Scale Fasteners - Tiger 1, King Tiger and Jagdtiger

[AlastairCooke]

Hi All,
I have been exploring a suitable source for more accurate fasteners for the inner hubs of Tigers with resilient (steel) wheels. As I have described on my F01 thread, a better scale look can be obtained with M2.5 hex bolts. This can be enhanced if 3.5mm A/F nuts are used as supplied by Knupfer. Standard M2.5 fasteners longer than 20mm are not available and so a custom solution is required. One size smaller 7BA part threaded bolts at 30mm with one size smaller nuts are available from BA Bolts which may suffice if building the hubs as per the instructions. If however you need a little extra length or wish to add detail at the back of the wheel, perhaps to shield the bearing, then you are stumped.

With this in mind, and to progress my build, I have obtained a quotation for the fastener design shown in the attached drawing.

As you can see the bolt is deliberately over length to allow for a range of hub designs. The bolts can be easily cut to length using a tool such as Knipex 97 32 240..

The inner hub requires 15 fasteners and so an upgrade set would consist of 125 bolts (120 + 5 spare) . Full disclosure here... due to my hub design I only need 72 (say 75) bolts and therefore would be prepared to over order and offer them at cost (plus VAT, P&P). The quotation I have from ACCU is as follows:
200 off (so enough for 1 set) at £1.59 each = £198.75 per set
500 off (enough for 3 sets) at £0.92 each = £115.00 per set (would probably order 600 to give 4 sets which may be a little cheaper)
1000 off (enough for 7 sets) at £0.66 each = £82.50 per set (would probably order 1100 to give 8 sets which may be a little cheaper)

I previously asked ACCU to quote just for my requirements... this was prohibitively expensive and so I did not go ahead. The cost to you will depend on the level of interest and the size of the order... ACCU are quoting October for delivery.

Is anyone interested ? If so respond by PM, thanks.

Alastair

[simon_manning]

Hi Alastair, when the first Kingtiger production began in 2009 from Armortek i bought some custom made wheel bolts from E.K.P., More or less as your design, 30 mm long, 8ba Hex Head, 7 Ba Thread, Blank Hex 8 Ba nuts tapped to 7 Ba thread to match the bolts, all in steel, The bolt pattern looks scale when fitted, i Have used this on both my kingtigers and sturmtiger, have a look on my Kingtiger build, hope this is of some help, regards simon manning.

[AlastairCooke]

Hi Simon,
Thanks.
The problem I have (entirely of my own making ) is that I have designed an additional item to go behind the inner wheels that replicates the actual hub. This means that the 30mm bolts from BA bolts are about 3mm too short hence the revised design. I have already procured 2.5mm studding and enough 3.5mm A/F nuts to use at both ends. However, with this approach security would rely on the bond of the nut to the studding on the inside. I have tried thin CA and will be trying solder. I believe that using a bolt with its integral head would be better.... hence the enquires I have made.

Alastair

[Armortek]

We still have some longer M2.5 hex heads available - see this post here:

viewtopic.php?f=2&t=8781

Note that these fasteners can failed if done up too tight.

[AlastairCooke]

Hi All,
Prompted by Simon Manning (thanks, Simon) I have had a very useful conversation with EKP Supplies. They can manufacture a M2.5 part threaded bolt with a 4mm A/F head. Whilst this not quite what I had in mind it is a decent compromise especially when a minimum order of 200 would be only £60 per 100 (ex VAT). I have measured and remeasured the studding I have cut to length and found that 32mm is just long enough. My plan would to have the bolt head on the inside of the hub and use the Knupfer nuts on the front. This way I get the look I am after with the knowledge that the assembly is not reliant on a CA glued fixing at both ends.

I note from Kian that Armortek still have some M2.5 x 32 bolts for sale but assume that they have the standard 5mm A/F head. I am planning to order at least 200 so will have some spare if anyone is interested. If I can get the order up to 500 the price drops to £38 per 100!

As before if you want some of these bolts please PM.
Alastair

[AlastairCooke]

Hi All
Have just received my order from EKP Supplies. Very pleased with the result, see images below.

bolt with Knupfer 3.5mm A/F nut and front view of inner wheel pair.

rear view with 4.0mm A/F head. Although slightly larger that the non-functional bolts already glued in place and showing a bolt head rather than a nut I am satisfied with the look and am more confident about the security of the fixings.

front view with outer wheel pairs.

I think it works...I have a full set spare (125 bolts) if anyone is interested...
Alastair

[Damon Resch]

PM sent. I’m interested in the extra set.

[AlastairCooke]

Hi All,
As I have had some interest in the bespoke bolts, I feel I need to explain how I have used them (in case anyone has not followed the F01 thread) and how they could be used...
I have designed my own replacement hubs because of the differences in the standard Armortek hub design and what I need for F01

standard hub

front view of replacement hubs without non functional bolts

front view of replacement hubs with non functional bolts (in brass 3.5mm A/F)

rear view of replacement hubs with non functional bolts and studs on the inner wheel set
To add more security the inner wheel studs have been replaced with these new bespoke bolts as shown in my previous post.
Now if you are intending to use the standard Armortek hub and have functional bolts you will need 15 per wheel giving 120 in total. If you are going to alternate the nuts front/rear as per the full sized Tiger as well as using Knupfer 3.5mm A/F nuts they you will have a head difference.

Solutions are

1. To use just 9 bolts per hub, as I have, along with 6 x 3.5mm A/F M2.5 non-functional bolts. This means that the head difference is on the rear of the wheel set and less visible.
2. To use 15 bolts per hub with the head at the rear and turn 6 of the nuts into bolt heads by means of solder and a file. I did not use the this method as the replacement hubs are made from 3D printed nylon.

Also note that my rear hub design on the inner wheel set required a bolt length of 32.5 mm. The bolts are supplied part threaded (10mm) and so could be shortened if needed.

Hope this all makes sense...
I ordered 200 bolts (at a cost of 72p each) and so have 125 spare. Presently I am willing to sell them on at 70p each (plus postage/shipping). If there is interest from several of you then I may be able to get more produced.

Alastair

[AlastairCooke]

Hi All,
Surplus stock now sold.

Alastair