Sorry about the double post, trying to figure out how to delete it.
Last edited by dajt; 08-21-2018 at 06:38 AM. Reason: Double post.
How you hold these parts while milling if that isn't revealing trade secrets?
With some wax?!
My favorite way to do it, is to drill the holes first.How you hold these parts while milling if that isn't revealing trade secrets?
Then bolt the part down to a sacrificial plate.
The rest is gravy.
Three ways to hold those kinds of brackets:
1) Add 1/2" on each side of stock, and use tabs to hold them in a vise.
2) Thin painter's tape on a plate, thin painter's tape on the bottom of the stock, superglue the two tapes together. This lets you mill five sides without worrying about vise clearance.
3) Wax on the bottom. Heat everything, melting the wax between stock and plate. Cool everything to let it set. Once done, heat everything again to remove the part.
I do that a lot for smaller parts, but I don't like the poor finish of larger parts when trying to machine off the bottom after flipping. Once you get towards the end, the part is vibrating more than it would with tabs.
I guess you could cast Bismuth or something into the voids. Maybe even hot glue would work? That'd be worth trying!
popspipes: what method do you use to hold down those U/W shaped parts (second from bottom)? Do you mill one side, then flip and deck? If so how do you hold them for the decking ops?
thx,
Warren.
EDIT: just to clarify, I use bolts and tape, etc. but I'm curious not *how* to do it, but specifically popspipes how you do it?
Those parts are made with two programs the first drills all the holes in a sized piece of stock, the second is done when the first is bolted to the fixture to do the contours and slots, works well, all the parts are done the same way except for the small control arms, those are made and decked off the back side, done in a vise.
edit: the top and bottom surfaces are finished on a belt sander to remove surface scratches and dings etc.
Last edited by popspipes; 08-23-2018 at 12:12 PM.
mike sr
I am doing secondary machining on the Tormach of interlocking wood puzzle pieces. I am using a Sherline tooling plate with 4 small Sherline vices. The tooling plate is mounted above the big vices and is easily removable. Works fine for the light machining I am doing and lets me remove it and still use the big vices.
If you have thru holes or openings in a part imho they cam up and hold best using the drill and bolt down to plate method. There are always a number of options to get things done.
As a side note I follow a number of very talented people on the model engine machinist forum. Some of the writeups and work is well worth the time to read and understand. And I always see crazy cool ways to fixture stuff. One recent build the guy mounted the part to a plate from under the part bolting it into an area to be machined out later. He milled 80% of a very detailed 4 cylinder model engine block with that one mount/setup. "super clever stuff imho" Anyway there are builds of things like rolls Royce 12 cylinder engine with a super charger on that site for some decent reading.
Getting the first 80-90% is the easy part :-)
It's what you need to do once the part is a weird shape and not firmly attached to regular stock, that's the problem.
Soft Jaws is of course the go-to solution, but also super annoying when you're only making one of something ...
Spent yesterday afternoon making a pair of small enclosures for race car gear displays with my 440.
Video of them being made is also at
Sprints and hillclimbs. This is my own car
Those boxes are destined for a pair of Hyabusa powered single seaters. One's based on a Dallara F399, whilst the other is a purpose built DJ Firehawk DJ RaceCars: DJ Firehawks, bike engine powered hill climb cars Lots of fun, but I wish I could afford to go road racing though!
Nice!
Much smaller piece: Magnetic glasses holder.
This is an aluminum version, with two neodymium magnets pressed into it.
I have a piece of titanium that I will try on next.
Made on my 440 (power drawbar, flood coolant, full enclosure, PP2.)