[wildwhl]

Yes Keen, it is quieter and cooler as well. I made some guesstimates from your photos and seem to be close enough in this case. Time will tell. The next few weeks have several machine upgrades intermixed with some long/significant runs of material removal. Should be a good test.

Bill

[MichaelHenry]

I am thinking of producing a range of products like this for sale. But I am not sure of uptake numbers will make it worthwhile.

I'd be very interested in any purchasing any PCNC 1100 upgrades you come up. 15L lathe upgrades as well if you ever get one of those. If you are maintaining a contact list, please add me to it.

Mike

[keen]

I'd be very interested in any purchasing any PCNC 1100 upgrades you come up. 15L lathe upgrades as well if you ever get one of those. If you are maintaining a contact list, please add me to it.

Mike

Thanks for your vote of confidence Mike - Duly noted.

Keen

[kstrauss]

No 1100 here so I'm only interested in 770 stuff!

[lixingwen1987]

Luoyang Derun Precision Machine Tool Bearings co.,ltd.

Add: Derun technology area , huaxia road, New technology zone,,Luoyang, Henan

TEL：+86-0379-65112328

FAX: +86-0379-65112392

TEL:+86 17184625318

Email:[email protected]

Web:http://www.DRZbearing.cn
http://www.DRZbearing.com

[cobrakai]

Hi Bill. If you look at the photos, it is installed under the preload adjustment nut, which is under the pulley.

I have had mine on since 2007 and the bearings run quiet and do not heat up. In addition to providing constant bearing preload, it makes the task of setting the correct preload much less critical.

I am thinking of producing a range of products like this for sale. But I am not sure of uptake numbers will make it worthwhile.

EG. I imagine most folk will just run the spindle with less than ideal preload, and if they do enough miles, when it gets noisy and fails, worry about it then and build then. I get the feeling only a handful of users would bother making this improvement.

Keen

How did you make it? And what material exactly? I have the Tormach and a manual lathe. I think it's a great idea and since I'm rebuilding my spindle it makes a lot of sense to use this spring. Would you mind putting up some more info such as dimensions?

[keen]

I was thinking of supplying a kit - depending on demand. I will give that some thought.

Keen

[cobrakai]

I was thinking of supplying a kit - depending on demand. I will give that some thought.

Keen

I'm hoping to get my mill up and running by the weekend, so I've been exploring other options. What are your thoughts on this... not to take away from your sweet design, but I thought it might work.

I measured the ID to 35mm and OD to 61mm of the preload spacer, so we have that much room to play with for the spring spacer thing. I found an NSK document stating various preload forces for a 7007C bearing. PDF download | Catalogs and CAD drawings | NSK Global (see page 7 of 11, labeled 152/153) They state loads of 60, 120, 250, and 490 Newtons as Extra Light, Light, Medium, and Heavy, respectively. This translates to approximately 6, 12, 25, and 49 kg, or 13, 26, 55, and 108 lbs. I assume our Tormach will want something in the "medium" range, or even the "light" range if you're running at maximum RPM all the time, per Tormach's suggestion of less preload for higher speeds.

You can get a belleville spring washer https://www.mcmaster.com/#94065K85 that has a working force of 30lbs at a 0.68mm displacement. It would fit over the spindle with 0.5mm play and the outer portion could rest on the preload ring. Two could easily be stacked for 60lbs, and then as the system heats up it would reduce to somewhere between light and medium preload levels. Or does preload increase with heat?


I could be totally missing something, but perhaps it's worth a shot?

[keen]

I'm hoping to get my mill up and running by the weekend, so I've been exploring other options. What are your thoughts on this... not to take away from your sweet design, but I thought it might work.

I measured the ID to 35mm and OD to 61mm of the preload spacer, so we have that much room to play with for the spring spacer thing. I found an NSK document stating various preload forces for a 7007C bearing. PDF download | Catalogs and CAD drawings | NSK Global (see page 7 of 11, labeled 152/153) They state loads of 60, 120, 250, and 490 Newtons as Extra Light, Light, Medium, and Heavy, respectively. This translates to approximately 6, 12, 25, and 49 kg, or 13, 26, 55, and 108 lbs. I assume our Tormach will want something in the "medium" range, or even the "light" range if you're running at maximum RPM all the time, per Tormach's suggestion of less preload for higher speeds.

You can get a belleville spring washer https://www.mcmaster.com/#94065K85 that has a working force of 30lbs at a 0.68mm displacement. It would fit over the spindle with 0.5mm play and the outer portion could rest on the preload ring. Two could easily be stacked for 60lbs, and then as the system heats up it would reduce to somewhere between light and medium preload levels. Or does preload increase with heat?


I could be totally missing something, but perhaps it's worth a shot?

You are on the right path....good work. My spindle had been running quietly and sweet since I did the mode back in about 2007 or 2008. Those springs are 1.5 thick. One may be a little light. I guess two with only a slight compression might be about right. Try both at high revs and note the spindle warm up difference. If two is no hotter, go with that.

Cheers Keen