Spindle wear & tear

[beacon14]

I've been using my HSD 2.2 HP spindle for a little over a year and a half, and I suppose I push it pretty hard compared to some. I've probably cut around 1,000 sheets of material, mostly melamine, some plywood and MDF, plus hours of solid wood machining. I may have even banged into a few things over that time but would rather not get into specifics.

Lately I noticed a slight change to the sound produced when the spindle was first turned on. Once warmed up it sounded and cut fine and was still producing more than acceptable cuts. But I've always wondered in the back of my mind how many sheets can I expect to get from this small spindle?

So I was going away for 2 weeks and figured it would be a perfect time to send the spindle in for a bearing replacement/preventive maintenance. Not being able to locate any kind of US based service for HSD I sent it to Precision Drive Systems in North Carolina. They sell and service Columbo spindles but their web site advertises servicing all makes and models and a phone call verified they would work on my unit.

Apparently they had a very hard time getting the case open - they spent several days alternating between the freezer and the oven (?!?) to get the locking ring/retaining ring/some similar gizmo to come off. Then they sent me a quote for $700 to replace the bearings, which I approved.

Finally heard back from them this morning and he tells me the spindle is "dead". They've put two sets of bearings in and can't get it to run without overheating! I told him I was a little shocked since the spindle was working just fine when I sent it to him for preventative maintenance.

He (the manager) seemed a little surprised to hear that it was working when it arrived (the paperwork clearly stated "bearing replacement/preventative maintenance"). He said he'd tell the tech's to give it one more try to get it working and get back to me tomorrow.

So if you're still with me, do they owe me a working spindle? Had I basically used that one up? Is it normal to have so much trouble dismantling or servicing a spindle? I thought I was doing the right thing by sending it out before it self-destructed. I know nothing lasts forever but I thought replacing the bearings would put it back like new.

I'm keeping an open mind since he still has to get back to me but just wondering what people's thoughts are. Meanwhile it looks like I'll be putting the old PC back on the machine to get a few parts cut this weekend until this gets sorted out.

[coach]

David,
they spent several days alternating between the freezer and the oven (?!?)
That would be a concern for me. Can you actually put a spindle in the oven? What other abuse did it take?
I would get a detailed bill and see if they put the oven and freezer operations in writing. Then I would figure they wrecked it.
If you heat metal it changes the structure and I bet it even changed the actual dimensions of the case. Maybe not much but maybe enough...(how hot I would wonder?)...I welded aircraft engine components for years and I know heat treat operations were critical.
David

[bcammack]

Wow. That's not the sort of story I expect to hear about PDS.

Did ShopBot have no recommendations regarding a service center for the HSD spindle? If they're offering them on their product, I'd be shocked if they didn't have support info on them at least to the point of telling you where to have them repaired.

[beacon14]

He did not actually say oven, but he did say "freezer", "heat up" and "several days going back and forth". I guess that's a trick they use to get stuck parts loose without beating on them. I suspect they also put it in a vice and beat on it to some extent. He mentioned something about "milling down some high spots" on the bearing seating surface, and that there might still be a couple of flat spots from when they took it apart.

I had called ShopBot and they said they just sell them, I'd have to go to the manufacturer for service. I did a web search but HSD is in Italy and I could not find any USA based support or authorized service.

Anybody at the show this weekend care to stop by HSD and ask them where to get service in the US?

[Brady Watson]

David,
I don't let anyone work on my spindle (after hearing numerous horror stories from others in the field). I did get some assistance from a friend that rebuilds industrial motors for a living, but other than this, I rebuilt my Colombo myself. I feel that most 'mechanics' these days really don't love what they do...and I don't want that energy (or carelessness) going into the heart of my main money making machine.

You can get parts for your HSD (AND service!) from http://www.ekstromcarlson.com/ (Click here (http://www.ekstromcarlson.com/hsdrepair.htm) for HSD page) I bought my Colombo bearings from them in the past. I'd put money on the small top bearing being the noisy culprit with your spindle. The 2 bottom bearings are usually OK. The top bearing is nothing fancy - It's most likely an ABEC-7 version of a GM alternator bearing, like the one in my Colombo.

Going forward, if you need another brain to sort things out & make a decision, give me a ring. While there are some important things that you have to pay attention to (like correctly aligning the bottom bearing pair to each other) - it's ain't rocket science. I'm confident that YOU can do what needs to be done.

-B

[harryball]

On this topic... is it better to proactively replace bearings or just wait until they begin failing? Not flying apart but cuts not acceptable and play in the bearings.

Are there any numbers on how many hours a spindle can cut?

My 4 HP HSD has begun to sound slightly different but otherwise runs without a problem. Cuts are good, no play, solid running.

/RB

[tmerrill]

Robert,
I don't have any experience with spindles, but after spending my career in maintenance at power plants, one of the worst things you can do is let electric motor bearing go until failure. To predict failure, the electric utilities have implemented a very comprehensive preventive maintenance program consisting of periodic vibration and sound measurements with computer analysis - far beyond what a ShopBot owner could do. So in my opinion it is best to be proactive. I think David did excellent by looking ahead, seeing a two week window and arranging for his service.

I might add that as any bearing fails, you loose tolerances and gain friction and heat, which increases the rate of failure. To the tolerances that spindles are constructed, I would want to be very proactive in getting one serviced. I very much agree with Brady - if you can do it yourself you are going to get a better job. I could tell you many similar stories as David's, some with shops we had done business with for years, where the skilled people moved on or retired, their replacements lacked skill and caring, and all of a sudden we had a multi-thousand dollar motor that was junk.

One recommendation would be to obain a stethoscope designed for listening to machinery. Grainger and MSC used to carry them as possibly Harbor Freight and other smaller suppliers would. Find out where on your spindle you can hear the bearings best. Mark these places with small pieces of electrical tape and get into the habit of listening to your spindle on a routine basis. Try to keep the conditions the same, such as rpm and operating time. You will be amazed at what you can hear and should be able to pick up on increased noise pretty well.

Tim

[tmerrill]

David,

Found this reference for HSD USA. Not sure if you were able to find it or if it helps at all at this time.


3764 SW, 30th Avenue
33312 Fort Lauderdale
Hollywood - Florida, USA
Phone +1 954 5871991
www.hsdusa.com (http://www.hsdusa.com)
supporthsdusa@hsdusa.com (mailto:supporthsdusa@hsdusa.com)

[ron brown]

It is far better to change bearings a bit early. Bearings will start heating a long time before showing any other signs of wear, in my experience.

As Brady said it isn't rocket science. I will also say some folks are just not mechanically inclined. I've never had a problem or fear of tearing into machinery. I have family members who have trouble changing the oil ... at the quick lube shop down the street.

Ron

[beacon14]

Well, miracles do happen. He called me back to tell me that somehow they were able to get it running within spec, and it's on it's way back to me. He said they had ways to fix things within a few microns, and they did some more tweaking of some sort. I'm certainly relieved.

Brady, thanks for offering to help but I'm not sure I want to get into that kind of repair. I've always been better at engineering than mechanics. I can usually figure out why something isn't working but I've always considered car repairs (for instance) way beyond my pay scale. Without at least some specialized equipment, considerable knowhow, and reasonable experience, or at least "a friend that rebuilds industrial motors for a living" I think it's more cost-effective for me to outsource this sort of maintenance and repairs.

Tim, thanks for the link, I probably saw that page and missed it, it's in pretty small print. I'll call them first next time.

Just to close the loop, the guy I spoke with confirmed that the upper bearing was "half burned up" and had apparently overheated at some point. I do have a problem with my cooling fan sticking and not turning on until I poke it with something. On occasion I've cut a couple of sheets before remembering to check it. Hmmm...

Thanks for all the input. I do think preventative maintenance is worthwhile (I take the car to Jiffy-Lube every once in a while). I also think in a perfect world I'd be using a larger spindle to do what I do, but I'm limited partly by the electrical requirements. I think I'll start putting a couple of bucks in a jar for each sheet I cut, to get ready for the next time.

[Brady Watson]

David,
Make sure they hook you up with a new cooling fan. It should not be any more than $80...or you can certainly source one yourself. I'd check the cooling fan power supply as well to make sure it is 'runnin steady' while the fan is spinning.

Glad you got it sorted out!

-B

[knight_toolworks]

the fans are only about 18.00 if you just buy the fan and run the wires. the fan and the housing from shopbot is about 200.00 when I called. it took a bit to take it apart but you just have to solder two wires. though I can't find one for 18.00 right now here is one
http://cgi.ebay.com/Tubeaxial-8300-DC-80x32mm-24v-6-0w-Fan-NEW-8314H_W0QQitemZ390063866810QQcmdZViewItemQQptZLH_D efaultDomain_0?hash=item5ad19e43ba&_trksid=p3286.m 20.l1116

[smreish]

http://www.northsi.com

I wanted to chime in my 2 cents. I am a Mechmate owner and wanted to offer a little past experience with this exact issue.

A very good spindle repair shop is the above link. They service all sizes and brands you can think of....up to 100's of HP.
They also sell "as-is" and refurbished models at a very reduced cost.
I purchased about 1.5 years ago a refurb 2.2Kw Columbo for my Multicam for 800.00 - no core.

Just another very dependable source for repair here in the states.

Good luck

Sean

PS.
I purchased my most recent spindle from PDS and received excellent service and technician-on-the-phone help. I would happily use PDS again.

[beacon14]

I've been waiting to reply until I had a chance to hook the spindle back up. Finally did so today and hit the start button while holding my breath. I was surprised how much different it sounds - much louder and courser. I didn't need to cut anything so I didn't bother to warm it up, just turned it on for a minute at 9,000 RPM to check it out. I also noticed when I turned it off that it came to a stop within a few rotations, seems like it used to run for 20 or 30 seconds before coming to a stop.

Should I be concerned? Is it the new grease and shielded bearings? I don't remember it ever being that loud.

[tmerrill]

David,
I don't think you are going to like the answer. I can't think of any situation where an electric motor should sound worst and have that quick of a coast down following a competent overhaul.

Did they warranty their work? I would get in touch with them immediately, state you are totally unsatisfied with their work and ask them how they will resolve it. The longer you wait, the more it weakens your case.

Just my opinion.

Tim

[bleeth]

David: I truly hope you get a proper resolution to this as there is little doubt in my mind that the repair job was not up to par.
If not and you end up having to bite the bullet I would suggest going to a much stronger spindle for the amount of cutting you do. Also, if you haven't in the past, make sure you operate it with warm up and cool down cycles. It is worth it in the long run. Next time, don't take your Ford to the Chevy dealer for work!!
I don't really think the folks at PDS are bad, but rather didn't really know the HSD that well. It certainly seems they owe you a proper running equivalent spindle.
I was looking at their new Manual quick change spindle at the show and it looks like it could be a good choice for a strong spindle with easier bit change and depth registration.
I'm surprised that SB doesn't have a list, however short it may be, of qualified HSD repair facilities considering how many they sell.
Sorry I didn't see this thread before the show. I would have been glad to bird-dog some info for you.

[Brady Watson]

David,
Your spindle will sound louder than it was before, if the bearings were replaced with ceramics. The original bearings are steel and tend to run quieter.

The motor shaft should spin freely by hand, without any noticable drag. It should not take 30 seconds to wind down, unless you disconnect power to the VFD and it's internal capacitor allows it to continue rotating until it is completely de-energized.

I understand about being overly critical about the spindle. It should be fine. Every rebuild spindle I have heard, whether mine or otherwise, has been louder than it was when new. I have a new 5HP Colombo & my original rebuilt 5HP Colombo...the new one sounds like silk. The rebuilt one sounds a bit louder. Both function perfectly, give beautiful cutting results and run within thier normal temperature range.

You'll get accustomed to the new sound in no time...

-B

[beacon14]

Thanks for the feedback you guys. Got back too late to call them today, I will call in the morning and see what they have to say about it.

What do these numbers tell you about the bearings they list on the invoice:

Bearing 7007 TGP-4 ($350)
Bearing 6202 ZTHB Barden ($35)

[tmerrill]

This page will give you info on the second bearing listed:

http://www.gmnbt.com/spindlebearings_selection.htm?kc=5wgGQ&tsid=google ppc&ex=41888d-eep549-tr1u1r&gclid=CIHAtY_t9psCFQZfswodQinPAQ

The first bearing appears to be an SKF series, but if so I can't find specific info on their website. Will keep looking.

Tim

[beacon14]

Thanks again for all the insight. I spoke with Alan at PDS, he said he was not concerned about the noise as long as the spindle did not overheat. He assured me that the repair has a 6 month warranty and that they stand behind their work.

So I went ahead and cut 9 sheets of melamine yesterday, and, well, it cut just like it did before. Noise during cutting was about the same as before even though the spindle by itself is still louder. After cutting a sheet, the nose of the housing was quite warm, almost hot, but I could hold my fingers against it without major discomfort. So I guess I have to consider that the unit is back in service, and I will keep an eye and ear on it for anything unusual or premature wear.

As for warm-up and cool-down periods, I always warm up (2 minutes each at 9K, 11-12K, and 14K), but I don't bother to do a cool-down period since the fan runs continuously and the housing cools down quickly after use. The spindle will be off for anywhere from 4-10 minutes between sheets (occasionally longer, like during lunch) but usually runs a few minutes before cutting the next sheet while the drilling is being done.

[harryball]

David has me hearing sounds now... :-)

OK, I've decided to replace the bearings in my spindle during the next lull. That may be another several weeks but I can cut ahead to make sure I have enough parts for 30 or so bat houses.

Anyway...

Was a decision made on where the best place for service is for the HSD (mine is the 4HP) spindles?

Why ceramic bearings? I know some of the reasons but does the ceramic take the plunge loads as well as the regular bearings?

If ceramic bearings are $700 or so (assuming the price is about the same for a 4HP) then does anyone know what a set of regular bearings would run?

Lastly I'm considering doing the job myself. I've torn apart and repaired/reassembled things much more complicated and precise than a spindle so I don't see why I couldn't do it. Anyone know a good source of parts and are they sold in kits or will I need to purchase each bearing? Is there a parts list somewhere?

/RB

[rhfurniture]

Very informative on the subject of DIY:
http://www.mechmate.com/forums/showthread.php?t=797
R

[bcammack]

I don't know if comparing Colombo bearing prices to HSD bearing prices is comparing apples to oranges, but the non-ceramic bearings for our 5HP Colombo spindle are approximately $400, delivered from Alpine Bearings. Just to give a ballpark cost amount.

[andrea]

Hello all,

I am Italian and i am working for HSD marketing department. I am doing a bench mark about HSD Service and postsale service. Bu the way my colleague Giorgio from Service dept can help you for any HSD question you may need.
marco.marchionni@hsd.it (mailto:marco.marchionni@hsd.it)

[wberminio]

Grazie!


Erminio

[harryball]

I emailed HSD, here is the response...

-----
Good morning Robert,

I’m sorry I can not help on your inquiry, HSD USA do not offer a rebuild program for the type of spindle mounted on your ShopBot machine, the reason we do not offer to repair the collets spindles is not price effective, the cost of the bearing plus labor time for the repair will amount to the same price for a new spindle.

Thank for contacting HSD best regards

Luca.

HSD USA
----

I have to admit personally I would not spend a chance on $800 with early problems vs. a new $1700 head. I would either run it until it caused problems then replace or if the bearings were available and $300 or less I'd give it a shot myself.

I guess my other option would be to sell my spindle head with full disclosure and buy another one. Though I wonder what it would bring. It would probably last an occasional user a very long time.

Mine is doing fine right now, just the pitch has changed a bit, not overheating nor any runout. I was thinking along David's lines of "preventative maintenance".

/RB

[navigator7]

@ David...if you are still watching this thread....

Do you know if any of the bearing inner races on your spindle spun on the shaft?

[beacon14]

Chuck, I'm afraid I don't even know what your question means let alone know the answer.

The spindle is still in service and has cut without mishap since the rebuild. (I know, I shouldn't have said that, especially with 45 sheets cued up to be cut this week)

[navigator7]

Richard,
I'll take that as a compliment intended or not.
Bearings have what's called B-10 life.
Many different types of bearings can go into the same housing but all may have a different B-10 life and part numbers to match.
The higher the B-10 life the higher the price.

The classic conversation at a NAPA counter: "Do you want the $5.37 bearing or the $52.29 bearing?"
"What's the difference?"
"Well they both fit, one is just more expensive"
"Ok, I'll take the $5.37 bearing. Give me two just in case."

Me personally... I'd buy the best bearing I could buy if it's on a steering axle but might go cheap on a wheelbarrow.

The difference is B-10 life and it costs money.

I've replaced my fair share of bearings in my career. I don't understand the use of heating an entire unit or cooling an entire unit...but I do under stand the use of heat and cold.

I'm sure you know what a bearing looks like. There is an inner race and an outer race. The inner race is often thousandths smaller than the shaft it is pressed onto. Therefore the shaft is cooled or shrunk and the bearing heated. Done properly the new bearing slides right on and is quickly locked in place as the temps normalize.

My thoughts while reading the thread was the potential the inner race spun on the output shaft. Or ...for that matter it could be the outer race spinning as well?

I've got no experience with your spindle type but bearings are bearings. What I'm describing has happened to all the equipment I've ever worked on or repaired.

Noise tells you something...and the more noise the more problems and heat.

If it's cutting fine....why not buy a temp gun and keep and eye on it and track the temps??

Work means heat so if your spindle is working it creates heat.
The question is ...what is normal heat?
Again...not experienced with CNC spindles I'd say if you can't hold your fingers on the bearing housing it too hot and work is being spent on driving the bearing or the tool is overloaded.

There is also something known as pre-load. Usually there is an output bearing or a group of output bearings that are pressed onto the shaft. The end is a tapered roller bearing. A washer and nut is used to tighten or "pre-load" the assembly.
Not unlike the steering axle on your car.

Too loose and heat and noise are created. Too tight excess heat and noise is created.

Just some ideas to make your butterflies feel better in the AM.
;-)

One thing is for sure....who can argue with results? If you are producing parts and not scrap...why fix anything??
;-)

[beacon14]

If you are producing parts and not scrap...why fix anything??

That's my plan for the moment.

Thanks for the info.

[coach]

David, How is that spindle working out?

[beacon14]

Still cutting away, thanks for asking.

Ended up cutting almost 700 sheets last year, so I guess it's cut around 350 sheets plus hours of solid wood machining.

I'm thinking of adding the new Z-axis to my machine, using it for the spindle, and replacing my airdrill (which also is ready for some preventative maintenance) with my existing Z-axis and a Porter-cable router. That way I'll have a built-in backup for when the spindle finally gives up.

[Swashc2]

I too have noticed the change in sound on my HSD spindle. I suspect the top bearing, but when contacting HSD, they said there is nothing to do but use until it goes bad.

Its a long story, but we are replacing our table and spindle with a new one. With that, I am curious as to if anyone in this thread has any suggestions as to which is the best spindle or spindle brand to go with our PRS Alpha 48x48 table. From what I have read, it seems like the Colombo spindle is serviceable if the bearings need replacement.

Any advice?

[EricSchimel]

I know this is a very old thread, but it came up when I was searching around for a solution to my spindle problems and I thought I'd share my experience:

My spindle started making odd noises recently. I checked it with a dial indicator and I discovered this:

https://goo.gl/photos/RHQwE43Hir3f1H6e8

I called around and got a bunch of quotes for spindle repair, all were $1200 to $1400. A new spindle from ShopBot is $1700. I went for the new one as I don't want to have to send out my spindle or deal with a rebuilt unit. This original spindle has lasted for nearly 10 years so it's likely that this one will as well.

[knight_toolworks]

thats about how long mine lasted. it started squeeling when it started up and I was sweating till I got the new one one had a bunch of emergency jobs to do.

[EricSchimel]

I'm in a lull right now so I'll be in good shape. Luckily for me ShopBot had a few in stock still. Should be a 15 minute swap out and I'll be back to 100% again.