Newbie- Non-router spindles for benchtop mill

[serriadh]

Feel free to halt me at any time if this is a blatantly stupid idea!

So, background: lets imagine I'm UK-based, and I have a medium sized (maybe 15" by 7") and reasonably rigid homemade milling platform that wants only for a decent spindle or two. The machine is intended primarily to mill engineering plastic and aluminium... engraving is not an intended job for this device.

Most projects and indeed most hobby shops seem to suggest direct-drive high speed routers, mostly intended for wood and plastic work. One of the most common over here seems to be the Kress spindles such as the 1050FME. German hobby sites also have things like this Suhner. There's also the lower power, lower RPM and smaller tool capacity Proxxon BFW 40/E. The latter has the small distinction that the manufacturer suggests it could be used for metal milling, which the other two do not.

Anyway, these sorts of router spindles probably aren't so great at machining aluminium, and are presumably going to need some reasonably fast feedrates. Their design also means that any other interesting toys such as automatic tool changers aren't really possible. Their small tool capacities also mean they won't be doing anything like face milling either, even if the mill platform is sturdy enough.

Personally, I'm keen on a belt-driven lower RPM head to which I could attach a nice motor. US people could get a mini mill spindle, though shipping across the Atlantic is going to be very pricey, almost to the point where I may as well buy a whole minimill that is already in the UK.

I've not found any separate belt driven spindles over here... has anyone else had more luck finding such a thing? Or should I just use a lightweight, high quality motor like the suhner, and worry about more capable tooling for a different, more substantial project?

Advice and opinions much appreciated!

[Jason3]

Hi there,

You might be surprised what you can do with the high speed spindles in aluminium - here is a video of a small machine, slightly smaller than your spec, with a high speed spindle in 6061:

YouTube - ER32 spanner set

YouTube - ER32 spanner set

That one has a pneumatic chuck, so is auto tool change capable but is a little pricy too. And as you said, no face milling, though I've found there's limited need for it with the excellent surface finish from that spindle.

If you haven't seen the Sherline IPD spindles they might be worth checking out - much lighter than the Mini mill heads, so shipping shouldn't be too frightening. You can ask them to use the USPS flat rate box too, which they were happy to do for me ($40/$50 anywhere in the world): http://www.sherlinedirect.com/index....category_ID=32

Generally 'budget' and 'auto tool change' are mutually exclusive, unless you are fortunate enough to pick up a steal on Ebay or you build your own system - which can be done: BT30 Spindle project

Another possibility would be making a tool release system for the Sherline spindles - it would need a drawbar, an air cylinder and some special tool holders, I reckon...

Best regards,

Jason

[Herbertkabi]

Hereby one more interesting spindle system, actually for Sherline mill.
http://shop.ebay.de/merchant/smaxchen
ebay Item 230341251246
Pneumatic tool changer - yes - but this is very interesting idea!
There is air cylinder inside of shaft (see fat region) air pressure comes through spindle housing (see small hole under upper bearing), there are thin seals inner side of bearings - will seal when pressured air acts.

I received this spindle today, not examinid yet but looks like well done thing.
See my Sherline direct drive spindle: Sherline spindle motor suggestions?
I built this one for my friend, final speed was 8.600 RPM my friend choiced, he thought he will not need higher. I tried it with 12k as well. Also 17.200 RPM was possible but by my opinion not for these cheap bearings.
I have a brand new Sherline spindle I bought after this experiment.
Now I will try this pneumatic toolchanger and will build a new direct drive motor for. Seems will change bearings to super precision ones ...oh dear ... then only housing I bought from Sherline for $160 ... perhaps I will leave this nice Sherline spindle for later projects and will machine a new Housing myself - this is much better idea.

Cheers,
Herbert,

Hereby AltaVista translation about:
This spindle was developed by us particularly for the SHERLINE 5000er milling machines. One can build it in addition, without problems into other housings. Important is only, which the two ball bearings sit properly matching in a housing. The gap of the both bearings sealed by two rubber seals (actually my one I bought has thin steel fasteners ... (Herbert)), those over the ball bearings lie by addition of compressed air. Air presses then on the pneumatic cylinder on the inside, which ejects the Werkzeugaufnahme. The Werkzeugaufnahmen are held by a feather/spring in the cone and changed pneumatically squeezed out. The tools who that by ER11 clamping devices in the Toolholder clamped. These clamping devices are available up to a diameter of 8mm. The tool holders, small file magazines,…. are likewise available with us. The wave must be built into a housing with 2 bearing seats, the exact distance of the camps is not important, since the achsiale pre-loading of the camps can be stopped with the help of a tightening nut.

[serriadh]

The sherline spindles are certainly an idea... there is a UK supplier (mill hill supplies) who have a couple of reasonably priced headstock assemblies, though their site is a little short of detail.

I'm limited in my ability to do any serious work on modifying an existing headstock/drive/motor setup due to the lack of a lathe which is in turn due to the almost complete lack of space available to me

The only slight problem there is the fairly small tool capacity of the sherline. The fact that it can take a power drawbar is a bonus. I was just reading another thread (one of the Hoss ATC ones) which suggested that morse tapers were not entirely desirable for ATCs compared to, say an R8 spindle which released collets more easily.

I appreciate that high speed spindles can indeed be pretty good... I'm more concerned with low-to-medium priced devices. I'm not necessarily very budget limited in the long term... I appreciate that you have to spend money to get capable equipment! I'd rather start with something under £300 that could be improved in the future, but that's not a hard limit. Its having my costs doubled due to shipping that I really object to... its money I'd much rather spend on decent quality tooling and collets.

If it boils down to 'you can either spend £600 now for a good spindle, or £250 for an adequate one and end up spending £600 next year anyway because you'll get pissed off' I'll spend the extra pennies

[jfseaman]

That's the kind of gadget I'd buy. No questions asked (it's German, he has a VAT number so pretty legit).

I have a small table I picked up at a surplus shop, it will need a spindle some day.

Originally Posted by Herbertkabi Hereby one more interesting spindle system, actually for Sherline mill. http://shop.ebay.de/merchant/smaxchen ebay Item 230341251246 Pneumatic tool changer - yes - but this is very interesting idea! There is air cylinder inside of shaft (see fat region) air pressure comes through spindle housing (see small hole under upper bearing), there are thin seals inner side of bearings - will seal when pressured air acts. I received this spindle today, not examinid yet but looks like well done thing. See my Sherline direct drive spindle: Sherline spindle motor suggestions? I built this one for my friend, final speed was 8.600 RPM my friend choiced, he thought he will not need higher. I tried it with 12k as well. Also 17.200 RPM was possible but by my opinion not for these cheap bearings. I have a brand new Sherline spindle I bought after this experiment. Now I will try this pneumatic toolchanger and will build a new direct drive motor for. Seems will change bearings to super precision ones ...oh dear ... then only housing I bought from Sherline for $160 ... perhaps I will leave this nice Sherline spindle for later projects and will machine a new Housing myself - this is much better idea. Cheers, Herbert, Hereby AltaVista translation about: This spindle was developed by us particularly for the SHERLINE 5000er milling machines. One can build it in addition, without problems into other housings. Important is only, which the two ball bearings sit properly matching in a housing. The gap of the both bearings sealed by two rubber seals (actually my one I bought has thin steel fasteners ... (Herbert)), those over the ball bearings lie by addition of compressed air. Air presses then on the pneumatic cylinder on the inside, which ejects the Werkzeugaufnahme. The Werkzeugaufnahmen are held by a feather/spring in the cone and changed pneumatically squeezed out. The tools who that by ER11 clamping devices in the Toolholder clamped. These clamping devices are available up to a diameter of 8mm. The tool holders, small file magazines,…. are likewise available with us. The wave must be built into a housing with 2 bearing seats, the exact distance of the camps is not important, since the achsiale pre-loading of the camps can be stopped with the help of a tightening nut.

[Herbertkabi]

Yeah,
I was syrprised when received this "gadget" today morning - near one hour I cant understand how it works - I thought it is some kind of stupid joke he sold me
Then I took and read describtion from ebay (I did not before ;-) ... did see two small holes on the shaft below of upper bearing and ... tried with pressured air - - -
- - - toolholder removes promptly


Perhaps somebody still not understanding how it works:

There is full system inside the shaft ->
nice 6-finger Gripper (visiable when toolholder removed)
Drawbar
Spring(s)
Air Cylinder,

I dont want too take it apart but I think it is all whats inside.

Pressured air -> in to Spindle housing -> in to Shaft through small holes
= piston inside the shaft makes his work

not any additional items needed.
no additional load to bearings ...
Ingenious !!!

Regards,
Herbert

[Jason3]

Herbert - that is indeed ingenious! Thank you very much for sharing that

Best regards,

Jason

[cncuser1]

This is interesting.
I would like to understand it a little better.

I assume that the outer housing is solid ( not telescoping), can someone confirm this?
Also how does the bearing arrangement resist the tool cutting forces that are along with the spindle axis? Is it the same method as the original sherline spindle?

[cncuser1]

Well this looked like a great idea
I was hoping for a bit more input on this

Anyone else have any experience with this spindle?

[japroach]

Another has been listed with a buy it now of $292 USD (excl VAT). A little higher than what herbert paid.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=230344059130

[Herbertkabi]

Originally Posted by japroach Another has been listed with a buy it now of $292 USD (excl VAT). A little higher than what herbert paid. http://cgi.ebay.com/ws/eBayISAPI.dll...m=230344059130

Yeah - Im too busy with my another spindle (ATC) Im building right now - I have not took apart this eBay one yet.

Spindle Im building - it changes 1/8 shank bits only (pneumatic).
I made one bad mistake and cant remove 1 degree tapered rotor from shaft anymore ... I just tried how well it fits and pressed it too strong ... and now it stays like for ever. I can not heat because Neodymium magnets, I can not use puller without implied damages ... at that there are two brand new SNFA VEB155CE1UM15 bearings on the bottom side ....
Now I have to sacrify or bearings or rotor. Bearings are expensive, high speed rotor I made myself, composed from tapered centre, SMC base, 120 tiny Neo arc segments ... reinforced with thin titanium outer sleeve ... lot of work

Cheers,
Herbert

[jalessi]

Please post pictures of the eBay spindle soon!