AS-202 was launched from Launch Complex No34, formally called LC-34. I had wanted to build a 1-72nd scale Saturn 1b since Dragon models announced the release of a kit back in 2019. The Dragon kit did not materialise and was never released, but at the time of the announcement I started looking into obtaining alternative parts to modify the proposed kit from a Block II  to a Block I version. Whilst looking for parts on the now defunct Shapeways site I noticed a seller offering  a set of hold downs.  I duly added them to a wish list  for future reference. When Scott announced the release of his kit in 2023 the search for replacement parts was started again I decided to invest in a set.

I had a vague ideal of setting the model on the hold downs, but no real concrete plan. On a Face Book group I noticed a post by BJ West, he was offering a complete set of blue prints for LC-34. I duly purchased a set, still with no real plan. As I started to assemble the kit the idea of constructing  a part section of the pad was considered.

The set of hold downs that the rocket is sat on at the pad

The set of blueprints 

The current plan is to make the top section of the pad with a few basic details, but construct it in such a way that there is the potential to upgrade it to a complete item at sometime in the future.

The drawings were looked at, there are 140 in the pad section of the collection, and copies made of the ones needed. From these screengrabs were taken of the sides and top views of the pad. The relevant dimensions from the drawings were converted to metric, and then scaled down to 1/72nd. the screengrabs then imported into fusion to construct a "virtual" cube. As the screengrabs are imported then calibrated to the correct size.

The hold downs were measured and a basic 3d model of them created and overlaid on to the drawing. Measurements were taken from the model at the points where contact is made and I was happy to find that everything matched within an accuracy of 1mm

Now it will be just a case of drawing over the imported screengrabs using them as references to create cutting templates.

The first template produced was for the top deck

As can be seen from these images taken around about 2017 the pad was a concrete construction. The top deck and the sides of the circular hole were clad with a stainless steel liner.

Gradually the pad was designed and drawn up.

The complete structure as drawn

As mentioned earlier the intention is to make a partial section of the pad, so the image below shows how the base will look like 

The centre circular section will be made from eight wedge shaped sections, These will be 3d printed, The main structure will be cut from 2mm thick styrene sheet

Hand rails for the top deck will also be 3d printed

The fire/sound suppression torus will also be 3d printed 

The rocket had support braces attached to the bottom of the fins, these located on to the hold down posts. The braces  can be seen in the right hand hand image (this image is from a built example of Scott's kit). The braces are 3d printed resin items and are delicate & brittle. They will not support the weight of the model. 

The solution to this issue will be to support the model on four posts, Initially I considered having rods extending up from the posts to engage into tubes set in the base of the rocket. This was the method used on the Saturn V build. Due to the construction of the kit this idea was not practical. The second idea was to use posts that incorporated magnets, and to fix magnets inside the base of the model. I managed to find some magnets that had a countersunk hole in them. These will be attached to the support rods with countersunk screws. 

A jig was made and the magnets attached 

The jig was centred to the rocket base with a drill, and the magnets placed inside. 

Epoxy glue was then used to fix the magnets into place. The jig will be kept and used as a template to get the correct spacing and location for the support posts 

With the rocket completed early November 2024 full attention was given to the base. When the 3d model was drawn I  took the time to create sketches from  the profiles taking into account a 2mm wall thickness. Screenshots were taken of these and used as a reference to create cutting templates. These were created using a combination of Solid edge and the Cameo software. The plan being is to place the 2mm styrene on the Cameo cutting mat and "cut" the sections. There is no way that the machine will cut through the styrene, but it will score the sheet. This will make a good start towards achieving an accurate set of parts

Shown below arwe the four files ready to go. Top deck, lower deck, sides A & B, and sides D & C.  

The sides and the bottom were placed in the Cameo and "cut", In the image above you can see I had dovetailed the sections to save on styrene. As I was about to send the cut command I realised that I would not be able to break the pieces out, they needed to be apart from each other.

The sections were all cut out, dry fit checks done and then all glued together

This created the main structure with four removeable bottom sections. 

A mock up of the top deck was made from card and paper to ensure the correct line up of all parts

The hold down posts will be bolted into position from the underside of the top deck. To achieve this they were fitted with threaded inserts that were held in place with epoxy glue. Making up the bits and pieces to do this meant I got to use some of my new tools. notably a mini pillar drill and an angle cutter. Both of these considerably help in making up accurate parts

The bottom section was made to be removeable to give access to the hold down post screws. This will be needed to give fine adjustments to each post to ensure alignment relative to the rocket. Bearing this in mind fixings were needed in the main body. The same solution was used. brass threaded inserts held in place with 5 minute epoxy 

The the four corner pillars were constructed and stiffened up with epoxy. These are held in place with screws, these in turn hold in the bottom deck. Eventually the screws will be substituted for threaded rod which will serve a dual purpose of holding the construction together and then being used to secure a plinth.

The next items to arrive from the printers were the hand rails. they were trial fitted to ensure correct sizes and locations

The handrails were followed a couple of days later by the liner sections. It was by pure coincidence that the printers had run out of resin, so he asked of he could produce them in FDM. This turned out really well as dimensionally they were spot on and FDM is a lot tougher and will accept having threads tapped into it

The sections were bolted together

Then they were fitted to the body. and attached to the bottom deck sections

Two top section templates were cut from thin styrene and the hold downs attached so that alignment to the rocket fins could be checked

With everything confirmed two top deck sections were cut from thick styrene and trial fitted

The top deck halves were fixed to the central liners by countersunk screws and bolts. which was in turn secured to the frame in the same manner

The bottom deck quarters were secured by drilling and tapping threads into the circular liners and the surrounding frame. To hide the screws and tidy up the underside a drop in section was made from very thin styrene Thge is a push fit and is held in place by the four leg supports

The top deck also had a thin skin created to cover the screws. this is held in place by the hold down posts as it is sandwiched between them and the structural top deck

The  four sides were also skinned over, and the skins were glued. The skins extended slightly and this gave the location for the top and bottom skins

Thin strip applied to the small tabs on the top deck to tidy up the appearance

Vertical stringers applied to the side faces

Strips of styrene were cut and small dowels inserted. These locate into holes drilled on the top deck. The hand rails will be glued to them. This means they can be painted. and just push fitted into place at final assembly 

A workmate Colin Willis who is an ace machinist knocked up some aluminium posts that are threaded at either end. This allowed for them to have magnets attached at the top and in turn they are attached to a disc of Perspex 

The First stage was trial fitted, the two sets of magnets lined up nicely and the stage is well attached. The Perspex disc is going to have a hole drilled in the centre, this will have a screw installed which will engage into a threaded hole in the main Perspex base section. This will allow the rocket to be rotated to line up the fins to the hold down posts.

The main Perspex base section was marked out and drilled, and counter bored to accept screws that hold the pad into place.

The main Perspex base section is attached to the pad with the centre section placed to see what it looks like. The next job will be to ensure that the centre section is in the middle of the circular opening in the pad and to mark out the position of the hole that will be threaded   

A square was used to transfer the profile of the circular opening onto the base. 

The centre of the scribed circle was then found, and checked against the centre of the Perspex. The two centres were perfectly aligned.

The Perspex was then drilled and tapped, and a hole was drilled through the circular section of Perspex. The circular section complete with the magnet tipped rods was installed to the base

Two of the hold down braces were cut from their base and temporarily fitted to a couple of the fins. Cuttinmg them away from the support was a hold your breath moment as they are extremely delicate

The first stage was installed to check the alignment of the brace to the post at two opposing fin positions. I was extremely happy that they line up within less than half a MM radially. The rocket is sitting 11mm too high, so I will need to remove 10mm from the aluminium posts

Each half of the the water deluge torus  is fed by a pipe that comes through the leg structure. A cross section of the area was created in Fusion 360 and a set of dimensions created to give a centre point of the opening

The holes were then marked, drilled, and shaped using a Dremel to the correct size and profile.

The original design of the torus was made using the blueprints for the pad. This included using the original thickness of the plate used to make the support brackets. This meant that the scale items ended up wafer thin, and by the time they had been posted to me a couple had snapped off as can be seen in the picture above. Whilst I was trial fitting them I managed to damage another one. I decided a redesign was needed. The support brackets were beefed up, they retain the original outside dimensions, but the wall thickness of the plate was increased. The original was made of four sections (two per half), this idea was scrapped and the MK II version is made from two pieces. A sacrificial support structure was added at the base of the brackets. This will stiffen up the assembly whilst it is being printed, and can be easily cut away when the time comes to fit it.

A couple of minutes after I had uploaded the new files to the print company and paid for the items the thought crossed my mind that as I had modified the brackets would they still fit. A quick mental slap on the wrist and a check in fusion was carried out. The picture on the left shows the dimension of the liner section of the pad where the torus engages and the right picture shows the bracket dimension. All is good with the diameter of the brackets being 0.2mm larger than the hole, a snug fit

Next job was to prepare the handrails and glue them onto the removeable base strips.

Once the glue was set they were removed, and are ready for painting

Apart from painting the pad the last outstanding job was to decide what to do about shortening the support posts. As I don't have access to a lathe the other option was to find a local machine shop. I could not find one, so I started to think of other options of making them with the tools I had at my disposal and hit upon the idea of making new posts from Acrylic rod.

I had a length of black glossy rod left over from the Big  Joe 1 build, this was cut to the correct lenght using a mini mitre chop saw

The next hurdle to cross was to accurately drill holes in the centre of the rod. 

A vee block was secured to the mini two axis work table, and the mini drill was attached to a mitre box to get it above the work piece. the centre of a rod was marked and clamped into place. The table was then positioned to line up the drill and a test hole was drilled

Working with Acrylic can be a bit tricky as if you go to hard and fast it melts rather than cuts and the dill then grabs, so a little water lubrication was used whilst drilling the holes

The holes were tapped, and again a little lubrication made the job so much easier. This time butter was used to help, it was amazing how much this helped 

All the posts tapped and ready to be assembled

The pad was stripped back to its component parts, sanded, and priming was started 

The pad structure & handrails were painted with a Medium sea grey paint

The pad was partially assembled and a trial fit was carried out

Minor adjustments were made to three of the hold down positions. The holes were slotted by approx 1-2mm

The hold-downs were painted with a custom mix. The only reference to the colour for them was from screengrabs taken from a video. They appear to be a Blue/Green, I think the mix turned out a little in the dark side, but near enough

The updated version of the water suppression torus was received from the printers. The modifications did the job, and the support ring was a definite help

The two halves were cut from the supports and were trial fitted. The fit was absolutely perfect, and no glue is needed. The assemblies were primed and painted Aluminium colour

The pad was again partially assembled and a final fit check carried out. Prior to the assembly two extra holes were drilled in the square section of the base. Once the pad was assembled and the fit check was confirmed as good the holes were then through drilled into the circular post holder section and small dowels inserted to lock it into position

Finally the pad was built up and secured to the base, the fire suppression torus and handrails fitted.

Job done