Class 24 build... oh no not another Stoke engine.

They'd probably know more than I do... I'm just fumbling along in the dark... now lets see, yes another three wheelsets so that's 72 more holes to drill.

 

Cheers Toto, I've just seen a fault on my drilling from earlier this evening... more haste less speed, tomorrow when I do the other three sets I'm going to start the drill run at the same point on each wheel... I'll use an axle shaft corner as the start point. This way when the wheels are mounted back on the axle each wheel will have holes that correspond equally to either side.

 

The simple answer is no, when the bogie is fully fitted out and painted it would never notice. It's just me being pedantic, between each wheel the radius of holes are out of phase by about 0.5mm ... if I hadn't said anything I doubt it would have been picked up on. The upshot is it won't happen again.

 

Following on from yesterdays drilling miscalculation which frustrated me all night caused me to hatch a cunning plan... but anyway more of this in a minute. So today after workshop alterations, modifications, clean outs and multiple cups of tea I got back on with the dividing head to carry on drilling out the holes on the remaining wheelsets, this is how I did the job just in case folk here find it useful and I'm happy to share knowledge and skills as Platform 1 MRC is very much a learning forum and skill share place.
So with the wheel removed from the axle I marked a line across the wheel face, the axle end to wheel is a square fit as such so I took the corners to mark against, the point of the Stanley blade indicated where the cross mark lies.

Then with the wheel screwed back in its axle and held in the vice I scribed a feint mark across the datum line and around the circumference of the wheel, this is the start point for the first of twelve 2mm holes.

Now to set up the work piece in the dividing head, the way to do this is to calibrate the turntable to the 0 point and tighten the knurling screw on the side, then pinch the work piece in the dividing head chuck jaws and check to see by lowering the drill head, once satisfied that the cross hatch marking align with the drill tip tighten up the chuck jaws with an anticlockwise turn taking care not to move the table out of alignment. Finally before drilling check that the turntable is still set at the zero position.

Once the first hole is cut loosen the turntable via the knurling knob and move the table forward by 30 degrees and re tighten ready for the second cut.

Continue this proceedure in 30 degree increments working round the wheel until you get back to the zero mark where you will have made twelve equally spaced holes all in the same orbit.

 

Anyway back to my lightbulb moment of the out of phase drilling from yesterday. So I took the offending wheel and measured the error, then taking an undrilled wheel from the other bogie I marked a line (as described) and offset with a second mark equal to the distance of the miscalculation, I then drilled this wheel as before. When finished the wheel was mated with its offending pair on the axle and to prove I'd corrected my mistake I passed a 2mm brass rod through the wheelset like so.

As can be seen the hole positions on each side of the wheelset align correctly, I did this on all the other wheelsets checking that all holes aligned which they did.

And finally both bogies sets have drilled wheels (96 in total) and the bogies are ready to recieve the outer frames ... when I've finished building them up.

Next job is to order the Class 21 wheelsets and extension pieces, then I can get my head around understanding the way that build will work, so for now it is carry on with the Class 24 and soon to make a start on the Class 21 bogies.

 

Oh yes the sub frame was only temporarily positioned so I could to see how the bogies would look set correctly apart, its just the way I work, a bit like thinking through to the next stages of build. What I'm aiming for is to coincide completion of the bogie build with making the sub frame, that way I can be certain of setting the ride height before moving forward onto the body. I appreciate its been a bit of a drawn out affair but to be fair I haven't really been giving the bogies masses of time recently.

 

What I'm also going to do Toto is order another set of wheels to drill whilst the dividing head is set at its correct position, I'll order the wheels for the 25 at the same time as the ones for the 21.

 

Once the dividing head is set to gauge then its no more than about 15 minutes per wheel... this includes time taken for making scribe markings and checking positions... the cost, well I budget wisely.

 

Well it was back on and forward with my Steve Beattie Class 24 build on the new workshop bench, I decided to shift emphasis onto putting the sub-frame together so that I could satisfy myself that the body would sit properly on the bogie inner frames. So the first job was to prepare all the sub assembly pieces which make up the bogie stretcher assembly prior to soldering to the underframe unit, this piece has two differing ends and the radiator end needs to be kept to the left hand side when fitting items. I marked the rad end with a felt pen on the side where components will be fitted but the top face of the underframe is stamped with the word radiator.

Here is the top face of the underframe.

And here is the business side of the underframe with the stretcher sides laid out.

Now the stretcher sides that go next to the radiator end have an extra couple of holes at their outer ends, one side of these carry the steam heating pipe whilst the other side carries electrical conduits, so by laying these items down on the flat ensures that the ends don't get mixed up/

Here the bogie stretcher side pieces are soldered on and the cross brace fitted too, note the tab on the top edge ... this will locate onto the base plate later on. On the left can be seen the felt pen mark mentioned earlier which denotes the radiator end.

 

This view shows those additional two holes on the radiator end side stretchers, the large hole carries the steam pipe. The slots at the end of the stretcher braces is to hold a small etch which needs to be formed to shape and will hold two tiny pieces that look similar to "seahorses", I chose to install these "seahorses" afterwards. The most important part of this build is to ensure that the bogie stretcher pieces sit totally flat on the underframe when soldering otherwise the underframe will not sit correctly on the bogies when they are fitted and the loco will run lop sided.

The next couple if images show the make up of the stretcher end box section, these pieces have half etch lines which when put together help with forming a correct alignment, these two items numbered 11 and 7 in the instructions make an internal back plate in the fabrication.

Then the base plate was lined up with the tabs on the cross bracing pieces and soldered in place.

 

Once the stretchers are complete I shall screw the underframe down onto a flat plank of wood and start building the rest of the underframe pieces.

And then the underframe located on the inner bogies.

Finally a general view showing all the etch frames laid out in the work tray for easy finding... look Toto those new vertical blinds are now fitted too.

 

I guess if I can build them then there is no reason why others cannot given a bit of pre planned thinking and patience, to be fair as we have said before these are not beginners kits not by a long shot but then its not as if I've been building loco's for decades either. For me the fun is in building them and the journey of making the loco... once built it just becomes a display item to me, that's when I just want to get on and build another one. Hopefully if folk can take something out of this build to go and do one for themselves then great because these really are superb looking kits even if a bit of time is needed to fettle the castings.

 

To be honest Toto I'd not given much thought to flywheels... is there anything to be gained by this? Both bogies are going to pick up current on each wheel with motors wired together so if there were dead spots one bogie would continue to collect current I thought.