Wolfgang spindle hmm

[mholod]

Wolfgang hi-speed spindle problems and solutions

After noticing many great comments about little Wolfgang spindle:

• Quiet and smooth
• Fast
• Triple ceramic bearings
• Super precise
• Cheap

I expected that I can’t go wrong with it.


However, Wolfgang spindle was cause of frustrations from the moment it arrived from USA to UK.
Due taxes and duties where charged promptly, thus equalling $100 to £100 and adding to the frustration.

Out of the bag the upper spindle bearing emitted noise characteristic for the misaligned bearing, which could be also felt as slight stiffness when shank rotated by fingers. That was causing the spindle to sound as a messed up mixer.
I wrote inquiring about that, however have received no replay. Consequently the spindle was left unused for around a year until the need arose for its use.


Well, first thing to fail was the small plastic circlip ring used to enable drawbar to push the collet out. That was replaced with a stainless steel circlip.

After few minutes of hi-speed no-load run the upper bearing was second to fail. It was not as much bearing failing as the failing of the glue that held it.

That resulted in axial movement of 0.06mm. Apparently the upper bearing was used to apply preload and with it sliding freely on the shank the axial movement was limited only by lower bearing play.
Maybe the lover bearing set was meant to be preloaded, however the initial position of the shank may have as well resulted in premature failing.

Shank is made out of two peaces: collet holder and shank (pipe) itself, and the bearing was glued across two joints.

As release of water dam the failing of the upper bearing soon was fallowed by whole thing vibrating as mad, thus consequently resulting in rest of the glue loosing it’s grip on the rest of the bearings.

From there on it was easy enough to disassemble the entire thing.

Light tap of rubber screwdriver handle had shank out (nothing to be lost anyway).

Bearings where loose, only thing holding them in place the brass ring.

Tap on the top of it to loosen the glue.

And easily enough everything is out.

Clear the layer of glue to clear pass for the bearings

Luckily enough bearings where loose and the tolerances where more than loose so the bearings came out with no problem at all.

Shank and collet holder are unfortunately not made out of one peace, which reveals how fragile this spindle actually is. It is contained of many glued parts and failing of glue at any of them results in spindle needing repair.

I decided to reuse same bearings as the spindle was not really to be used for any serious work after realising how fragile it is inside. They did appear to be smooth enough anyway, had done no work at all and suffered no significant hammering except excessive vibrations.

Rebuild

For the start everything was cleaned and degreased.

First I had lower bearings glued the collet holder. Luckily enough the bearing where snug on the collet holder, otherwise it would impossible to rebuild the spindle.
It is important to have the bearings aligned correctly. That was achieved by gluing one bearing at the time and having the glue settle while everything is positioned inside the spindle

The lover bearings glued to the shank.
In order to apply preload the small spacer is inserted between bearings.
Once the glue settled the outer diameter of the bearings was ready to be glued. In this case both bearings have to be glued at once. Brash dust cover can be used to apply slight pressure on the outer ring of the bearing while glue is settling in order to have preload applied.

Upper bearing can be used to keep the shank in correct position, however the pulley has to be removed to achieve that.

Upper bearing holds shank in correct position.
Dark ring on the shank shows the previous position of the shank in the spindle. It was moved upward in order to prevent lover bearing seating on the collet holder and the pipe joint.

Finally the upper bearing is to be glued both bore and outer diameter at once.

Pulley has nice shoulder which will seat on the inner bearing ring, thus preventing any rubbing. Also can be used to press upper bearing in order to create preload while glue is settling if lover bearings are not used to create preload, however that my create problems if spindle heats up.



Testing

After seeing that the spindle shank is made out of two peaces which have got fallen apart I had no hope at all that the thing once reassembled will have its original precision.
I was right, however it was not as bad as I was afraid it would be.
The runout of the shank is 0.01mm.
After testing the shank I had solid carbide end mill inserted in collet and and gauge tip close to the collet resulted in 0.024mm.

The measuring further down on the resulted in even higher runout, around 0.05mm.

Conclusion

Even with above mentioned runout this spindle remains the most precise one that I have. I have experimented with ER8 which had runout of 0.01mm, however cheep Chinese collets had this to 0.03-0.05mm.

ER8 spindle plans

ER8 collets and shank

Given time and effort the collet holder could be reground (what I may as well do) and spindle would have zero runout as intended.

I don’t know was I just unlucky to get spindle from the batch that had bad glue or Lucas was just clever enough to send odd one to the UK , but now once properly glued it is not falling apart.

In any case for the money it was relatively good deal. If only the shank is machined out of one piece the spindle would be much sturdier and could last many bearing changes without los of precision and would definitely change the toy into serious piece of machinery.

[Jay C]

Wow. I never had issues with my Wolfgang. I did notice that the design (multiple metals) has changed a bit though. If you start a new thread on your DIY spindle please post a link here. I don't used my Wolfgang much anymore, using the low TIR precise bits collets and a Colt I haven't needed super tight tolerances for SMD circuits lately. But it's there when I do.

Jay

[Drools]

Sorry to hear of your problems, it looks like you have it back to a working spindle with a lot of time spent on your part. Did you mention what kind og glue you used to reassemble the spindle?
I think it the spindle is originally put together with locktite (red) for permenant.

[mholod]

Originally Posted by Drools Sorry to hear of your problems, it looks like you have it back to a working spindle with a lot of time spent on your part. Did you mention what kind og glue you used to reassemble the spindle? I think it the spindle is originally put together with locktite (red) for permenant.

It was fun working on the thing. After all that was also opportunity to see how it looks inside.


There are so many kinds of loctite. I used a loctite glue also.
I had option to use loctite 641 designed to be used to glue bearings, however in order to enable people to change bearings this glue is not superstrong as loctite 648.

I hope that need for the bearing change will not arise soon for loctite 648 holds quite well. Heat gun helps a little thou, but if I try now to disassemble the spindle I would not be able to do so at least not without serious damage to the bearings.

Just to mention that loctite 648 is or can be used with activator, but the 648 is the strongest if allowed to set without activator (was told so), thou it takes little longer to set (longer to set at least still on steel, but steel on bronze - it sets instantly).

[mholod]

Originally Posted by Jay C Wow. I never had issues with my Wolfgang. I did notice that the design (multiple metals) has changed a bit though. If you start a new thread on your DIY spindle please post a link here. I don't used my Wolfgang much anymore, using the low TIR precise bits collets and a Colt I haven't needed super tight tolerances for SMD circuits lately. But it's there when I do. Jay

Pleased to hear that your spindle works well. I want to do some cutting in wax, or maybe even directly into metal (anniversary present for wife) and would use some small mill bits, that way need for precision.

Wolfgang has quite a smart design of the spindle, I think that that is probably the best solution for precision and rigidity (not two part shank thou).

I will use 2x angular(full ceramic 7001, 12mm bore, 24mm diameter) in back-to-back preload configuration and one normal grove(hybrid) bearing. Taking into account the amount of work this bearings will do (little) I would probably be better of with some cheap deep groove, but I like to produce (and have) nice quality stuff. Will post plans when complete. Those angular bearings, that I have, are not shielded. I'm not absolutely certain how to go about that thou.

Well I could have bought another wolfgang for the money I have spent on bearings, but then I would not enjoy making the stuff.

[Drools]

Do you have the pictures in a larger format? I assume you resized them for the thread?

[mholod]

Originally Posted by Drools Do you have the pictures in a larger format? I assume you resized them for the thread?

Hi res images [here 63Mb]. Hope all are included.

[lucas]

Originally Posted by mholod I don’t know was I just unlucky to get spindle from the batch that had bad glue or Lucas was just clever enough to send odd one to the UK , but now once properly glued it is not falling apart.

You where just plain unlucky (like many others), and NO I didn't send anything: I still have my 2 spindles, they are rebuild and still working fine but use them only a few hours per month.

Originally Posted by mholod In any case for the money it was relatively good deal. If only the shank is machined out of one piece the spindle would be much sturdier and could last many bearing changes without los of precision and would definitely change the toy into serious piece of machinery.

The 2 wich I have DO "feature" a one-piece shank and collet holder but this doesn't garantee remounting without loss of precision, see below.
I bought them in august 2008.
Pic of a DB300 in pieces is below, single piece shaft.

Originally Posted by mholod Given time and effort the collet holder could be reground (what I may as well do) and spindle would have zero runout as intended.

The spindles wich I have also need the collet holder to be reground after re-assembly, simply because the tolerances on the bearing mounting to the shaft and housing are too high and it's impossible to reglue in the same position as they were.

To me it's evident that these can be very good spindles for the money but it's "hope and pray" to receive a good one.
All the changes he continously made to the design confirm this:
From ceramic to stainless bearings, shaft modifications, 2 belts iso 1, etc...

Luc.

.

[MrWild]

Glued bearings? They don't look ceramic either. Not my idea of a precision unit, and if it needs rebuilding right out of the box, it's overpriced too.

[Drools]

Hi Lucas, your spindle looks like the one I have but how do I know for sure without disassembling it.
I use my WG just for PCBs now and the big porter cable foe everything else.
Maybe Richard will respond to this thread with his thoughts.

[mholod]

Originally Posted by lucas You where just plain unlucky (like many others), and NO I didn't send anything: I still have my 2 spindles, they are rebuild and still working fine but use them only a few hours per month.

Lucas, please accept my apologies. Some time ago, I was looking for the instructions (or images) on how to rebuild wolfgang spindle and for some weird reason I come to conclusion that name of guy from wolfgang is Lucas. My apologies.

Thank you for constructive comments, for I didn't know that there are models that feature one piece shank and also I believed that one piece shank would solve great deal of problems.

Well, in any case I haven't found images of disassembled spindle thus I have decided to post some in order that people can have an idea how to go about the thing if it goes wrong.

Regards,
Mitar

[wolfgang314]

This thread was brought to my attention by a customer of mine, and I don't normally intervene on the reviews, but there are probably a few questions that I could answer to help things out.

Unfortunately, at the moment I'm right in the middle of my "Big Move" and am trying to piece my business back together in it's new location. I'll have more space and time to better serve my customers.

Mholod, I have to apologize,... you were one of the unlucky 15-20 customers that has received this poorly executed design of the TB-350 Spindle. It seemed sound in testing, but when it got into the "real world", it simply feel apart.

I still use the two piece spindle shaft design (which I'll explain in a later message), but it as been greatly improved. If you would like me to send you a replacement spindle for the one you have, please let me know. I'll have it out to you as soon as things get back to normal here at no extra charge. I stand behind my products and take it personal when one of my designs don't meet up to my customers expectations.

I do apologize for the inconvenience. You can respond to me in this thread and I'll try to get back to you ASAP, or you can contact me directly at WgE314@Gmail.com if you need to speak to me in person.

Thank you.

WgE.