HSD, bearings and drilling...

[harryball]

I revisit this only because I see this topic pop up on the forum regularly. After today, my fears of drilling with my HSD spindle are officially laid to rest.

I took the opportunity to stop by the HSD booth at the IWF and asked in person "Will using my spindle for drilling damage the bearings?" The factory rep seemed puzzled by the question and I clarified about drilling shelf pin holes, predrills etc... I told him I'd heard that using the spindle for drilling would shorten the bearing life if not destroy them. He asked where I had heard such a thing. He assured me the spindle was designed to take pressure while drilling. Not deterred I pressed the issue.

After bringing in a second rep and then calling an engineer, lest there be any doubt as to the ability of the HSD spindle to withstand "drilling" pressure the 4HP spindle (my flavor) is used in a mortiser (yes, a MORTISER) which spends its entire life under "drilling" pressure. There is no danger of destroying your bearings just because you drill a bunch of shelf pin holes. Abusing it is a different story as with anything. High pressure drilling with inappropriate bits of course WILL damage bearings. Not all bits are designed to bore straight down and should never be used in that manner as they can start fires as well. It still sounded as though burning your shop down would be a greater danger than destroying your bearings.

While I'm sure there will be someone of a different opinion (which is fine) I for one am of the opinion that drilling pressure will not harm my spindle.

/RB

[gpari]

It says in my Colombo manual that the spindle NOT be used for excessive drilling and all cuts should be entered at a certain angle.

I'm sure all spindles are designed differently. Just need to know your tools and their limitations.

Good info for all the HSD owners...

Gabe

[harryball]

Exactly Gabe, that's why I said my HSD. I was surprised to learn the spindle is used in a mortiser. I figure if it can survive mortising, it can certainly survive drilling shelf pin holes.

Don't get me wrong, for you production guys running full tilt, air drills and such are a good solution and anytime your spindle is not running it's not wearing. For me, it's nice to know I can stop worrying about reducing my spindle bearing's life by years by drilling a few holes.

/RB

[jharmon]

Very interesting. Thanks for the info.

FYI - I have the HSD 2.2HP spindle and when I saw somewhere about this topic I sent an inquiry to shopbot support and this was the reply:

********** *

You are always going to do some amount of plunging with a spindle, but the bearings are primarily designed for side loading. If you occasionally drill some holes it is not a problem. If you are going do a lot of line boring on a regular basis then it is better to get the air drill.

*********&# 42;

Given that I made a bracket and mounted a die grinder for my drilling needs since there was no way I could supply enough SCFM for the air drill.


33485.jpg

Only trouble now is no dust collection for it!

Jim

[rhfurniture]

I think you need to check on this with the spindle manufacturer, as it all depends on the type of bearings used in the bottom of the spindle. I know my Fimec and probably the HSD's run up to 18k and have double angular thrust steel bearings which are of course fine with drilling - they are designed for Z thrust. Others, maybe in spindles running to 24k may have ceramic bearings that could be vulnerable. On the Fimec website HM motors are fine for Z thrust, while HT (designed for saws) are not.


R.

[scottbot]

Thanks for clarifying that.
I've got a 4HP HSD as well and want to use it to drill a bunch of holes for a dust collection grid on my bench top.
Now I know I can do it without worrying about killing the bearings.

[bill_lumley]

Jim , don't worry about dust collecting with drilling . It is chips you are creating and they mostly just fall on the material near the hole . I have the air drill and the lack of dust collection is not an issue . I drill first and then cut and in the cutting pass' much of the drilling debris is picked up anyway as the lowered spindle pass' over it . The SCFM issue is not a bit worry . I drill shelf holes and at most I have to have to split my drilling into two files to allow the compressor to recharge . I have a 'wheelbarrow' style PC compressor that works fine as long as I am under about 100 holes per file . A bigger tank would help but I don't need to go there yet .

Bill

P.S. How do you plunge that drill as it appears attached to the spindle ....

[jharmon]

Hi Bill,

I have the die grinder affixed to the primary Z and I plunge with MZ.

I set this up to create mosaics. These things have thousands of holes. Works great for that.


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33501.jpg

Jim

[pappybaynes]

Jim,
Did you make the bracket to hold the die grinder?
Thanks,
Dick

[jharmon]

Hi Dick,

I designed it and then sent it out to a local machine shop for fabrication. I am brand new to ShopBot and don't feel confident enough to be able to do an aluminum project yet. Bracket 2.0 will most likely be cut on the 'Bot though!

Jim