Hello Ladies and Gentlemen
Could anyone advise me in one way or another on how to disassemble the valve gear on a Athearn usra light mikado, as I'm in the compulasary rebuild phase of things after reading up about the problems.
What I need to know in particular is how to get the grub screw I think? out of the eccentric crank and what is the prefered tool(s) to be used for doing this. I've got to get a better set of (jewellers) screwdrivers for this kind of work instead of the cheap set I've got that is a bit limited and basic.
The mikado is the donor loco for one our locally made Berkshires and Australia's only berkshires the SAR 720s bar the frames which were made here in the usa, the berks shares a lot of the running gear with the usra mikes so the usra mike makes the ideal donor mech for a 720 body kit
Any addivice would be apprecatied thankyou
I used one of my micro hex nut screwdrivers from my set. You could technically use pliers or tweezers to grip the screw and hand twist it but that takes forever and isnt recommended.
Hope this helps!
Charles
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Modeling the PRR & NYC in HO
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I suggest call Athearn.
I have a Chellenger and I broke an eccentric rod when trying to change a traction tire. I called Athearn and they were helpful if you can get to the right tech expert. I recall talking first to David(?) about the problem but needed more detailed help on both what my replacment part assenbly would include plus, as you are dealing with, exactly how to go about disassembly and reassembly. I needed to talk with a part time tech expert, Wayne as I recall, and he was extremely helpful in lots of exact instruction. I believe he first helped me understand what part(s) I was getting and in a subseqent conversation walked be through a tricky disassembly step. This may have been 3 years ago, so people could have changed.
When working on this I wanted a set of hex drivers for steamers rods. I measured the hex rod bolt and it seemed a fractional mm measurement. Maybe made to scale. So I did not order a set of small metric hex sockets but did obtain the right tool by finding a replacement driver that came with the tool. I'd still like to have a set that would work for most rid bolts.
Paul
Modeling HO with a transition era UP bent
SAR 500.....I'm in the compulasary rebuild phase of things after reading up about the problems...
To what problems are you referring? The only ones of which I'm aware is a cracked gear issue with some (I have six of them, and so far, no problems) and the fact that these locomotives are very nice runners, but very poor pullers due to improper weight distribution.
Wayne
If you're in a pinch and need a hex driver that will fit, check out your local hardware. Look for their "cap head Allen screws", I've actually taken the loco in with me and tried them until I found the right one. If you need more leverage than just finger power you can epoxy a couple of threaded nuts onto the screw itself, but usually all you need is finger power.
Yes the cracked gear issue and the weight I forgot to mention that, their got earn their keep as I plan to run a scale train for the division I model which is the equivalent of (australian)14 x 36' box cars allowed tonnage.
Cam
Thankyou Charles
Thankyou Paul I didn't think of doing that,I'll do that and check my local hobby tool supplier to see if I can get the correct size
I'll keep that in mind Areibel I've got a funny feeling I might be doing that yet
[quote user="SAR 500"] ...I forgot to mention that, their got earn their keep as I plan to run a scale train for the division I model which is the equivalent of (australian)14 x 36' box cars allowed tonnage.[/quote}
I know that you're speaking of Berkshires, but there's some information HERE on adding balanced weight to the Athearn Mikado.I still don't understand why you need to disassemble the Athearn valve gear, though. If you plan to use it on Berkshires with larger drivers or different driver spacing, all that needs to be changed is the length of the eccentric rod.
I did read that and plan to do that at some stage with the weight.
Its getting to the gear on the axle which is spilt that I'm having the trouble with and the only way so far that I can see is to undo the valve gear and drop the wheelset over the wheel drop, remove wheel via the the puller, take broken gear off and replace with NWSL one then reassemble. Otherwise could someone enlighten of another way in how to change one over please
http://www.endofthelinehobbies.com.au/
railway section ho then go to Australian locomotives then second from row down on the right rocky river sar 720B loco kit
(Doing this on a table havnt mastered the copy paste link yet)
SAR 500...Its getting to the gear on the axle which is spilt that I'm having the trouble with and the only way so far that I can see is to undo the valve gear and drop the wheelset over the wheel drop, remove wheel via the the puller, take broken gear off and replace with NWSL one then reassemble. Otherwise could someone enlighten of another way in how to change one over please
That's pretty-well the procedure, but all you really need to remove is the screws which hold the eccentric cranks in place. After the bottom cover is removed, that will allow you to lift out the main driver in order to replace the gear.When you mentioned disassembling the valve gear, I thought that you were thinking of drilling out the rivets which hold the rest of it together.
doctorwayne SAR 500 ...Its getting to the gear on the axle which is spilt that I'm having the trouble with and the only way so far that I can see is to undo the valve gear and drop the wheelset over the wheel drop, remove wheel via the the puller, take broken gear off and replace with NWSL one then reassemble. Otherwise could someone enlighten of another way in how to change one over please That's pretty-well the procedure, but all you really need to remove is the screws which hold the eccentric cranks in place. After the bottom cover is removed, that will allow you to lift out the main driver in order to replace the gear.When you mentioned disassembling the valve gear, I thought that you were thinking of drilling out the rivets which hold the rest of it together. Wayne
SAR 500 ...Its getting to the gear on the axle which is spilt that I'm having the trouble with and the only way so far that I can see is to undo the valve gear and drop the wheelset over the wheel drop, remove wheel via the the puller, take broken gear off and replace with NWSL one then reassemble. Otherwise could someone enlighten of another way in how to change one over please
I hoping it was just that sort of procedure and nothing else.
I'm hoping I dont have to do that with any locos in the near future, but this pick 'a' part athearn mikado (picked up cheap for parts off ebay) that I have for practice before I get onto the actaul donor locos, I might have too or I just need the correct tools and elbow grease as it has a stubborn grub screw, or someone stuck a drop of super glue or loctite on it.
SAR 500...I just need the correct tools and elbow grease as it has a stubborn grub screw, or someone stuck a drop of super glue or loctite on it.
Yeah, I have a couple of unmodified ones still in their boxes, and just a little while ago attempted to remove that screw...it wouldn't budge. In most instances, that's better than the ones that wind their way out as the loco is running, but not so convenient if you need to remove it.
doctorwayne SAR 500 ...I just need the correct tools and elbow grease as it has a stubborn grub screw, or someone stuck a drop of super glue or loctite on it. Yeah, I have a couple of unmodified ones still in their boxes, and just a little while ago attempted to remove that screw...it wouldn't budge. In most instances, that's better than the ones that wind their way out as the loco is running, but not so convenient if you need to remove it. Wayne
SAR 500 ...I just need the correct tools and elbow grease as it has a stubborn grub screw, or someone stuck a drop of super glue or loctite on it.
Yes agree their, I'm hoping the one I've got to work on comes out and goes back in without hassle I'll find out soon enough.
Back on the mikado rebuild... got said screwdrivers and work a treat, should have treated myself to some ages ago then we got stuck into it, pulled the valve gear apart on the pick apart loco and had to drill the screw head out on the driver's side valve gear... not happy, worst part is the donor loco(one to date) I'm going to perform this work on also needs the screw drilled out so I can drop the wheel set out and replace the split gear only thought now is where do I get 1mm dia x 4.5mm long screws (I pulled out the vernrier calipers and double checked that one) for the valve gear if I need any as I have another 5 mikes in the cue that are going to get rebuilt and a possible chance I'll encounter the same problem . Any help please and thankyou
To top it off I need to get the NWSL qaurter II to boot after we found out the wheel set wont fit in the qaurter1 that I have, so any help and advice on qaurtering driving wheels please and thankyou