Sunday, 29 June 2008

Bespoke bracketry

A friend of mine makes underwater cameras from plumbing accessories so that he can observe the fish in his pond. He needed a bracket to hold a piece of pipe with an adjustable tilt angle so he asked me to make one. Here it is: -

I don't know how long ABS will last in a pond, but as long as it is years rather than months it is no trouble to print it again.


  1. Damn! You're living the dream. :-D

  2. Good stuff - although I can't imagine how a Hepworth self sealing sink trap helps with underwater photography ;->

  3. Hi:

    I've read most all your posts, and I'm following much the same path as you are-- converting a 3-axis hobby cnc mill to a repstrap. I converted my 3-axis mill to cnc, so I know the basics, but would love to know more about your control scheme.

    I couldnt find much about how you are controlling the motion of your machine, after reading most of your blog.

    Are you converting to Gcode, then running the parts, or do you have firmware that completely emuates a RepRap?

    Any help you can offer to prevent me from re-inventing the wheel would be much appreciated!


  4. Hi Dave,
    I start with G-code from either Enrique's Python code or the RepRap host but I don't use that to control the machine. I just extract the tool paths.

    I use Python scripts to control the machine using UDP packets over Ethernet. I don't send G-code directly to my controller because interpreting it and converting the units, which are in floating point, is better done on a PC. My firmware only has to handle the Bresenham algorithm, which only uses add and subtract.

    To do what you want to do with an existing CNC machine you should take a look at what Brendan Erwin is doing in this thread:,12143,page=3

    He is using EMC2 to read the gcode and control his CNC machine. The extruder commands use machine specific codes, M101, etc. I think he has set up EMC2 to understand these and redirect them to something that can drive the extruder.

  5. Thanks for the tip. I'll jet over there!

  6. S0lstice, I am the friend that NopHead made the parts for, I appreciate that the HepVo valve might seem like an odd choice, however it is the perfect housing for an underwater camera. IP68 units are really expensive, so I messed around with DIY solutions. Normal plumbing pipe with compression fittings works well but is a lot of messing about to get a decent seal, the HepVo is a good size for a bullet camera, it has a little condom like device internally that keeps the camera in place and both ends have screw caps for easy assembly.. Nophead kindly cut me two perspex lenses, one for each end, which slide into the end caps, I slip the bullet cam in add an IP68 gland and some outdoor cable a little some Ferenox for a final seal and presto a really cheap & sturdy IP68 camera housing. It’s been running for 6 months now and is still going strong and thankfully leak free.

  7. Do you mean Fernox LS-X? I've heard good things about it, but not tried it yet (for conventional plumbing, I mean).

  8. Hi s0lstice, yes sorry midnight typo, Fernox LS-X is indeed what I used. I've used it for many plumbing jobs and works well; it's really intended as an alternative to PTFE on threads, not as a sealant in this way. I couldn't use Silicone as it's not safe for the fish, so I tried this. I used it as an extra seal around the gland and the the front lens. It didn't work so well and came off after about 3 months. I'm guessing the alge in the pond broke it down. I've now got some aqua safe silicone sealent, which is much better. All in all, the HepVo has turned up to be an excellent and very cheap way of making an underwater camera.