How best to get started


#1

Hi folks,

I have looked around for a how to get started thread and am either missing it or it doesn't exist, hence the question here. I am wondering a few things about this project and would like to make sure I understand things prior to getting going.

Is the wiki the best place to get up to date information? Specifically pertaining to the laser cut parts. I have found a local shop that will do the cutting for me but want to make sure I am using the right cut files.

Also wondering if the wiki list of parts is the latest incarnation for a guy that wants to start getting the parts assembled as well.

I am looking forward to this. Thanks for access to all of the information and experience.

Jim


#2

Hey Jim,

Welcome!

The wiki is probably the best place to start: http://wiki.openrov.com/index.php/Main_Page

The BOM is out of date - we're working on updating it now - so maybe hold off on ordering everything. The laser cut files should be good to go and can be found on GitHub:

https://github.com/OpenROV/openrov-hardware


And don't hesitate to ask questions!


#3

Hi David

Any idea when the BOM will be updated I’ve been ordering parts vfrom the european one. Which parts should I hold back from ordering

Thanks
Martin


#4

Thanks David, I appreciate the quick response. i will order the acrylic and have it cut, and read through the blog to get going.

The obvious question is when do you think the BOM will be updated so that I can begin sourcing parts. I'd like to start before April, which was the earliest that the kits were available. If you need a Beta tester for the new kits to make sure they are complete and ready to go let me know ;-) I would be glad to pay to be a guinea pig.

Jim


#5

Hi David

A time frame of when both BOM might be updated would be very appreciated:

US BOM: https://docs.google.com/spreadsheet/ccc?key=0Ar0hfvA_8EUVdFBnQm8tdmltTWZ5cEtvQ2p3UjktWHc&hl=en_US
EU BOM: http://kitbom.com/simonech/openrov-23-eu-suppliers

In the mean time, it would be extremely useful to have any available info about which parts in either BOM will NOT work with the laser cutting layout given for current version of openROV2.3 on github: https://github.com/OpenROV/openrov-hardware ?

For instance :

  • the US BOM list webcam: Microsoft Lifecam HD-5000,
    while the EU BOM lists: GENIUS WideCam F100 Full HD 1080p webcam.
    The tutorial videos also show the GENIUS webcam
    So do both cameras work with the current 2.3 e-chassis layout ?
  • both BOMs list Hitec HS-65MG Micro Metal Gear Servo for the servo. But according to this thread: http://openrov.com/forum/topics/servo this servo is not compatible with current e- chassis layout. There is a mention of hs-81 servo which should be bought instead. Correct ?
  • Are there other parts we need to hold off from ordering until different part numbers are indicated in next updated BOM?

Thank you!

Alain


#6

Hey Alain, et al,

Right- sorry about that. I'll try to get the most recent changes into the BOM asap. In the mean time, the two things you've noticed, the Webcam and Servo are what I know off-hand has changed. We are now using the Genius WideCam F100 instead of the HD-5000, and we are now using an HS-81 servo instead of the HS-65 servo.

I'm a little worried about having different versions of the BOM in so many places because it's hard to know which are up-to-date and which are not.

We'll try to clean this up this week.

Thanks for pointing all this out!

Eric


#7

I should also note that the blue acrylic listed on the BOM from McMaster-Carr ended up being a very translucent blue that is not the same as what we've been using. I'm trying to figure out what the right "blue" is from McMaster, but since we order our large amounts from a place that sells it cheaper in bulk, it will take some figuring out.


#8

Battery tube caps: The US BOM does not list anything. The EU BOM lists the following:

1 1/4" Rubber cap , McMaster-Carr 40005K49
http://www.mcmaster.com/#catalog/119/3747

But part number 40005K49 does not exist. So I suspect it should be 40005K39 ?

You may want to add it to the US BOM

Thanks


#9

Just looked it up--

Yes! You're right. It should be part number 40005K39

http://www.mcmaster.com/#40005K39

Thank you for finding that. I'll correct the BOM now..

Eric


#10

This is awesome guys. i will post issues as I find them once started as well.

Jim


#11

syringe reference: BD 1ml Syringe - ref 309628 (quantity=2)
The syringe is not listed on either BOM's. You may want to add it. I finally spotted the above reference: BD 1ml Syringe - ref 309628 on this tutorial http://wiki.openrov.com/index.php/Assembling_and_Gluing_the_end_caps

After unfortunate purchases and not able to find anything with the correct diameter in local pharmacies, I finally bought the right ref. 309628 on Amazon.

Thanks


#12

It would be nice to have a photo or video of the air vent procedure:

<<After placing the end caps on the tube, you pull the plunger out momentarily, listen for air to escape, then replace it.>>

Is the plunger cut? at what length. Does its end remain inside the cut end of the syringe ?

Thanks


#13

Hey Alain,

Right- the plunger gets cut so that it is flush with the outermost layer of the assembled end cap. In other words, it protrudes out beyond the syringe housing as far as it can go without peaking beyond the total height of the end cap.

When you place the electronics tube, this vent port will be captured by the shell of the OpenROV.

Hope this helps. We'll try to get some photos on the wiki soon!

Eric


#14

Very helpful. Thanks.

Actually (sorry I did not notice it before) but you do have photos and explanation about this step here: step 3 of http://wiki.openrov.com/index.php/Potting_the_wire_pass_throughs_in_the_end_caps

Thanks


#15

I could be nice to have the actual lenghts needed of the diffrent tubes listed.

ie. i cant find any place how long the battery, prop shrouds and main tube actually needs to be. i think the main tube is 180mm from the eu-bom. could be that i've overlooked it somewhere.

the battery button, spring connector and the belden 1353A tether is also missing in the bom.

i tried to use autodesk inventor viewer to measure the tube parts, but the viewer does not support measuring(i'm used to solidworks viewer that has this function)


#16

This is an excellent thread and very timely for me.

I am about to head to the States for a holiday, and while there I will start purchasing some of the electronics for the project. Of interest at this point in time are the command-and-control and propulsion. As the servo has been confirmed (HS-81) I'd like to confirm the ESC and motors, please.

Thanks,

Greg.


#17

the motors and the esc's in the bom are correct.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8622

http://www.hobbyking.com/hobbyking/store/__7189__Turnigy_Brushless_ESC_18A_w_Reverse_programm_.html


#18

However, the linked ESC's are curently out of stock. http://www.hobbyking.com/hobbyking/store/__24290__Turnigy_TrackStar_18A_1_18th_Scale_Brushless_Car_ESC_USA_Warehouse_.html?strSearch=trackstar%2018A should be a drop-in supstitute that actually provides less power than the original links, potentially helping with the overpowering problems we've been having.


#19

just for clarification:

the esc will make no diffrence to the power draw of the system. the power consumed is a function of the torque needed at diffrent speeds on the motor. a 100-amp esc with the same motor woulnt cause any real increase in amp-draw.

The voltage applied to the motor from the esc dictates the desired speed.(percentage of input voltage with corulation to the throttle values)

the amp draw is a result of the torque need to optain the speed set by the voltage. if the speed can not be obtained the amp draw increase dramaticly.

some high-end brushless motor datasheets note the A/Nm figures, thats is used to estimate the amp-draw at certain torque values.(line 13: http://www.faulhaber.com/uploadpk/EN_3564_B_MIN.pdf)

to reduce the power problem on the openrov, we probably need smaller props, or diffrent amounts of blades and angle of blades.


#20

Darn.

Just received HK order, with the servo off the old BOM.. Didn't realize parts had changed.

Will be checking the discussion threads a bit more thoroughly from now on.