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- Aug 8, 2009
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Greetings Folks,
I am nearly finished with my Trout's Twin engine and I plan to post the rest of the build soon in the thread I have going for that but today I was thinking about some of the things I have learned with this build, being only the second engine I have machined. The first engine was so simple (Elmer's #25) I consider it to have served mostly as an introduction to the mill, lathe, the folks on this forum and the tool suppliers, all of which are now a part of my psyche.
Keeping in mind my methods aren't necessarily going to be considered the proper way, they nonetheless worked for me this time around. I may have to use different methods on future projects, but I'll get there when I get there.
Key learnings gained from my second engine build (Elmer's #44 Open Column Twin), real or imagined, in no particular order:
Drilling holes without DRO's: After scribing lines & mounting the part on the mill, I learned to eyeball a center drill bit (with magnifier) over the intersecting scribes then lightly tap the drill bit to the surface, observe the tiny dot I've just made then tweak the table to zero in.
It's hard to mill out the inside corners of a rectangular opening on something like a steam chest without getting corner bulges from overshooting the table movement. I offset the corner holes then on the last pass milled to the actual corner locations.
Its too easy to run a tap crooked through thin metal especially. I resorted to using a tapping block or mill/drill spindle as a guide or the tailstock on my lathe.
I often wish for thin parallels. Those thick ones get in the way frequently when drilling holes close to part edges.
It's really handy to have at least two pairs of digital calipers. One 4 inch and one six inch. Three would be even nicer.
Dull or broken small drill bits make good pins for linkages.
There is such a thing as too much compound on the buffing wheel. Put just a dab on the wheel while its turning and put it on frequently.
Having a sink next to the work bench was the best addition to my shop ever, for many reasons.
Sharp edges on newly-milled parts can easily split your skin open in between the finger print creases. This really sucks as compared to a cross-grain skin cut.
Using a hacksaw blade as a parting tool works pretty good if you don't need to position the cut precisely.
Red Loctite sets up faster than you might think.
Polishing every single part on your engine is too much work.
Miniature end mills work just as well in a drill chuck. Saves having to swap out the chuck with an end mill holder every time.
Hammering/smashing round pieces of 45% silver solder into flat pieces makes it melt faster .
It's difficult to clamp work directly to a 4" rotary table. You'd better have a smaller clamping set if you plan on it.
You can't drill into music wire so don't try using that for your crankshaft if you need to put pins in it.
Rough cutting on your metal chop saw for model engine parts isn't practical. It's like measuring with a micrometer, marking with chalk and cutting with an axe. If you don't have a horizontal band saw, even an angle grinder with a thin cutting disk is better for roughing out parts.
Fly cutters give you big bang for the buck. They don't cost much but are worth their weight in gold when it comes to reducing the thickness of a good-sized piece of metal.
When it comes to finding out which part is making the mechanism stick, Occam's Razor principle (the simplest solution is usually the correct one) almost never applies to model engine making. In other words, the hole you open up to relieve stress is not what was causing the stress.
Converting the X2 mill to belt drive is well worth the money.
Dykem works much better than blue Sharpies.
Lines scribed in Dykem show up much better with the light cast at a sharp angle on the mill.
Buffing wheels can throw your part faster than a speeding bullet. If I dare the buffing wheel to grab the part I am holding and hold it extra tight, I can usually win the contest, but not always. It's when I don't dare the machine and think about something else that it wins.
The $24 spent for a floor mat to stand on while working at the lathe is worth twice as much.
A shop with music makes better engines. Classical and Jazz make the best engines. Followed by Country, New Age and Rock, in that order. Rap and bagpipes is not music, I don't care what anybody says, but accordion is.
Putting a DI on my mini lathe tailstock was worth the $11 at HF and worth the 15 minutes it took to install.
Installing a plastic cover over the apron gears on my mini lathe was damn good advice.
I am nearly finished with my Trout's Twin engine and I plan to post the rest of the build soon in the thread I have going for that but today I was thinking about some of the things I have learned with this build, being only the second engine I have machined. The first engine was so simple (Elmer's #25) I consider it to have served mostly as an introduction to the mill, lathe, the folks on this forum and the tool suppliers, all of which are now a part of my psyche.
Keeping in mind my methods aren't necessarily going to be considered the proper way, they nonetheless worked for me this time around. I may have to use different methods on future projects, but I'll get there when I get there.
Key learnings gained from my second engine build (Elmer's #44 Open Column Twin), real or imagined, in no particular order:
Drilling holes without DRO's: After scribing lines & mounting the part on the mill, I learned to eyeball a center drill bit (with magnifier) over the intersecting scribes then lightly tap the drill bit to the surface, observe the tiny dot I've just made then tweak the table to zero in.
It's hard to mill out the inside corners of a rectangular opening on something like a steam chest without getting corner bulges from overshooting the table movement. I offset the corner holes then on the last pass milled to the actual corner locations.
Its too easy to run a tap crooked through thin metal especially. I resorted to using a tapping block or mill/drill spindle as a guide or the tailstock on my lathe.
I often wish for thin parallels. Those thick ones get in the way frequently when drilling holes close to part edges.
It's really handy to have at least two pairs of digital calipers. One 4 inch and one six inch. Three would be even nicer.
Dull or broken small drill bits make good pins for linkages.
There is such a thing as too much compound on the buffing wheel. Put just a dab on the wheel while its turning and put it on frequently.
Having a sink next to the work bench was the best addition to my shop ever, for many reasons.
Sharp edges on newly-milled parts can easily split your skin open in between the finger print creases. This really sucks as compared to a cross-grain skin cut.
Using a hacksaw blade as a parting tool works pretty good if you don't need to position the cut precisely.
Red Loctite sets up faster than you might think.
Polishing every single part on your engine is too much work.
Miniature end mills work just as well in a drill chuck. Saves having to swap out the chuck with an end mill holder every time.
Hammering/smashing round pieces of 45% silver solder into flat pieces makes it melt faster .
It's difficult to clamp work directly to a 4" rotary table. You'd better have a smaller clamping set if you plan on it.
You can't drill into music wire so don't try using that for your crankshaft if you need to put pins in it.
Rough cutting on your metal chop saw for model engine parts isn't practical. It's like measuring with a micrometer, marking with chalk and cutting with an axe. If you don't have a horizontal band saw, even an angle grinder with a thin cutting disk is better for roughing out parts.
Fly cutters give you big bang for the buck. They don't cost much but are worth their weight in gold when it comes to reducing the thickness of a good-sized piece of metal.
When it comes to finding out which part is making the mechanism stick, Occam's Razor principle (the simplest solution is usually the correct one) almost never applies to model engine making. In other words, the hole you open up to relieve stress is not what was causing the stress.
Converting the X2 mill to belt drive is well worth the money.
Dykem works much better than blue Sharpies.
Lines scribed in Dykem show up much better with the light cast at a sharp angle on the mill.
Buffing wheels can throw your part faster than a speeding bullet. If I dare the buffing wheel to grab the part I am holding and hold it extra tight, I can usually win the contest, but not always. It's when I don't dare the machine and think about something else that it wins.
The $24 spent for a floor mat to stand on while working at the lathe is worth twice as much.
A shop with music makes better engines. Classical and Jazz make the best engines. Followed by Country, New Age and Rock, in that order. Rap and bagpipes is not music, I don't care what anybody says, but accordion is.
Putting a DI on my mini lathe tailstock was worth the $11 at HF and worth the 15 minutes it took to install.
Installing a plastic cover over the apron gears on my mini lathe was damn good advice.
