2021 POTD Thread Archive

[Winegrower]

Low temperature alloys are also used to support/backup features of a machined part too thin to withstand tool pressure without deformation.

Huh, learned another thing today!

 

[woodchucker]

why not just use sand? Rather than having to melt the cerrobend twice?

 

[Tio Loco]

More welding practice... a new base for my aged, still being resurrected, CalKing horizontal band saw.

Cut up the last of my stash of lab table legs (see https://www.hobby-machinist.com/thr...in-your-shop-today.67833/page-511#post-886970) and reconfigured into a usable, human height base that is actually mobile.

While I was at it, re-routed the a/c cord to the bottom of the saw, and out the back side so I'm not constantly tripping on it while trying to use the it. Still want to make a catch tray for the saw poop, but that may be a 3d printer job.

 

[rwm]

why not just use sand? Rather than having to melt the cerrobend twice?

I have tried sand with poor results (kinking.) The Cerrobend melts in boiling water so it is not a big deal to melt/remove it. I'll give it a shot next opportunity.
Robert

 

[extropic]

I have tried sand with poor results (kinking.) The Cerrobend melts in boiling water so it is not a big deal to melt/remove it. I'll give it a shot next opportunity.
Robert

Actually, the melting point is 117° F.

My bad. Cerrolow 117 melting point is 117° F. The melting point of Cerrobend is 158° F (higher than most residential water heaters).

I think most home hot water heaters are set higher than that so the risk of a burn injury is greatly reduced.

Even a hair dryer will serve.

Wear the proper PPE and stay safe. I'm harping on the PPE because I've had a very close call myself and I learned my lesson. Please heed the advice.

 

[johnnyc14]

I have been making and selling some parts from 1/2" CRS rod that have a rectangular feature . Using a 5C collet block in the mill vise along with a vise stop makes consistent set up fast and easy. I decided to add a second collet block to my set up so the milling on 2 parts could be done with one set up. I previously bought a collet block set from KBC that contains a square and a hex block as well as the nuts to mount the collets into the blocks. I just ordered another square block of the same part number from KBC to match the one I already had. After it arrived I quickly found out that the outside dimensions are different than the one I had. I called KBC and asked that they check the others they had in stock and sure enough they were all inconsistent in size. The collet is dead center in the block but outside dimensions on the 2 I have vary by .010" from each other.





With the 2 blocks mounted side by side in the vise the rod is .005" higher in one of them.





The blocks are very hard so correcting this in the mill was not an option and I don't have a surface grinder. I made up a stepped plate to fit under the 2 blocks. One block sit on a pad that is .005" higher than the other. The overall width of the plate is .010" less in width than the 2 collet blocks side by side.





Running the indicator over both of then now shows the same height with a minimum amount of work. I have engraved marks on the plate and the thinner block so it's easy to orient them correctly.





This is my vise stop set up.



Just another example of how import tooling can be disappointing.

 

[brino]

Just another example of how import tooling can be disappointing.

...but also an example of a great work-around for such issues!

Well done!
-brino

 

[pontiac428]

Matched pair cost extra. Cucumber water for customers only!

 

[Doug Gray]

Very well thought out, effective solution.

 

[Hawkeye]

I've had good results with sand, but that was on a much larger tube (3/4") and the sand had to be packed in VERY tightly, with both ends crimped over. For such thin tubing, the sand would have to be very fine.