{"id":7450,"date":"2026-01-02T12:07:26","date_gmt":"2026-01-02T11:07:26","guid":{"rendered":"http:\/\/www.railway-models-and-art.co.uk\/blog\/?p=7450"},"modified":"2026-01-02T12:07:26","modified_gmt":"2026-01-02T11:07:26","slug":"mok-8f-8425-still-working-on-the-motion","status":"publish","type":"post","link":"http:\/\/www.railway-models-and-art.co.uk\/blog\/?p=7450","title":{"rendered":"MOK 8F 8425 – Still working on the motion"},"content":{"rendered":"\n

In between the festivities I have been making further progress on the 8F chassis and motion. Way back I had bought a full set of motion from Premier in ignorance at the time that sometimes for whatever reason the kit centres don\u2019t always match those of the Premiers rods. In this case the coupling and connecting rods are fine but most of the others aren\u2019t. I had previously spent some time fitting forks to the radius rods but I hadn\u2019t assembled enough of the motion to check that they would actually fit.<\/p>\n\n\n\n

\"\"<\/a>
Premier Radius Rods – too long for the MOK 8F<\/figcaption><\/figure>\n\n\n\n

Spoiler alert, they don\u2019t.<\/p>\n\n\n\n

Which was a bit of a shame because I had also fitted a sliding block for the reversing links. Hey ho, I still had the kit rods so I made those up.<\/p>\n\n\n\n

I had in the past, determined that the Combination levers for my engine should be fluted, whereas the Premier rods are plain. So, they too are in the spares box, as are the Union links because I couldn\u2019t see how I might make them forked.<\/p>\n\n\n\n

Returning to the coupling rods, after shortening all the bushes I decided that I couldn\u2019t live with the brass bushed for the two front axles because they ultimately become the \u2018crankpin nuts due to lack of clearance on the prototype. So using the nothing looks like steel than steel maxim I made some replacements from steel and I also made up some of the large flanged nuts that retain the rear of the coupling rods.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

After this image was taken I did thin down the flanges somewhat.<\/p>\n\n\n\n

Next up was recessing the coupling rods at the first pair of holes.<\/p>\n\n\n\n

I\u00a0machined up a stub of bar that was a close fit in the coupling rod holes and fastened them to my Metalsmith drilling plate. Using the stub of ba as a locating pin I was able to adjust the mill tables until it dropped smoothly into the hole and then swap the stub out for a 4mm slot drill which I used to recess the our hole for the flange of the bush.<\/p>\n\n\n\n

\"\"<\/a>
Recessing Coupling Rods<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
Recessing Coupling Rods<\/figcaption><\/figure>\n\n\n\n

You will note the black marker spot on the side of the rod. This was to ensure that I didn\u2019t inadvertently recess the wrong end\u2026<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

Here we are to date with the bits that are fitted so far working without catching or unscrewing them selves when the loco runs in reverse. The next job is the return cranks when I will determine if the Premier Eccentric rod, fits or not.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n","protected":false},"excerpt":{"rendered":"

In between the festivities I have been making further progress on the 8F chassis and motion. Way back I had bought a full set of motion from Premier in ignorance at the time that sometimes for whatever reason the kit … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[6],"tags":[],"class_list":["post-7450","post","type-post","status-publish","format-standard","hentry","category-mok-8f"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7450","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7450"}],"version-history":[{"count":1,"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7450\/revisions"}],"predecessor-version":[{"id":7461,"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7450\/revisions\/7461"}],"wp:attachment":[{"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7450"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7450"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.railway-models-and-art.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7450"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}