May 21, 2021 at 11:44 pm #18597
I was walking along the front lot earlier looking for sections that still needed raking, when I heard the rumble of an antique motorcycle engine coming around the corner. I turned around and found that it was a tiny bright red Austin Healey Sprite. I remembered that I probably have one of those packed away somewhere in the basement, possibly even in the right scale. I eventually took a look and found a Healey 3000, as well as a 32’nd scale Sprite. It was a nice AirFix box of the 1958-1961 Sprite MkI. (1997 re-box of 1961 tooling). However, the contents weren’t so nice and I recalled that I had set it aside deciding that it wasn’t worth spending time on it. But seeing the real thing drive by, gave me renewed motivation.
Fig. 1: You can’t judge a book by its cover – you can’t judge a kit by its box-art !
I had built many model cars when I was a kid, but never a 1/32 scale, and this one looks like the tiniest of the tiny. (I use two large magnifying glasses while doing intricate work, but here I could make use of a microscope!) I started work on it and found that the tooling, moulding, casting were even worse than I had initially thought. The front fender pontoons were lumpy. The three sections making up the front end of the car did not fit properly. The hood seam in front of the windshield was scored different thicknesses from one segment to the next. Door seams were irregular. Rocker panel seams were different heights and shapes between left to right side. Other body features that were supposed to be the same, were different sizes and shapes from each-other, and not symmetrically positioned on the left and right sides. The headlight lenses are nice but the dome sockets they are to fit into on top of the hood are not smooth and semi-circular but are instead elongated leaving excess at the top and a gap at the bottom. There are other inconsistencies that I won’t bother listing, plus more I’m sure to discover. (Once again, it seems that I’ve stumbled into an overly difficult model to work with.) But I decided to stick with it anyway. One of the problems for me in this smaller scale, has been motivation, so I decided now that I have a bit, I should make use of it.
Fig. 2: Sprite in another of the many standard colours, ‘Mint Green’.
I assembled the front end body sections, and started the prep by sanding down those seams and all the lumps on the curved surfaces. I’ve never used body putty on a motorized car, fearing that it may crack under flex during competition, but here I couldn’t avoid it and decided to take the chance. I filled in the top hood seam and the small body-fit gaps in the front, as a start.
Fig. 3: Kit contents.
There is something else about the body that doesn’t seem quite right. I almost bought a 3000 Mk III when I was a youngster, but I don’t know much about the Sprite, so I started searching the references to learn a bit about the car. If I’m going to the trouble of building it, I want to do it right. I couldn’t find matching wheels in my collection, so I tried the body onto a ‘Carrera Go’ chassis, and even at that 1/43 scale, the chassis was too large for this tiny body ( ~10.5 cm x 4 cm; ~4” x 1 ½” ) .
With the kit wheels in place, the body looked very high off the tech block. I thought the problem may be that the wheels were out of scale too large. Doing a search and some arithmetic, I found that the kit tires are properly scaled and do correspond to the vintage Sprite tires, “Cross-ply 5.20-13 tyres”, which are apparently 23.1” or 587mm overall diameter (on nominal 13” rims). The kit wheels have a Rim diam = 11mm, Tire diam = 18mm, giving a Track clearance = 7mm with tires touching the inside of the fenders, and that already appears far too high for the tiny sportscar. Adding a 2 mm tire/fender clearance on the model, (which would be more realistic and would be needed to allow for minimum body roll), gives 9 mm track clearance, and would convert to 288mm, or 11.3” road clearance on the real car. (That 2mm tire/fender scale clearance converts to only 2 ½ ” tire/inside fender clearance available to the real car, still far too small.)
I don’t own a sports car, but the road clearance from the bottom of the rocker panel of my mini-van is only 8 ½” ; the other cars in the garage are lower. Since the wheels are to correct scale, the only conclusion I can draw from this analysis is that the model is out of scale too shallow. As a result, they had to cut the wheel arches too close to the top of the body. The shallow body also gives very little clearance for the tires inside the fenders thus the whole body is raised far too high off the track. All of this is even apparent from photos of the real car. (Exterior photos, as well as photos under the bonnet show that there is plenty of space, and structure, between the top of the tire and top of the fender.)
Fig’s. 4 & 5: Body proportions of the kit and the real car.
It’s very obvious from comparison of these two photos, that the model body is out of scale too shallow, streamlined. (Compare the heights of the door panels, the heights of the fenders above the cut-outs, and the space from top of tire to top of fender.) Unfortunately, it’s an effect that can’t be corrected on this model without major surgery. On the other hand, using smaller wheels helps with the body height and track clearance, but makes the wheel cut-outs on the model look even larger . (I may have to do what I see done on my Ninco XK120 and many other sportscar models – build a step drop between the body and chassis. Even on the real car, some chassis components show below the bottom edge of the body. However, such a step will limit my chassis design and it’s dynamics.)
This thing has given me so much trouble; Looks like my initial assessment was correct and I should have just left it in the box! In any case, now it’s become a challenge!
So I have been searching for correctly scaled rims and tires. I have worked out four possible chassis designs to fit this tiny body, but until I have the wheels in hand I can’t finalize the adjustments on the body or the detailed dimensions of the chassis. I’m looking for rims 13” nominal which usually work out of be 13mm diameter at the centre ridge and 11.5 mm diameter at the outside edge, depending on the manufacturer. I need 5mm wide for the front pair and 7mm for the rear. Corresponding tires would be 18mm diam before truing. It’s going to be difficult to compensate for the shallow body; I may have to do other adjustments, but I want to get the best balance possible.
I am always doing what I cannot do yet, in order to learn how to do it. Vincent Van Gogh
May 21, 2021 at 11:56 pm #18598
I’ve now found in my parts collection a set of rims and tires correctly sized for the front wheels; seem to fit well. Now I need rear wheels: a nominal 13” Alu rim, with 11.5mm diameter at edge, 7mm wide, plus corresponding tires. So, I am on the search!
Fig. 6: Sprite body shell viewed through magnifying glass; sanding dust from first stage still on the body. (More body work yet to be done, possible further adjustments, but have to first find the correct rear wheels .)
PS: The Sprite has a Bonnet; since it doesn’t have a trunk, does it still have a Boot?!
May 22, 2021 at 8:39 am #18600
That’s a wonderful start to a very cool car.
Jim O made a Sprite.
Jim M also has one that he got from Chris Walker.
They are both on the database, and have a completely different stance. It’s always up to the builder in the end.
A word of caution. Very narrow cars don’t like wide tires on the rear, or they just roll over in the corners. Equal F/R might be a better choice. The Sprite is very narrow.
I look forward to seeing it completed. I have the same kit on the back shelf somewhere.
Even though I may be new at this myself. How can I help you build your car?
May 22, 2021 at 10:23 am #18602
Hi Felix very cool car. I have models of an Anglia, Escort, A35 and Triumph Herald. I used Pendle wheels. See my pic of the Anglia. Front wheels .. 11.47mm x 5 … Rear 14mm x 7.43mm. The rear takes a larger Dart tire. I have a spare of Pendle wheels 11.47mm x 5mm if you want them for free. Pm me with your address and I will drop them I the snail mail.
May 22, 2021 at 10:35 am #18603
I also found a set of 14 x 7.5mm wheels which are the Anglia rears. You can have those if you want. Let me know sometime. Dave
May 22, 2021 at 9:00 pm #18606
Thank you Ken, Dave, for your useful advice and encouragement.
Yes, it is an interesting little car. I just wish they had done a proper job on the model; a lot of flaws to work with, some impossible to correct.
You’re right Ken, I don’t want to use wide tires on the rear. I ordered a set of wheels from Pendle that I though might work from their description, but when I tried them in place they were too wide. I would like to try 7mm on the rear as the upper limit on width; if that fails I may have to go with the 5mm as on the front.
Thank you for your very generous offer, Dave, as well as for taking the time to take photos. I do already have the 11.5mm diam x 5.1 W rims, with corresponding tires. I got them from Pendle, for use on the front. I also have their nominal 14” rims in a 6mm width, with tires, but the diameter ends up being too much for this tiny body. As a last resort, I may have to end up going with the 14″ ones, but I would prefer to stay true to the scale of the original car. Also, at that rim size, truing the tires down to fit this body leaves them out of scale very low profile. That would probably work better if I were doing a modified race version.
A lot of problems created by this squashed body! Surely if 14” rims are available in 6 and 7mm widths, the 13” ones should be available in those widths, somewhere !?
Thanks again guys; Greatly appreciated. Felix.
May 23, 2021 at 11:41 am #18607
RS Slots has 13 x7 mm wheel.
May 23, 2021 at 1:15 pm #18608
Art just sold 6-pair of 13″ wheels.
2-pair of 5mm. 2-pair of 7mm. And 2-pair of the very rare 9mm. All were premium BWA’s.
BWA used a better quality aluminum, or a better tool/cutter, or both. They have a super shiny finish.
I was fortunate to already acquire several sets from Art over time, or I would have jumped on those rare wheels.
There are a few 3L GP cars that still need to be built. It’s hard to build one without a pair of 13×7’s and 13×9’s.
Even though I may be new at this myself. How can I help you build your car?
May 24, 2021 at 11:35 pm #18611
Thanks Dave, Ken, for the extra info. I will try the RS Slots, order a few of their rim sizes and keep them as back-up. Actually, I’m the fellow that bought those BWA ‘unobtanium’ rims from Art, plus six sets of corresponding tires. The medium rims are 7.6mm wide and the tires go to 8.8mm wide; I knew they would be too large for this tiny body. The small rims are 5.1mm wide and tire options go to 7.2mm, so those may work, but as you advised earlier, they look a bit wide once placed inside this body. (May be better to save the BWA’s for another build, where I need to match front and rear rims.) The 5mm ones I have from Pendle have flat sidewalls on the tires, barely the width of the rim, but will do for the front. In the end, it looks like it’s best to go with those same 5mm rims on the rear and look for a D’Art rear tire with a bit of a bulge to give about a 6mm overall width. Thanks again for the good advice.
- This reply was modified 1 month, 4 weeks ago by Felix.
May 25, 2021 at 8:58 am #18613
You did well in buying those wheels. They are identical in size to what RS Slots makes in the UK.
Colin Sparks from RS Slots took over where BWA left off.
The main difference is the shine of the aluminum. They spec out to the exact same dimensions.
The only wheel RS Slots didn’t copy are the 13×9’s. Not enough call for that size.
Even though I may be new at this myself. How can I help you build your car?
June 7, 2021 at 10:25 pm #18635
Part B: I’ve returned to work on the Sprite. I was hoping that I would be on to starting the chassis by now. Unfortunately I have found more defects in the tooling that cannot be ignored. I had noticed from the start that the shape of the front wheel cut-outs is wrong, but hadn’t decided whether to correct it. Comparing photos 4 and 5 in my first post, above, shows that the front wheel cut-outs are elongated rather than circular. The following two photos, below, also illustrate the same. (The box art for the kit does show the correct circular shape.) It’s a small detail but, elongated wheel well cut-outs just don’t suit a classic sports car.
Unfortunately, I have found more errors in the tooling of the domed headlight sockets/pods. I had already mentioned at the start that “The headlight lenses are nice but the dome sockets they are to fit into on top of the hood are not smooth and semi-circular but are instead elongated leaving excess at the top and a gap at the bottom.”. (This refers to the elongated shape of the front face of the sockets that the headlight lenses are to fit into – evident in the 6’th photo of the first post, ‘sanded body shell viewed through magnifier’.)
I now find three more flaws, making a total of four distinct errors in the headlight domes. On the real car, the headlight pods on top of the bonnet have a very pronounced curved shape; the origin of the name “Frog Eye”. The profile of the tops of the pods ends horizontally as it reaches the front. The front face of the sockets is vertical so that the headlights aim horizontal. These three features show up clearly in the photo below, as well as in the earlier photo of the Mint Green sample.
Fig. 7: Circular wheel arches; profiles of headlight domes.
Note the circular shape of the wheel well cut-outs; the pronounced curvature of the headlight domes, top surface ending horizontally at the front, front facing edge is vertical.
On this model there is almost no curvature on the tops of the headlight domes in side view. [The model tooling appears to employ almost straight tubes embedded onto the top surface of the bonnet.] The profile of the top surface of the pods at the front, end at a slightly upward angle above the horizontal. When viewed from above, the seams between the domes and the bonnet surface look good and are curved, but this is only by virtue of the intersection of any cylinder partially embedded at an angle into a curved or even planar surface.
The fourth flaw in the tooling of the headlight pods is that the leading edges are cut backward at an angle, so that the faces of the headlights point at an upward angle to illuminate the tree-tops! (Much more visible with the model in hand than in a photo.) This also results, (when viewed directly from above), in a small open gap between the back bottom edge of the headlight socket and the front top edge. This may have been done to make the casting step easier. [ However, I have the Gunze 24’th scale model of the Triumph TR2 Le Mans ’55, with the same type of headlight pods; that kit has none of the four tooling flaws on the headlight assemblies of this one – the front openings in the sockets that hold the round headlights are themselves round, not elongated; the headlight pods have a very pronounced curve; their top surface ends horizontally at the front; and the front facing edge of the socket is vertical – all as it is on the real cars, both the Sprite and TR2. ]
Fig. 8: Elongated wheel arches on the kit body; profiles of headlight domes.
Note the elongated front wheels well cut-outs; the almost straight profile of the headlight domes, ending at a slight upward angle at the top front, and the front facing edge cut back at an angle (not as visible here; slightly visible in photo-3, of first post).
I knew there were problems with the tooling of this kit but didn’t count on there being this many. Now that I’ve started, I need to finish it properly. I know I am going overboard with this tiny model, but I consider it an exercise, an opportunity to apply a few of my ideas and techniques. I will try to make some adjustments to correct the elongated front wheel cut-outs and the four flaws in the headlight pods and sockets. These may seem to be trivial considerations, but it’s the fine details that define the charm of this little ‘frog-eye’ body.
I must from time to time ask, how did I let myself blunder into this agonizing absurdity?
June 28, 2021 at 9:58 pm #18709
Part C: More work done on correcting the wheel-well cut-outs:
Fig. 9: Another view of the elongated wheel cut-outs, the kit wheel as reference. Also, the front edge of headlight pods.
Compare the profile of this wheel cut-out with that of the photo of the front fender of the “Irish Blue” car in my June 7 post (Fig. 7). A very obvious difference in the shape of the cut-out compared to the real car.
[By the way, in this kit the Right front wheel cut-out has a different profile, and is more elongated (at the top) than the Left one; another error in the original tooling. The right-side white insert plate does not fit anywhere close, into the left-side cut-out.]
Note here again, the backward tilt of the face of the lens socket on the headlight pods. (The body is horizontal; bottom edge of rocker panel is parallel to the bottom edge of photo, can be verified by cropping. )
Fig. 10: Black backing sheet cemented in place; Adjustment plates placed loose inside wheel-wells.
A black 0.5mm flexible polystyrene sheet used as a backing plate has been cemented to the inside surface of side panels. This is needed for support, strength, and 3-D alignment of the adjustment plates to be cemented inside the cut-outs. Centres of the white insert plates are press cut. Blue outline is to guide the initial cut; Red line is a guide to the final cut. This is a loose placement to check fit and alignment; they will be tighter after final cementing. (This indicates that a sub-layer of black 0.5mm backing sheets, cut to shape, should be added under the white plates to raise them.)
Fig. 11: Sub-layer pieces and white plates chemically welded into place.
A sub-layer of black 0.5mm backing pieces, shaped to the same profile, were added before the white plates, to account for surface contours of the fender areas. The white adjustment plates were cemented on top of the backing pieces; guide markings dissolved away, but can be re-marked. (Ink migrated to the seams but does not represent gaps.)
Fig. 12: White adjustment plates sanded down.
All components had fully fused and cured. White layer is sanded down to a smooth junction with the original body surface. As most probably already know, the worse thing one can do during this step is to sand using a regular sheet of sandpaper in hand. That would guarantee cutting into one of the materials on one side of the junction, deeper than on the other. I used several shapes and sizes of sanding blocks with various grades of sandpaper fused to them, in order to ensure that only the white insert plates are cut down, and only until they reach a smooth junction to the surrounding original surface.
(The seams do not appear to have any space for putty fill, but I will try to press some in. The next step in the work. . . . . . )
Hope this may be of some help and interest to some members. Felix.
- You must be logged in to reply to this topic.