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300mm Dome Build

Really there's no option. The 300mm Dome from Darren is really a must. Yes it is costly, but wow - what a masterpiece. I read some background information and various blogs and really although costly it really sets off your R2. I'd highly recommend that you get the pennies together and purchase it. Darren also provides everything that you need, so although you think its just the inner and outer dome, its all the other parts that are just too hard to source individually. The dome comes laser cut, so its just a process of using a saw to remove and label the panels. I should have taken an actual shot of my dome but got so carried away, I had to start on it.

Once you spend any time reading the blogs, you then see the effort builders put in on getting a shine on the dome, and you realise that no alternative is going to give you that r2 look you want. The aluminium dome is the crowning glory and so I do think there's no choice.

The not so obvious advantage of the 300mm dome is the additional supplied parts. You tend to consider the dome as just that, and inner and outer dome. In fact when you start to explore pictures of r2 in detail, you realise there's actually much more than just the dome. If you look at the accompanying picture, you can see there's actually the dome, then the blue ring at the bottom of the dome and then a large aluminium ring. So if you are considering using an alternative dome, such as bar-b-que domed lid, or the squirrel dome, you still need to consider, how do I create the blue ring and then the bottom most ring. In addition how do I get this all to rotate ? With the 300mm dome you get all this. The 300mm comes supplied with an inner nylon ring. This nylon ring mounts to the rockler bearing . This nylon ring inturn connects to the dome. So not only are you getting the inner and outer dome, but the other necessary parts, that you still need to source, and then in addition you get all the required mounting screws and bolts. So your pennies alos include all these required parts saving hours of labour and time and sourcing outer required pieces. Im not Darrens. marketing department, but you'll not regret it.

The dome consists of a number of pieces. The outer dome, with the laser cut panels. The inner dome, (a solid dome as in picture opposite) a bottom ring (if you examine a picture of R2D2 you will see a circular band just below the bottom blue ring ) this is a separate machined aluminium ring. Incidentally the blue ring is actually attached to the outer dome. If you look at the picture opposite you can see the bottom of the outer dome is a ring. The very bottom ring is not that tall and is a scrap piece that can be removed and thrown away, but above this and attached to the dome is the ring. This you need to cut off carefully and keep safe, as it will eventually form the blue bottom ring.

The dome first requires you to push out the scrap pieces inbetween the panels and dome. The laser cuts the panel and dome but leaves some scrap inbetween the panel and dome. These are very easily pushed out. Then you can get the saw in place and saw through the tabs removing the panels. Opposite is the completed Outer dome with all the pieces removed. Again I labeled all the pieces and the inside of the dome before removing any panels so I knew exactly where the panels would fit. Darren recommends that you remove as much of the laser slag as possible before removing the panels and he has some tutorials here ..

I had read on one of the blogs that one builder regretted not using a sander on the inside of the dome before removing the panels, so before removing any panels I used my mouse sander to sand down as much of the inside of the outer dome as I could. It was difficult as the mouse sander is flat and so didn't fit easily on the curves of the inner dome, but I did as much sanding as I could before removing the panels.

Daren describes using a flat side of a file to remove laser slag from the removed panels. As I had sanded down the dome first this didn't work and I ended up using my mouse sander on the cut out panels. I think in hindsight the recommendation to use a mouse sander before removing panels, is possibly not the best, but having used the sander I'll never know. It seemed to work out ok for me and sanding the slag worked ok. Don't forget you need to remove the slag from the dome inner surface as it sits over the inner dome and you want as snug a fit as possible, between inner and outer dome.

I safely stored all the panels so I could retrieve paint and attach later.

I'd read lots about hours of sanding and being a programmer, so naturaly lazy didn't fancy sanding much. In fact it looked fine Out of the box But I worried what if 1 year down the line I should have sanded, and it was then going to be too hard to sand around the fitted blue panels. So reading a bit on the Astromech forums and builders logs, there seemed no option but to sand. I decided to start with 240 grit wet and dry sandpaper, I know others say use 180 but i felt it too course. I thought about a block or mouse sander but was worried to abrasive and harsh, and I had said I was trying to avoiding being lazy. Once I began to sand with the 240 you could really notice the spin lines. So my choice which seemed to work was start with 240 then progressivly move to 400, 600, then 1000, and finally 1200. Then to superfine 12000 steel wool, and then aluminium polish.

Here is a close up of the spin lines. OMG I've made it worse ! and now it was too late, I had comitted myself to sanding and I had to now continue, but in the end it worked out.

So I bought 10 sheets of 240 and got a big bucket of water. I took the dome outside onto my back step in the garden. Then tore a square of paper bigger than my hand and then soaked it in the bucket and began sanding with my hand in small circles using the curvature of my hand and rubbing in circles, and slowly moving round the dome. I would stop and then wet the paper more and start again, constantly going back to wet the paper. The water helps lubricate and makes the sanding a bit easier, and the water helps clean off the sanded aluminium. I just used a gentle pressure, in small circular movements, much as if you are using a cloth to polish your car but in this case sandaper on the dome. I'd frequently dip the sandpaper in the water, checking the sand paper, and sand a bit more, until examining the sand paper it looked worn, and then I'd tear off a new piece, soak this and start again.

In addition every 10 mins or so, I'd get some clean water and pour this over the dome washing the grime and tiny sanded aluminium grains. I started at the dome bumps and moved around the dome until I had sanded the whole dome, and arrrived back at the bumps. I set my self this sanding task each free weekend, with around an hour to 2 hours in one session. Each session was separated by a week and used a different grade. As mentioned it gets very tiring and initially you could clearly see the spin lines, but after a bit of sanding the lines did sand out. The progressive 400, 600, then 1200 moved the dome surface closer to a closer shine, and I'm very happy with the results.

I also used the 240 and 400 on the cut out panels. I didn't spend as much time on these. OK - the spin lines were visible, but I figured as these would be painted with primer and then blue the spin lines wouldn't show and the 400 would be smooth enough and also provide enough surface for the primer to adhere to.

With sanding complete, the next stage is the inner panel. I'd saved some 240, 400, 600 and 1200 for the inner dome, as there are areas of the inner dome that show through the cut out panels of the outer dome, and I wanted these to be of the same consistency.

I then placed the bottom ring (the one that will eventually be painted blue, and that was part of the bottom of the inner dome) over the inner dome and then placed the outer dome over the inner and using the hole in the middle of the center of the inner dome, I centralised the outer dome.

Next I checked the spacing around the bottom to ensure the bottom of the inner dome was centered correctly, and slightly adjusted the dome to ensure the spacing was even. You need to carefully ensure this is correct, as my next stage is to mark the cutting on the inner dome.

I planned to only have two pie panel openings in the roof of the dome, and had bought Jag hinges for these openings. I wasn't going to have any side panels opening. The two roof openings were only so that I could see into the dome for any alignment on the rockler bearing, and not for any periscope.

Here you can see there is an obvious gap, between the bottom of the inner dome and the top of the blue ring. I'll need to later cut the bottom of the inner dome to remove this small gap.

Once I was happy with the fit, and that the outer dome fitted snugly with no gaps between the inner and outer dome ( i did have to turn the dome to get completly happy with the fit) I drew with a pencil the pie panels on the roof . I fitted the pie panel with the holoprojector and drew the circle needed for this roof holoprojector. I then drew the circles for the lower two holoprojectors, the dome bumps, and the panels. I drew the large rear logic and two smaller square logistic aperatures and finally I drew the areas where the inner dome would show through.

I removed the outer dome and checked the pencil marks could be seen. Then before starting any cutting I worked on the pieces that show through from the inner dome and using water and sandpaper, sanded the areas that would show through, with 400, then 600 then 1200 so that they matched the same sheen on the outside of my dome.

With the pencil lines marked on the inner dome I took a small drill and drilled a number of holes. These would form the pieces I would eventually cut out. The panel pienes I drilled the holes on the inside of the lines I drew so that the panel that would fit over would have a small lip on which to sit. For the holes I drilled just on the inside of the lines drawn.

Once I had all the holes drilled the next stage was to cutout the pieces. I intended to use a pad saw, which is basically a standard hacksaw blade in a handle.

Having completed the holes I then drilled a larger hole in the centre of the panel I wished to cut out. This hole had to be big enough to allow the saw through to allow me to cut from the inner hole to the sides of the piece I wish to remove.

I found the easist way to do this was first to measure the depth of my saw blade and then to drill small holes in a cross pattern, Then in the center I used a larger drill bit. This then meant I could get my saw into the hole and begin cutting.

For the circles I cut from the centre to the side in a cross pattern leaving small pie pieces.

Once I had made sufficient cuts I then pushed the pie pieces in with a rounded hammer end, and then bend each the panels in turn, in and out until they formed a fracture where it broke around the holes and could easily be removed.

I was able to use a screwdriver and with a few gentle taps with a hammer bend the pieces across the drilled holes

I did this against all of the small pieces and then was able to bend them back and fort until they snapped. With the holes for the Holo-Projectors these have to be a little bigger than the holes on the outside to accomodate the holoprojector side casing, so although I had carefully made the hole the same size, once I tried to fit the holo projector, I realised I needed to "open" the hole quite a bit, so yet more file-ing. I did my usual check of file-ing and then checking the projector fit, and then more file-ing, then stopping and rechecking until I was satisfied with the result. It did turn out that the inner hole isn't perfect, but its hidden by the perfect laser cut outer dome hole anyway.

I then repeated the bending back and forth on the remaining pieces until all had fractured

With all the pieces fractured and removed, it was back to the file-ing, and I used a half round file, to then file off the half drilled holes. It took a fair bit of effort but I was left with a reasonably round hole. I then carried out the same action on the other holes and the pie pieces, until all the holes were complete. Its my intention to add JAG hinges to the dome pie panels, and looking at the forum it says you need to make the lip as small as possible to allow the pie panel to open without catching, so I have a bit more file-ing to do on the bottom hinge edge until I'm entirely happy. I had to do a similar effort with the rear and front logic ports.

Once the holes were complete, I refitted the other dome over the inner and checked alignment, and then moved onto painting.

With it now Easter and late April the sunny weather has returned (here in Northern Ireland we get about 3 sunny days and then its back to rain) so as it was sunny and the green house was heating up to simulate an oven, I decided to paint the frame and the dome at the same time. I had read in the astromech site about self etching primer and couldn't track any of that down in the UK, so I looked at Halfords Primer. It seemed to indicate this was self etching, but I couldn't actually confirm this, but in the absence of any other suitable source in the UK and as used for car body paint, I felt this was perfect. If its good enough for a car body its got to be good for R2D, and now looking back I've no regrets.".

I started with a fine dusting, and then by the time I'd dusted the last part started back, and gradually in the sun allowing each spray to dry I built up a nice layer of primer on all the parts.

The inner dome has a blue panel that show through from the inner, so I also sprayed this with primer. I knew roughly where this panel lay as I had marked it with pencil, but as I added primer, obvioulsy I couldn't see the pencil line. In my haste I should have masked the area on the inner dome and then painted this, but as sunny and warm days are hard to find, I thought it best just to "crack on" and do my best. As It turned out I ended up having to sand back the primer and it would show through on the outline panel next to it and on the bottom ring, so masking the area should have been done. Less haste more speed as they say.

The recommened process is the Kryder Blue, suing Rustolleum paints of purple and blue, but I just couldn't source these in the UK. Homebase do have Rustolleum and have satin white (which I'm using for body and legs and feet) and have metallic but no purple or blue.

So I decided to go with the BMW Mini Hypo blue. I bought a can on ebay and this came with the blue and the clear coat. I had primed all the parts (aluminium and resin) with Halfords Grey primer and then sprayed this BMW Hypo Blue onto the previoulsy primed parts. To me it looks to be the perfect colour, and I suppose without being able to check against a US Kryder Blue I'll never know how close it is, but it looks perfect to me.

I found the Hypo bluepaint and nozzle and evenness of the paint perfect, and once I'd applied several layers and with no runs (not like the satin white Rustolleum, which I wasn't as sucessful with, and had to go back several times and re sand and remove runs) I was very very happy.

As its unusual to get sunny days in Northern Ireland, I took advantage of the weather and painted the blue and white parts in the same day. The Rustolleum white was a nightmare and ran in several places whereas the blue and the primer were perfect. Once the top coat seemed dry in the sun I applied the clear coat that wwas supplied with the hypo blue order. I again carefully allowed each fine mist to dry and then added another building up a layer. I also applied the blue to the primed inner dome, for the pieces next to the holoprojector that shows throu. I then left the pieces in the sun to dry and then carefully touching only the unpainted backs lifted each piece into the green house, which served as my oven. I left these overnight and they loooked to be hardened, but I did leave this for 2 weeks before touching, just in case.

With the panels painted the next stage is adding the holoprojectors and then bonding the inner and outer domes, then finally adding the panels. I have 2 small JAG hinges, so I need to fit these to the 2 top panels.

So I placed the outer dome over the inner and found that with the bottom blue rig added there was a small gap. I measured this as 6mm (about 1/4" inch). Checking the forums others had found this too. I suppose its better to have the inner dome too big than too small. Some lived with the gap and so there was a small visible inner dome above and below the outer blue ring, I wasn't happy, and felt I would regret later not trimming this. So I drew a line right around the bottom of the dome 6mm from the bottom, to make my cut.

So measuring from the BOTTOM of the inner down up about 1/4" or 6mm (you will need to make your own careful measurement, as i did (see pic and ruler) I drew a line and then cut on that line.

To ensure I got an even line I placed the dome on a table and raised a felt pen tip 6mm up and moved the dome round drawing the line. Using a dremel cutting disk, I cut a slot so that I could insert my hacksaw blade and began to cut. It was difficult, and immediately I thought "Why on earth did I do this". It was extreemly difficult to keep a steady and level line, so I adopted a method of cutting across the dome along the line at a tangent, by doing that I could keep a very level line, although it took several cuts and a considerable long time until, at last, the small 6mm ring was removed. It was then a bit of smoothing and sanding to get a nice edge, but now there is no visible gap, so I'm pleased with the end result.

I just couldn't stretch to the aluminium Holoprojector, so used the superb resin offerings from Azman, and this included the circlips and the lenses. I primed these parts with the Halfords Primer and then added Rustolleum metallic silver. Its not perfect but was the best match I could get to aluminium.

I bought a pair of circlip pliers rather than trying to fiddle about and they were only 3 on ebay. I then placed the holoprojector face down and dropped in the lens with flat side up, I pressed the lens down into the holoprojector with my finger and then when the lens was tight I added the circlip

The circlip went in fairly easily. I then shook the holoprojector to ensure the lens and circlip was in position and it wasn't going to come loose.

Next was the two retainer halves. I had decided to use araldite to hold the two halves together as I didnt want super glue seeping into the ball and locking the holoprojector, I wanted the holoprojector to move. So on the bottom half of the retainer I cut 3 squares of felt 10mm by 10mm and then stuck these using araldite to the bottom retainer, so that I had 3 pieces of felt equally spaced by 120 degrees. Once the two halves were joined together then the felt would act as preventing the ball moving and scraping. I left these felt pieces in place to dry over night before I joined the two halves.

To mount the holoprojectors I decided to use 3mm x10 countersunk screws so I drilled 4 3.5mm holes. I thought 4 would hold the projectors and make them kiddy proof.

However in hindsight 3 is enough, as when I tried to fit the projectors the bottom hole is hard to get at. In addition the orientation of the holoprojector is crucial. Also I found that although I drilled 4 holes, I had made the inner dome hole much bigger, and where I hadn't been that careful the hole (although not seen from outside) is just too big and the mounting hole falls inside the inner hole. However, with 4 holes I was lucky and 3 are ok.

I put the inner and outer domes temporarily together, to check positioning, then I poked the front holoprojector out through the inner and outer hole and using a felt pen marked the hole mounting positions. I needed to be very very careful the outerdome was in the correct final position, as once the holes were drilled there's no going back. Ok there is as the holes are only on the inner but you still need to be careful the inner and outer don't move.

Keeping the inner and outer domes in position I added and marked the back holoprojector. The top panel holoprojector can be drilled later but I wanted to check all 3 positions before drilling, as once one holo is in position it really fixes the position of the outer dome. The orientation is important as the holo can move quite a bit but the movement up and down is greater in one direction, so I used reference photos to be sure. Also I opted for aluminium all over, I noticed in some the outer holo ring is blue.

Having doubly ensured the positioning of all 3 holos, I then drilled the holes in the inner dome and countersunk the holes for the screws

I then fitted the screws and placed the outer dome in position, which then held the screws in position. I then fitted the holoprojector using the mounting holes. It was extreemly fiddly, but I managed to get the holos in position. As the dome is slighly curved the screws will point in towards the centre point. So you will find that when you come to fit the holo, you will need to allow some slight movement in the screws. If you've glued the screws in place, you may find you cant fit the holo over the screws. I'd recommend not gluing the screws. You may be concerned the screws will turn, as you attempt to tighten the nut, but I found that the outer dome held the screws in position so I didn't need to worry on that point.

Then using a M3 washer and nut I held the holoprojector in position. I only needed to fit the two side holos. Obviously top one is a lot easier, because the dome panel covers the top holoprojector. So only the two side ones are in place. I'm ver pleased with the result, and the resin holos painted aluminium work well. However, I could replace these with aluminium one should I ever decide to.

With the holoprojectors correct and in position, the next stage is bonding inner and outer. I didn't wnat to repeatly take the inerr and outer domes apart as sliding the inner over the outer again and agan increased the chances of accidently scraping the inner blue painted panel. I decided to use Araldite to bond the inner to outer as this worked well on skins and I needed a tight bond on those outer edges of the panels and the very bottom piece of the outer dome. I obtained a small glue brush, mixed the 2 part araldite and carefully spread a thin layer onto the inside of the outer dome, ensuring all these panel surrounds were covered and would adhere to the inner dome. Prior to this I checked the blue inner dome panels, and used the aluminium polish, to polish those inner dome pieces I'd previously sanded.

I then very carefully placed the outer dome over the inner and positioned it correctly, carfully checking no glue on the blue or aluminium panels, and then using multiple clamps ensured the outer dome was secured to the inner dome. I found inserting the nylon ring helped push the inner dome out slightly. I placed lost of clamps on the bottom of the dome to ensure the bond here was strong. This meant I had to balance the dome on a hoover handle as I couldn't set the dome down. Then I left this to dry overnight

Once the inner and outer domes were fitted I realised I couldn't now see the numbers I'd written on outer dome to match the panels. But I was able to work out what these were. I wasn't going to bond the panels using araldite but using clear silicone (the same white silicone you may use to edge your bath to the tiles in your bathroom. This I felt meant I could prise them off. So I drilled 8mm holes in the innerdome panel. So that once the panel was siliconed, it could be pushed off from behind.

You can see in the picture the inner dome at the bottom, not quite as shiny. Here i will drill holes through into the nylon ring. The blue ring will then cover up the screws.

I spread the silicone on the inner dome and then placed the panel in postion, using a small clamp to hold it in position whilst the silicone dried. I didn't want the outer panel to slowly drop down whilst drying. Here the view from behind showing the holes in the inner dome - so that if I do need to remove them I can push them off from behind.

This is the small outer panel surround. Here the inner surface of the dome shows through. The outer surround here was fixed with silicone. The dome bumps can be seen here as well but for the moment I haven't added the bumps so you can see the blue paint on the inner dome showing through here.

Here I added the blue ring, so the very bottom now has the blue ring "dry fitted" for checking. Once fitted the large aluminium ring will sit below that. This bottom aluminiun ring is screwed to the nylon ring. I did have a slight problem with the blue ring, it was just ever so slightly large. So it was a loose fit. I could have cut the ring, but i was afraid a single cut would be too much and the ring would have a vertical gap. I also wasn't confident it wouldn't be visible. How could I once cut repair it ? So in the end I added LOTS of silicone behind the ring and this filled out the small gap behind the blue ring. It meant it was a small bit proud of the dome, but I'd have to live with that. Maybe one day I will cut it, but with silicone, I can easly cut it off later, should I wish to.

For the outer top pie panels, again I had holes behind on the inner dome, to push the panel off should I need to replace or repaint it. All these panels are secured to the inner dome using clear silicone. I then used clamps to hold the panel in position whist drying.

I only wanted two of the top panels to open, so had two of the small JAG hinges to do this. I have hinges on the front body panels as well but where these were to be mounted butted to the edge the hinges for the top panels just sat slightly down from the edge. Here from behind you can see the positioning of the hinge. I used araldite to attach the hinge, and at first I used small drops so that I could easily remove and reposition the hinge if it was in the wrong position. You need a spacer from the hinge to the pie panel and so I used a piece if scrap inner dome, which I had left over from cutting the hole in the inner for the panel.

I found that initially when I tried to open the panel it would catch on the bottom edge. As I had only "tacked" the pie panel in position on the hinge I could remove it. Then by carefully sanding the bottom edge of the panel at an angle, I could just provide enough clearance to allow the panel to open. I didn't reduce the length of the panel (from top to bottom) but just chamfered the lower edge. This allowed the pie panel to easily open.

Now the top panels are complete, with the exception of the holoprojector top panel. I placed the holoprojector in position, and added the blue pie panel, and then adjusted the holoprojector position so the panel fitted correctly with a small surrounding gap. I then took off the panel and drilled 3 holes for the 3mm countersunk bolts that would hold the holoprojector in position.

With the holoprojector in position, I then siliconed the blue panel in position.

I placed the eye against the dome in its approximate position and checked for the clearance between eys and dome. I had seen other builders attach sand paper to the dome and then use this to sand the rear surface of the eye so it had the correct curvature. However, I found that Azman Sugi's resin eye was pretty close, so I just ended up sanding down the rear surface until I was happy with the fit.

Having painted the eye with primer, and found any imperfections, I then used 600 grit sandpaper and water to sand the imprefections, so the outer surface was smooth, I then used 100 grit to achieve a smooth surface. I felt it was easier to mask off the hinge areas than attempt to paint it blue and then add the aluminium hinges. So I sprayed the eye first. This wasn't as sucessful as I hoped and when masked off the area on the blue, and sprayed the hinges, the blue paint came off. So it was back to sanding and priming all over again. I again used 600 grit wet and dry sandpaper running under the tap. Anyway I found the surface of the eye has sort of wrinkled and looked crinkly, so as this is the main focus of the dome, I wanted it perfect, so the 600 sanding did no harm, and then primed it again, using halfords primer.

I ensured that all the old paint was removed, nothing worse than getting edges of old paint showing through, especially on the eye, so I needed to check it was completly smooth. It took longer and leaving the primer to dry over night before applying BMW hypo blue.

Now the surface looked perfect I sprayed the eye again. It was easy to spay as the long resin sprues lifted the eye off the surface. This time the paint was perfect. However, this time I sprayed the primer with silver on the hinges first. Then I cut very thin (same width as hinges) masking tape and placed this over the hinge, then sprayed blue. Lifting the masking tape to reveal the hinges. Perfect !

I then placed the painted eye against the dome and marked the position on the dome with pencil, carefuly drawing the inner circle as well. Thius would then give me the positioning of the 4 screws. I had to be ultra careful as once the hole were drilled in the other dome, they needed to be 100% correct as I didn't want later to have to reposition the eye and find a hole was off. I used quite a few reference photos to ensure the positioning especially the distance from bottom of the eye to the bottom of the dome.

When I was happy with the position I drilled the holes in the outer dome. Then I put the eye in place and marked on the eye from behind the position for the holes in the eye. I then tapped the holes to M4 and added bolts from behind to hold the eye in place. I was happy with the result, so I then removed the eye added the black lens (using clear silicone to hole the lens) and bolted the eye back in place.

I had purchased from the US the recommended rockler bearing / lazy Susan . This has small white plastic plugs, which I removed. The 300mm Dome from darren comes with the screw and nut fittings that mount through the bearing, but there are no holes on the outside bearing ring that go all the way through, so I had to first drill the existing holes, once plugs were removed. The inner ring is the one that moves the dome, and the outer is screwed to the top of the frame.

Before I did any mounting of the rockler bearing, I did a complete test fit, of bearing, the acrylic ring, the JAG dome plate, and the inner dome, with all screw fittings, just so I could be assured it all fitted correctly before doing anything.

Having test fitted, I removed the outer dome and then checked the movement of the bearing, ensuring it moved freely. In drilling the outer holes right through I had to be careful no swarf fell into the bearings, and that the holes weren't enlarged so encroaching on the ball bearings. I was surprised at the force required to move the bearing, and this made me realise how powerful a motor is required to move the dome.

I also checked the alignment of the dome to the top of the frame and essured it was centred, once I was happy I carefully removed the outer dome and then maked positions of 3 scres that would mount the bearing to the frame. Here you can see (although the dome plate is fitted ) you can see the wood screws I used to attach the rockler bearing to the frame. Again I only attached 3 screws at first and rechecked alignment by refitting everything.

I now need to drive the dome. More instructions here. I made my own motor bracket for the pitman motor. I cut the frame and attached the bracket and motor in place.

I screwed the bracket in place and then used a wheel and hub to rest on the inner surface of the rockler bearing.

I used the wheel from servo city and the centre hub and attached this to the shaft. With a 12v supply this will then drive my motor.

I then used a spring to main the tension on the motor to connect to the bearing. I drilled a small hole to hold the spring on one end of the frame. My concern was in the amount of tension used to try and prevent slippage. I have heard that the motor isn't the strongest and have to say i'm concerned it may put strain on the gearbox. So im not particularly happy - but in the asbsence of anthing else, it will have to do.

Prior to screwing the rockler bearing and fitting the other outer screws to the frame I removed the bearing and added the long threaded countersunk screws to the inner bearing. The rockkler bearing inner ring sits higher than the outer, so the other bearing ring sits flush on the surface of the top of the wood frame. The inner bearing sits proud of the surface so its not touching the surface as it moves (neat design).

With the screws (that come with the 300mm dome) all fitted these point upwards and protrude through the inner rockler ring. The idea being the dome plate and acrylic ring fit over these protruding screws. I had purchased the dome plate from JAG with the intention of mounting the electronics for the logic arrays. As it turns out these will actually mount on the inner surface of the dome, so the plate isn't going to be used for the purpose which I intended. This is because the dome lifts clear of the rockler bearing, so any attachments to the plate would mean I couldn't lift the head off ! So once the bearing was in place I then slid the dome plate over the screws.

As you can see the dome plate is fitted in above picture then some nuts, which provide a spacing for the acrylic inner ring, but also hold the screws and dome plate in place to the inner rockler bearing.

Once the nuts are in place the next stage is fitting the Acrylic ring. This ring eventually sits inside the inner dome, and the inner dome is screwed to this ring. This allows the dome to be lifted clear of the bearing so you can easily remove the dome. The screws that hold the dome are hidden by the outer blue ring. Its a tight fit to place the ring over the screws but it fits, securely attacing the dome. I found that that the inner dome and ring are very tightly fitted, but if you simply take your inner dome, pour ver hot water over the dome it will expand and then easily fit over the acrylic ring. You need gloves to pick up the heated dome, but it works well. The dome isn't to be fitted yet as the aluminium ring is next.

Now with the acrylic ring fitted the next stage is the outer lower aluminium ring. In this picture I've just placed the outer ring so you can see it more clearly. In the next picture you can see it in position. This ring is also supplied with Darrens 300mm dome. Which just makes me think how fanstatic this dome from Darren is. If you managed to source a dome, you still need some mounting kit and then this lower ring. Its only at this stage you notice, when you look closely at pictures of R2 that there is an aluminium ring at the bottom of the dome below the blue ring ! Once you get to this stage you tend to go "Oh Yes "

Here the outer ring is in position. It simply and neatly fits on the outside of the acrylic ring, and then turns with the dome itsself. This outer ring then sits flush with the top of the frame and thus skins, so its this that must remain fractionally clear of the top of the frame so it doesn't snag or drag on the top surface of the frame. The clearance and be increased by adding a nut or washer to the screws that protrude up through the rockler bearing. If you look at the rockler bearing picture you can see these screws. The Nylon ring then sits on these screws, and this nylon ring is then attached to the dome. So when lifting off the dome you lift the nylon ring attached to the dome, so its this that provides the mounting.

Next stage is to attach the nylon ring to the dome. This is achieved by drilling 6 self tapping screws (these are supplied with the 300mm dome) through the dome to the nylon ring. I spaced the 6 screws around the dome evenly and ensured that they didn't interfere with the existing vertical holes in the nylon ring. At one time I did have problems getting the nylon ring back into the inner dome, as its such a tight fit, but by simply pouring hot water over the inner dome it expandd and allowed the ring to fit. So at this stage the nylon ring as been in position and tighty fitting. All I needed to do was attach the ring

I drilled six holes through the bottom of the inner dome and into the nylon ring and then used the self tapper screws to secure the dome and ring. These screws would then be hidden by the blue ring. I added clear silicone and smootehed this with my finger and then slid the painted blue ring over the bottom into position. Any excess silicone I removed with the end of a match.

Finally I added the lower aluminium ring. This is secured to the nylon ring using the larger 6 self tapping screws. So I again evenly spaced the screw holes checking they didn't interfere with the previously drilled fixing holes to the dome or the holes that attach the nylon ring to the rockler bearing. I then counter sunk the holes so the screws would fit snugly.

I then turned the dome (with the previously fitted blue ring) upside down, fitted the lower ring and drilled into the nylon through the holes, and then fitted the self tapping screws. To ensure the lower ring was in the correct position I removed the rockler bearing from the frame and used the rockler bearing screws and the JAG dome plate and attached this to the nylon ring. The lweer ring then fits snugly onthe outside of the dome plate, ensuring the correct positioning. Now the dome and lower ring are attached to the nylon ring, and this will then mount to the rockler bearing.

That's it complete with the blue and the lower aluminium ring. The lower aluminium ring helps here as it prevents the blue ring moving and so the silicone can set.

With the nylon ring attached to the dome and lower ring I can then start to install the front and rear PSI's. I've seen the psi used as bottom of a milk container but I purchased some psi diffuser block set from Darren and saved on the postage as he put them in the 300mm dome box. I didn't use Darrens technique of attaching the diffusers by the included block but glued the block to the nylon ring.

I have 2 small Dual Led Blinker circuit boards for the PSI from Fiber Optic products one with green one one with yellow leds. These are powered from 9v battery and flash between the two leds. I drilled holes into the psi diffuser so that the 2 leds can fit inside. The circuit will then be attached to the psi and the 9v batter to inside of the dome using velcro strips.

With the led holes drilled I then used Araldite to glue the bottom of the PSI to the nylon ring. I had to trim the bottom of the smaller PSI to fit as the block supplied was too large, which I why I went down the glue route rather than the Darren fitting. I then used silicone around the outside to hold the psi to the dome.

The larger PSI diffuser block fits on the rear, and again as I had glued the smaller front PSI diffuser I used glue on the larger one, together with silicone.

Finally the last piece, to complete the dome. The topper. Here I used a washer and drilled out a larger hole. You can see the a spare original washer. I then took an axle end cap. A cap you might see on the end of an axle rod to protect the bar end of an axle. I cut the top off, and primed this. Yo can see the cut off primed pice in grey primer and the bottom, remainder, of the axle end cap.

I then sprayed the small cut-off end cap blue and then using silicone adhered the end cap washer and the top of the 300mm dome, to the top of the dome, and that completed the dome. Phew ! :-)

Just some pictures of the dome, as it is at the minute. I have a small fleck of paint that come away and some sealant that I used to hold the panel in place, so I'll need to come back to those

There's a small fleck of paint missing here on the rear panel, so I'll need to touch this up. The display is the Tecees version 2

I have two dome bumps to fit here, but in the picture you see the blue painted on thre inner dome showing through. I have 2 resin bumps that I need to sand down a bit and fit as yet

I agonised over this larger rear panel, should it be blue of left as aluminium ? As Its just siliconed to the inner dome I can push it out and paint it. I'm convinced in the film that the panel got damaged and they just stuck a replacement on, and it never got painted .

The Holo's are from Azman, and to be honest I'm very very happy and don't think I'll ever upgrade to Aluminium

I found that I needed considerable tension on the motor spring to allow the dome to turn, and when it did it was pretty noisy. So looking at various helpfiles and videos I decided to replace the 5/16" metal ball bearings with acetal ones (ref 9614K57 ).

It was a fairly simple process. Remove the screw on the side of the rockler bearing and all the ball bearings drop out, This allows the rockler to come apart. I then cleaned the grease off using Acetone, and used grade 1600 sandpaper to sand out any imperfections on both halves of the bearing. I then added the new bearings, and replaced the screw. I had 200 (2 packs) of the bearings but left enough space for the acetal bearings to move. This made an amazing difference.

So thats it do far. I now add the dome to the bits and pieces I have so far.

I wasn't happy with the dome drive . It just kept slipping with the heavy aluminium dome. It was ok with the dome off but the rubber wheel kept slipping. So I sanded down the inside of the ring with heavy grit sandpaper. The idea being more grip. This didn't work. So I posted . on astromech for help. It was suggested to use grip adhesive, like that on ladders ie something too make more grip. So I cut a strand, and stuck it to the wheel.

unfortunately this didn't work

I was reluctant to increase the strength of the springs, but i added a spring that had twice the resistance, this really ensured a good grip to the rockler strip, but it still slipped. I reduced the motor voltage to 9 volts, so not such a torque when drive applied. Made no difference. So I purchased the A&A dome gear.

This immediately cured the problem. It works so well now. The domegear consists of a toothed ring thats bolted to the rockler. I then replaced the rubber wheel witf the small toothed gear. I had to drill 4 holes in the toothed wheel and i used the mounting hub i used for my wheel. I had heard that increasing the sring resistance could burn out the motor, so this gear is by far the better option.

I was reluctant to buy a slip ring, the cost just seemed too high. I had decided that my dome wan't going to do the "full circles" with the head wizzing round and round. My dome needs powered by 9 volts for the electronics so I have a large 12v lead sealed battery in the main body, so I have asmall 9volt switching regulator that powers the auruino and the lights feed off the arduino supply. So All i needed was 9v dc supply from my switching regulator.

So as the head just moves left and right the 12v power lead up to the dome will simply move with the dome movement. I have a simple 12v power connector, that the lead plugs into in the dome. So I can easily lift off the dome and unplug the lead. To prevent the lead snaging on the drive wheeland I gluded a small hook into the centre top of the dome. So the power lead comes up from the body and loops over this hook so keeping the lead centred. So now I have power to the dome, from the main batteries in the body. As its centered it won't snag on anything. So I don't need a slip ring or a dome plate. OK I don't have servos or periscope so this does the job perfectly.