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Re: M4A1 76mm (design stage)

Posted: Wed Dec 15, 2021 8:51 pm
by RiskyR
So I spent quite a few hours on redesigning and working out the suspension. I think I've got a first prototype now, so I'll print one the check if it works as I designed it!

I've designed it in Blender V3.0 (I like how the program works, very nice for scratchbuilding complex parts), then imported in Fusion 360 and reworked so that it can be printed and finally checked in Ultimaker Cura slicer.

The first prototype will be printed tomorrow, so hopefully some "real" progress soon!
M4A1-14.jpg
M4A1-15.jpg
Here you can see the difference between my old 'static' bogie (right) and the redesigned working unit (left).
M4A1-16.jpg

Re: M4A1 76mm (design stage)

Posted: Wed Dec 15, 2021 8:59 pm
by Tiger6
Gotta ask the question - what can Blender do that F360 can't?

I've never tried Blender so I have no idea about what it is fully capable of? I'd always assumed that it was similar to XSI which I did briefly play with a long time ago, but never got on with (I'm used to sketch and extrude modelling, not tweak points on faces).
I have seen some videos demoing the mesh functionality in F360 that seem to be similar to XSI's modelling style, but not yet taken the plunge to try them out - not really needed to so far, but might be useful in the future?

Re: M4A1 76mm (design stage)

Posted: Wed Dec 15, 2021 9:13 pm
by RiskyR
F360 is a great program to build things from scratch as well, but I've been using blender for several years now, so it's more of a personal preference.
I'm also not very experienced in scratchbuiling stuff in Fusion (except for smaller, simpler items).

The biggest advantage in Blender, for me, is the possibility to draw lines, create vertices and faces by hand. Added bonus is the fact it can edit existing meshes very easily. This I haven't discovered yet in Fusion, only basic editing.

The biggest advantage of Fusion is that it is way more powerful in repairing/tweaking "faulty" meshes.
For instance I build my meshes in blender to look good, but may not be very good internally to print. This is something Fusion can fix easily with the Mesh Repair > Wrap function.

Re: M4A1 76mm (design stage)

Posted: Wed Dec 15, 2021 9:19 pm
by Tiger6
To be fair the video's of the F360 mesh editing did look a bit rudimentary - it was clear that the guy doing the demo wasn't used to that way of working, but I was curious as to what others thought of it.

At the end of the day we all have our prefered methods, there is no wrong way to do something well :thumbup:

Re: M4A1 76mm (design stage)

Posted: Thu Dec 16, 2021 6:07 am
by Kaczor
Tiger6 wrote:Gotta ask the question - what can Blender do that F360 can't?
Blender if superior when making soft shapes and "sculpting". F360 is more suitable for machined precise parts.

Re: M4A1 76mm (design stage)

Posted: Sat Dec 18, 2021 7:17 pm
by RiskyR
So I've been busy with the suspension the last couple of days. The top one is the first prototype, but had a lot of flaws.

The bottom one is the second prototype, and everything looks and fits a lot better. Every part has been modified. The springs still don't work as I want to so that will need some rethinking.

Overall quite happy with the current version.ImageImage

Verstuurd vanaf mijn SM-G960F met Tapatalk
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Re: M4A1 76mm (design stage)

Posted: Sun Dec 19, 2021 9:21 pm
by RiskyR
Third (complete) redesign of the suspension. I think I'm getting close to a good working suspension now! With some luck the third prototype will be printed somewhere this week. :)

Re: M4A1 76mm (design stage)

Posted: Tue Dec 21, 2021 9:23 pm
by RiskyR
So while I wait for the next prototype to be printed (my dad does the printing, I do the designing), I've spent a lot of time on the hull to make it useable and printable. Also spent some time on the tracks and thinking how to make these without breaking on the first test run..!

So sorry no real progress, but this is how it is going:

Re: M4A1 76mm (design stage)

Posted: Thu Dec 23, 2021 4:06 pm
by RiskyR
Third prototype has been printed, and now it works! Still some minor adjustments to be made, but I'm very happy! :D
IMG-0094.jpg
IMG-0095.jpg
I've been thinking about the gearbox options. How nice would it be if that was printed as well?
After some research I've found a 1/10th scale KV-1 model on Thingiverse with a completely modelled gearbox.
I've resized this to fit in the sherman, but the motors wouldn't fit because of the resizing, so I've spent some time redesigning the housing to relocate the electric motor and a testprint is being made as I post this message.

Difference between original (left) and modified (right)
M4A1-30.jpg
M4A1-26.jpg
And it looks quite good! Hopefully this will work well when used... fingers crossed...!
M4A1-27.jpg
M4A1-28.jpg
M4A1-29.jpg
Right hand gearbox still has to be modified... but I'm going to do that after the test print of the left hand gearbox.
If this doesn't work I'm not going to spend a lot of time redesigning the other side :crazy:

Re: M4A1 76mm (design stage)

Posted: Thu Dec 23, 2021 6:58 pm
by Rob1970
Awesome work, but this is the point where I tell you to get a steel-geared gearbox for a Heng Long Sherman from AliExpress (for about €25 if you shop around a little...) and save yourself the agony of stripping those 3D-printed gears the first run you take on long grass... ;D