Thread: Myturn sl7

This is going to be an awesome thread looking forward for the future updates!!!!

Cooper

Here is my Sunday efforts.

More pics

I made a bit of a stuff up machining the leadscrew drive pulley

Can you explain how you made the error?

Hi Andre,
Thats a bugger. Where did you get your pulleys and belts from?

Cheers,
Ew

The bore is on the because I did it in the milling machine and the pulley must have been cocked in the vice, but I did set it up on parallels.

Andre
Anyone, & everyone can make an error.
Its just that we dont hear about it as much as the good stuff !
Good to see that you are still "into it".
How the shaper going is it operational yet?
regards
Bruce

Any reason why you didn't bore it in the lathe?

Is that last photo a picture of the drive pulley?

Is there any particular reason if that is the drive pulley in the photo why you removed the parallels?

Boring or enlargeing that hole with a slot drill will create a reasonable amount of down force,also holding it with an ali clamp is not a problem but the amount of down force will cause you fixture in most cases to slip or move slightly against the ground face of the vice,you can also get this same result effect with most jobs if the job is not held against a positive stop,sometimes if you need to machine this way a piece of paper or emery can aid in giving a little more friction and stopping the workpiece/fixture from moving.

As Bruce said we all make mistakes, it just gets less as you get better but you still make them.

If it helps any, I would have done that pulley in the 4 jaw on the lathe. I would have placed small blocks of aluminium on each jaw onto the pulley so it cleared the side flange.
This way you could use the dial indicator on the front flange and the face to true it up.

With you using grub screws you could bore it larger in the lathe, then press fit another piece of aluminium in, then bore it again to save it.
You might be better off using some locktite to help hold it in there.

Dave

Thanks for the replies guys, The pulleys I bought on Ebay for $12 with free postage so I will order another one, The reason I machined them in the mil is the last pulley which I machined in the lathe deformed a little bit. I was considering machining the new pulley in the mill again but hold it a 3 jaw chuck mounted to the table would this work

PS
Bruce the Shaper is still in bits I am currently soaking the parts in caustic soda in a hope to remove the grease and paint after that I just need to save the $$$$$ for new bearings and It will be up and running at my new shed in Sydney

Originally Posted by welder

Thanks for the replies guys, The pulleys I bought on Ebay for $12 with free postage so I will order another one, The reason I machined them in the mil is the last pulley which I machined in the lathe deformed a little bit. I was considering machining the new pulley in the mill again but hold it a 3 jaw chuck mounted to the table would this work

Use a 4 jaw on the lathe with a small boring bar, as suggested.

Any other way is just asking for more of the same trouble you've already experienced.

Mill or lathe makes no difference re the deformation issue, so why not use the lathe ?

The four jaw will cause less deformation than a three jaw as it's supported by an additional point.

Rob

Make sure you include those mistakes in your folio, any mistakes and evidence of those mistakes is evidence of constant evaluation for the folio. Markers love that stuff

At least it's only a $12 mistake, I would definitely do it in the lathe next time. With it spinning in the lathe chuck it's much easier to set it true.

If you really want to do it in the mill put a dial indicator in the spindle on the outside and the face of the pulley before cutting the bore also check the bore in case the factory has any errors between the outside and inside. This will make it true to the spindle so it should turn out spot on, but it's going to be fiddly to set up.

Dave