Jump to content

Project Rhocaravan


richyb66
 Share

Recommended Posts

As expected the side frames went together quickly, this is the left hand side frame with the door at the back. As there's no frame across the sill area, we cable tied a piece of wood across to hold the frame together. This is just the central frame area, basically the pieces that meet at 90 degrees. It needs to be extended at the front, back and across the top to meet with the perimeter frame which will have angles and curved sections meaning we can't use the plastic joining pieces. Instead these joins will be welded.

 

WP_20171108_20_50_51_Pro.jpg

 

Here's the LH frame clamped to the chassis showing where it needs to be extended at the front.The hardboard on the floor has the beginnings of the right hand on it. The wooden step inside is roughly the height that the inside benches will be. The top left hand square will house a window and the door is at the far end.

 

WP_20171108_22_05_03_Pro.jpg

 

The perimeter frame needed to be made next and we marked out the shape on the pieces on the plywood that was the original floor. For the curved corners, a double thickness of 12mm was cut to shape with a jigsaw and then screwed in place so we have a form to bend the tube around. This is the front part of the frame - 3 straight sections with 2 bends. At the bottom corner there's an offcut of tube used to set the position of the battens. We'll bend this first piece starting here so we have a long length of tube to work with - a long lever.

 

WP_20171110_14_29_30_Pro.jpg

 

Here's the first bend being formed. We used a blowlamp to heat the tube and gently pull it tight around the former. It takes a bit of time and it's difficult getting an exact match all around the curved part of the former so we just aim to get a smooth curve. The important thing it that when we make the frame for the other side, it matches as close as possible.

 

WP_20171110_15_13_32_Pro.jpg

 

The process is continued around the top of the frame.

 

WP_20171110_15_34_04_Pro.jpg

Edited by richyb66
  • Like 1
Link to comment
Share on other sites

We then spun the plywood around and marked out the rear part of the frame. It's similar to the front but with one more bend and straight piece.

 

WP_20171110_17_31_18_Pro.jpg

 

This is the first of the rear parts, just the second to go. We managed to get the front pieces shaped to within about 2mm of each other, more than good enough for what we need and withour the use of any fancy tools.

 

WP_20171110_19_16_18_Pro.jpg

Edited by richyb66
  • Like 2
Link to comment
Share on other sites

Made some good progress since the last post. The curved front and rear tubes were positioned around the central frame and welded together. The overall length of the frame is now bigger than the plywood template so one end overhangs but using guide pieces for the tubes allowed us to line everything up correctly and ensure we end up with two near identical frames.

 

WP_20171111_19_31_26_Pro.jpg

 

WP_20171111_19_31_41_Pro.jpg

 

For the welding we're using the same setup I used when I made the frame for my hardtop. It's a small MIG welder, Argon shielding gas, low power setting, 0.8mm wire and near maximum wire speed. The welding itself is straightforward, just remember to clean the surface of the aluminium before welding to remove the oxide layer. The welder was playing up a bit but I cut it some slack due to it's age.

 

The wire is very soft and bendy and so you need to use a PTFE torch liner instead of a steel one otherwise the wire snags up. Also the end of the liner has to be as close as possible to the drive roller so if the wire starts to drag in the liner (which it does), it doesn't kink and end up filling the inside of the welder with scrap wire. We did have to persevere a bit to get the welder behaving itself and another trick is to keep the torch lead as straight as possible to reduce the chance of the wire becoming pinched in the liner.

 

This is the weld before and after cleaning it up

 

WP_20171113_20_46_29_Pro.jpg

 

WP_20171114_20_23_17_Pro.jpg

Edited by richyb66
  • Like 1
Link to comment
Share on other sites

The frame were welded up on one side, flipped over and welded on the other before being stood upright to weld the horizontal welds. Here's the right hand side frame (non-door side) in position on the chassis. It's even the correct overall length.

 

WP_20171112_08_25_09_Pro.jpg

 

WP_20171112_08_25_27_Pro.jpg

 

With the left hand side similarly finished we had to put both frames on the chassis to get a feel for the finished size. A couple of cross braces were clamped in position to hold everything together.

 

WP_20171114_22_01_33_Pro.jpg

 

Here's Jackie sat inside, the step she's sitting on is around the height that the inside benches will be and then there'll be 50mm or so of cushion on top.

 

IMG_20171114_220451.jpg

 

and stood alongside

 

IMG_20171114_220634.jpg

Edited by richyb66
  • Like 1
Link to comment
Share on other sites

Final job this week was a couple of hours in the garage last night starting on the new floor. We're using 12mm plywood and the floor will be made in 3 pieces. The overall width of 1500mm is wider than a 1220mm sheet so we'll have a joint along the centreline where it can be supported by the middle chassis longitudinal.

 

At the front, the floor needs to be extended to a point to make the front of the caravan pointed. This extends the overall length past 2440mm (the length of a ply sheet), so we will add a single transverse piece at the front which will sit underneath the kitchen area.

 

Here's the first half of the floor

 

WP_20171116_21_14_33_Pro.jpg

 

which had a rectangular hole cut in it so the molded wheelarch cover could be screwed in place from underneath

 

WP_20171123_21_58_03_Pro.jpg

Edited by richyb66
Link to comment
Share on other sites

  • 2 weeks later...

The right hand side part of the floor is just a mirror image of the left hand side and at the front, a third piece was added which has a point at the centre.

 

WP_20171123_21_58_03_Pro.jpg

 

With the floors in place we positioned the side frames and drilled 8mm holes down through the floor and chassis rail so the frames could be bolted in to position.

 

WP_20171123_21_57_37_Pro.jpg

 

WP_20171123_21_57_53_Pro.jpg

 

We'd already planned out the floor layout on CAD and this was drawn on to the floor so we could start building the seat benches. We used a combination of new timber, 12mm plywood offcuts from the floor and timber from the original trailer tent frame. Initially the battens are screwed down in to the floor but eventually we will screw them from the underside upwards so we can use longer screws for more strength.

 

WP_20171124_15_50_37_Pro.jpg

 

WP_20171124_17_36_17_Pro.jpg

Edited by richyb66
  • Like 1
Link to comment
Share on other sites

The seating benches will provide important support to the lower half of the main sideframes. The sides of the benches were made from 44mm square timber for strength and we added 3mm thick aluminium angle brackets either side of the frame vertical members to attach the 2 parts together.

 

The angle brackets were rivetted to the square tube using 4.8mm diameter peel rivets which are more resistant to pull-out than normal bulb rivets. The angle brackets were screwed to the timber with 5mm screws which will later be replaced with 5mm bolts.

 

WP_20171125_10_40_37_Pro.jpg

 

WP_20171125_17_02_36_Pro.jpg

 

In the photo above you can see some screws in the grey wheelarch moulding. Due to a measurement error on my part, I didn't have the wheelarch in exactly the correct position in our CAD model. This meant that it clashed with the right hand side bench and moving the bench would compromise the foot space under the table. The wheelarches are generously oversize (possible also used on 13" wheeled trailers) so we decided to remove 80mm from the length of the moulding by removing a band of material from it.

 

For now we will use the wheelarches as they are but as they're so oversize, we will probably make smaller versions in aluminium and free up some more space under the benches.

Edited by richyb66
  • Like 2
Link to comment
Share on other sites

Looking good...

 

As a caravan owner, the scourge of caravans is water. You may have already thought about this but think hard about preventing water ingress, especially to those wooden battens.

 

I have no idea how you would do this but if you're interested, Bailey have a system called Alutech which might help with ideas:

 

http://www.baileyalu-tech.co.uk

Link to comment
Share on other sites

Here's the side benches, they'll need to support not only the seating, but also the bed when it's in sleep mode.

 

WP_20171125_17_02_50_Pro.jpg

 

WP_20171125_20_21_49_Pro.jpg

 

Across the back there's a 500 x 500 corner seat and a narrower bench which will have more storage underneath.

 

WP_20171125_20_22_05_Pro.jpg

Edited by richyb66
Link to comment
Share on other sites

No, the front panels will finish at the edge of the wooden floor and they'll be a window each side of the centreline.

 

We want this to look just like a caravan, not a lump of badly cut cheese.

Edited by richyb66
Link to comment
Share on other sites

  • 2 weeks later...

Been a bit quiet the last couple of weeks and only managed a few evenings in the garage. Next job was to get the side frames tied together with some cross members. At this stage we still need to be able to dismantle the frame because we need to treat the underside of the floor (probably with stonechip) and we'll need to run somne underfloor wiring for the rear lights.

 

To attach the crossmembers we cut some 25mm lengths of 25x5x3 aluminium angle which was drilled so a piece could be bolted either side of the cross member with M6 bolts right through and then the angle was rivetted to the side frames with 4.8mm peel rivets.

 

This is the crossmember that goes underneath the rear window and we also added a central vertical bar to give the curved rear panel some support.

 

WP_20171207_21_33_56_Pro.jpg

 

The roof structure was the next to build up. We'd modelled the basic roof up on the CAD but this was just to give a rough idea of the sizes. The clerestory style roof ( https://en.wikipedia.org/wiki/Clerestory#Transportation) has a step in it either side and we need to consider how this will be panelled in to maintain a leak free roof. The plan is to get the main frame built with the minimum of supports and them add lightweight structure to support the panel joins where required.

 

This is the roof looking towards the rear of the caravan and the stepped portion is visible to the right

 

WP_20171207_21_29_33_Pro.jpg

Edited by richyb66
Link to comment
Share on other sites

 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...