Very Little Gravitas Indeed*

Discussion in 'Workbenches, including workshop techniques.' started by adrian, 30 January 2017.

  1. Ian@StEnochs

    Ian@StEnochs Western Thunderer

    I prefer to fit the wheel to the axle before drilling for the taper pin. My jig is illustrated below, a simple piece of brass faced off at 31.25 (S7 BB) with a reamed 3/16" hole. I usually press one axle end on in the lathe completely and just start the other until almost through the wheel face. Both are put in the jig and the 2nd pressed fully home. This ensures that the two parts of the axle touch in the middle with the wheels at the correct BB. If you make the axle slightly over length it is easily faced of and centre popped leaving it flush or slightly proud of the wheel face depending on prototype.

    To quarter I drill through the crankpin hole in each wheel at the appropriate quartering and throw for each wheelset. A pin each side then locates the wheel ready for drilling. Nothing seems to be standard on the locos I build, hence the plethora of holes on the end, hence there is another blank made ready for the next set of wheels. There are also a number of differing positions for the taper pin depending on whether the gearbox gets in the way or not.

    Ian.




    IMG_1295.JPG
     
  2. Steph Dale

    Steph Dale Western Thunderer

    A-ha, thanks Ian; that's exactly what I was thinking of doing. Apart from perhaps doing the quartering through a fulcrum so one jig can be used for any/all wheels...

    Steph
     
  3. Locomodels

    Locomodels Western Thunderer

    Well I have made it at last with a few pictures and an explanation of how it works.

    Firstly this is a multi use tool enabling wheel sets, using telescopic axles, to be drilled for taper pins either left or right leading, and in either S7 or 0 Fine. In addition the drilling plate forms the back-to-back gauge and there is also an add on setting piece for cranks at 120 degrees.

    As you will see it is made with dowel pins to keep all the component parts in line. Also you will notice that there is a shim, at the bottom, that can be removed, to change from S7 to 0 Fine.

    As there are pictures of the jig both with and without a wheelset in place I think that it's method of use is self-explanatory.

    Whilst it might appear rather complex to build, it does do the job very easily. Of course first you have to have the jig. Either purchased or home made.

    Whilst it is OK for setting the b-to-b, I now use shouldered telescopic axles which are, of course, self-setting when pressed into the wheel boss.

    It has proved difficult to load the pictures and I hope that I have managed it with these two. If not I will try again with some other shots
    I hope that this has satisfied your curiosity into my methods.


    Paul.


    Jig with 120 degree setting piece in place, with both S7 and 0 fine drilling plates.JPG Jig with S7 wheels clamped in 90 degree position..JPG

    Jig with 120 degree setting piece in place, with both S7 and 0 fine drilling plates.JPG

    [​IMG]


    Jig with S7 wheels clamped in 90 degree position..JPG

    [​IMG]
     
    Last edited: 24 April 2017
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  4. adrian

    adrian Flying Squad

    Thank you very much for that - it doesn't seem that complex now that I have seen it, I reckon I could machine that in my lathe. One query if I may the axle centre line does it align with the 45deg. bevel or is it slightly offset by half the crankpin diameter?
     
  5. Locomodels

    Locomodels Western Thunderer

    Adrian,

    Well thought out that man. Yes it is half a crankpin lower. Probably not really needed as the 90 degree angle is not critical. The important thing is that all the wheelsets are the same. Also the screws that bear upon the ends of the axle are not really required, as holding the wheels firmly whilst drilling would probably be sufficient.

    As you say it looks far more complex than it really is, just an assembly of flat plates, which the dowel pins help in lining up. An interesting and satisfying project to build and, once you have it, you will never wear it out in one lifetime, no matter how prolific you are. Happy jig building!

    Paul
     
  6. Obblygobbly

    Obblygobbly Active Member

    To get around any varying diameter crankpin problem you can quarter the wheels by pressing them against 90 degree surfaces in the same direction, like here (sorry for the rubbish drawing)

    Kpinz.jpg
    The darker grey is the far side of the jig. The smaller orange dots represent the crankpins - the upper one on the far side.

    I have only tried this in 2mm scale, but it works reliably.

    It assumes the crankpins on any one wheelset are the same diameter
     
  7. Steph Dale

    Steph Dale Western Thunderer

    That approach works well in other scales too, I've made one much like that for HO. usefully the approach will also accommodate multiple axle diameters providing you don't mind your quartering not being at exactly 90°.

    It is consistent across a wheelset though, assuming axle diameters are the same.

    Steph
     
  8. adrian

    adrian Flying Squad

    Thanks for that - it makes sense when it's explained. Just out of interest how do you set up the wheels in 2mm. I've only done one 0-4-0 in 2mm and the wheels are inserted into an acetal muff all fitted to the chassis bearings. Once in they will not be removed from the chassis, I was just wondering how a quartering jig would work with the wheel set in the chassis.

    Anyway for the tender wheels the quartering was not essential at this stage so the wheels have been finished off.

    wheels - 1.jpg

    Insulation has been achieved by drilling the axle out and glueing in a length of 2mm GRP rod. The axle is then parted through to the rod and filled with epoxy resin.
    wheels - 2.jpg

    In the meantime I keep looking for simple projects to practice with Onshape drawing package so I decided to use the quartering jig to play around with Onshape. To that end I have created this set of parts

    Screen Shot 2017-04-30 at 00.24.49.png

    Assembled, the yellow frames are for 90deg. quartering,

    Screen Shot 2017-04-30 at 08.11.40.png

    The red frames are for 120 deg. "quartering"

    Screen Shot 2017-04-30 at 08.11.55.png

    I do need to practice some more with Onshape to become basically proficient, that said even at my newbie level of understanding there are several nice features I have found in it. The ability to mix units when dimensioning is great, for example the with of the base unit block has to be the wheel back to back minus double the width of the axle support, for which I'm using 1/8" steel plate. In Onshape I can define the width of the base unit as "31.25mm - 1/4in". It's also extremely easy to generate an engineering drawing from a component part.
    Screen Shot 2017-04-30 at 00.25.42.png

    As I've got a free account all of this is publicly viewable so I think the link to the jig if interested is this :
    Onshape

    I've got the metal bar stock now so making it is the next stage!
     
  9. Obblygobbly

    Obblygobbly Active Member

    The wheel sets on the underframes I built (a while ago now!) were removable. I made keeper plates out of PCB. Personally, I would never make chassis with fixed wheels unless it is absolutely unavoidable. Quartering, back to back setting, checking for smooth running etc are all easier if you can remove wheels from the chassis easily.

    I will be doing a few more soon, so will build a new jig on the same principles as the old one.

    Edit

    Makes painting much easier too.
     
    Last edited: 2 May 2017
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  10. Lancastrian

    Lancastrian Western Thunderer

    Going back to the 8F wheels, they were all built with Vee rims. When passing through works, wheel sets were often mixed up. So, you could see an 8F built with solid axles displaying hollow axles, or even a mix of both ! One member of the class, 8169 was photographed in May 1947 with what looks like a WD type wheel, with webs between the spokes, but with cast balance weights. The pony wheels were the same type. It ran with these until early 1962 when it emerged from Horwich works with the correct pattern wheels. When 48403 came out of Horwich works in May 1962, it wore the wheels which (4)8169 had fitted previously, and ran with them until withdrawal in July 1965.
    It is quite feasible for locomotives to return to traffic after a works visit with plain rim pony wheels, especially during BR days when "foreign" workshops were used to service/maintain the loco fleet.

    Ian
     
  11. adrian

    adrian Flying Squad

    A little while ago I had reason to post a couple of photos on the Guild forum to show properly fluted coupling rods, actually a connecting rod and a combination lever but you know what I mean.

    We all seem to have our own little pet peeves in model making, one of mine is valve gear. Many years ago I was lucky enough to examine a couple of O'Gauge live steam loco's built by the "Parkers" a father and son team from Manchester. The valve gear on these loco's was stunning, it was correctly machined and in steel and it looked just right. So I understand it is a personal thing but I find it strange when people obsess to the nth degree over paint colours getting the precise shade of green or maroon etc. but are quite happy to accept completely the wrong colour for the valve gear. Valve gear was made in from steel and no matter how hard you try nickel silver is not the same colour as steel. Second big bug bear is "profile milled rods" - milling fluting with an end mill just looks completely wrong, the shape at the end of the fluting should flare out not end in a semi-circular hard stop.

    So the reason for this post - despite intending to build my JLTRT [sic] 3F out of the box - one thing I was not going to countenance was the etched rods. So a quick guide on how I ended up making correctly fluted steel rods.

    Step 1 - get a couple of lengths of steel strip 1/4" x 1/16" and mark out the dimensions for the rods. There were no suitable drawings in the Wild Swan book on the 3F goods engine - however there were some good dimensioned drawings in the Wild Swan 3F tank (Jinty) loco book. They looked very similar so I used these dimensions to draw out the shape.
    coupling_rods - 1.jpg

    Step 2 - I then drilled out one crankpin hole in each rod and then using a steel peg used this to locate and clamp the two sets of rods together.I could then drill the remaining holes assured that the two sets of rods will match.
    coupling_rods - 2.jpg

    Step 3 - first step of machining is the thinning of the rods between the crankpin bosses. The rods are clamped on to the vertical slide in the lathe and a 5/16" end mill is used.

    coupling_rods - 3.jpg

    So now the rods look like this.

    coupling_rods - 4.jpg

    Step 4 - fluting the rods is then done using a woodruff cutter(203)

    coupling_rods - 5.jpg

    So now we have something that looks like this, unfortunately slightly too enthusiastic on one of the cuts which has ended a bitt too close to the crankpin hole:rant:. Hopefully it won't be too noticeable when fitted.

    coupling_rods - 6.jpg

    Step 5 is cutting out the rods. it would have been nice to mill out the rods and bosses on a milling machine but I don't have one (yet!) so it was done the old fashioned way - by hand. First rough cut out using the piercing saw.

    coupling_rods - 7.jpg

    Step 6 - final finishing with files. I made a couple of little filing buttons to provide a guide for filing the bosses, surfaces were then draw filed and burnished to end up with this.

    coupling_rods - 8.jpg

    Step 7 - making the forked joint. The knuckle joint is forked, one method is clamping the rod in the lathe and using a slitting saw but I didn't have one thin enough. So the slot was made by hand and this was one of the most stressful bits, I tried using the piercing saw on a bit of scrap but a single cut was too thin. So after a little trepidation and a couple of test pieces the slot for the forked joint was made with a junior hacksaw! :eek:

    coupling_rods - 9.jpg

    So I still have to file down the other half of the joint and make the bolt/rivet but I'm happy they are the right colour and correct fluting!
     
  12. David Halfpenny

    David Halfpenny Western Thunderer

    Bookmarked, Adrian, thanks! D
     
  13. Dikitriki

    Dikitriki Flying Squad

    A very useful set of pictures Adrian. Depressingly, I realise that I have every bit of equipment to do the same myself.....if I knew how to use them.

    Richard
     
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  14. David Halfpenny

    David Halfpenny Western Thunderer

    Cheer up, Richard, nobody's born knowing how to do it :)
    It's like Writer's Block - the hardest bit is getting started.
    To defeat fear of messing up, just mess around with bits of scrap till you have a 'feel' for how metal peels.
    Maybe even get a narrow cold chisel and carve grooves with it.

    David
     
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  15. adrian

    adrian Flying Squad

    Like @Martin Shaw , modelling has been restricted whilst completing domestic duties - re-felting the garden shed roof in my case.

    However I did manage to grab a little time to finish off the rods. The main rod knuckle joint was thinned down for the forked joint. The joint is drilled and reamed 1/16". I then turned up a brass top hat bush and at 1/16" it is just possible, although it's cutting it a little fine, to drill a 12BA clearance hole. Tight - it's a 51 thou hole in a 62.5 thou bush!!:eek: I then use a 14BA steel nut drilled and tapped 12BA. So the assembly is a 12BA steel countersunk bolt from the rear, brass bush and 14BA steel nut.

    rods - 2 (1).jpg

    The bosses were then drilled and fitted with Scale-hardware bolts. So now I have a completed set of rods I can use these to start on the chassis of the 3F.

    rods - 1 (1).jpg
     
  16. Locomodels

    Locomodels Western Thunderer

    Splendid work, a proper job.

    Paul.
     
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  17. adrian

    adrian Flying Squad

    Thank you - having seen the quality of your work your comment is appreciated.

    Technically this next bit is not really "on your workbench" more stuck on the floor whilst I get it sorted job.

    A few on here may have noticed that whenever there is a question asked about tools I always chip in with a recommendation to look to the secondhand market - so I have once again practiced what I've been preaching. A small vertical milling machine has long been on my list of next purchases so I have been watching with interest peoples experience with the small Proxxon milling machines. I've not had much success trying to find secondhand small desktop milling machines but after finishing the coupling rods by hand I was once again flicking through various sites. On Friday a potential candidate flagged up on Advert - All Ads . A couple of emails and phone calls later I purchased the machine and it turned up today!

    Leinen - 2.jpg

    Leinen - 3.jpg

    Leinen - 4.jpg

    So it's a Leinen jig boring machine. BCA Jig Borer - Miller

    A rather nice solid machine with an 8" rotary table built onto the x-y table. Yes it is in need of a little restoration, a damn good clean up and paint however the main issue being the lack of any motor. This will be the first thing to tackle but at the moment I'm trying to decide whether to fit a small single phase motor at the rear similar to the original fit and use the belt drive system as original. Or use the mounting system point at the side of the head to fit a modern DC motor. Most of my work will be small scale so I think high speed is more important than power. I note with interest on the lathes site a mention of a very rare high speed (60,000rpm) machine. BCA Additional Pictures so I'm podering if some similar would be possible with a DC motor.

    Overall it was slightly more expensive than the Proxxon MF70 but even with buying a motor, sorting out the drive system and painting I reckon I'll have a running machine for less than the price of the Proxxon FF230. It will also be something a little more unique, I have been doing a little more digging into the history of the machine. On the cross-slide it was stamped with "B.E.C." with I initially thought was for an engineering college (Birmingham?) but according to the Lathes website this is the mark of the importers B. Elliot & Company. Leinen Milling Machine

    It also has the serial number stamped between the Leinen trademark of a precision bench vice.
    Leinen - 1 (1).jpg

    Finally on the front of the machine is a brass plate for Thos.P.Headland. who were apparently
    1939 Suppliers to the Aircraft Industry - Graces Guide

    Leinen - 1.jpg
     
  18. JimG

    JimG Western Thunderer

    Adrian,

    What a nice machine - well worth digging around for. I bet it is more rigid and accurate than the Proxxon mill. Will the spindle bearings stand up to the higher speeds you are considering?

    Jim.
     
  19. David Halfpenny

    David Halfpenny Western Thunderer

    What a cracker, Adrian!

    I suggest going for either DC or better still a three-phase motor and variable speed convertor. Your instinct for high speed is good as long as you lubricate properly and don't overspeed the spindle - Tony Griffiths (of www.lathes.com fame) can advise on speed and power: it's a chunky machine but it's still a 'tickler' rather than a 'hacker'.

    Crunch Question: Did you get any collets with it?

    (Obviously you don't need to know this, but it may help others.
    I've long coveted a BCA, and saw one in Tony's shop years ago, but turned it down because it was Imperial and life is too short. Besides, I couldn't get it down to my workshop with its cast iron stand.
    Eventually I bought two Proxxon machines and fitted each with a rotary table. (This doesn't make them Jig Borers by any means, though keeping track of the tables with DROs helps.) One was the MF70, which is 20 000rpm. The other was the big TBH drill which is 4 500rpm and takes collets (avoiding the curse of milling in an unsuitable drill chuck) with a KT150 X-Y table. Both suffer from lack of clearance under the tool, and the TBH lacks a precision down-feed, but it's quill is long and solid so I get by. I've spent a great deal more than Adrian.
    You can see a couple more BCAs for sale at Tenga, who used to make them and sell them for five-figure sums: Tenga Engineering New CNC Turret Milling Machines) David
     
    Last edited: 30 June 2017
  20. adrian

    adrian Flying Squad

    A good point - I've seen comments online that the spindle speeds are limited to about 3000rpm max due to the bearings, they also point out that the slower speeds are useful for fly-cutting etc. So a DC motor drive looks a strong contender at the moment, they even suggest sourcing one from an old exercise treadmill!
    Somehow I don't think I'll be putting the machine under any serious pressure, it'll mainly be 7mm scale modelling. I will probably be in touch with Tony, he prints service manuals for them and seems a good source for belts. I don't believe he's still going and not retired - I remember visiting Tony in the early 80's with my Dad - in fact I think my Jones & Shipman pillar drill came from Tony.
    There's the rub - no collets. However I have a few lines of enquiry at the moment - the most promising is someone over on the model steam forum producing a BCA ER20 collet chuck. Model Steam Engineers - BCA Collet chuck . There seems to be plenty of BCA users on this forum so plenty of advice available.
    Just to tempt you then there is a Mk3 on ebay at the moment - collect from Reading. BCA MILLING MACHINE No3 | eBay