Marks Holt 75

[G54AUST]

Still loving your work Mark. Keep going strong Mate. So glad you have covered the build in such detail.

(Would be interesting to see how many "views" this build has clocked up. Angie, does the forum have a counter ???)

And yes, you are correct, in ref to Georges drawings. An absolute pleasure to peruse.



Kind Regards,

Trevor,
Melbourne, AU.

 

[dnalot]

(Would be interesting to see how many "views" this build has clocked up. Angie, does the forum have a counter ???

Yes there is a counter, 18000 + views for this build. If you look at the "A work in progress" page you will see the count on the right of the listed threads. Some may have noticed I have slowed down. I tore a ligament in my right thumb about 6 weeks ago and have been working one handed since. Unfortunately my left hand is not very talented and is all thumbs.

Mark T

 

[awake]

Ouch! I hope your thumb is recovering!

 

[cooksservices]

Incredible attention to detail, the finish on your parts looks amazing. This has definitely given me a standard to aim for. Thank you for sharing!

 

[dnalot]

I present here something perhaps a little unexpected. On the old “Cole casting kit” the crankcase side covers had the Holt name in the casting. A nice touch but the font was wrong. On the scratch built engines I have seen photos of, the name was eliminated. I have made my covers with the “Holt” name on them in a font that is much closer to realistic. On some old photos all 4 covers had the name cast in, on others only one cover per side had the name.

All made of aluminum and sandblasted to give a cast look. The letters were cut out on the mill and then epoxied to the cover before sandblasting. After sandblasting the letters were sanded smooth. (Mounted temporarily with cap screw) I hope you like the look.

Mark T

 

[dnalot]

Thanks for your comments guys. And thanks to those just watching

Mark T

 

[gbritnell]

Great detail touch Mark! At the time I built mine I thought about it but just never did it. When I built the radiator I drew the logo up in CAD and cut it right into the top tang with a .031 end mill. Kind of like manual CNCing.
gbritnell

 

[Foketry]

great and nice job , if you want, I also drew the logo for radiator

 

[dnalot]

Thanks George, Foketry for your input. .031 end mill, now that's a small bit. I will be doing something for the radiator but have not looked ahead that far. Next I think will be the flywheels because I have the material on hand.

Mark T

 

[kvom]

If you're using CNC, why not mill the letters and cover as one piece? The result looks great regardless of method. I need a bead blast setup.

 

[dnalot]

If you're using CNC, why not mill the letters and cover as one piece? The result looks great regardless of method. I need a bead blast setup.

That's my problem, I'm not using a CNC, wish I were. I have a cnc router but the spindle speed is 10,000 to 30,000 RPM. Aluminum melts at that speed and grabs the cutter. And yes you do want a sand blaster, not everything needs to be shinny.

 

[CFLBob]

That's my problem, I'm not using a CNC, wish I were.

If I may plant a thought - the project of converting a manual mill to CNC is an interesting project itself. However, the First Law of just about everything in the universe applies, "there's no such thing as something for nothing." Jobs like the letters get easier, simple jobs like hogging out the four quadrants of the cover or cutting it to size can end up taking more time. Some jobs, like carving intricate stuff in metal, are about impossible without CNC. Those don't show up here because we're a Model Engine Makers' forum, not an everything forum.

 

[Robert Ritchie]

Once again you amaze me, really enjoy your work!

 

[Robert Ritchie]

Nice work Dnalot, enjoyed your post

 

[dnalot]

This time its flywheels, made from cast iron.

Fairly straight forward, turn on the lathe and then move to the mill to cut the spoke detail. I used a four jaw chuck to rough out the wheels. Then they were mounted to a mandrel with a key way. The final cuts were made truing up the wheel and reducing it to its final size and form. On the mill I removed the majority of material using a plunge cut and then ran the bit full depth along the cut line to smooth things up a bit. On the larger wheel I used a radius cutter to soften the edges and add a little detail.

After a little filing the center of the wheels were sandblasted and the outer rim was sanded smooth.

A little dip in a bucket with Parkerizing solution turned the wheels nice and dark. A little light oil dressing and the wheels are done.


Mark T

 

[dnalot]

Thanks your your comments. Thinking I will tackle the headers next.

Mark T

 

[johnmcc69]

Wow! That looks GREAT! Fantastic work.

John

 

[Robert Ritchie]

Once again you've amazed me with your flywheel work! Looks so sweet mounted on your motor, full speed ahead nice job.

 

[CFLBob]

I love the wood screws holding the work onto a table-saving fixture. I've got to copy that!

I've been using a 1/2" (thick) aluminum plate and tapping new #10-32 holes to mount things.

 

[gbritnell]

Very nicely done on the flywheels! Starting to look quite impressive!
gbritnell