Class 22 Diesel (next project)

[Ron LadenParticipant @ronladen17547]

As per the 0-4-0 I intend to machine the buffers in aluminium – all one piece not sprung. The 0-4-0 buffers turned out well but its not quite as simple with the class 22 as the buffer plates are not round but elliptical.

I have thought of machining them round then scribe around a template and file them to shape but it would be nice to machine them if I can, but how..? I also thought of making them round and then mount them on the rotary table and cutting with a large radius machine the two horizontal edges and then with a smaller radius machine the ends. That would still mean blending in (I think) as the two mating radius would not generate the correct shape.

So still thinking about it but if anyone cass pass on any tips or methods of manually machining an ellipse it would be appreciated.

[duncan webster 1Participant @duncanwebster1]

Google 4 centre ellipse, then make a jig to hold the stocks off centre on the faceplate, this will allow machining of 2 of the curves, but then you are into filing

[Ron LadenParticipant @ronladen17547]

Thanks Duncan

I sketched out the shape which is stretched a bit, I think machine it round and then cut and file to shape is going to be the easiest.

[Nick Clarke 3Participant @nickclarke3]

Just a thought – is the oval buffer the same width as a round one or the same height or something in between??

Also why turn it round as none of the round will remain in the finished buffer head? – why not plot some coordinates and rough it out standing on end in the mill, finishing with the file.

Edited By Nick Clarke 3 on 24/07/2019 08:38:31

Edited By Nick Clarke 3 on 24/07/2019 08:39:06

[Ron LadenParticipant @ronladen17547]

Nick, actually I will not be machining it round the complete one piece buffer assy is coming out of 50mm bar so it starts off round.

Ron

[Ron LadenParticipant @ronladen17547]

Working on the design this morning I wondered if I was proficient in CAD would it make things much easier..?. I fear though I am too long in the tooth to start now and I dont have a leaning towards computers. So its paper and pencil which I understand and for me it seems to work, though I dont produce proper drawings (unless I put something out) but more in the way of working sketches.

 

Edited By Ron Laden on 26/07/2019 08:31:58

[Ron LadenParticipant @ronladen17547]

They say that variety is the spice of life and although the class 22 is the main project at the moment mainly because it will come together quite quickly. I will be filling in with parts for the TE and I was working on a few ideas for it yesterday. Just to add to the workload and not fully decided yet but I may also fit in the part drawn below and slowly, slowly make some parts to go with it as I like the look of the finished item, but what is it..?

I think I know a man who will know exactly what it is..

 

Edited By Ron Laden on 28/07/2019 10:33:40

[Ron LadenParticipant @ronladen17547]

Hopefully things should speed up now as I have the bogie side plates and the motor mounting plates. Laser cut which I make no excuses for, my right arm will no longer allow me to carry out any serious hacksawing otherwise I would have cut them manually. I am very fortunate in that I have a friend who cut them for me FOC plus they were cut on a new machine that had only been commissioned 2 weeks ago, the edges are very clean indeed which is a bonus. I still have work to do on the plates so I do have to put some effort in.

[Jeff DaymanParticipant @jeffdayman43397]

Looks like nice clean cutting work Ron. Good to have a friend in that biz!

[Ron LadenParticipant @ronladen17547]

First job on the motor plates was to machine a 1.0 mm deep recess for the axle bearing shoulder. The motor body length makes things a little tight between the wheel back to back when the plates and bearings are added. The bearing shoulders I have reduce from 3.0 mm to 2.0 mm thick and with the recess I should gain a further 2.0 mm which will leave 1.0 mm end float when the motor assy,s are mounted on the axles.

The recess is 4.5 mm wide x 1.0 mm deep which I did as two 0.5 mm cuts using the rotary table, worked well using a 8mm 3 flute HSS end mill (ARC premium range) .

A bit of video below of the second cut and the finished result.

[Ron LadenParticipant @ronladen17547]

I put in the spring slots on a couple of the motor plates to see how it was looking, the gap between the plates will be 3mm when the axles are mounted in the bogie. The usual is to slot the plates and locate them onto a tie bar but I thought I would give the springs a try. I think it should work ok, I cant envisage any problems with it but if there is I still have space to add a tie bar.

p.s. The blue springs fitted here are what I consider medium strength but I will fit the green heavy springs on final assembly, picture of the different strength springs on a previous post.

Edited By Ron Laden on 09/08/2019 08:47:27

[Ron LadenParticipant @ronladen17547]

Apart from slotting the motor fixing holes for belt adjustment (awaiting a 5mm end mill) the motor plates are finished with the bearings fitted. I loosely put an assy together to see how things were looking and it seems ok.

The only mistake I can see at the moment is the tie bar fixing holes at the end of the plates next to the bearing. I had it in mind to use hex head screws to mount the tie bar but as you can see there is no space for a hex head, dont know what I was thinking there. All is not lost though as I can csk the plates and use csk screws.

I also have to spot through the 3 holes from the plate to the motor rear end casting then drill and tap M5 for fixing, the motor front end comes with M5 mounting holes.

So its coming along and although I had it worked out on paper its always a relief when it comes together in the flesh.

[Dave Smith 14Participant @davesmith14]

Ron

Very nice job you are doing there. I have absolutely no problems with laser cutting parts, life is to short to spend hacksawing and filing. I am building a Don Young Aspinall class 27. My retirement present to myself from work was any thing that could be laser cut was. I ended up with over 300 parts!

Dave

[Ron LadenParticipant @ronladen17547]

The motors have had the brush wires soldered, they were crimped but whilst I had the motors apart I thought belt and braces and soldered the connections. I have also added the M5 mounting studs to the rear cover, the covers are cast aluminium and quite soft. The front cover is 4mm thick and comes with 3 x M5 tapped holes, the rear though is only 2mm thick with no holes. With only 2mm of soft material I thought it stronger to fit the screws from the inside and use retainer to lock them in place. The front motor mount plate will be fixed with hex screws and the rear mount plate with nuts.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ron Laden on 12/08/2019 17:05:33:

The motors have had the brush wires soldered, they were crimped but whilst I had the motors apart I thought belt and braces and soldered the connections.

I doubt it will make a difference unless the motors are used lots but soldering isn't recommended for terminating flexible connections. The solder wicks up the braid and reduces it's ability to soak up vibration whilst also creating a stiff point where stress concentrates and causes fatigue failures.

Can't say how much it matters in practice. I've never seen any figures comparing the reliability of solder vs crimped joints on flexible wires and have broken the rule myself many times fixing old cars.

Dave

[Ron LadenParticipant @ronladen17547]

Thanks Dave but I,m not too concerned, I put just a small spot of solder on the crimp to make sure it didnt work loose and I couldnt see any sign that the solder had wicked up into the braid.

Ron

[Ron LadenParticipant @ronladen17547]

The 4 motor assy,s are completed, just starting on the bogie frames.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ron Laden on 17/08/2019 08:22:28:

The 4 motor assy,s are completed, just starting on the bogie frames.

Very good! I like the way you go neatly from concept to reality. But could you slow down by about 2000% please? Your rate of progress has got my inferiority complex into meltdown!

Dave

[Ron LadenParticipant @ronladen17547]

Dave…and there I was thinking I really need to get a move on and stop dragging my feet..lol

I was hoping to be at the building of the body stage by now but to be honest I am not rushing, when parts start to come together though I like to keep things moving along.

Its Jason that you need to watch, his rate of production amazes me and I think at times he seems to have two or three projects running side by side and all to a very high standard, impressive.

Ron

[Ron LadenParticipant @ronladen17547]

Centre drilled the holes on one of the bogie plates to use as a template for drilling all four plates, going to drill as a four plate sandwich to achieve two matched pairs.

Hindsight is a wonderful thing and I think it would probably have been better to have gone with 4mm maybe even 5mm for the plates over the 3mm I have gone with, having said that I have convinced myself that the 3mm will be ok. The 0-4-0 I built is all based on 3mm for the chassis, running gear and motor mounts and that seems to be a tough little loco, it has run quite a few miles now with no issues.

A piccie of the plates mounted to the axles just to see how it is looking so far.

Edited By Ron Laden on 18/08/2019 09:28:30

[Ron LadenParticipant @ronladen17547]

Just goes to show that assumptions can be dangerous, for the two main chassis rails I based the design on 50 x 25 x 3mm bright steel angle, thinking it would be readily available as a standard size but I didnt bother to check and its not. I could have sworn I,ve seen it in the past but maybe not, unless it was and is now discontinued.

I now have the option of either 40 x 25 x 4mm steel or 2" x 1" x 3/16" alu angle, so I will probably go with the alu. The 2 inch (50mm) is a prefered dimension, it should be strong enough plus I have a lot of chain drilling to do so the alu will make that a bit easier.

[Ron LadenParticipant @ronladen17547]

Hooray for the DRO,s I fitted to the mill, first time I have really used them since adding them a couple of weeks back, what a boon they are.

I sandwiched the bogie plates for putting in the various holes, the DRO,s made it a doddle for placing the holes, money well spent I think.

[Ron LadenParticipant @ronladen17547]

The spring mounts are a permanent fixture and I fitted them to the plates with M4 cap heads which I locked with 638 retainer. I then put them up on the mill and machined off the socket and filed two vertical edges, no big deal but I think they now look a lot better than cap heads.

[Ron LadenParticipant @ronladen17547]

Gave a pair of the drives a quick test run, top speed 850 rpm which will be 8 mph so thats worked out ok.

They are reasonably quiet when running, in fact I think you would hardly hear them out in the open as they will get drowned out by other track noise….I may need to add a diesel sound system..

[Ron LadenParticipant @ronladen17547]

Had a productive morning, I,ve been running in the drive assys in pairs just to get them settled in so to speak. Of the eight axle bearings one is running hot compared to the others which are all no more than luke warm after half an hour of running. I am not too concerned about it though as I know its not tight on the axle and I suspect there is a slight misalignment between the two bearings on that axle. The motor is not struggling or hesitating so I will keep running it in, the bearings are oilites running on a steel axle so I think it will settle in.

Made up the 8 bogie plate tie bars and currently working on the bogie mount/pivot plates. I had planned on using 60 x 10 bright steel bar but found I had enough 80 x 10 standard bar so have gone with that. I was also going to go with a thrust race for the pivot but I may just go with a plain spacer, what ever I go with needs a decent surface to run on so I flycut a 60mm wide band 0.2 mm deep.

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