Making Things : Welding Vs Castings Vs Bolt Together Vs Glue

Bill- I don't think I'd have a problem building that the way you're proposing either. I made a tool block in exactly the same manner and for exactly the same reasons (no mill, marginal welding capabilities) and it's held up well. I would likely make two changes though: I don't think I'd use glue. For one, I always like to be able to take things apart later if I can, and for another, the glue (unless it is extremely hard) will likely be softer than the mating steel which can in some cases contribute to "wiggling" rather than prevent it. I would also try to run a pair of screws side by side if room allows rather than just a single row. I realize your sketch is more concept than build sheet, so perhaps you've already thought of that.

I do like the dowels as Jim suggested, because they fit so snugly they can stop a lot of shifting from getting started.

-frank

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I like Jim Dawsons idea of dowels also. Dowels will provide, as Mr. Dawson said, will provide shear load or minimize the side to side movement of the parts, assuming the dowels are fitted properly, and the screws, or better yet I think, through bolts will provide compression.

Vlad
 
Thanks for the responses.

Will have a go and see what happens

The advice given above has made me ponder upon another issue and I think other newbs might benefit as well so I will start another thread for Screws vs Dowels vs Taper Pins.
 
BillWood said:
I will start another thread for Screws vs Dowels vs Taper Pins.
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Good idea! It is related, but will be more searchable under a new title.
Looking forward to the discussion!

-brino
 
Modern adhesives are amazing, mind you. 3M has a body panel glue that is super effective, it makes a super strong join for lap joins and the like where welding sheet sections are too risky.
 
What I have not seen in this discussion is the answer to welding stresses in a welded fabrication; it is stress relieving, generally done by heating the weldment in an high temperature oven, to about 900 deg. F. for a period of time and allowing it to cool in the oven. Also it is done by a high frequency vibration process. The company that I apprenticed with back in the 1960s had one oven that was about 20 ft high and wide and 40 ft. long. Things such as oil refinery distillation towers were stress relieved in it. Most all weldments that were fabricated there were stress relieved, except things like bridge towers that did not require it. My personal favorite method for building machine parts and accessories is making the pattern, having a casting made and finishing it in an appropriate fashion, including a scraped finish when called for. Steel is a poor material for any machine part that slides, as it tends to gall up. Steel against cast iron is OK for such parts as gibs that do not need to move a lot, such as on a lathe compound rest, but generally, cast iron is better, especially if the gib is long and has to be scraped to fit and bearing.
 
Riaan said:
Modern adhesives are amazing, mind you. 3M has a body panel glue that is super effective, it makes a super strong join for lap joins and the like where welding sheet sections are too risky.
Click to expand...

An entire family of general aviation airplanes starting with the Yankee have used metal adhesives with a honeycomb structure between panels, starting in the 1960s: https://en.wikipedia.org/wiki/Grumman_American_AA-1

Most of the new aircraft rely heavily on bonding composite panels together for the large body structures...wings, fuselage, empennage, etc. Still lots of other production techniques used for smaller systems, like the hydraulics and electronics.

To what the OP originally asked, price out the steel needed for making that lathe attachment from pieces versus milling it out of one giant piece of billet. The cost of larger/longer tooling alone would cost as much or more than using your current tooling and buying multiple small pieces to fasten together.

What a great thread!
 
Out of spectrum here, in the down hole oilfield stuff I deal with everyday. Most everything is connected together with threads. All kinds of threads are used, Vee, Acme, Stub Acme, and all kinds of special threads. Some things get welded together. Some of the parts we use are castings of some sort. All kinds of heat treats and hardening methods are used, too.
Things I build in my home shop are primarily bolted together. Socket heat cap screws are my preference. I use very little welding in the things I do. But that is fixing to change with a couple of new toys (welding equipment) in my collection.
 
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