Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Other Topics => Topic started by: EL34 on October 07, 2010, 06:25:55 am
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My CNC operations all look like preschool compared to this project I have been following
The guy is making a pair of miniature V8 engines from scratch.
He is making everything
Block, oilpan, heads, pistons, crankshaft, manifoild, you name it
Hard to tell the scale until you see one held in his hand
check out the pics on this post
http://www.cambam.co.uk/forum/index.php?topic=1208.0
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wow, that's wild! What does he plan to power with it?
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Don't know
I did not read all the text on the 3 pages of post.
He may have mentioned that
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Yeah, some of the stuff folks are fabricating at home nowadays is amazing.
I have a crazy hankering to build a 1/3 scale RC Piper Cub one day, but from a kit so it doesn't really compare.
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> What does he plan to power with it?
If he'd scale the ports properly, that's about 8 Horsepower at 20K RPM. Large lawnmower, go-cart, small lawn tractor. Needs gear-down.
His ports are teeny, suggesting he knows what he is doing and doesn't feel it should turn 20K RPM. I'm eyeballing 4HP at 10K RPM, somewhere in there.
He may plan to run it at non-scale RPM, at 1,000-4,000 just like a 283. Crank won't break. He'll need a VERY mild camshaft to keep it lit at those speeds. Less than 2HP, which of course is more than enuff to run a table saw.
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The man I bought most of my tools from 30 some yrs ago when I was an apprentice tool and die maker was WAY into model building.
He built 1/8-scale 427 FE Ford motors for Ford execs.
He CAST his own blocks cranks and heads in his home FOUNDERY!
he also scaled his own tap and dies! so say if he wanted to tap a 1/4 scale 1" hole, he wouldn’t use a 1/4-20 tap. He used his 1/4-32 tap he custom ground.
Those running 427's were amazing, but they absolutely paled to his 1/16 sized railway system that circled his yard and even had crossing gates across his drive way. so very weird to see a 4-4-0 engine, coal car 4 passenger cars and caboose pull up to the side of his shop to get water.
He had taught steam engineering at the University of Toledo for 50 yrs before he died.
What was amazing is there was absolutely nothing digital, not even an indicator or calipers anywhere.
All was made with math and hand cranks.
Not me!
Today I finally pulled the trigger and bought some tooling for my shop.
I just purchased a CNC mill and router.
It is a conversion from a newer CMM. Its base and gantry are made of 6" thick granite, has 18" of X travel and 24" of Y and just under 8" of Z.
It is all ball screw and I am unsure of the motor types. The resolution is PHENOMENAL! .00001"
The Z plate contains a self contained mill head from a shop smith, a little underpowered, but I was using a 3/8" 2 flute end mill and removing .100 deep passes at .250 wide through CRS and it didn't bog down and left a VERY nice finish. Beside that is a porter cable trim router.
After I finish here, I'm ordering a 14" band saw capable of 12" re-saws, 9" oscillating spindle sander, 2hp dust collector, Air filtration unit, 24" box pan brake and what ever else I can get with the money I budgeted from Grizzly.
The guy who did the conversion lives about an hours drive north of me and as part of the deal, he'll teach me his bobcad and bobart programs and we'll build a 4th axis lathe out of some of his "junk"
We’ve designed a table that will allow me to reposition it on the carriage to let me machine up to 36" on the Y. That cost me a 4' x4' x .750 sheet of Kaiser Alum. Now I only have 5 left, 4 that is, after I machine the new table out of one.
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I read a PopMech article back in the 80's about a guy who built scale engines, both Ford and GM. AND he built screw-type roots blowers for them too - amazing stuff!
Hay Stingray, you may want to do a ballbar test on your machine once you get it set up, leveled, and settled. If you don't have the ballbar equipment (I am assuming not due to the high$$$ investment), it is WELL worth paying for - in accuracy and actual drive longevity once you get it tuned up based on the results. I've seen absolute loose as a goose crap machines tuned to hold some pretty decent tolerances without dancing to get there. You just need a tech that knows what he is doing. Sounds like a nice setup, those granite CMM gantry's are HEAVY! Lots of vibration damping there!
You will love BobCad, it is very intuitive and easy to learn. Some great features without having to learn something based on autolaugh or cadkey. What version will you be running? I've got an old instruction manual around here somewhere. If it is the same version, I'll send it to you.
Good luck!
Jim
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you may want to do a ballbar test on your machine once you get it set up, leveled, and settled. If you don't have the ballbar equipment (I am assuming not due to the high$$$ investment), it is WELL worth paying for - in accuracy and actual drive longevity once you get it tuned up based on the results.
Ball bar is huge $$$ (like $10k) - unless you know a cheap source?
My alternative was to cut 4" circles at a known depth at the furthest extent of the machine, then measure with calipers. No where near a ball bar test but a little on the cheaper side.
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Contact your local Mazak, Haas, Okuma, etc. dealer. Most of these guys will have a ball bar for their installs. Explain that you are on a budget and you just need some help. If they think you may be a future customer, most will be happy to send out a tech just to give them something to do if they are not busy - which may be the case right now. A few bucks to them is better than having a tech sweep the floor for nothing. Gotta wheel and deal! The Haas guys are usually very cool. If your budget can handle it, it is well worth the $$. Even if you had the $$ to buy one, you need to have the knowledge to interpret the data to know what to do - level, servos, backlash, square, etc. A guy who has had the training and some experience, can whip through in a very short time. I went through the Renishaw training with two of my techs years ago. I know quite a bit about the controls and those guys toasted me - because they live it every day.
Post some pics!
Jim
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I read a PopMech article back in the 80's about a guy who built scale engines, both Ford and GM. AND he built screw-type roots blowers for them too - amazing stuff!
I remember this guy appearing on TopGear a few years ago. He spent lord knows how long building a mini Ferrari. Incredible!
http://www.craftsmanshipmuseum.com/scerri.htm
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Ok, that Ferrari blows the doors off the mini V8's
The 16 cylinder motor by iteslf tops anything I have ever seen.
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http://www.youtube.com/watch?v=oNuzvSNO7X8 (http://www.youtube.com/watch?v=oNuzvSNO7X8)
Not at the level of that Ferrari, but interesting.