Geoff
Hi-poster
Posts: 171 
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Post by Geoff on Mar 19, 2014 5:05:07 GMT
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Post by Doug on Mar 19, 2014 8:04:24 GMT
thanks Geoff that does look good I especially like the method for making buffers I will use that I think I have started to get the parts together, first off the wheel castings  the chassis rails are almost cut I dont want to rush welding them up yet as it is easier to machine them and drill holes while they are in bits  I have identified bearings and other hardwear I need including the bar for the axles I will get that next month when I order the material for my Speedy build. |
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Post by Doug on Mar 21, 2014 22:13:04 GMT
The frame is coming along nicely I need to get the wheels done next so I can assemble the frame properly and weld it  |
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jma1009
Elder Statesman
Posts: 5,913
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Post by jma1009 on Mar 21, 2014 23:15:05 GMT
hi dug,
i wish i could weld ali as would love to make a light bogie driving car, so am impressed that you would use ali.
i am not sure i would use ali for a wagon as to get it 'scale' it needs to be quite thin section. plus of course the pics of the wagon you wanted to build had wooden framing and whether wooden framing or steel channel framing all wagons had proper 'W' irons for the axleboxes to fit into. i cant quite understand why you have departed from same other than for expediency. i have always taken the approach that it's best to copy fullsize. it took me about 5 mins to hacksaw out each 'W' iron then another 5 mins filing to size. say 40 mins for all four? steel channel for 5"g wagons is easily cut up from 1" square box section steel as used on school chair legs and table legs and much else besides
cheers,
julian
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Post by Doug on Mar 22, 2014 7:04:24 GMT
hi dug, i wish i could weld ali as would love to make a light bogie driving car, so am impressed that you would use ali. i am not sure i would use ali for a wagon as to get it 'scale' it needs to be quite thin section. plus of course the pics of the wagon you wanted to build had wooden framing and whether wooden framing or steel channel framing all wagons had proper 'W' irons for the axleboxes to fit into. i cant quite understand why you have departed from same other than for expediency. i have always taken the approach that it's best to copy fullsize. it took me about 5 mins to hacksaw out each 'W' iron then another 5 mins filing to size. say 40 mins for all four? steel channel for 5"g wagons is easily cut up from 1" square box section steel as used on school chair legs and table legs and much else besides cheers, julian Hi Julian I understand what you are saying and bear with me it will look right in the end my diversion from original won't be very noticeable when complete, I will be fitting W irons and faux leaf springs, brakes etc. and as for the reasons of doing it this way, mainly because I wanted to explore a rapid way of building my waggon with stuff I had lying around like my wheels Ali sections Ali bar etc. i have a few more tricks up my sleeve to save money yet. BTW what size bolts did you use on the plank bars? I am going to need to stock up there are LOADS! |
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jma1009
Elder Statesman
Posts: 5,913
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Post by jma1009 on Mar 22, 2014 11:14:44 GMT
hi dug,
apart from the 'ties' at the bottom of my 'W' irons which are 8BA, everything else is 10 BA. this is actually overscale and 12 BA would be more accurate, but 250 10 BA bolts and nuts (150 of them specially made from 1/16" dia flat head brass rivets) was quite fiddly enough for me!
i used individual planks from 6mm x 18mm strip, machined down to 5/8" width. however lots of people use 6mm plywood, scoring the sheet to give the planking effect. this would be a lot quicker and arguable stronger than individual planks and if filler is added to the sides and ends of the sheet no one will know!
using coach bolts turned down for buffers is an excellent tip from the link provided by Geoff, though the scale diameter of the buffer heads should be something like 1 3/16" dia.
cheers,
julian
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Post by Doug on Mar 26, 2014 7:28:28 GMT
Ok some progress the wheels,  the rear was faced off first then the bore for the bearing the whole lot is then clamped in the fixture and chucked in the three jaw chuck  notice the profiled tool for cutting the inside rad on the tread  there is a slight taper on the wheel to match the ones on my loco so the profile is the same  the bearing fitted and held with retainer its not going to budge (no load on it anyway but not taking any chances)  two wheels down two to go then its on with the axles and the frame  |
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Post by Doug on Mar 28, 2014 20:44:50 GMT
Now got a rolling chassis  |
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jma1009
Elder Statesman
Posts: 5,913
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Post by jma1009 on Mar 28, 2014 21:10:41 GMT
very quick and impressive dug, but what about suspension?
cheers,
julian
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Post by Doug on Mar 28, 2014 22:39:13 GMT
very quick and impressive dug, but what about suspension? cheers, julian I have not fitted any do you think i need it for such a small wheelbase? With almost no load I guessed it would be silly to bother. i have seen a few hard chassis driving trucks with suspension over the top of the frame under the seat. my next plan is to fit a solid draw bar through the chassis to transfir the pull through the waggon. Then make some w irons and fit the side rails. The axle boxes and faux leaf springs will be cast from resin. When all that's done I can get on with the planks and metalwork up top. Then finally the brakes. oh forgot the buffers too which I have the m12 coach bolts for. i thought I would run it round the track on Sunday when I test my new seals on butch just to make sure it won't derail |
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jma1009
Elder Statesman
Posts: 5,913
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Post by jma1009 on Mar 28, 2014 22:58:00 GMT
hi dug,
give it a good push into the curves and see what happens! dont also forget that when coupled up between loco and driving trolley there are all sorts of other forces that might affect the wheels on the rails.
i think my personal view would be to elongate the holes for the axles in the ali blocks into slots so the axles can move up and down and fit some springs into the slots with a suitable spring retainer over the axle. or you could do the above and fit springs into the false spring castings on the outside as per lots of simpler loco tenders.
passenger trolleys are sometimes 'unsprung' with rubber mountings for the axleboxes and if the chassis has a bit of flex in them, but of course passenger trolleys have quite a load - unlike your wagon.
cheers,
julian
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Post by Doug on Mar 28, 2014 23:10:29 GMT
hi dug, give it a good push into the curves and see what happens! dont also forget that when coupled up between loco and driving trolley there are all sorts of other forces that might affect the wheels on the rails. i think my personal view would be to elongate the holes for the axles in the ali blocks into slots so the axles can move up and down and fit some springs into the slots with a suitable spring retainer over the axle. or you could do the above and fit springs into the false spring castings on the outside as per lots of simpler loco tenders. passenger trolleys are sometimes 'unsprung' with rubber mountings for the axleboxes and if the chassis has a bit of flex in them, but of course passenger trolleys have quite a load - unlike your wagon. cheers, julian Ok thanks Julian I will give it a full test. I was planning on doing the simple push test as I did with speedy's rolling chassis and when I have the buffers and coupling rod and base board done I was going to sandwich the chassis betwixt loco and driving truck (single one first then passenger truck) and see how it behaves all the rest is cosmetic so won't have much impact. Hopefully. edit sunday 30/3/14 right I completely understand what you were saying Julian the fixed axle system just won't work I have a sneaky feeling you already knew what would happen lol. Plan b will now be implemented with all due haste. I have also shot myself in the foot with my lubrication too I mentioned last week it would prob. Break and guess what. Looks like my butch wants to come apart again. |
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Post by Doug on Apr 3, 2014 7:24:30 GMT
a Small update ;
I took the rolling chassis to the track to test it out and found a small but significant problem, the rails are not totally flat which is no big supprise as the same is true in full size what this means for the truck though is because all four wheels are fixed and the two axles are fixed rigid when you get to a bump one wheel comes off the track alot like a chair on an uneven floor this is obviously bad as i may spill my tea! so, I ave a plan ,the propper way to do this is to put springs on all four corners and i am thinking more from an engineering persective that I will try something a little simpler, if i remove one axle and make a pivot bracket for it in the middle of the axle it will alow one axle to twist in relation to the other this will make a three point contact (thinking milkmaids stool) so it will allow travel over rough rails without leaving the tracks. so i will see what happens next time i test it.
I am quite enjoying this, as its a really good lesson on whats improtant on the bottom end of loco's and waggons.
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jma1009
Elder Statesman
Posts: 5,913
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Post by jma1009 on Apr 3, 2014 9:27:19 GMT
hi doug,
re suspension you also need to consider the drawhooks. if you have a fixed axle at one end and if the drawhook height is wrong or varies when coupled up there may be a tendancy to lift the fixed axle off the rails. i would fit the solebars to the headstocks, fit 'W' irons, and let the axleboxes deal with the suspension in the 'W' irons as per fullsize. you can leave your existing ali blocks where they are at the moment for lining everything up but ultimately i would remove them from the axles and inner longitudinal beams.
what diameter are your wheels and what is the width of the tread?
cheers,
julian
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Post by Doug on Apr 3, 2014 10:53:12 GMT
hi doug, re suspension you also need to consider the drawhooks. if you have a fixed axle at one end and if the drawhook height is wrong or varies when coupled up there may be a tendancy to lift the fixed axle off the rails. i would fit the solebars to the headstocks, fit 'W' irons, and let the axleboxes deal with the suspension in the 'W' irons as per fullsize. you can leave your existing ali blocks where they are at the moment for lining everything up but ultimately i would remove them from the axles and inner longitudinal beams. what diameter are your wheels and what is the width of the tread? cheers, julian the wheel dia is 3" and the treads are about 29/64" I like the plan but how would i make the springs soft enough? arnt leaf springs very stiff? i have set the frame or center buffer height the same as my two loco's (3.5" i think of the top of my head) regards, doug |
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jma1009
Elder Statesman
Posts: 5,913
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Post by jma1009 on Apr 3, 2014 11:26:10 GMT
hi doug,
yes loco leaf springs if made as per fullsize are usually too stiff. if you want a 'quick' short cut then fit coil springs above the axlebox and underneath the solebar. these can either be hidden by dummy leaf spring castings, or replaced with the proper thing later on.
cheers,
julian
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Post by Doug on Apr 3, 2014 11:45:37 GMT
hi doug, yes loco leaf springs if made as per fullsize are usually too stiff. if you want a 'quick' short cut then fit coil springs above the axlebox and underneath the solebar. these can either be hidden by dummy leaf spring castings, or replaced with the proper thing later on. cheers, julian ok thanks will do |
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Post by ejparrott on Apr 3, 2014 12:22:32 GMT
Build leaf springs exactly as Doug Hewson describes for all his models serialized in EIM, they work perfectly.
I'm sorry Doug, but you're re-inventing the wheel as I said previously. You would have been far better off building it as per full size like I said, it worked perfectly well for a hundred years or more so why re-invent it?
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Post by Doug on Apr 3, 2014 14:49:23 GMT
Build leaf springs exactly as Doug Hewson describes for all his models serialized in EIM, they work perfectly. I'm sorry Doug, but you're re-inventing the wheel as I said previously. You would have been far better off building it as per full size like I said, it worked perfectly well for a hundred years or more so why re-invent it? that would spoil the adventure tho  the main reason for going the route i have is the wheel castings which have a 33mm hole in the center "perfect for a 35mm bearing" so i would like to think i am not reinventing the wheel just making it suit my perposes. the main issue you end up with is size thing dont always scale down well and a coal waggon that would carry 10 tons that i am using is going to carry a few grams of coal and a cup of tea (hopefully) so not exactly the 100wgt or so it could carry at this scale so leaf springs worry me a bit. Our track has at least 5mm of deflection in it in a couple of places so i want to be sure i dont throw the waggon off the track and i am taking all advice on board, and as long as i am enjoying the experimenting part i dont see too much harm in it. I tried a fixed frame system and it had flaws, i like what Julian did with his so I am going to follow his advise and spring it off the axleboxes but with coils instead of leafs that way i get way more flexability on how stiff it is and hopefully enough travel to take up the undulations of the track.  best regards, Doug |
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Post by ejparrott on Apr 3, 2014 15:21:11 GMT
Believe me, long trains of empty wagons run at Gilling with the springs Doug designed, if you don't believe me, ask him!
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