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Thursday 29 November 2018

Rope with Fusion 360

When finding out how to represent a rope in Fusion 360 I looked up 'coil following a path' this, it turns out, has a name, 'Helical Sweep.' It is more commonly used for curved springs.

Creating the rope is two helical sweeps at 180 degrees rotation to each other.

I found a pretty good video to show me how to create a single helical sweep:

There's no point in going in to detail, the above video explains it clearly.

As a reminder, mainly for me, here are the steps:

  • Create some parameters to make it easier to adjust. [sweepRadius (mm) 10mm, Revolutions (no units) 5, twistAngle (deg) Revolutions * 360]

In model mode

  • Create a path, as a continuous tangent line or curve in a sketch. It will cause an error and fail if it has any awkward kinks from one line segment to the next. I used the 'Tangent Arc' line to make a nice curve.

  • Create a 'plane along path.'

  • Create a sketch on the plane, just created, with a construction line the length of the sweepRadius of the coil and a normal line of any length but about 10mm worked for this model That normal line following on from the sweepRadius construction line. (I revisited this sketch to create the second coiled strand needed for the rope effect, I just did the same lines mirrored.)

Go to Patch mode.

  • Create a sweep following the path, with a twist angle set to the variable twistAngle. That gives a flat helical shape.

  • Create another sketch on the front plane, including 3D geometry.

  • Select the inner edge of the included 3D geometry to create another path.
  • Create another plane along path, selecting that helix. Move the plane to zero on the path.

Back to the model mode

  • Create a sketch on that plane, with a shape centred on the start of the point of the path, usually a circle but could be any shape.

  • Select the shape and create a sweep along the helical path.

I needed two of these coils intertwined to make a nice looking rope.

I used the same sketch for the sweep radius but created another construction line and normal line in the opposite direction from the centre.
Using the same spiral sweep I created another coil.

I needed to patch the patches and stitch them to make them both solid models. I adjusted the diameter of the strands until they just merged, which was 20mm.

I textured them using 'weathered leather,' as that was the best I could find to match a hemp type rope.


For the parameters I ended up with:
sweepRadius = 10mm
Revolutions = 5
This was over a 300mm length of rope.
Each of the two rope strands was 20mm diameter.

Tuesday 20 November 2018

Fitting a Defender front door

The doors on Fender are, to say the least, a bit rusty.

Some time ago I purchased a pair of new doors and had them sprayed black ready for the full respray in the future.

This weekend I fitted the first of them.

Not a particularly difficult job but it took a while as this is the first time I've done it. There's no point in going in to detail but I will mention a couple of things that may or may not help anyone else doing this job.

The first thing I did was to check that the door hinge bolts were free. I sprayed them with penetrating oil but luckily all of them on Fender came out easily.

With the door removed I took the opportunity to paint under the hinges with black which will be the final colour of the rest of the car.

To save repeating it at every stage in this post, I used a lot of White Lithium Grease. I sprayed it on every, screw, bolt and hole. This is primarily to reduce corrosion but, in the case of bolts, to help to keep them free to remove in the future.

I bought a kit of all the parts to replace the window runners which includes the plastic filler pieces which go on the outward side of the window channel.

The felt lined window runners fit inside the lower part of the plastic filler strips.

The runners are held in by small screws. I did watch a video where they used small dabs of adhesive instead of screws but I decided I liked the screws better. Easy enough to drill a 2mm hole and fit the self tappers. I only used 2 on each runner at the top and one on each of the long runners where they touched the frame at the lower end.

The kit with the runners included aluminium strips that fit behind the window runners. I have no idea what they are for but I fitted them anyway.

The top bracket on the hinge side is held on by a single bolt and needs to be transferred to the new door.

As I had the doors apart I fitted a new window regulator. The doors use a lot of 10mm long M6 bolts, with spring locking washers.

This shows how rusty the steel work of the door was. I am glad I chose to replace the whole door rather than attempting a repair.

There is a foam strip across the door just under the window opening. I'm not sure what it does but I had some, so I fitted it.

The door latch caught me out. It needs to be fitted BEFORE the window runners are installed. There was a bit of back tracking at this stage to get that in.

I gave the catch mechanism a good clean up before refitting.

I used a new handle. I don't know how some of the these OEM and after market suppliers take their measurements because the pivoting puller caught on the door and needed to be trimmed to fit!

The doors I purchased did not come with one of the brackets. I had spotted this so I had already made the lower hinge side brackets and included a cut out to support the central door locking cable conduit.

The extra bit on the bracket is enough to block the glass when trying to fit that, therefore the bracket has to go on after the glass has been fitted.

This is held on with M6 x 20mm bolts and spring lock washers.

Not only was one bracket missing but the bracket on the other side is in the wrong place. If I had not already had them painted I would probably have sent them back because they were advertised that they were for this age of Defender! I made something to bridge the gap out of a bit of galvanised strapping.

As a slight upgrade, I chose to fit the newer style rubber door seal to the bottom of the doors.

This required an extra couple of 5mm holes, one drilled at either end, just up the side from the bottom of the door.

In addition, all the holes along the bottom of the door needed to be enlarged from 4mm to 5mm. If these doors were designed for a newer model, which is what I had suspected, why did they only have the smaller holes for the older door seal.

They are nicely made doors but I am not impressed by their attention to detail.

I fitted my design of central locking solenoid bracket.

When refitting the doors it is worth noting that the fillers for the hinge on the A pillar side are not the same as those for the door side of the hinge. The forward ones have cut outs to accommodate the spring of the captive nuts

I replaced the captive nuts. I would have preferred those like the originals I removed, which are proper nuts in a spring frame. Unfortunately, the hole in the bodywork was not quite big enough for me to fit the type I had so I was forced to use spire chimney nuts instead.

It might have been easier with two people but I was able to line up the door myself and use the latch to hold it in place while I got the first of the hinge bolts in.

I made sure the window was open so that I could release the catch from the inside as well as the outside, just in case something did not work properly.

I was pleased with how the door lined up with minimal adjustment.

As soon as the door was on, and the hinges bolted down, I refitted the check strap to avoid accidents.

I had to tuck the central locking solenoid cables up in to the bracket to avoid them fouling on the window mechanism.

In typical Land Rover style, Fender now has one odd colour door :-)


Update: 8 December 2018:

I've now done the left hand door as well. I kept track of the time so I now know it took me over 9 hours in two sessions, just for the one door. I wasn't rushing but I'd have to do a few more if I was to ever get any faster.

I remembered to fit the condensation shield or whatever the bit of plastic sheet is called.
I bought some PU adhesive in a mastic tube. A bit messy but I think it's the right stuff to attach the plastic sheet.

I used some 1000G plastic from eBay and the old one as a template.

I will have to revisit the right hand door at some point to fit the plastic to that door.


Thursday 15 November 2018

Discovery 4 recovery points

The Land Rover Discovery 3 and 4 have heavy duty towing eyes front and back. This is a step up from any earlier Land Rover, which do not come out of the factory with any recovery points.

The manual says the towing eyes on the Discovery 3 and 4 are not for off-road recovery however there is more than enough anecdotal evidence, to satisfy most, that the points are more than adequate. The rear one particularly looks very strong and the front looks stronger than most people fit to a Defender.

It is therefore a little bit controversial, and perhaps a little redundant, to fit extra towing points for off-road use but that is what I have done. I'm just not entirely comfortable relying on having only a single connection at each end of the vehicle. Having eyes either side of the vehicle allows me to use a bridle which requires two attachments.

I could not find any third party recovery points so I designed my own.

I had them made by a local blacksmith friend.

He had them galvanised for me and I painted them so that they stand out.

The contrasting colour is not essential for off-roading events however it is common practice for competitive motor sports.

Today I fitted them.

The front pair fit under the wishbones. They are a long way back, so they are not very convenient and I suspect that I will use the factory fitted ring most of the time.

As I get to know the car, I hope I will come across somewhere further forward that I could mount something but for the time being this position will suffice.

I would have preferred some bolt holes directly on or through the chassis but, so far, I have not found anything suitable. The bolt holes I have used are through 3mm steel plates, welded along two edges across a corner. That, along with the front guard, should spread the load over a large area.

I fitted them under the front guard which I had to cut to be able to attach the shackles.

I plan to use soft shackles so I made sure all the edges are smooth.

The slots I cut are at a slight angle towards the centre because that is the angle formed by the use of a bridle.

The rear Jate rings are much easier to fit.

The M14 bolts just fit above the exhausts and can then be slid in to place through the existing hole intended for the fully fitted tow bar.

These, at the rear, are therefore mounted in positions that I am very confident will be strong enough for any off road recovery situation.

I'm pleased with the results. They are untested at the moment but I'm confident they will do their job.


LR Discovery 4 front recovery points drawings (PDF)
LR Discovery 4 Jate ring drawings (PDF)