Class 27 From kit to completion.

I hadn't really planned on doing much this evening because I've had quite a heck of a day at work what with dealing with electricians, non existent plumbers who leave joints weeping and old plasterboard ceilings that have gone well past their sell by dates and need over boarding to cover up thick nasty DIY artex patterns that look as if they have been put on by a blind man using a stiff yard brush. Anyway the etches beckoned and here we are with the first steps of the bogie frame construction, a production line will follow but this is what I decided was the way forward. The bogie frames make up into a box section comprising of an outer face, an inner face, a single top wrap and a multi part lower wrap, so taking the outer face I scored a centre line on its inside face... the centre is defined by a small hole in the frame, I then marked the centre point on the top wrap and putting the both together I soldered along the seam which is defined by a rib on the wrap. Now with the both joined the downward curve can be made and soldered, then the outer part of the side face can be bent to the inward curve of the wrap and soldered. The excess solder on the wrap will be used to tin the joint when it come to fitting the inner face in place, I soldered the outer face on its inside edge so that the bogie face can remain tidy. Now the inner face is soldered on its inner side but first I shall fit the lifting lugs to the outer face before this happens. So here are the pictures of this evenings performance.

 

I must have drawn the short straw then Steve... I will PM you with what I propose to do, in a nutshell the set comprising 3 Part 48 and 1 Part 48a are not separated on the fret. Also I cannot work out where Part 44 goes as it is not mentioned on the instructions... are these some sort of lamination strengthener for Part 46 ?

cheers Yorkie

 

Not an issue Steve... I'm a scratch builder and can take all these aspects in my stride, however as we have all agreed this is a Forum road test to fault find areas which will need attention prior to any general release. I'm not phased at all and this is a totally normal procedure because ultimately you will need a snagging list in order to take this kit forward in the public domain.

 

Nice one Dundee... those roof vent are so critical to getting a good overall look, I say this not as any criticism but because visitors always look down on a layout display and what is on the top of a loco is what is seen first. Anyway thanks Paul I really appreciate all your input in the upgrades. It wouldn't happen if it wasn't for you.

 

Part 44 needs to be removed from the production frets in that case otherwise it will only cause confusion.

 

The Class 27 wheelsets arrived today as planned and this evening I wheeled the inner bogie frames with the intent to prove the correct ride height, so first off I marked the buffer centre line across the width of the buffer beam and then added a black and a white tape either side of this mark so making a very easy visual aid to align the measuring ruler to. Sorry about the quality of definition of these pictures but it is the principle and not the aesthetics which is important here. The result of this test told me that the bodyshell needed to be lowered by 2 mm as the whole is sitting too high, so the inner bogie pivot braces need to be set 2 mm lower inside the side frames prior to soldering up.

And the prove the Class 27 needs to ride at 24mm from rail top to centre of buffer is shewn to effect against the Dapol Jinty... so tomorrow its set up the pivot beam in the correct place and solder. After another height test to prove the new height will be correct I shall then prime and black the inner frames in preparation for dressing with motor gear drives and pick ups.

 

The centre crossbeam of the inner bogie frame also acts as the bogie pivot and has the nuttaged pin which located onto the stretcher beam of the mainframe, by lowering this crossbeam 2 mm the bodyshell will sit at the correct height. However because of the profile of the cross section of the bogie stretcher it may be that by lowering the unit such an amount the top of the bogie inner frame may become restricted in its rotational axis. I cannot say definitely for sure at the moment which is why a test needs to be undertaken with a completed bogie (hence awaiting replacement Part 48 and 48a) pieces will halt the proper building of the second bogie. It may be I have to modify this middle top area on the inner bogie frame in some way if a wider swing is required to the loco get through tight curves ... we shall see.

 

Not sure yet Andy... if it does I will have to make modifications and record the difference so Steve can amend the etches on the production batches. I will keep you abreast of the build as things occur... and looking at the stats on this thread I suspect half the world is watching in as well. Oh well stand on a pedestal as they say and expect to be shot down.

 

After further measuring I need to lower the bodyshell by 2mm and not 2.5mm as previously thought so I've amended the previous posts to reflect this, now I have two options, 1: reduce the mainframe bogie stretcher beam by reducing its depth by 2 mm, the risk is that I may loose the datum point for the bogie pivot and the body may not sit properly balanced. If I do this I risk weakening the stretcher's integrity or 2: set the centre pivot plate 2 mm lower inside the inner frames. The problem this throws up is the pivot beam will sit correctly but the flange sides of the pivot beam will foul the route of the Delrin chain... so a notch needs to be cut but this will weaken the pivot beam at the most critical point. The top of the inner frame sections will also need to be reduced in order that the bogie can swing without hinder and the buffer strengthener plate needs to be removed also as this too fouls the swing of the bogie at the headstocks. Some major strengthening will have to be done and the inner bogie frames will need to be modified on the production batches but having a removable inner bogie is still a major advantage when it comes to maintenance. It is just a case of thinking this one through for the best route forward, right now the jury is out but anything can be achieved. I shall build up the outer bogie frame and fit it to see how that relationship works before committing to employing the mini disc and chopping out sections of etch.