X2 belt drive conversion

[bogstandard]

Tim,

You are doing wonderful and innovative work on your making of the parts, and you are showing that you don't need a lot of gizmos to get the job done.

A lot of it is laziness and impatience on our part, and if we all did what you are doing, more of the basics of machining would be understood.

I think you have a good improvisation head on your shoulders, and you should let it keep leading the way.



Getting back to grass roots machining, great!!


John

[CrewCab]

A lot of it is laziness and impatience on our part,

Bogsie  ................. stop giving all the secrets away 

CC

[spuddevans]

I think you have a good improvisation head on your shoulders

And it's getting bigger too

Thanks for the encouragement John, it means a lot to me

I did think about using a rotary table to mill out the curved slot, but the arc's radius is over 4.5" and I only have a little 4" diameter rotary table, I didn't think having roughly 2.5" sticking out unsupported would be too good, so I figured that using the belt-drive base could give me the needed support and provide me with the perfect matching radius I needed, and after figuring out how to remove my fingers from being close to the milling cutter I just gently milled it away.

I do find that I spend more time looking at the workpiece and the machines I have figuring out just how I can best achieve the results needed, than the actual time spent milling or turning it !!


Tim

[sbwhart]

I think you have a good improvisation head on your shoulders

I do find that I spend more time looking at the workpiece and the machines I have figuring out just how I can best achieve the results needed, than the actual time spent milling or turning it !!


Tim

I think thats very true for most people Tim:- I quite often find myselfe thinking about something I'm three or four weeks away from making. It sometimes gets me in trouble with the Boss, she'll be rabbiting on about something, I'll be lost on thought about making something, and then she'll say OK thats agreed then, what what was that   

 

Stew

[bogstandard]

Dave,

If you look back at old mags and books, you would be surprised how easy a lot of the supposedly difficult jobs were got around.
It is only the last few years that specialist tooling like rotary tables and boring heads came within the modellers price range.
Before that, everything was done just as Tim is doing, and to me should be the way everyone should start off.
Get the basics under your belt, gizmos can come later to make the job a little easier.

I honestly think that is why the older generation of model engineers make things look easy. It isn't because they are any better machinists, but they have a greater understanding of the principles involved in making the part, and when they get to using modern techniques, using modern tooling, it looks just like they are using black magic to make the parts.

Modern machinists are getting a mental blockage, that assumes modern bits and bobs are needed to do the necessary procedures, whereas they should be thinking that they only assist in making the job easier to do. The last two hundred years or so of engineering have proved that the modern way of thinking is all wrong.

Just to reiterate, Tim is showing the ways how it used to be done, and good for him.

Now if we could get someone to show us how it was done before metal planers, milling machines or vertical slides came onto the scene ........... hacksaws and files (complete with aching arms and loads of sweat) spring to mind. Remember all those old piccies of rows upon rows of benches with chaps standing there filing away at hunks of metal. They were called fitters, because they were making parts so that they FITTED together correctly.

A hundred jobs (or even more) replaced by one CNC machining centre, turning out millions of parts that fit together perfectly. But can it make a one off, at short notice, from a fag packet sketch? I very much doubt it.

That is where we come in, but unless you have the basics, you will struggle.


Bogs

[Bernd]

Bogs, truer words were never spoken like those above. 

Bernd

[spuddevans]

Today I started by milling down the middle of the underneath of the motor mount, to bring a bit more clearance for the belt.




I tried the large pulley on the spindle of my mill and found that the bore in the large pulley was ever-so-slightly too small, so I mounted the 4jaw and trued the pulley as best as I could and took off 0.22mm, checked it and it was ok. Then I filed the keyway a bit deeper, and then mounted it on the mill just as I did for milling the spindle-lock-slot and drilled and tapped M6 for the grubscrew.




I then mounted my vice onto the mill and set about drilling and tapping M4 the grubscrew on the small pulley.



And here are both pulleys (the smaller one is resting on the bottom of the larger one) showing the grub screws.



That's all for today,



Tim

[raynerd]

Nice job Tim - did you get your grub screws online, I need to find a supplier. I normally get my machine screws locally but one thing they don`t seem to sell for some reason is grub screws.

Your certainly not far off now!

Chris

[CrewCab]

Chris

Have a look Here

CC

[raynerd]

Thanks for the link CC - good price. I`ll get some ordered.

[spuddevans]

Nice job Tim - did you get your grub screws online, I need to find a supplier.

Have a look Here

Would you believe it, that's the exact place I got my grub screws from 


CC beat me to it 


Tim

[CrewCab]

Chris,

Before you melt the plastic have a look at this link

I've dealt with each of them and in my experience they are both good people 

CC

[spuddevans]

Not a lot done today, just hacked off a bit of round ali bar, chucked it in the 4jaw and turned down a section, drilled and tapped it M6.



Then I turned it around and gripped it by the smaller diameter that I just turned down, faced the other end and then knurled the body. This is where it fits


I loctited a M6 stud into the "ear" for the Knurled knob to attach to. Then I just cleaned up the faces of the belt-drive componants.


Tim

[spuddevans]

I got a bit more done yesterday, I started on a spring-loaded spindle lock.

I started by finding a suitable reclaimed spring that had an inner diameter that was the same as the width of the slot milled into the large pulley (about 8mm). I then rigged up the belt-drive base on an angle plate on the mill to drill it and found that I didnt have enough headroom on the z-axis to use a conventional drill-chuck  It then occurred to me to try the ER32 collet chuck as its a lot shorter than a drill chuck and there was just enough room if I held most of the drill in the chuck and only had about 40mm of the drill showing.


(ps. this photo is a mock up of my setup as I had taken off the clamps before realising I hadnt taken a picture, that's why it's held with just one engineers clamp.)


So I drilled 9.5mm(the outer diameter of the spring plus a tiny bit for clearance) to 15mm depth, then swapped out for a 8mm bit and drilled through the final few mm.

Then I drilled and tapped 2 M5 holes either side of the locking pin hole.

Then it was back onto the lathe and I chucked up a short length of some unknown steel and turned it down to 7.5mm on one end, a small 9.4mm section and then turned the piece around and turned the other end down to 7.5mm. Then I rounded the ends over with files, and then sanded it smooth.



Then I just took a small piece of 2mm thick ali, drilled 2 M5 clearance holes and a 8mm hole (which I also reamed 8mm as the drill left a slightly triangular hole) and mounted the whole lot onto the base.






Tim

[Darren]

Very nicely done, I wish I had a spindle lock on my mill....

[spuddevans]

Very nicely done, I wish I had a spindle lock on my mill....

Thanks Darren, I hope this will save trying to remember to remove the locking pin before starting the mill up  


Chris (craynerd) asked me if I could show some more details of the spindle lock so here's a couple more pics.





Notice the "ledge" in the hole that the spring compresses against





And here's a pic of all the mill belt-drive conversion parts minus the belt and mill



And all the parts individually



For larger resolution pics go to Linky


Hope this is what you wanted to see Chris, if you want to see any pics of anything else just ask and I'll do me best to post them.


Tim

[sbwhart]

Good Job Tim.
 

Well explained and shown the spring loaded lock is a great idea.

Cheers

Stew

[raynerd]

Excellent pics Tim, really appreciate it. You know the knurled nob and the slot that it locks down onto on the motor mount? - is that to allow you to swing the motor mount back and change the tension on the belt? I noticed on hoffmachine plans, he just had a straight slot but I don`t understand how a straight slot will allow it to swing through the angle.

http://www.hossmachine.info/images/belt%20conversion%20motor%20plate.jpg

[spuddevans]

You know the knurled nob and the slot that it locks down onto on the motor mount? - is that to allow you to swing the motor mount back and change the tension on the belt?

That's right, it's for tensioning the belt. I cant say why hoffmachine's plans call for a straight slot, I dont see how that'd work unless you have 2 straight slots, one for each side of the motor mount.



Tim

[spuddevans]

Ok, so no progress for a bit there, unfortunately real life caught up with me 

But this morning the postie brought me some goodies, the mini V-belts from Chris. So being the impatient sort and having a couple of hours free, I started in to putting the whole belt-drive conversion kit together.

Here's the before pic



1st off I removed the motors wiring from the control box, (very easy to do as the motor is connected by insulated spade terminals inside the box) and then I removed the 4 hex screws holding the old motor mount on the mill head and lifted the motor off. (handy hint, before removing the old motor mount, use the locking pin to lock the spindle and, after loosening the grub screw, undo the splined-type spindle nut, it loosens the opposite way that you think) then undo the 4 philips screws shown below.



Then I removed the 4 long philips screws that hold the plastic motor base on.



Then I tried to attach my new motor mount using the same long screws, here I came accross a problem. I had drilled and counterbored the 4 mounting holes as per the plans, but now that I had my mill in bits I found that the screws were slightly larger than the screw-holes, and the screw-heads / washers were also bigger than the counterbores.
So a quick bodge/fix was called for. I gripped the motor mount in my bench vice and carefully opened out the holes with my hand drill, turned out ok.



That being done I turned back to the mill and removed the steel spacer from the spindle and I also removed the white plastic gear that sits just behind the spindle ( looking from the front ), this left this little pest,



Well with a little persuasion from my friend the hammer, it soon popped out the underneath and I was able to mount the new base.



Then I mounted the large pulley onto the spindle. Here's a pic showing how I access the grub screw on the pulley.



And this is why you need the grub screw, unless you have some kind of special tightening tool you have to make do with a couple of allen keys and tighten it the best you can.



Turning back to the motor mount, the gear on the motor is retained by a circlip ..... and by a quite strong press fit. I did not want to wreck the gear while removing it so this is how I leavered it off.



Then I mounted the smaller pulley onto the motor and decided to try the motor in its place and...


and



 


So, after making a "Tim's forehead" shaped impression on the workbench for several moments, and then regaining semi-consciousness  I then removed the pulley (which is not as easy as installing it considering I had to hammer it on, I almost ruined it getting it off) and mounted the pulley in the 3jaw to remove about 4mm from the bottom.



Then I Hammered mounted it back onto the spindle, just in case anyone's worried about me whaling on the pulley to mount it, I was careful;


Closer view



And this is how it all looks



I almost made a boo-boo with the size of knurled knob, almost too big. So if anyone else is making a similar conversion, make sure the knob is smaller than 30mm.



And ( finally ) the obligatory B.L.O. (bits left over) shot.



Larger versions of the pics can be found HERE

Tim

[bogstandard]

It has turned out very well Tim, well done.

But you have forgotten one thing.

You don't say if it works or not.

I assume because you have done such a good job, it does.

John

[sbwhart]

Well done that man.

 


Great job well explained, thanks for showing Tim.

   

 

Stew

[spuddevans]

You don't say if it works or not.

Oops,   Yes, it works just fine. Soo much quieter and smoother.

I also forgot to mention that I also had to reverse the motor wiring (but not the earth, obviously) as now the motor needs to run in the opposite direction.

Edit: I've since realised that there is no need to reverse the motor's direction with this belt drive conversion




My next project is to tram the mill up as best as poss, and to allign the mill head with the z-axis (which it currently is not alligned that well).

So yet more piccies will be on their way.


Thanks for looking,

Tim

[bogstandard]

Tim,

Maybe you should knock up one of these.

Tramming then becomes a joy rather than a PITA.

http://madmodder.net/index.php?topic=822.0

or Stews smaller version

http://madmodder.net/index.php?topic=1077.0


John

[Darren]

Lovely tidy job there Tim....

Bet you're pleased as Punch.....