piece.
    • Closed side of syringe down and flush with 3mm piece.

  27. Open side of syringe up.
    • Open side of syringe up.

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  32. Angled part is to the right.
    • Angled part is to the right.

    • The disk should be centered with the syringe.

    Is there a good way to align the center of these larger pieces on the syringe center?

    Josh Stein - Reply

    The syringe should do a pretty good job of aligning the parts to be concentric. If you are having issues, please email support@openrov.com -Brian G.

    OpenROV (Sofar) -

    @ Brian G - Josh Stein is right. When you get to the 3rd layer (3 mm)/4th layer (6 mm) joint, the ID increases to form an eventual CBore with the syringe. Is visual alignment here good enough?

    Ben - Reply

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    Prior step is adding clear 1.5mm piece.

    This step is adding clear 6mm piece.

    The instructions should say this.

    Ciel - Reply

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    How long should I wait from when I cement this part before I do the superglue or epoxy steps? Minutes or should it cure overnight? Thanks!

    teds - Reply

    It depends on what type of cement you are using. Worst case, you should wait on the order of minutes for all of the acrylic cement to cure before moving on. -Brian G.

    OpenROV (Sofar) -

  37. The DB-25 connector connects all the electrical components to the controller board.
    • The DB-25 connector connects all the electrical components to the controller board.

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    I came to the conclusion that I royally screwed up and messed up my cabled endcap. I have glued it wrong and epoxied it into place. Please make sure you check everything before you glue parts into place. I had to buy the endcap replacement kit so I can fix my mistake. Impatience and rushing steps can lead to this so please be careful. It will cost me 60 dollars to fix this.

    Matthew Walden - Reply

    Later in the docs this component is called the heart of the system. On one side it connects to the boards inside the waterproof cylinder. On the other side it connects to all of the motors, batteries, external comms, and future expansion wires. Take your time on this step. Make sure the wires are pressed into their channel, the superglue seal is good, and the epoxy-ed area is filled in.

    Sean Leary - Reply

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  41. Use superglue to connect the DB-25 to the acrylic. This bond will also help the epoxy flow in a later step.
    • Use superglue to connect the DB-25 to the acrylic. This bond will also help the epoxy flow in a later step.

    • When working with cyanoacrylate (super glue) it is recommended that you wear gloves, safety glasses, and work in a ventilated area.

    Unopened Superglue has a short shelf life (~1 year). Opened superglue much shorter than that. Invest in new glue!

    Ciel - Reply

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  43. Do not get glue in this hole.
    • Do not get glue in this hole.

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  46. It is very important that the DB-25 is completely flat.
    • It is very important that the DB-25 is completely flat.

  47. Wait until the superglue has completely dried before completing this step.
    • Wait until the superglue has completely dried before completing this step.

    By pulling the wires through in groups, working from one side to the other, I was able to keep the wire paths parallel, and thus it was easier to make this fit neatly.

    teds - Reply

    Thanks for the feedback. -Brian G.

    OpenROV (Sofar) -

  48. These wires need to be flat and not protrude past the top piece.
    • These wires need to be flat and not protrude past the top piece.

  49. Double check that the wires are flat.
    • Double check that the wires are flat.

  50. Make sure to press down on the white piece directly over where the wires are during the entire time that the cement is drying.
    • Make sure to press down on the white piece directly over where the wires are during the entire time that the cement is drying.

  51. You will use epoxy to create permanent waterproofing for the endcaps. There are a few things you want to keep in mind:
    • You will use epoxy to create permanent waterproofing for the endcaps. There are a few things you want to keep in mind:

    • The epoxy has two parts that mix in the nozzle to get an even distribution.

    • Before you open the tube hold it upside down to allow the air bubble to travel to the top. Air mixed in the epoxy can cause issues.

    • Remove the cap, as well as the tip and then install the mixing nozzle.

    • The first part of the epoxy might not be properly mixed so squirt out a little to make sure that the epoxy you do use is evenly mixed.

    • Wear gloves when handling epoxy and have paper towels on hand to clean any surfaces that it happens to drip on.

    Can I use a grey epoxy, or does it need to be transparent? Also, should I be worried about the viscosity of my epoxy being different than the recommended one?

    I'm considering using jb weld - 3960 psi, Set time 20-25 minutes, Cure time 15-24 hours. Provided I mix correctly without the mix injector, would that work well for this purpose?

    Felipe Adachi - Reply

    It looks like your question was already answered on our Forum. https://forum.openrov.com/t/epoxy-requir...

    OpenROV (Sofar) -

  52. Now we are going to use the epoxy.
    • Now we are going to use the epoxy.

    • When working with epoxy it is recommended that you wear gloves, safety glasses, and work in a ventilated area.

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    Is this electrical tape? If so what is the point of it?

    Ethan Lane - Reply

    I think it is just to prevent the epoxy from flowing elsewhere

    Fe3C -

    Ethan - Yes it is electrical tape. It is used to keep the epoxy from flowing out as it is curing.

    OpenROV (Sofar) -

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  57. You will fill the wire cavity with epoxy through this hole. It is designed to allow the epoxy to flow through.
    • You will fill the wire cavity with epoxy through this hole. It is designed to allow the epoxy to flow through.

    • The epoxy will settle after a while and the level in the hole will go down. Check back after 30 minutes and fill with more epoxy in this hole.

  58. The epoxy will flow around all the wires. Make sure to wiggle the wires around so the epoxy gets in between them all.
    • The epoxy will flow around all the wires. Make sure to wiggle the wires around so the epoxy gets in between them all.

  59. If epoxy leaks from around the metal part of this connector, use a paper towel to wipe it up before it hardens.
    • If epoxy leaks from around the metal part of this connector, use a paper towel to wipe it up before it hardens.

    Sometimes epoxy will leak from the DB25 pins. When this occurs you must clean the epoxy out of the holes before the epoxy cures. In my case I used a thin wire and repeatedly, stuck the wire in the epoxy filled terminal and then wiped it clean. It required about 120 insertions of the wire before the wire would be completely free of epoxy. This occurred on 3 of the 25 pins.

    Paul Young - Reply

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    A good way to do this is spin the endcap while applying the epoxy...

    OpenROV (Sofar) - Reply

    It's not completely clear from this picture.... I think the hole is not supposed to be filled, is that correct?

    Adrian Cotter - Reply

    I had the same question about this step.

    Rick Fritsch -

    The hole should not be filled. Sorry for the confusion. -Brian G.

    OpenROV (Sofar) -

    it’s not clear what we are aiming to do with step 62-63. Is it simply to fill the gap between the syringe and the hole it passes through in the acrylic circle (piece 9)?

    Chris O - Reply

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  66. Fill until epoxy comes out this end.
    • Fill until epoxy comes out this end.

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  71. Continue your build by progressing to Guide 3.
    • Continue your build by progressing to Guide 3.

Finish Line

50 other people completed this guide.

OpenROV (Sofar)

Member since: 09/28/2013

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12 Comments

HELP!!!! STEP 11 is confusing me!!! We don't have any endcap pieces that look like the ones in that picture. I'm starting to think that the illustrations from STEP 11 are from an earlier (maybe a 2.6???) version of the OpenROV. Can someone please confirm this?

We don't want to continue if we are missing pieces needed for our build

Joey Maier - Reply

Those pieces in Step 11 are for demonstration purposes only to explain the concept. Starting at Step 12 you should have all of those parts (yours will be clear though instead of smoked colored). -Brian G.

OpenROV (Sofar) -

I had to do some tipping to get theair bubbles out of the wire wet port. By taping off the connector side hole and tipping the air bubble to the wire side I was able to inject a second time which pushed all the air out. Next time I would inject from the bottom with the angular side upwards.

cmacphee - Reply

Thank you for the feedback! -Brian G.

OpenROV (Sofar) -

Step 32 Is there a good technique to assure these pieces are centered on the syringe? The previous section used the motor shaft to assure alignment, but that isn't an option here. The hole diameter on the larger pieces is much bigger than the syringe, so using the syringe as an alignment jig won't work either.

Josh Stein - Reply

How much bigger is the piece that you are seeing. They should be pretty close. If you send a picture to support@openrov.com we can help you out. - Brian G.

OpenROV (Sofar) -

To what extent do the DB-25 & the Acrylic Plastic handle heat?

I seem to have gotten extra epoxy drips on the nozzle in steps 57~60, and while removing the nozzle a droplet of epoxy got into one of the ports of the DB-25. I am planning on using the heat gun to melt/weaken the epoxy and then remove it. If this is going to damage it please let me know, I'll try to figure another alternative.

Thanks!

Ahmed Al Hameli - Reply

I just used a snapped steel string from my grand piano to poke a hole through the epoxy that got in the hole, then used the tiniest sewing needle i could find around the house to dig it out.

Tamanya -

Step 47: It's recommend to smooth the edges of the hole, where the wires go through, a little bit. Otherwise you could damage the isolation of the wire at sharp edges. I also fixed the DB connector with hot glue to avoid/close gaps where the epoxy glue can go through later.

Andreas Franz - Reply

About 2 Ton Epoxy: I couldn’t find the exact product in Romania and the company that sold me the acrylic cement offered another adhesive in place of 2 Ton Epoxy called SCIGRIP SG5000 (Methacrylate adhesive) which they say it’s even better, but at a closer inspection of the data sheet there are some differences like: Tensile strength - 35-40Mpa , Viscosity, cps - Part A 90,000 - 150,000, Part B 150,000 - 200,000, (they don’t provide viscosity for the mix but I guess should be somewhere in between), and the one worries me most - Maximum Tensile Elongation - 5 - 10% (as compared to 1% for 2 Ton). The data sheet says “Excellent environmental & chemical resistance, permanent bonds in harsh environments.” Can you please tell me if it’s ok the solution they suggested? Thank you in advance.

Razvan Zaharia - Reply

Why do people even trust the salesperson when they say that their brand doesn’t make the product you want, but then suggests you buy “something else with a long name that we all don’t understand“ instead? Because we all know, If you buy that, there’s an ~ 72% chance it’s not going to work.

You’re better off looking up 2-ton epoxy online and buying it online/from a hardware store near you.

Tamanya -

I don’t know if it’s because I screwed up somewhere or if I glued the things on wrong, but the whole endcap and the electronics that go in the acrylic tube are not lining up when I plug in the DB-25 connector. Please advise.

Tamanya - Reply

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