Making A Depth Stop For The Straight-Line Engine

[Music] g'day chris here and welcome back to clickspring the most common operating mode for both the rows and straight line engines is when the cutter travels with an adjacent guide controlling the depth of cut but there's an occasional need for a depth stop to permit the guide to be retracted in some circumstances in fact this straight line machine possibly had one fitted in the past using these two holes if so it's now long gone so time to make a new one [Music] it's a fairly simple tool to make but there are some subtle design cues worth following from the machine itself that'll help the tool fit in visually with the style of everything around it the tapped holes of course are already in place so i need to pick off their position exactly as is a perfect use case for these little transfer screws i really have a need for these but for this one task they're pretty much indispensable [Music] [Music] the work is carefully positioned with enough overhang on each side to be trimmed off later and then the position is marked with a tap from a soft face hammer [Music] [Music] [Music] once installed with some temporary fasteners the perimeter and the adjustment screw position can be marked out [Music] the area where the adjustment screw is to make contact with the cutter slide is an irregular shape so i'm not overly concerned about centering it just that it looks about right by eye so [Music] [Music] and from here on the features are fairly arbitrarily positioned along the centerline of the piece but a bit of manual marking out doesn't hurt to help keep track of what's coming up [Music] for the thread pitch and overall design i'm following the existing guide adjustment screw for precedent the brass fitting has a fine knurled finish with slightly worn and soft edges a sort of bell profile and a concave face and i'd like the thumb wheel on the stop to sit comfortably alongside that so time for a quick custom form tool to make that profile [Music] [Music] formation of the thumb wheel starts with a diamond knurled surface [Music] [Music] [Music] [Music] the guide adjustment screw has a fine thread pitch so that rotation of the thumb wheel will permit fine control over the position of the guide and something similar is required for the depth stop adjustment too the thread would also benefit from having a smooth surface finish making it well suited to single point threading [Music] once trimmed to size the threaded rod becomes a good way to hold the part for the rest of the profile work [Music] [Applause] the threaded rod is already a fairly tight fit but a drop or two of retaining compound removes any doubt making it a reliable join [Music] okay so that's the depth adjustment screw complete now to finish off the main body of the tool starting with the threaded hole [Applause] [Music] and with that hole complete we get a first chance to check out how things are going with a quick test fit of the adjustment screw next up the end of the tool body needs to be profiled to match the closing screw countersink and it also needs a thread and slot formed to permit that closing now of course there are multiple ways these features could be formed the curved perimeter would suit a rotary table and the closing slot could be formed with a slitting saw but for a one-off like this as often as not it's maybe a little easier to just get stuck into it by hand the belt sander is a great tool performing a freehand cosmetic curb surface and a bandsaw cut cleaned up with files will be presentable enough for what this tool needs [Music] now as i mentioned before i prefer the tool to blend in as much as possible with the surrounding machine so with the part cleanup i've given it a decent brushed finish on the machined surfaces and broken the sharp corners with an abrasive stone but other than a light grain i've mostly left the unmachined original surfaces as they are the small pits and dents give the metal a bit of character making it look like it's been around for a while and this will help it catch up to the antique look of the rest of the machine the fasteners on the straight-line engine mostly have a slight dome and soft edges it's part of the reason it's so pleasant to operate and is a big part of its visual character too so it's definitely worth carrying the idea through to the fastness for this tool as well [Music] and that's all of the bits and pieces complete in its present state with the closing screw left quite slack the depth adjustment screw is a free and smooth fit it won't take much closing force at all to give that a tighter feel and remove all play so let's fit it to the machine and give it a good test run [Music] do [Music] i'll cover the use of the depth stop in more detail in a separate video but briefly there are occasions when it suits an engine turner to back off the guide and to set the cut depth by other means like for example when finishing off a radial pattern like this for which there's no suitable reference surface along which to run the guide in this case a depth stop on the cutter slide is one way to solve the issue now it still takes great care to ensure that the cut is a seamless match to those alongside it and the stop has a few limitations in how it can be used but for this and some other situations it's a great option to have available and it'll play a key role in some future engine turning videos thanks for watching i'll see you later [Music] [Music] you

Channel: Clickspring

Views: 231,602

Keywords: guilloche

Id: sl89zm4_yKc

Length: 16min 2sec (962 seconds)

Published: Sat May 28 2022