lathe milling spindle?

[bertie_bassett]

Had a spare couple of hours today waiting to pick someone up so decided to make use of my time and have drawn up a scale drawing of what iv made, shows most of the important measurements a d details

[vtsteam]

Oh, good choice for motor. Those are made by EMP -- same as mine, and also Simon's bike. Bertie, what size ESC are you using?

I'm guessing that you'll probably want a 24V power supply. Usable voltage depends where yours develops enough power for mill and material chosen. 6364 k250 is definitely both larger and slower than my motors, which is good.

I think with solid carbide you/we will be able to mill steel with an 1/8" mill at least. if you have the power at the voltge  for you, hopefully larger mills -- that's what I'll be interested to see when you're operational. 1/4" (or better) in steel would definitely be nice.

Incidentally, aircraft load these motors in thrust. That's what they're designed for. With an 1/8" end mill the motor will not be heavily loaded in thrust or it will snap. Not saying angular contact bearings aren't preferable, but I do wonder if they are absolutely necessary on my own motors. Likewise with a very small range of usable mill sizes I probably will have, I also wonder if a set of ER-11 collets was necessary for me! Mine might end up being a pretty simple conversion.

[Arbalist]

Only just seen this thread. Nice idea Bertie, I particularly like the motor choice as I've been wondering what you could do with these motors!

[mattinker]

I managed to get hold of a xyh 6364 from giant shark, shows as out of stock but if you search for c 6364 or n6364 you can find the same .motor in stock??  Mines the 250kv one as its the lowest kv around. Should give a max speed of 3k rpm at 12v. Though I can rewind ut for a lower kv If required.

Thanks for the n 6364 tip, I've ordered one! That will be all for the budget this month, I'll see about the bearings and the esc next month.

Regards, Matthew

[bertie_bassett]

Incidentally, aircraft load these motors in thrust. That's what they're designed for. With an 1/8" end mill the motor will not be heavily loaded in thrust or it will snap. Not saying angular contact bearings aren't preferable, but I do wonder if they are absolutely necessary on my own motors. Likewise with a very small range of usable mill sizes I probably will have, I also wonder if a set of ER-11 collets was necessary for me! Mine might end up being a pretty simple conversion.

im sure iv seen at least one person not bother with extra bearings, or even collets, just outing a milling bit directly into the motor!

iv also seen other with plain ball bearings used to take up sideloading. In my case I couldn't see a reason not to use the double row AC bearings so that's what I went with.

for your motor size I think skate bearings may be the easiest option?

you do need some sort of bearing housing, even if its just to hold onto the thing! got to remember the outside spins round!
as far as I can make out the usual application for these motors is for the rotating bell to be the front end, with a prop shaft bolted to it. the original motor shaft seems only to be there for the bell to rotate on ( why it sticks out the back end iv no idea though)
in our case I think we are actually using the motor backwards ?

a lot of the designs out there are for home made cnc machines where they seem to be striving for perfection when it comes to stiffness and runout. personally I think its overkill for hobby use. if it spins and cuts without shaking itself to bits id say its good!

glad you found the motor matthew, took me ages to find one in in stock. no idea what the differenc ( if any) is between the n,c and xyh is

[vtsteam]

I build and fly R/C planes Bertie, and use this brand of motor (EMP) a lot -- they have the shaft out the back so you can reverse the mount (sometimes necessary to fit in a cowl, etc.) On outrunners generally the bell is spinning (the part the has the magnets.

[bertie_bassett]

ahh so that's how they work.. was rather confusing when I opened the box up and found the bolt on shaft! have never had one of these in my hands before.

good to know who actually makes these motors, might make finding another one easier. I assume they are a reasonable make if you use them a lot?

matthew, did you order the 6364 or 6354?  iv just checke mine and I actually orderd the 54 version, glad I did as the 64 would be too long for the shaft!

[mattinker]

Hi Bertie,
I have ordered the 6354, I just checked my spindle, it's 100mm long, the 6354 is according to the specifications 55.8mm long, so I would have a little over 45mm to fit the bearings in.

Thanks for the heads up! Thought full!!

Best wishes, Matthew

[bertie_bassett]

that's good, didn't want you to have the wrong one!

you can get away with 51mm of shaft for the motor as the grubs screws are set back a little, that give a little more for the bearings.

my original plan was to have the collet end of my shaft sticking out a bit further so you could actually get a spanner on the flats, however iv had to sink the head into the body and rest it right up against the front bearing.

sinking the motor mount into the back plate gained a couple more mm too!

[mattinker]

Bertie,

So my two separate angular contact bearing may be an easier solution. I'd like to keep the flats accessible. Just a thought, the chuck is not hardened, you could drill holes for a "c" spanner a little closer to the thread.

Post some pics so that we can see the progress!

Regards, Matthew

[vtsteam]

ahh so that's how they work.. was rather confusing when I opened the box up and found the bolt on shaft! have never had one of these in my hands before.

good to know who actually makes these motors, might make finding another one easier. I assume they are a reasonable make if you use them a lot?

I don't know what the status of EMP is now. Lots of retail and nline outfits re-brand their motors, and there was a really big sell-out through online outfits of many in their line about 3 years ago -- I was buying smaller motors for $3 each and bought quite a few to have as stock for planes.

I think the fact that the model you have is no longer listed is the same situation. Older stock. I don't think the factory went out of business, I think they modernized their line of motors, and these older models were dropped. They are pretty recognizable once you've worked wth one -- though the colors vary. That seems to relate to the letter designation in the part number.

Anyway, I always liked them and always thought they were good motors for the money.

[bertie_bassett]

It wasn't. So much the bearing size that dictated the length of my bearing housing.  Its purly down to the fact I based the design around 40mm stock. If id stick with my original plan the housing would have been 40mm plus the 2 end pieces making a total of 60mm  thus only 40 for the motor. The beari gs are still where I originally wanted them with 10mm spare between then so I could have made it all smaller, but then I don't think it would have been as sturdy.

I may have asked befor but what thickness are the bearings your planning on?

Not really done any more progress tbh apart from locktighting  the bearings inn place ( big mistake  as I still needed to dismantle to weld a nut on    )

[mattinker]

Bertie,

Single row angular contact 10 x 28 x 8. I'm going to make the body from home cast Al with a standard electric drill 43mm to mount on. I haven't drawn it up yet!

Regards, Matthew.

[bertie_bassett]

Made some progress lately, turned up a screw nut from a lump of old motor shaft which happened to have the right thread in it. And turned up a nut to be welded to the spindle body.
Welds look ugly but they will hold I'm sure

Have ordered the rest of the metal up for the slide and base. Just waiting on delivery befor I can make any more progress.

Things may have to go on hold for a while longer though as tomorrow I need to go dismantle a machine and try to fit it in my small van. Oh and then reassemble said machine in a workshop.

[mattinker]

A mystery machine eh! My motor showed up today, looks as I thought it would. I'll have to wait until next month to get my bearings and ESC.

Nice to see the photos, regards, Matthew

[bertie_bassett]

thought id pick this project back up while im waiting for bits for the new mill.

first I cut up some more stock and bored it out to fit the screw nut id previously made



left the bore a bit shallow so I can use a bit of gasket to get the clearance done to a minimum and hopefully avoid to much play in things

iv not got anything to make the round base out of so for now iv decide to make it fit onto the compound topslide. With a 6mm base plate the center of the milling spindle should be on center height with the lathe

 so cut and filed some 6mm plate to fabricate a big t-nut and cut a base plate then sat the spindle on top to see what thing would look like, and found a small issue



id forgotten the motor was bigger then the body
also with the spindle where the tool post should be I can only go 18mm past center before I run out of screw 



so after a few choice words I started weighing up my options

1: raise things up another 6 mm, motor now clears but spindle is 6mm above center height


2: rotate the spindle and compound 90 degrees  so that motor has clearance, get me back on center height, plus can use the topslide to give extra reach. lose the fine infeed though


3: go back to original plan and remove compound, still lose fine infeed + limited reach beyond center

4: find a smaller motor? took me long enough to find this one

5 : drill and bolt the new spindle to the back of the main slide - lots of hassle but would gain height and reach

6: anything iv not yet thought up


currently thinking of No2, as it give the most advantage with little disadvantage- can feed with the apron instead

iv also decided on a height of 200mm for the vertical slide as this is a 5 1/2'' lathe so 200 will clear the biggest part ill ever turn

[BillTodd]

7, drive the spindle with a belt , gain torque with reduction gearing?

8.0 mount lathe on end to pretend it is a miling machine
8.1 mount lathe on swivel so pretend mill can become pretend lathe but will flip back to pretend lathe when you least expect it


*8 & 8.1 are copyright Microsoft

Bill