don young 4f

[greg hallParticipant @greghall]

Hi

I'm new to this forum so apologies if my questions have been asked before.

My (23 year) Tich build is now well advanced using just the Tim Coles, LBSC and a few other technical books and I am thinking about the next model. Is there enough information on the 4f plans to build it without the original articles? Are these available from anywhere? What is the best practical way to make the crankaxle, solid or built-up? I have an old Myford super 7.

All input greatly appreciated

Greg

[greg hallParticipant @greghall]

are the plans enough

[Nigel BennettParticipant @nigelbennett69913]

Well, Greg, nobody's replied yet…

Don described the 4F as a "beginner's loco" in ME Vol 141 (1974?), so acquiring the relevant issues would be a great help. In my opinion, Don was better than a lot of others as far as drawing errors are concerned. As with all things, though, make one bit to fit the next!

I've not built a 4F, but I have built a Clayton steam wagon, which uses the same cylinders and valve gear. Robin Dyer did make the Clayton Joy slideshaft with straight slides for ease of manufacture; IIRC, Don's were curved as per usual. It's a tricky thing to get right either way.

I made my crank from solid to try out my then newly-acquired Super 7; interesting exercise and I've no worries about it coming unglued! I hacksawed out a lot of the excess material before turning it – but measure three times, have a cup of tea, come back and check again, and cut once…

If you've built a Tich and got it to work well, I would say you can build pretty well anything with a high chance of success. Perhaps you could ask somebody who has built one for more advice.

[Mike ClarkeParticipant @mikeclarke87958]

Hi Greg,

I am just putting the finishing touches to my 2P (Don Young) – it's a near identical design to his 4F, with the same tender.

Because ME magazines are so cheap and plentiful, I don't see any reason not to get a set. Alternatively My Hobby Store will copy you a set (probably be about £20 – you'd need to email them if not currently listed for sale). I think Don Young is a great writer – so it would be a shame to miss out on his words. He certainly gave me the confidence to tackle my first build…..I didn't follow every word, but the notes came in handy when I didn't have a clue how to tackle certain bits.

I silver-soldered my crank.

Regards,

Mike.

[greg hallParticipant @greghall]

Hi and thanks for the helpful amd enthusiastic replies! As a result the 4f is confirmed as the next project, I'v always liked it in full size from my trainspotting days.

[Mike ClarkeParticipant @mikeclarke87958]

It's a nice looking engine – best of luck with it. I have some castings for the 4F, message me if interested.

Regards,

Mike.

[Another JohnSParticipant @anotherjohns]

Greg;

If you find Nick Feast's Q1 series in fairly recent Model Engineers, you might read that its running gear and the 4F have some similaritites.

I might be wrong, of course, but even still reading Nick's construction articles might be of interest, as he does write it as he sees it, and I found them to be a great read.

Another JohnS

[nick feastParticipant @nickfeast85472]

Series ran from ME4353 to 4405. I've built a Clayton and 2 Q1's and made a solid circular centre for the crank axle each time. Apart from giving a better chance of alignment of the throws and axles, it makes for a much smoother running loco. Totally un-prototypical, but if you want something to run hard, it works.

Straight slides work fine but cranking the top end of the vibrating levers improves valve timing. Robin Dyer didn't have access to the software available on the net today. Dockstader and others.

The most accurate way to position the slideshaft pivot point on the frames is to do it when all the parts have been made. If the reversing lever can be moved from full forward to full reverse with the crank fully forward and fully back, relative to the cylinder (it's inclined at 8 or so degrees), without imparting any movement to the valve, then it's in right position. Suspension shoud be in the normal laden position, which may not be mid point on its travel. Fiddly but perhaps easier than setting eccentrics.

Tender mounted axle pump is essential if you make the crank as above, a 1/4" ram will keep the boiler fed.

Make it as heavy as you can and it will pull three or four adults. 3 1/2" gauge locos are great if you can get the train moving, there will be more power than you can use.

Nick

[Bob YouldonParticipant @bobyouldon45599]

Hello Greg,

I think you could having built a Tich, probably go on to build the Don Young 4F straight from the drawings. Don’s drawings are clear and very easy to work from but as someone has mentioned do try and obtain a copy of his “words and music” on the subject.

On the issue of the crank axle I have built each of mine up using Loctite and cross pining (I’ve previously built three, yes three 4Fs between other jobs) The only castings you really need are the wheels and perhaps the cylinder block but other than that everything else can be fabricated from stock materials. I think I completed the first 4F in about sixteen months. it’s nice to have a design without any inherent errors, a tribute to the skill of the designer.

The finished locomotive is an excellent performer, steams well and is not too big to carry around although they will benefit from some additional weight, the straight sides to the firebox will easily accommodate a couple of hefty lead weights.

Take a look at **LINK** shows one of my locomotives in steam.

Should you take the plunge and decide to build a 4F you will not be disappointed with the end result.

If you have any queries on the design, building etc please do not hesitate to contact me.

I’ve popped some photographs of my last pair of 4F’s in my photographs into the albums section

Regards,

Bob. . . . . .

[greg hallParticipant @greghall]

Hi Bob

Thank you for your reply. After much helpful advice from yourself and other members I have decided to build up the crank axle because of the age of my lathe and the need (I imagine) for the pins to be made from better steel than the webs.

Already seen your video – loco looks and sounds great.

I worked in isolation on the Tich for many years, but now with the internet and this forum I hope to make fewer mistakes and complete a 4f in a reasonable length of time!

Thanks

Greg

[Adrian Parker 1Participant @adrianparker1]

Hi Greg

Sorry I have only just noticed this thread. I am also (slowly) building Don Young's Derby 2P (Very similar to the 4F) and have just run the chassis on air.

I can confirm that the two most difficult bits are the Joy valve gear slide and the crank axle.

I milled the Joy slides from a piece of gauge plate mounted on the end of a length of steel bolted to a rotary table.

This is easy enough provided you have a vertical mill. You can buy a gunmetal casting to produce the slides in the lathe but this is ridiculously expensive nowadays. The most difficult task is holding the assembly together for silver soldering and Don made a couple of mods on the 2P to make life easier. These are detailed in his Locomotives Large and Small magazine No 26 February 1986.

First the slideshaft which holds the assembly together is moved from the middle of the slides to the top and the holes for the fulcrum pins are carried through on all four slides so that a temporary piece of silver steel can be inserted to facilitate assembly. Silver solder the slideshaft first, clean up remove the holding bar and fit the fulcrum pins last. My fulcrum pins were silver soldered by a good friend with a oxypropane set but I see no reason why they should not be held with Loctite 603.

I did use retaining grade Loctite on my Crank Axle but I can't really recommend it. I have rebuilt the crank axle twice now as it has fallen apart twice. The first time the joint was broken by a sliver of corrosion in storage and the second it simply failed when air testing. These are all really issues with my workmanship NOT the Loctite which is theoretically quite adequate. The latest iteration is still loctited and fitted with rollpins in each joint. If this one gives up I will have a go at silver soldering one.

I think that there are two basic problems with using Loctite. The first is that the joints must be very clean and the second is that we tend to have insufficient clearance in the joint so most of the Loctite is wiped away on assembly.

A remaining decision is the smokebox door as Don's design is not as the Midland prototype with multiple "dogs" around the outside. I have not decided what to do about this yet.

Finally, just a recommendation from my own mistakes. It would be wise to not make a final decision on the next model until you have steamed the Tich at your local track a few times; this experience may well modify your thinking!

Good Luck with the build.

Adrian

[greg hallParticipant @greghall]

Hi Adrian

I do have a vertical mill but no power feed so it's difficult to get a fine finish. It looks as if I should make the crank axle and slides first, see how it goes.

I've always liked the large flat smokebox door on those old midland engines so dogs it will have to be!

Greg

[Adrian Parker 1Participant @adrianparker1]

Hi Greg

I don't have power feed either but have found that finish is OK if a newly sharpened milling cutter is used and the bearings of the mill are in good condition.

Adrian

[Bob YouldonParticipant @bobyouldon45599]

Good Morning Adrian,

I would agree the LMS door is a bit of a problem being fitted with clips and having no centre dart etc; on my 4F’s I was faced with the same problem, looking at the full size door and front there is a reinforcing ring and I made this integral with the door, it being machined from a piece of round steel material, the door is fitted with the door furniture, hinges and clips as in full size but everything is flush on the inside except the clips and bolts in the twelve and six o clock positions where they are 8BA bolts with 9BA heads; so to remove the door the two bolts and their clips are removed and the door comes away complete for tube cleaning etc, when refitting the door, a wipe round on the sealing face with a smear of thick steam oil will seal the door adequately. I have attached a photograph of the full size smokebox door and one of my 4Fs which shows my method of door fixing.

I have always cut my slides from BMS steel plate mounted on the face plate, low speed and plenty of cutting fluid and at the end you have plenty of spare material, enough over for another locomotive! I always use a good quality piece of cast iron for the die blocks again machined up on the faceplate; I fit the fulcrum pins using high strength Loctite.

I trust the foregoing is of some assistance.

Regards,

Bob Y

[Bob YouldonParticipant @bobyouldon45599]

Good morning Greg,

The building of the crank axle is a fairly straight forward process using the Loctite high strength retainer method. Bore all four webs together this ensures each centre is identical and by final boring, the holes for the axle seats can be made with the correct clearance for the Loctite; start assembly by washing and cleaning each item thoroughly, I end up boiling each item on the cooker in an old pot with a spot of washing up liquid, that should remove all traces of oils etc lay the items aside to dry and avoid touching any areas on the components to be assembled with the Loctite. The first items to be dealt with is the crank pin / web assembly, assemble these items with the Loctite and set aside for 24 hours, next the webs can be assembled onto the embryo axle remembering to include the pump eccentric, now the webs haven’t got to be exactly 90⁰ but try to get them almost there; again leave the set up for at least 24 hours before handling. Now we come to pinning the webs, for the pins I use 2” round wire nails! Again clean them check the diameter, remove the point and find a drill that’ll give clearance for Loctite, drill the pin holes and pop them in with a drop of Loctite in both the hole and on the pin, again leave for 24 hours after which the pins can be carefully finished and the pieces of the axle can be carefully removed from between the crank webs.

I hope the foregoing is of some help.

Regards,

Bob Y

[Bob YouldonParticipant @bobyouldon45599]

Hi Adrian,

Take a look in my photograph album and I've posted two pictures of MR / LMS smokebox doors as I have described above which may be of some use.

Regards,

Bob Y

[Adrian Parker 1Participant @adrianparker1]

Hi Bob

Many thanks for that and the impressive photos. I will try and do something similar as I do not like Don's single handled dart idea.

regards

Adrian

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