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28 Sqn AVRO 504K double trouble


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3 hours ago, hendie said:

I'm sure there must be some combination of factors playing into the end result, but what those factors may be is anyone's guess.

 

Those lines sound suspiciously like an Everything But The Girl lyric Alan...

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On 5/8/2022 at 1:02 AM, TheBaron said:

Superb sleuthing Holmes. :clap2:

 

Going on that desk, yon fireplace must indeed have been a thing of beauty Alan.

 

It was a very nice fire surround Tony - I was a bit peeved when I sold the flat and the first thing the "developers" did was rip it out and paint everything white.  but it wasn't my flat anymore so hey...

 

On 5/8/2022 at 3:30 AM, perdu said:

Detective work of the highest order Alan, utterly enthralling stuff.

 

And I love the sewing machine marble computer desk, my mom used to own one of those Singers with the treadle pedal, instant 'take me back fifty-six years' to our old council house in Moseley.

 

thanks Bill - glad you liked it.

 

On 5/8/2022 at 4:32 AM, The Spadgent said:

Nice one Alan. Yup, that’s pretty much how I try and solve the issues at work. It’s an iterative process so cutting those processes into chunks and testing is a great way to corner the blighter. 👏👏👏 we can all sleep well again. 😃🤓

 

 until next time. don, Don, donnnn. 🫣😆

 

I've lost count of the number of elephants I've eaten by now Johnny.  Even one bite can be a bit much at times.

 

With sleuthing being over for the time being other things started moving forward at a decent rate of knots.  I already had one of the main struts modeled so it was a simple task to add a few more greebles and turn it into the strut carrying the pitot. 

The plane here is to add a couple of pieces of 0.2mm wire to represent the probes 

 

Screenshot-2022-05-08-101508.jpg

Aaaand.... I think we are almost about done on the externals now.  

 

Screenshot-2022-05-10-172008.jpg

 

Before we head indoors though I paid a small visit to the engine room.  I had thrown one a couple of these onto the build plate a session or two ago as a last minute adder.  Absolutely no thought was given to orientation and I just used the auto-support function since it was just a test print, and the main point was to check out the fuselage anyway, but there was no point in wasting printing time so in they went.

Ignore the broken and twisty bits - I was a bit heavy handed removing the supports, BUT wow - the level of detail is impressive.  (I did prime these in my sludgy Alclad so the camera had something to focus on)

 

P5110001.jpg

 

In slightly closer detail - even more impressive.  The camera shows that this printer is capable of printing detail finer than the eye (or at least my eyes) can see.  

 

P5110005.jpg

 

That engine was oriented to print from the rear face forward.  While that was okay for the purposes of that particular print it would mean that the cooling fins on the rear of the engine would not be printed completely as areas such as those arrowed below would have no supports.  Each and every single cooling fin would need supported as it started printing.

 

Screenshot-2022-05-09-120201.jpg

 

With the Wapiti engine I printed the cylinders separately to get around that and it was a bit of a faff assembling everything afterwords - but worth it due to that engine being very prominent at the front of the aircraft.  This engine is mostly hidden by the cowling ands there's really only one cylinder fully visible.  So I am going to cheat.

 

By adding a thin web between the exhaust pipe and the cylinder we have created a single entity that supports all the cooling fins in one easy step.  Okay, it's not accurate but that gap is less than half a millimeter and it's all going to get painted black, plus it's hidden at the back of the engine so it's never going to be seen.  All this allows the engine to be printed as a single component which makes things a lot easier.  Painting it? - not so much.

I also adjust the cooling fin spacing a little by moving from 40 to 35 cooling fins so they may be slightly more visible on the final print.

 

Screenshot-2022-05-09-120915.jpg

 

Now, we could head indoors.

 

I began by creating a very basic interior.  The drawings I have do not have any dimensions that I can work from so everything is done by eye based on reference shots.  The "basic" interior gives me a base point to start working from.

More detail and parts are added and existing detail and parts are tweaked at each stage to try and get the whole thing to work together (or not).

 

Screenshot-2022-05-07-161236.jpg

In front we have a couple of switches for the observer to play with. He's going to get bored very quickly

 

Screenshot-2022-05-10-171651.jpg

 

but at least the guy in the back has some reading material to keep him busy.  Some compromise has been made for scale effect and for printability - bear in mind that the largest gauge shown here has a diameter of around 1.5mm and the whole instrument panel os only about 6 or 7 millimeters high.

 

Screenshot-2022-05-08-121845.jpg

Things do start to take shape and fill up pretty quickly in the interior though.

 

Screenshot-2022-05-10-171748.jpg

 

Then you remember that this is about all you will ever see from the outside, and most of that will be obscured by the wings.

 

Screenshot-2022-05-10-171813.jpg

 

There are not a lot of good shots of the floor structure inside the 504 and with no dimensions to work from it's very much a work in progress tweaking positions of items at almost every step.  The great thing about a parametric CAD system is that you can go back to any point in the design history and modify any feature or dimension in a few clicks - then pray that it doesn't blow the rest of the model up.  With these interior components it's really not a worry as any rectification work is straightforward, but with the fuselage and it's design tree being several hundred features long, any oh crap moments can potentially involve a lot of pain and a large investment in time to clean up afterwards.

 

Screenshot-2022-05-11-074509.jpg

The seats received some remedial work and this is the current state of play indoors.  I will need to adjust a few dimensions to allow for assembly clearances but all that will be left until the interior is complete

 

Screenshot-2022-05-11-074540.jpg

 

As a break from the digital sessions I ventured downstairs to test and confirm my theory about the ghost surfaces that kept marring the model.  

It would appear that for the most part, my theory was correct and it was indeed the extruded surfaces of the access panels that were causing the issues.

 

P5110006.jpg

 

There is still an ever so slight marring of the surface visible on the port side panel but I think that may well be down to the orientation and a lack of supports when printing. At worst, a few minutes with micromesh would soon sort that out.

 

P5110007.jpg

 

The primer really helps see the details.

I think the stitching has worked out quite well. It's visible without being over imposing. It will pop back a little bit once the PC10 goes on and I think the finished effect will be just about right.

 

until next time folks.

 

 

 

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I like your thinking re getting the cooling rings printed. You should be able to remove that skin from the bottom cylinders too, using a nice fresh #11!

By the way, there are no exhaust pipes on a rotary. Those are induction pipes. The fuel/air mix is routed through the crankshaft, and those pipes, into the cylinders. The burnt gasses exhaust directly through the exhaust valves into the atmosphere.

 

Ian

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8 minutes ago, Brandy said:

By the way, there are no exhaust pipes on a rotary.

 

Oh my.   :blush: how embarrassing.  Thanks for the info Ian. 

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4 hours ago, hendie said:

Screenshot-2022-05-09-120915.jpg

 

That fin is a very elegant solution. You have to keep on your toes with this printing lark. 😅 nice primed fuselage too. And the innards, Heck the whole nine yards. 😇😁.

 

J

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Returned home tonight from a large Italian meal out with the family to find that you'd thoughtfully provided the finest of desserts in Avro form here Alan.

 

As others have said, top brain work on that fin at the rear of the engine, in fact what am I saying? The whole thing is looking bloody marvellous in every detail!

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Posted (edited)
13 hours ago, hendie said:

I think the stitching has worked out quite well. It's visible without being over imposing. It will pop back a little bit once the PC10 goes on and I think the finished effect will be just about right.

 

13 hours ago, hendie said:

The camera shows that this printer is capable of printing detail finer than the eye (or at least my eyes) can see.  

 

I think the surface detailing generally is quite exquisite and I’m amazed and delighted at the fidelity with which it has printed.  Amazed - just cos it’s amazing, and delighted cos I’m glad I stopped prevaricating and got one  :penguin:  Just the little step of learning to 3D model to hendie standards now….. :wall:

 

13 hours ago, hendie said:

By adding a thin web between the exhaust pipe and the cylinder we have created a single entity that supports all the cooling fins in one easy step

 

I agree with Johhny, Ian and Tony that the web to  the induction pipe (credit to Ian for that bit of info) is an elegant and clever solution.

 

And it got me thinking.  Does the web necessarily have to extend all the way back to the induction pipe?  Could it perhaps just extend as far as the limit of the cylinder cooling fins?  If you still needed a support to get it to print properly from the rear maybe you could draw in just one or two 0.15 or 0.2mm rods to connect each web to the adjacent pipe - which would easily be trimmed away with minimal effort.

 

The only potential benefit of course is preserving a tiny visible gap between the cylinder and induction pipe on the one visible cylinder so it may be disproportionate effort anyway. But funnily enough I’ve never had a problem suggesting more work for other people :whistle:

 

Just thinking.  Probably misguidedly.  Getting back in my box  now :D

 

 

Edited by Fritag
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5 hours ago, Fritag said:

And it got me thinking.  

 

I knew there was a reason we kept you around on this forum Steve. :D     That is an excellent idea - thanks.

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  • 3 weeks later...

An update from the trenches, small though it may be.  Life has really been getting in the way around here recently but I think I have it beaten... almost. 

The basement renovations are complete... almost.   Tiles have been laid in the past week.  I fitted the toilet back after the bathroom was tiled only to find that the shi... sewage pump had packed in :rage:   .  I fixed it last time (a few years ago now) but after these last few months I wasn't about to open up that hole again so called the plumbers - the good one's, not the one's who attempted to do the bathroom.  Once that was all taken care of I had to fit a new storm door on the walkout, only to find that when the storm door was closed, there wasn't enough room to close the outside entrance to the basement. :rage::angry: .  Off it came and I had to build out the whatever it's called of the door frame to create enough space for both doors to live in harmony.

Then the wife forced me to do some gardening.  Gardening in over 90 degrees is no fun, take it from me.

All I have left to do now is apply sealant around the bottom of the toilet, and fit a vanity unit. That is if I can ever find one that is affordable and doesn't look like it was made from fold-up cardboard and drawing pins.  A job for another day.

 

To celebrate still being alive after all that the family in a rare display of unity decided to go out for dinner last night.  There we were, sitting on the banks of the Chesapeake Canal waiting for the starters to arrive when one of these things approached with some rather loud engines grumbling away

 

IMG-20220530-WA0001.jpg

 

What was it?   It was one of these apparently - an LARC.  Look at the size of those tires!   a LARC (<- linky) which stands for Lighter, Amphibious, Resupply, Cargo.  They're having a larf surely... Lighter ?  According to Wikiwotsit: It could carry up to 100 tons of cargo or 200 people, but a more typical load was 60 tons of cargo or 120 people

 

20220530-203031.jpg

 

Anyways, I shouldn't really be polluting my thread with floaty things, especially noisy floaty things. So...

 

between all the chores, other chores, and even more chores, and chores still do do, and chores still to be thought of, I managed to steal some time to get out of the basement to do some modeling of the digital kind.

 

and I made one of these.

 

Screenshot-2022-05-23-123256.jpg

 

Which goes inside amongst all these bits of wood and helps the drivers steer up in the sky. The interior is not accurate by any stretch but compromises had to be made as everything was done by eye as there was no hard data to work from

 

Screenshot-2022-05-24-124550.jpg

 

I also revisited the upper wing and added the control cable pulley's which I had missed previously.

 

Screenshot-2022-05-26-122515.jpg

 

then created a bunch of STL's to play with and set things a printing last night before I headed out.  It was still doing its thing at lunchtime today so this evening I should see some results.

 

Capture.png

 

All the modeling is complete with the exception of the propellor which I have been kind of avoiding as a) I don't enjoy modeling them, and b) I'm not very good at them. Those two things could well be connected. 

Sadly I now have to get back to work as lunchtime is over and I'm probably late for a meeting.

 

 

 

 

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1 hour ago, hendie said:

100 tons of cargo or 200 people

Presumably the limit on people is space, not weight ;)

 

Your sprue print layout looks very nice indeed.

 

Regards,

Adrian

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4 hours ago, hendie said:

 

Which goes inside amongst all these bits of wood and helps the drivers steer up in the sky. The interior is not accurate by any stretch but compromises had to be made as everything was done by eye as there was no hard data to work from


Would it be possible to print the interior as part of the fuselage, I.e. in one print?  Just curious - it would be quite difficult to paint that way 😂

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4 hours ago, hendie said:

 

Capture.png

 

That is a very neat layout you have there. Dang nabbit, you’re getting me all juiced for some printing action. 🙀🙀 Must finish moths first!!! 👐👐

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3 hours ago, AdrianMF said:

Presumably the limit on people is space, not weight ;)

 

Built for Americans... could be either these days

 

1 hour ago, mark.au said:

Would it be possible to print the interior as part of the fuselage,

 

Oh, it's certainly possible Mark and I considered printing part of the interior integrated with the fuselage, but as you commented, painting it would be incredibly difficult so I chose to separate the interior for printing purposes

 

11 minutes ago, The Spadgent said:

you’re getting me all juiced for some printing action.

 

Any idea what's on the cards next Johhny?

In the back of my mind I've been toying with the idea of printing a stained glass Dalek - the idea just keeps coming back to me

 

 

 

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11 minutes ago, hendie said:

Any idea what's on the cards next Johhny?

In the back of my mind I've been toying with the idea of printing a stained glass Dalek - the idea just keeps coming back to me

I have to finish Dewey first. I was thinking of an imperial probe droid. I think there was one kit but it’s rare as you like. @Andy Moore built it and made a fantastic job of it too.  The stained glass Dalek sounds ace.  I loved the pure glass one too. So very 80s. 🤗

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9 hours ago, hendie said:

 LARC (<- linky) which stands for Lighter, Amphibious, Resupply, Cargo.  They're having a larf surely... Lighter ?

The Australian Army still uses these. I've been for a ride in one around Sydney Harbour many years ago before they moved the school.

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Hope the print went well Alan; looks darn tootin good in the virtual world.

 

Darn tootin? - hmm , experimenting with new phrases; don’t think I’ll bother with that one again… :blush:

 

12 hours ago, hendie said:

All the modeling is complete with the exception of the propellor which I have been kind of avoiding as a) I don't enjoy modeling them, and b) I'm not very good at them. Those two things could well be connected

 

Ah.  Sounds like the opportunity for a hendie tutorial.  You improve your skills, we learn.  Win Win! :winkgrin:

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Glad to hear the basement renovations are almost complete. I don't know where you find the time to do that, work, draw and model. The hours on your side of the pond must be longer than African hours?

Liking you renders very much.

 

Colin

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On 5/31/2022 at 6:41 PM, The Spadgent said:

I have to finish Dewey first. I was thinking of an imperial probe droid. I think there was one kit but it’s rare as you like. @Andy Moore built it and made a fantastic job of it too.  The stained glass Dalek sounds ace.  I loved the pure glass one too. So very 80s. 🤗

 

tentative beginnings have began to be begun on a probably very long term Dalek project.

 

On 5/31/2022 at 11:04 PM, Bell209 said:

The Australian Army still uses these. I've been for a ride in one around Sydney Harbour many years ago before they moved the school.

 

That would be cool (and noisy)

 

On 6/1/2022 at 1:47 AM, Fritag said:

Hope the print went well Alan; looks darn tootin good in the virtual world.

 

Darn tootin? - hmm , experimenting with new phrases; don’t think I’ll bother with that one again… :blush:

 

Prints went reasonably well Steve, thanks.  I will post some shots when I get around to having some spare time.

 

 

On 6/2/2022 at 3:40 AM, heloman1 said:

Glad to hear the basement renovations are almost complete. I don't know where you find the time to do that, work, draw and model. The hours on your side of the pond must be longer than African hours?

Liking you renders very much.

 

Colin

 

thanks Colin... if you have any spare hours I take 'em

 

On 6/1/2022 at 1:47 AM, Fritag said:

Ah.  Sounds like the opportunity for a hendie tutorial.  You improve your skills, we learn.  Win Win! :winkgrin:

 

it's much more fun when I sit and watch you improve your skills, or as the latest buzzword has it "upskill".  I hated the term as soon as it infected my aural senses.  Why do people feel the need to invent new words and phrases when there's a perfectly good English language laying around just crying out to be used?

 

Anyhoos, let's try this upskilling ( :puke: ) malarkey and see what transpires.   As it happened, things were not off to a good start.  I could not find any decent drawings of propellers on 504's and the only reference I had was this rather uninformative drawing.

No section views or other useful info was to be gleaned anywhere.

 

Screenshot-2022-06-02-113027.jpg

 

Step 1, the easy part, was to plonk the drawing into solidworks, scale it to the reference diameter I found (and can't remember at the mo'), then trace a spline around one of the blades - after drawing a circle and constraining it to give me a starting point and some basic reference.

 

Screenshot-2022-06-02-121203.jpgStep 1

 

The circle was extruded to provide a very basic hub, which I wanted to provide some form of visual cue while embarking on the next phase.

 

Screenshot-2022-06-02-125129.jpg

 

 

***EDIT

bloomin forum just ghost posted on me again.  I was creating this draft before I headed out for dinner, and now don't have time to add anything worthwhile before I leave so you'll just have to wait until tomorrow now.  Apologies to you all, but the forum has a mind of it's own sometimes.

 

 

 

 

 

 

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Ghost post!

 

The bane of my life too and a perfect name for what it is and what it does.

 

Do feel free to come along and show me how again Alan thanks.

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Back again. This time hopefully there will be no ghostly button pushing.

 

Where were we?  Ah.. splines.  With the spline drawn (on the front plane) to give me a basic outline, I then created a series of planes perpendicular to the front plane at strategic points along the blade length and forgot to take any screenshots.

I viewed the blade as having three basic lengths, or segments. The first being the rapid transition in shape from the hub out until it reached a basic aerofoil shape, second being that aerofoil extending along the blade, and the third being another rapid shape transition as the blade reached the rounded tip

In the first section I placed the planes closer together, spaced them out in the middle section then scrunched the planes together again as we reached the blade tip.  I ended up with a total of 20 planes, each one requiring it's own sketch. 

 

Screenshot-2022-06-05-102305.jpg

 

Before I could begin sketching however, I needed some dimensions to work with. 

I turned all the planes (visibility) off, then one by one turned them back on and on another sketch on the front plane I added points where the plane intersection the blade spline.  Dimensions could then be taken for the overall height at that "section", and for the height from the center of the hub to the uppermost point.  The point to notice here is that this is the two dimension height in front view only, not the actual chord length which will be longer

 

Screenshot-2022-06-03-121827.jpg

 

On each plane I created a square from construction lines constraining them to the center axis of the hub, then began the process of creating the individual sketches.  For the actual aerofoil shape I opted to keep things (very) simple and use two circles (leading edge and trailing edge), connected by two arcs (at a tangent) and trimmed out the middle parts.  Essentially my aerofoil consists of a thin bit at one end, gets thicker in the middle, and ends up with a very thin bit at the other end, which also describes about 99% of dinosaurs.

Those entities were then constrained within the construction square by making the leading and trailing edges tangent to the horizontal construction lines.

 

Screenshot-2022-06-03-122259.jpg

 

note: that shot above was an early version which all went pear shaped, as is the screenshot below,, but they serve the purpose of showing the principle in action.

The reason I used the construction square was to give me some fine control of the chord length - by adjusting the height above the centerline or the overall height, the aerofoil would stretch or shrink (due to the constraints) to accommodate the new dimension.

The aerofoil section would still need fine tuning but at this point I am just looking to get a basic blade form to work with.

Each sketch was built upon the previous sketch and as we moved further out from the hub I increased the rotation and started slimming the shape down to something more approaching a blade form.

 

Screenshot-2022-06-04-165550.jpg

 

I think I may have mentioned this before but it's worth bringing up again - when lofting, it is important that each sketch has the same number of entities, or vertices, and it is also important that when selecting the sketch for the loft that you pick the same relative point on each sketch - like so...

 

Screenshot-2022-06-03-124203.jpg

 

otherwise, as you can see here where I deliberately (honest!) picked random points, the loft can go a bit haywire.

 

Screenshot-2022-06-04-122030.jpg

 

Once I had all the sketches in place I created a full loft - and ended up with this monstrosity. :christmas:

 

Screenshot-2022-06-04-122258.jpg

 

Ugly as it may be, it was at least a starting point.  It was a blade... of sorts.  Probably with the aerodynamic qualities equal to spinning two badgers on a rope so further work was needed :D 

 

Working my way backwards and forwards along the blade I adjusted each sketch until lumps and bumps disappeared, or at least smoothed out.  Any reference photos I could find (i.e. none of this type of blade) weren't really of much help so in the end I opted just to wing it and hope for the best.

This shot shows how the planes were spread out and you can see how I arranged them much closer at the blade tip to help with that rapid shape transition. The planes themselves are hidden in this view, but each one of those squares/rectangles is on one of those planes.

 

Screenshot-2022-06-04-161733.jpg

 

I managed to achieve a reasonably smooth shape transition along the blade without too many lumps, bumps, or carbuncles

 

Screenshot-2022-06-04-165450.jpg

 

one thing SolidWorks doesn't handle well (or I still need to upskill!) is closing off a loft to a point.  I've tried it but never been happy with the end result.  The loft approach I used left me with this small flat spot at the blade tip

 

Screenshot-2022-06-04-161429.jpg

 

which thankfully is easily resolved by adding a dome on that face

 

Screenshot-2022-06-04-161544.jpg

 

It's not perfect by any means, but it's a blade.  I have to keep reminding myself that the blade itself will be less than 25mm in length when printed and on screen any defects always appear to be magnified, so I will only be certain when I print off a test run 

 

Screenshot-2022-06-04-172936.jpg

A final check reveals that the loft conforms to the drawing profile very closely so that's a bonus.

 

Screenshot-2022-06-05-102222.jpg

 

Once I was happy with the loft I used the circular array tool to create the second blade. A mirror operation would not have worked in this situation as that would have ended up with one leading edge and one trailing edge heading into the wind.

All that was left was the fun part - adding some greeblies on the hub to make it look more interesting

 

Screenshot-2022-06-04-165231.jpg

 

Those blade roots look a little funky from this angle but they match the drawing so I think they'll stay.  

To be honest, it would probably have been a much easier operation to scratch build one from laminated wood. Having something in your hands and being able to turn it and look at it from different angles and actually touch it while the shape takes form would be a lot easier than trying to wrangle something like this on a screen.  3 dimensional objects on screen still have limitations.

Had sectional views of the blade been available this would have been a much easier task, but the internet let me down again. How inconsiderate.

At a guess I'd say this took me about 6 hours or so and of that, around 2/3's of the time was spent tweaking dimensions... and I may yet go back and do some more tweaking.

 

 

Just a few small items left to model and the print machine can run in anger again.

 

Win win you say?   :hmmm:

 

 

 

 

 

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This is a magnificent piece of work.

A different scale, admittedly, but I wonder what Wingnut Wings could have made of the Avro 504, had it survived? The Friedrichshafen raiders, Home Defence, training, service in dozens of air arms, and a further lease of life as banner towers and barnstormers. Options galore! Alas, not to be.

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Brilliant stuff. I hate lofting, I always just end up modelling, raw and crazy but I know I shouldn’t. You can re-normalise splines in max to have the same amount of knots and set the start to whichever you want soo masking a loft process easier but I still hate it so there. You’re making jolly god use of it so I’ll shut my cake hole. 🍰🕳.

 

23 hours ago, hendie said:

tentative beginnings have began to be begun on a probably very long term Dalek project.

Dribble! 😉

 

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