High speed CNC spindle

[mu38&Bg#]

I had the stainless. I am aware of it's properties which is why I had the material on hand for another project. If the bearing housing sucks, then it sucks, and I make another. I spent quite a bit of time reading up on dynamic balancing. I occasionally have the need to balance an electric motor for RC or maybe an electric ducted fan unit, and I do have two KP31 compressor wheels waiting for me when I decide to build a turbine. So, I might go for an all out dual plane balancing rig. I've been churning it over in my head. One additional problem is the nut needs to be balanced. Balanced ER nuts are expensive. I made a model in SW to sort out how much material needs to be removed and where, but it still needs to be checked. To get the performance I think it will be capable of, I'd like to dynamically balance it.

Yes, static balance can be acceptable. I just don't want to install the bearings only to find it's not balanced well enough then have to take it apart. Maybe I'm too worried about the bearings.

I now have a compressed air, or I have a 500W chiller available.

Ken, I visited a friend last night with a slot car track at his house. He's been into slot cars since the 60's. I didn't know much about slot cars other than a little bit about motors. Some of the chassis were pretty wild, wire EDM steel plate, etc. for some open euro class.

Greg

 

[Ken I]

I did not want to say your method is wrong!

Cheers Florian

I dind't think you did. As my reply states - your method is better.

No offence taken either way - thanks for the post.


Greg,
This has been an interesting post keep it up.

Some open class slotcar stuff can get really silly with rpm's and speeds people generally don't believe unless they see it. I've been doing it since 1966 although most local stuff is in the "tame" (read less expensive) categories.

Regards,
Ken

 

[ninefinger]

Check out these links for building your own high speed balancing tool (the 1st link leads to the 2nd)

http://www.technologie-entwicklung.de/Gasturbines/Balancing_Tool/body_balancing_tool.html
http://www.technologie-entwicklung.de/Gasturbines/Balancing_Tool/Available_Parts/available_parts.html

But this is going down the road of building a tool to build a tool to build a ...

Mike

 

[mu38&Bg#]

Well, I decided to try the software. The author offers an eval copy. I think it will come in handy for other projects and balancing RC hobby motors among other things. The price is reasonable to purchase if you have a need to achieve the kind of balance levels this offers. The method he recommends requires making a temporary bearing housing as I won't be able to reach the areas needed to add or remove balancing material. I need to get a couple sensors in and then progress will continue.

Greg

 

[mu38&Bg#]

Slowly, I move forward. I've made a temporary aluminum housing in which I'll be balancing the assembly. The accelerometers arrived and I played with the software yesterday. It does indeed work very well and is very sensitive. I could have made a balancing cradle for the shaft, but I had a piece of aluminum tube approximately the right size. I still have to make the cap that holds everything to the collet holder. I'm heading into the shop and should have some more photos later.

 

[mu38&Bg#]

I didn't get very far the other night. I'd begin the assembly for balancing tonight, but I'm going to play with slotcars.



I machined a groove in the back of the cone to hold balancing putty.



I machined the cone on the shaft the first time around, but in the 5C chuck with a cheap collet. I decided it could be better and put it in soft jaws. I skimmed the outside of the cone and added the groove on the back side.



This is the cap the clamps everything to the shaft. Turned aluminum with milled cups for hall sensor magnets. I might not need the magnets if the RC controllers works, but it will be there.



The parts before assembly.

Greg

 

[mu38&Bg#]

I got all the parts together in the temporary housing for balancing. I'm ecstatic! I ran it with it's motor and it's smooth as silk! This whole project will be worth it just for the reduction in noise.

 

[steamer]

th_wwp

 

[mu38&Bg#]

Yes, pictures will come. I'll take photos (maybe some video) during balancing, and then final assembly.

 

[Florian]

(maybe some video)

I hope its not only Maybe ! I WANT to see it running / being balanced ;D 8)

Cheers Florian

 

[mu38&Bg#]

I'm still working on balancing so there will be some video. The lower end is very close to balanced, the motor end needs more work.

 

[Florian]

But it sounds like its working well?

 

[Ken I]

Greg - I'm hoping you will do a post on the entire ballancing act - I'm very interested in how you did it etc. etc.

Ken

 

[mu38&Bg#]

I'm in the middle of it right now. Between the balancing, taking video, and working on customer drawings it's going a little slow, but so far very promising in the balance that can be achieved.

 

[mu38&Bg#]

OK. The balancing is about as good as it's going to get, and much better than I thought I could achieve. I do have a bunch video clips, but I'm unsure if I'll be able to put them together in a way that makes sense. I made some mistakes early on and I'd have to edit that out. Right now, I'm, reassembling the components into the bearing housing. I'll touch up the balance on the motor end if needed afterwards. I won't be able to conveniently add or remove mass at the collet end once assembled.

Cutting won't happen until after I get a mount made for it.

Greg

 

[mu38&Bg#]

This is it! I have photos and details, but that might be later. I'm spent. The collet nut will be balanced as well.

 

[steamer]

That looks great!

:bow:


Dave

 

[mu38&Bg#]

Text is here. I haven't even looked at the balancing videos.

 

[Swede]

Beautiful!! Did I miss it, what is the power output of this gem? :bow:

 

[steamer]

Excellent choice for Grease!....

Dave