2014 POTD Thread Archive

[bedwards]

Congrats on your first paid job (may there be many more).
Did you cut the 6mm bores at the split with a ballnose while the pieces where apart?

No, I didn't have one and I didn't have a small enough cutter to do it with my horizontal either. I chucked it longways in my 4 jaw and drilled it from the end. Had to flip it to drill from the other end as my bit was not long enough either. =[ Good thing is, the bores met. I also learned how to dial in a rectangular piece in a 4 jaw. The bore didn't have to be real smooth so I drilled it to size. I did have some problems with it galling even though I retracted the bit to remove chips and used Tap Majic as a lube. The parts were going in the engine room of a boat so the finish wasn't critical and the rough bore finish will actually help hold the cables better.


bedwards

 

[Walsheng]

Re: Cold saw

I'm trying to build a cold saw out of parts I had sitting around in the shop. Still need to rig up a switch, guard, and coolant.

Any suggestions?

I have been working in machine shops for 45 years. Worked in shops with machines run from line shafts with flat belts flapping all over the place and guards ripped off machines and piled in the corners.
And I must say, that is the scariest looking machine I have ever seen. :lmao:
You have GOT to post pictures after the guards are in place!

I do have one suggestion, make sure your insurance is up to date!

John

 

[jumps4]

I made a brass shaft coupling for a model I have been working on from time to time for years.
steve

http://www.hobby-machinist.com/showthread.php?t=19633

 

[Jimmy]

Re: Cold saw

I have been working in machine shops for 45 years. Worked in shops with machines run from line shafts with flat belts flapping all over the place and guards ripped off machines and piled in the corners.
And I must say, that is the scariest looking machine I have ever seen. :lmao:
You have GOT to post pictures after the guards are in place!

I do have one suggestion, make sure your insurance is up to date!

John

That's a valid point! However, that is just a test fit for the blade. That's an old wood blade I put on there just to see how it lined up. The guard and the flood coolant are still in the "to do" category, along with the switch and wiring. However, I did test it with that blade and it's not so scary when it's just turning 50 rpm. I remember an old John Wayne movie where they had a radial arm saw that was about a 24 inch with no guard. The guy running it used it to open his pack of cigarettes.

Have you ever seen a cold saw that was chain driven?

 

[Walsheng]

Re: Cold saw

That's a valid point! However, that is just a test fit for the blade. That's an old wood blade I put on there just to see how it lined up. The guard and the flood coolant are still in the "to do" category, along with the switch and wiring. However, I did test it with that blade and it's not so scary when it's just turning 50 rpm. I remember an old John Wayne movie where they had a radial arm saw that was about a 24 inch with no guard. The guy running it used it to open his pack of cigarettes.

Have you ever seen a cold saw that was chain driven?

I can't say I've seen a chain driven cold saw.
I have seen a home made saw mill with the blade directly run off the drive shaft of a cut in half pickup. There wasn't a guard or safety device withing 2 miles of that place. Put together and run by a guy with 8 fingers named Lucky!

I'm sure you will make it safe, just couldn't pass up a good old fashion ball busting.

John

 

[Marco Bernardini]

Finished assembling the gearbox on that Colchester Triumph that I'm repairing Got the drive pulley and belts back on and set the matrix clutch pressure. Time flies when you're having fun.

View attachment 76345

I'm trying to calculate how many Chinese lathes will be produced with the metal used for the "shell" of your Colchester…
:roflmao:

 

[savarin]

Hopefully swmbo will allow more shop time tomorow.

A couple of days before I could finish it (damn shopping)
Proof of concept, it works, faced off some 54mm dia steel bar.
It took a bit of time to centre it correctly so it didnt walk out the chuck.



The reason for this steady was for some large dia aluminium I will be machining soon and wanted the bearings to prevent the brass fingers from marking the surface of the aluminium.
The bearings marked the steel so I'm unsure what will happen to the aluminium, but, you cannot feel these marks, maybe its just polish.

 

[Marco Bernardini]

The bearings marked the steel so I'm unsure what will happen to the aluminium, but, you cannot feel these marks, maybe its just polish.

Try to double the bearings, placing two on them on both sides of every finger. More contact surface will reduce this drawback, perhaps.

 

[blaser.306]

A couple of days before I could finish it (damn shopping)
Proof of concept, it works, faced off some 54mm dia steel bar.
It took a bit of time to centre it correctly so it didnt walk out the chuck.

View attachment 76391

The reason for this steady was for some large dia aluminium I will be machining soon and wanted the bearings to prevent the brass fingers from marking the surface of the aluminium.
The bearings marked the steel so I'm unsure what will happen to the aluminium, but, you cannot feel these marks, maybe its just polish.

View attachment 76392

Just a thought , throwing it out there! Is it also possible that one of the "fingers" when set isn't absolutely perpendicular to the work? The picture almost appears as if one of the roller marks seems more narrow than the other , like one of the bearings is rubbing a bit more than rolling. Jus a thought as I could see it being fun to get everything lined up to run true at the same time.

 

[savarin]

Just a thought , throwing it out there! Is it also possible that one of the "fingers" when set isn't absolutely perpendicular to the work? The picture almost appears as if one of the roller marks seems more narrow than the other , like one of the bearings is rubbing a bit more than rolling. Jus a thought as I could see it being fun to get everything lined up to run true at the same time.

That is a very distinct possibility, it was a real bugger getting it all aligned due to the weight of the bar.
I just eyeballed it until it rolled ok just to test it out.
I was thinking that maybe letting the cross bar for the bearings float so they self align may be better. Might be worth experimenting here.
I also wondered if the fingers could be machined out to accept just one central bearing would be better.