Recently I bought one of these https://www.ebay.co.uk/itm/0-190-4-...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649 I have had a 3/16th reamer for some years and it has served me well but on the last few builds I noticed that the axles were stiff in the bearings and I struggled to free them off. Recently I was talking to Richard Lambert of Finney 7 and he mentioned that recent Slaters axles were marginally thicker than 3/16 so he had been putting them in the lathe and rubbing them with emery to take a skim off. Some time ago a gent on the GOG forum had found a source of 4.87 reamers (which are just larger than 3/16) but they were still around £30 I think so I never bothered. A recent search for something else turned these up so I bought one and today I had cause to use it and it's excellent leaving the axles nicely free running.
Nice catch Rob I've just bought one also, I too have noticed the stiff axle syndrome so this will pay its way when the time comes to do the Britannia. Thanks for the tip off.
So there's only seven available now ... I bet cncpoorboy wonders why they are suddenly shifting so fast
We'll you know what they say ......... If you can't beat em ....... Just a thought ..... If you go dreaming these out, will that have any effect on using the jig axle pins or would you simply wait until the build is finished on your jig then use the dreamer as you fit the axles. Cheers Toto
Well the chassis jig pin positioning is determined by the side rods as you know, so each side / coupling rod sweated together identically will accept the coupling rods over crankpins as the same distances should apply when axle bushes are reamed. If the axles won't fit into the axle bushes because of a size differential and the bushes are reamed precisely the measurement between axle centres should have remained the same. A rotation problem will occur if "slop" has been introduced into the wheelset and too much freedom has been introduced into the bush or a tight spot or "flat" occurs in the rotation of the crankpin governed by an ill fitting axle / wheelset. Sp unless I've got this wrong the order of construction should be 1) make up the coupling rods 2) set the jig pins to the coupling rod dimensions 3) solder bushes 4) ream bushes to accept axles and 5) fit wheelsets and coupling rods.
Just for future reference (when you cant find the exact size of reamer you need), adjustable reamers are available. Certainly available for 6mm and above, but you might struggle to find a 4mm one
Another thing to bear in mind, if the bearings are square, the axle hole may not be perfectly on center, to overcome any inaccuracies, mark up (dot from a center punch) on the bottom side of the bearing, allowing easy re-fittment of the bearing the right way, so any inaccuracies are always in the same place, and the jig will have set up the chassis to allow for these inaccuracies. Paul
Personally I wouldn't ream them until the chassis is constructed and would follow the steps outlined by Paul. *Note* I would only use the reamer if the axles are tight not as a matter of course but when you need to open them out, having the tool to do it saves hours of pain. You will find that bearings supplied in kit's (mostly the round top hat variety) will vary considerably in all dimensions as will the holes that they are meant to fit in.... The latter to be fair is more prevalent on older hand drawn kits where in my experience many of the holes are over etched and require all sorts of ingenuity to get around it.
and here they are ...... picked up two and they come in a handy little storage box to keep them in decent nick ........ and out of the box ......... and there we have it. One for the drill compartment. cheers toto
