Another Lathe ? Thread

[0011001100]

Looks good. Having gotten my lathe last summer as well I can say I thoroughly don't regret it. Where are you sourcing your graphite from? And how is the vac setup working for you? I haven't touched graphite yet because of the mess it makes.

 

[dhbarr]

Finally, I hope to start turning 38-mm nozzles for characterizing some propellant. Tell me what’s wrong with #14 through 19 nozzles for a Kn of 161 to 298 for two grains at 2.25” long X 1.25” OD X 0.5 cores. Just seems like lots of nozzles.

Do a #16 first, run some tests; then you should have a good idea whether to go up or down.

 

[NorthwoodsRockets]

Looks good. Having gotten my lathe last summer as well I can say I thoroughly don't regret it. Where are you sourcing your graphite from? And how is the vac setup working for you? I haven't touched graphite yet because of the mess it makes.

I got my graphite from Dan Patell last summer, but he got it from the Graphite Store.

Granted I was only working on a 29-mm nozzle, but I couldn't have been happier with how the vacuum graphite pre-filter worked. Someone posted a link this link: https://www.bing.com/videos/search?...36FB645D334E643B66C536F&view=detail&FORM=VIRE. It cost me $8, a bucket, and piece of pvc pipe I had lying around. However, I have seen a recommendation for the Dust Deputy.

 

[prfesser]

There is a method for leveling a lathe...actually, just for insuring that the bed is parallel to the spindle axis:
https://www.practicalmachinist.com/vb/general/rollies-dads-method-174787/
Best -- Terr

 

[NorthwoodsRockets]

Do a #16 first, run some tests; then you should have a good idea whether to go up or down.

Thanks. So, does it make sense for me to have #15 through 19 (maybe just 18) so I can go up or down two from 16? OR, do I need a broader range? I'm going an hour north to test motors with Al where it will be easier to trouble shoot if things don't go as planned. So, I'd like to be prepared (not to mention having been a Boy Scout ages ago.)

 

[TimothyG]

There is a method for leveling a lathe...actually, just for insuring that the bed is parallel to the spindle axis:
https://www.practicalmachinist.com/vb/general/rollies-dads-method-174787/
Best -- Terr

Ignoring proper lathe set up is responsible for the majority of lathe damage I've seen over the last 13 years of working with lathes. Nicest cuts I've ever seen on a lath are from a base modle grizzly that a gunsmith had taken weeks to set up after he built a proper support for the base into the foundation and cast the feet in concrete. It was so level you could do some tricks with a laser along the length of his ways. This allowed him to run tighter bearings along with a few other upgrades. He could turn a 28" barrel without a follow support, between centers while turning down the contour. Leveling and rigidity are overlooked way to often by hobbyists.

 

[dhbarr]

Thanks. So, does it make sense for me to have #15 through 19 (maybe just 18) so I can go up or down two from 16? OR, do I need a broader range? I'm going an hour north to test motors with Al where it will be easier to trouble shoot if things don't go as planned. So, I'd like to be prepared (not to mention having been a Boy Scout ages ago.)

S
Ahh, being away from your test site makes a difference, yeah. No need to do every size was my point

You should be able to get very good numbers from, for instance, only doing every third size. What does 13/16/19 sim as?