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Jun 28, 2017, 08:43 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Quote:
Originally Posted by Dukejet
Lockey ... you sound discouraged?

More pieces = more fun! Lol...
Doesn't bother me Duke .. I have a CNC machine (well ... almost) to cut out all my parts, I am thinking about you guys and of course, thats not all of them, I still have the wing and skins yet

I was really pissed yesterday though because I spent all day trying to get the CNC machine cutting properly and still don't have it sussed yet and my guru CNC mate now lives an hour and a half away (since I moved) so he can't just pop over and help me, we were texting most of the day (as he is at work) but its not that easy to sort over the phone .. needs to be here with the machine .. we were going to use team viewer last night to link but the PC is really only half the problem .. oh well I guess it will get sorted eventually .. I was almost ready to throw it in the bin yesterday

Lockey
Last edited by Lockey; Jun 28, 2017 at 11:08 PM.
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Jun 28, 2017, 11:07 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Well I don't often get it this wrong .. (thank the lord) not only are the parts all cut out the wrong way round for the grain, they are miles away from the correct size (machine not cutting correctly grrrrr)

Of course I keep saying to you guys .. "make sure you get the grain of the foam the right way or it won't roll properly" doh

Will have to start again ... .. not happy Jan

Lockey
Jun 29, 2017, 05:50 AM
Registered User
Lockey

You have calibrated your machine ? it does move 10mm when you say move 10mm and such like. It took me ages to get my machine to move the right amount but that may be because, a, I made it and, b, I didnt have a clue what I was doing to start with. Then I had to go about correcting the skew in the x/y axis, I was never any good at trigonometry at school and that made getting the right skew correction figure a bit harder.

One thing not to forget when cutting it to allow for the cutter diameter. I found the easiest way was to get the drawing into dxf (I'm tight and use Draftsight free) then use the offset command to enlarge the part by half the cutter diameter. Again because I'm tight I use DXF2Gcode to convert the drawing to gcode, using this method even my home made bodge job of as cnc machine can cut so that parts just slide together, of course it is all dependant on the variability of the thickness of the material you are using.

Hope the about is some help, and keep plugging away you'll get there in the end.

Bill
Jun 29, 2017, 06:06 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thanks for the advice Bill, yes I am sure I will get it right in the end

I am using Sketchup for the CAD .. then "Vectric Aspire" for doing the G code and then "Universal G Code Sender" and am trying to make sense of the grbl commands etc

Lockey
Jun 29, 2017, 06:50 AM
Registered User
scorchythebear's Avatar
Sorry to hear about your CNC woes Lockey. I think with these things the learning curve is initially quite steep, but once you overcome that then the positives going forward will far outweigh any annoyances you're having now. I know the 3d printer I built took a bit of calibrating and messing around to begin with, but it works beautifully now.

Regardless good to see you've made a start! I'm going to carry on cutting this evening so I can get some work done at the weekend.
Jun 29, 2017, 10:10 AM
When cows fly!
Maybe I don't need a CNC machine....I usually have to cut things out twice! Don't need a machine and my inneptitude to add to the woes
Jun 29, 2017, 05:59 PM
Registered User
scorchythebear's Avatar
Good point David Same goes for me but double. Still it'd be nice to have such a thing

I made a boom!

Sadly it has developed a crack which I've tried to repair with some epoxy but I might just make another one.

Lockey do you find the HK foam a bit rubbish to sand or is it just me?
Last edited by scorchythebear; Jun 29, 2017 at 06:05 PM.
Jun 29, 2017, 06:19 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Quote:
Originally Posted by scorchythebear
Good point David Same goes for me but double. Still it'd be nice to have such a thing

I made a boom!

Sadly it has developed a crack which I've tried to repair with some epoxy but I might just make another one.

Lockey do you find the HK foam a bit rubbish to sand or is it just me?
Man thats a nice boom "boom boom" sorry couldn't help myself .. wouldn't worry about the crack, especially at the bottom like that .. when ever you have an inward pointy bit or corner on a bend or roll, it is prone to cracking so I add extra tape at that point before rolling, remember we had the same problem with this on another build ..

Yes the Depron rubs down much nicer than the HK stuff .. what are you using ?

Don't forget mate that you have to put a servo somewhere into one of them for the elevator

Lockey
Last edited by Lockey; Jun 29, 2017 at 06:25 PM.
Jun 29, 2017, 06:46 PM
Registered User
scorchythebear's Avatar
It only cracked when I had glued it and was applying the masking tape to hold it. But yes I should have reinforced it a bit like we did on the Taube wing (I think it was).

As you say if it was going to go then that's an OK place.

I have a nice new box of depron but I also have some sheets of HK stuff left as well as a box of off cuts so the boom is the Hobbyking stuff. It's not terrible by any means but you need to go easy sanding it, whereas Depron sands like soft wood.

The other one is still unrolled so I'll remember to look at servo placement for the 'uppy downy' thing.

Enjoying it so far. Yes there are more small parts than I'm used to, but foam is cheap and I have loads of it to practice on
Jun 30, 2017, 06:42 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Didn't get the CNC machine calibrated but I did get some building done on the Sea Vixen

One mistake I made was to score the line where the tail fin joins the boom .. this was a big mistake and made it very weak .. I noticed that Adam (scorchythebear) didn't score his and it worked out just fine .. nice one Adam

If you are using Hobby King foam, use clear packaging tape on the outside and pre-roll the parts, you will find the foam tends to spring back a lot so remove the tape and then roll again .. I found once it has been pre-rolled, it will not crack when you roll without the tape .. just take a little more care

Lockey
Last edited by Lockey; Jun 30, 2017 at 07:14 AM.
Jun 30, 2017, 07:27 AM
Registered User
scorchythebear's Avatar
Now that's proper progress! Great stuff It always nice to see a big bit like the wing done.

Me not scoring the tail fin was a complete fluke by the way but it did go together readily enough
Jun 30, 2017, 02:12 PM
Careful,.. confident,.. CRASH!
Dukejet's Avatar
Great work guys! Your doing and awesome job Lockey
Jun 30, 2017, 08:29 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
As I was forming some of the parts yesterday, I realised that its not easy to get some of the shapes I would like to get .. for instance .. rolling the top and bottom parts for the fuselage, if we want the shape to be similar to the original plane, I think it would have to be in more pieces .. see the pics as an example .. maybe it would work with 3mm Depron, but I was never a great fan of 3mm Depron .. AND .. just another thing I have to keep in stock

I will try this using 6mm Depron, because it does tend to hold its shape better than HK foam .. HK foam does tend to be a lot more springy and wants to spring back to being flat

HK foam does roll a lot easier than Depron in that it can be rolled (if you are very careful) without using tape on the outside BUT does not seem to want to hold the shape as good as Depron does .. especially whilst the tape is still on the outside ..
I tend to roll the HK foam first with the tape on and then I remove the tape and finish the rolling and I find it will hold its rolled shape better this way

Of course .. this will only work if you roll the foam in the correct direction .. with the grain .. I know most of you guys probably know this but maybe there are a few out there that don't

Lockey
Last edited by Lockey; Jun 30, 2017 at 08:59 PM.
Jun 30, 2017, 11:12 PM
When cows fly!
Looking good! Can't wait for the maiden


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