Ready to give up on HSD

[gene]

I cut 3/4 plywood single pass at 13k 2 flute compression cutter with my spindle . i think its 6 or 7 yrs old

[Brady Watson]

Not real sure my options but, up for ideas!?

Yes. Ditch the HSD and buy a Colombo. A lot more spindle for a little more money. I rebuilt mine when it got a little noisy. I probably could have just left it alone. It's now 12yrs old and has at least 750,000 parts on it. SB sells them via the 'secret menu'.

-B

[mcmark]

One thing I never do is run my spindle at 18K. Actually most of what I do is 3K, 6K, or 10K depending on the material. The spindle nose is only slightly warm after a days use. Plus at a lower RPM, there's less airborne particles. The chip just falls to the table. My 2.2 HSD is about 6 or 7 years old and the previous owner wasn't anywhere near as kind to it as I am.

[rb99]

Sounds to me like you are using your spindle many more hours per day/week/month/year than the average SB owner, so your bearings are wearing out. They do wear out... I have read about Columbo spindle owners getting similar use between rebuilds as you. I think you need 2 spindles, so when 1 is getting new bearings/serviced you have the other to keep going with.

[jerry_stanek]

Is the fan working properly when you say it gets real hot

[Eppert]

Sorry I didn't state this in the last message, with the current RPM / feed speed, heat from the spindle really hasn't been much of an issue. I do think that I was creating excessive heat with my old configuration.

I would like to have the ability to run at a slower RPM and lower the feed speed a bit BUT, of course time is money. I am currently working 12 ~ 16 hrs a day 7 days a week and turn away customers on a regular basis (what a terrible problem to have right ) I truly need to purchase 2 more CNC's but, that isn't in the cards after the recent move. I have a local rep for Columbo but, I will have Shopbot take the first crack at it.

I have no issues with having to replace bearings (I came from the moulding industry and am well trained in replacing Thrust bearings) I understand the fact a bearing is a wearable item but, Anyone ever found someone that can / will rebuild an HSD for a DECENT price?

[Eppert]

Is the fan working properly when you say it gets real hot

Yes it is and I keep it cleaned off on a regular basis. I would love to be able to say (facepalm) no but, I like to create way better challenges for the fine folks here on the forum

[Brady Watson]

These little spindles are throw aways, sorry to say. They don't offer rebuilds on them because they are just like your blender. It costs more to fix and is more trouble than it's worth. Just go out an get a new one. Frustrating I know, but reality nonetheless. Who is going to pay $500 for bearings, plus 4 to 6hrs shop time on top of that, plus supplies on a spindle that costs less to just buy?

I would still get a Colombo. They *seem* to outlast the HSDs about 3:1 from what I have seen on the road. Of course your results may vary.

-B

[Gary Campbell]

Troy...
A couple other items to consider:

The HSD spindles come with an "S6" service or duty cycle AND a percentage. Percentages run 40, 50, 60.... %, etc. Your manual will have the proper number for your spindle.

S6 means that the spindle can be run continuous, with the load vs unloaded mixed at the given percentage. For example 60% would be periods of load 60% of the time, the other 40 would have to be run unloaded to ensure it wouldnt over heat. IF, and I say If because I dont have the AMP data to support your loading, you are running extended times with the tool loaded, your solution would be to use a higher HP spindle, which would reduce the load on the spindle motor.

My experience teills me that you are not oveloading the spindle, due to your listed feed and rpm settings. What I believe could be happening is that you are running the rpm too high, creating heat, and that heat is cooking the bottom bearings due to extended run times.

The best (and cheapest) test would be to use a digital thermometer to monitor your bit temperature over a days cutting. If the bit gets over 135 degrees, the chipload is too light. Light chiploads do not remove enought heat from the bit, dull it faster, and create heat due to flute rubbing in the cut where material has been removed. This gets worse as cutting continues.

I have not tested this with your bits and material, but I would bet that a 5/16 bit at 6 ips would run best somewhare around 13K rpm, when sharp. Excess rpm can heat up, and therefore dull a bit in a few minutes. How many times a day do you change them? Are they new or resharps?

BTW, Brady is correct, the higher priced Columbos do have a more expensive bearing set, they also have a heavier bearing housing that dissapates heat faster. A pay me now, or pay me later, that only a few with extreme cut times ever have to learn.

Hope this helps.

[Eppert]

Gary,
Yes you are right it is an S6. However 99.9% of my runs are around 1.5 minutes to 1-2 minutes load ~ unload.
From all of the help that I have received via email, phone calls and the forum, it appears all the veterans have similar advise which is to lesson the RPM's (Like you had just said) I do, however, wonder if I may want to increase feed speed, lesson the RPM's a bit and just go 2 passes. It doesn't appear to cost me much time but, may save me a bit of money.

Just for poops and giggles, I am going to replace the ceramic bearings in one of my HSD paper weights with a "standard" bearing just as an emergency back-up / trial. Curiosity has finally gotten the best of me with ceramic bearings.

On the temp monitor All I have done so far is a hillbilly test. (grabbed with my fingers ) never have had one of them close to burning me. And no it wasn't spinning for the smartallicks out there