Thanks Forest for the file, I am looking for mounting motor and tube plates as you have used. Is it possible to buy from you these g10 pieces or do you have cad files to let it cnc produce from china? motors will be hp2212 1000 kv and 12 mm tubes for a v octa.
Forrest Frantz > Schaich MartinFebruary 19, 2016 at 7:30am
Nomex core carbon sandwich panels do not survive as motor mounts. the material needs to withstand high point loads. But, end-core balsa carbon sandwich panels are excellent. These are even harder to find in the appropriate thickness.
yes ... i could cut the motor mounts for you. but first, let's talk requirements.
Are you flying over grass or granite? This affects how durable the motor mount needs to be and if it is a single or double plate.
Do you have access to Scotch Weld 2216 adhesive (mandatory for bonded joints)? I can get a tube for you if you can't, but it's expensive, especially the applicator.
With 12mm tubes using the hp2212 with 19mm bolt pattern, you have 13.4mm bolt separation, which will make getting the bolts into the motor back-plate difficult (but not impossible). As an example, i use the T-Motor MN3508-29 motor with 24mm bolt pattern, which is just wide enough. A slotted system would work where you push the bolts up through the motor mount and then slide them inwards as you evenly tighten all four bolts.
Have you cut your mast yet? Or is there room for the mast to extend farther out to provide more room/area for the adhesive bond?
Schaich Martin > Forrest FrantzFebruary 23, 2016 at 12:18am
Nomex core carbon sandwich i was planning to use for the EP! Not for Motor mounts, there i like the balsa solution.
Forrest Frantz > Schaich MartinFebruary 23, 2016 at 6:39am
also, to save a little weight, you can trim the part of the X that sticks out on each side but not the part of the X that would be bonded to the tube (it needs the full 40mm of length (about 30mm of bond length).
Schaich Martin > Forrest FrantzFebruary 23, 2016 at 9:41am
i prefer your balsacarbon mounts to make an octa!leave the idea of alu x fixation!
then i take your advice for the scotch 2216.
So can you supply me the 4 motor mounts and the 4 motor/x mast combination for zip fixation?
Let me know your costs? I will glue the middle x tubes one full length and the other half.
Where do you buy the tubes and whats there weight?
Forrest Frantz > Schaich MartinFebruary 23, 2016 at 6:35am
stay with scotch 2216 on any critical bond (motor mounts & structural gussets)
the tubes are a bit heavy but they look durable so not bad
some Al X w/ screws weigh about 3g each for 18g total for a hex. so one possibility is to bond the Al X to the tube as a + and secure the motor with 2 screws (all that's needed; but check before each flight to ensure they are still tight).
Forrest Frantz > Schaich MartinFebruary 17, 2016 at 8:12am
I updated the Custom Octa CAD worksheet for the V tab. So the V tab is good. But I haven't checked the other tabs. If you have any questions, let me know. The worksheet has macros that are safe, so OK to enable.
You will notice that the prop rotation is different than what is stated on the DIY website. That is because this particular prop spin layout solves to a better solution (otherwise all of the roll factors are the same and the roll factors are different, which is less than optimal).
Schaich Martin > Forrest FrantzMarch 13, 2016 at 11:06am
In your excel file you are using very small Minimum Prop to Prop Spacing, do you really recommand 0.1" spacing? Interferences could have a great influence! Some people recomand 27% of Prop size, what is your advice?
Replies
Thanks Forest for the file, I am looking for mounting motor and tube plates as you have used. Is it possible to buy from you these g10 pieces or do you have cad files to let it cnc produce from china? motors will be hp2212 1000 kv and 12 mm tubes for a v octa.
I found a producer for nomex sheets:
http://www.sierrafoxhobbies.com/de/rocket-building-parts-and-access...
what do you think about them?
Nomex core carbon sandwich panels do not survive as motor mounts. the material needs to withstand high point loads. But, end-core balsa carbon sandwich panels are excellent. These are even harder to find in the appropriate thickness.
yes ... i could cut the motor mounts for you. but first, let's talk requirements.
Are you flying over grass or granite? This affects how durable the motor mount needs to be and if it is a single or double plate.
Do you have access to Scotch Weld 2216 adhesive (mandatory for bonded joints)? I can get a tube for you if you can't, but it's expensive, especially the applicator.
With 12mm tubes using the hp2212 with 19mm bolt pattern, you have 13.4mm bolt separation, which will make getting the bolts into the motor back-plate difficult (but not impossible). As an example, i use the T-Motor MN3508-29 motor with 24mm bolt pattern, which is just wide enough. A slotted system would work where you push the bolts up through the motor mount and then slide them inwards as you evenly tighten all four bolts.
Have you cut your mast yet? Or is there room for the mast to extend farther out to provide more room/area for the adhesive bond?
Nomex core carbon sandwich i was planning to use for the EP! Not for Motor mounts, there i like the balsa solution.
I can get the scotch 2216 see in switzerland:
http://www.mouser.ch/Search/ProductDetail.aspx?R=EC2216virtualkey51...
some recommended uhu 300 is there any result out in the meantime?
I was planning to use 12 mm carbon braided tubes from:
http://www.pitlab.com/pitlabshop/accesories-for-multirotors/carbon-...
If I am using the HP2212 with 19 mm do you think if fixed with the alu x cross delivered with the motors will work because there are 33mm wide?
for the flightcontroller i will use not apm anymore trying pixhawk clone.
also, to save a little weight, you can trim the part of the X that sticks out on each side but not the part of the X that would be bonded to the tube (it needs the full 40mm of length (about 30mm of bond length).
i prefer your balsacarbon mounts to make an octa!leave the idea of alu x fixation!
then i take your advice for the scotch 2216.
So can you supply me the 4 motor mounts and the 4 motor/x mast combination for zip fixation?
Let me know your costs? I will glue the middle x tubes one full length and the other half.
Where do you buy the tubes and whats there weight?
stay with scotch 2216 on any critical bond (motor mounts & structural gussets)
the tubes are a bit heavy but they look durable so not bad
some Al X w/ screws weigh about 3g each for 18g total for a hex. so one possibility is to bond the Al X to the tube as a + and secure the motor with 2 screws (all that's needed; but check before each flight to ensure they are still tight).
Hello Forrest
with great interst I follow this forum and learnt a lot! Sorry for my english.
My question where do I find your excel file for the motor calculation.
I have some HP2212 1000kv from rctimer left from my quad and i like to fix them on a v ship.
did you test this motors as well or calculateed? are they suffizient to use for a v octa?
I used up till now propellers 9x4.7 and 30 A esc.
Thx for your reply in advance
Regrds martin
I updated the Custom Octa CAD worksheet for the V tab. So the V tab is good. But I haven't checked the other tabs. If you have any questions, let me know. The worksheet has macros that are safe, so OK to enable.
You will notice that the prop rotation is different than what is stated on the DIY website. That is because this particular prop spin layout solves to a better solution (otherwise all of the roll factors are the same and the roll factors are different, which is less than optimal).
Custom Octa CAD.xlsm
In your excel file you are using very small Minimum Prop to Prop Spacing, do you really recommand 0.1" spacing? Interferences could have a great influence! Some people recomand 27% of Prop size, what is your advice?
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