Mill Power feed

[Darren]

I was thinking the same thing John,

Although the finish is much better than I was getting by hand it still could be improved upon. I too believe the tool grinding needs some more thought...I will work on it.

There are some other improvements that could be made to the circuitry...later when I've figured it out.

[Darren]

John,
I've tried searching for that picture you put up with your flycutter shape, but I can't find it?

Do you know where it was? Or maybe put it here too when you get a moment 

[bogstandard]

Here you are Darren.


http://madmodder.net/index.php?topic=850.0


John

[Darren]

Thanks John,

I had another go and reshaped the tool bit a little to look like this





The result was indeed a bit better, still getting some lines as you can see. Two bits of alloy, different finishes, I assume one is softer than the other.





Just practice and fettling now I guess.

[Twinsquirrel]

Looks pretty good to me Darren!!

[sbwhart]

And me, if I was getting that standard I would be very chufed

 

 

 

 

Stew

[Darren]

Ah yes, thanks chaps, it's not bad

But then I've seen Bogs flycutting, now that IS a finish......

And he wasn't even trying...... 

Mine is almost there, just a touch more to go, I believe it's in the tool grinding....practice, practice, practice..

[Divided he ad]

Looks pretty good from here Darren, I bet that looks real good in person? Photo's always make it look different to real life! (well I always look about 4 inches small!?  )


I'll be more than happy to get rid of those damn deep lines you get when your hand goes over the top of the wheel rotation!!!   

1 line every 10mm or so..... Does my nut in    It takes forever to file, lap and polish the damn things out!


Looking forward to getting this thing made 






Ralph.

[Darren]

I think I'm trying too hard 

I had a look at some utube videos and everyone seems to be setting the feed much faster than I am, like a train in comparison.

So I reshaped the toolbit and this time honed it with a diamond stone.

This is the result, bit of tiny brass, sorry it's so small...that's a 1mm drill bit to give an idea of size.





I noticed tonight how much the whole mill is vibrating (fly cutter is not balanced ). The mill is not bolted down and it's also on a flimsy table.
So I think I'll leave it at that for now till I remount the whole machine.

Ralph, if you come over Sat you can see it in action 

[bogstandard]

Darren,

I have many years of experience in sharpening cutters and setting feeds and speeds. What you are achieving here are your first tentative steps into precision machining.

Give it a little more time and experience, and all of a sudden, you will find that good finishes appear without even trying. I am not boasting at all, but that is the honest truth. From the time since you have realised you can do good work, rather than bodgit jobs, you are making remarkable progress, and that is no BS.

John

[Darren]

Thanks John,

All this effort is an attempt to try some methods for building your engine. It may look like I've sidetracked, but not really. Just trying a few things before going for the real thing 

Thanks for the compliment, from yourself it carries some weight...

I've said this before, I have struggled for some time with machining. Some pointers from all the guys here has really made it start to happen. I just watched and listened.

Monkey see......

[Divided he ad]

Ralph, if you come over Sat you can see it in action 

Yes I will and erm... Yes I will 


That brass looks very good finish indeed.... Looks very nearly good enough to polish!? .... I really want a finish like that    


Soon, with a little help ehh Darren? nudge, nudge, wink, wink     

 

I noticed tonight how much the whole mill is vibrating (fly cutter is not balanced ). The mill is not bolted down and it's also on a flimsy table.

I have some bits that might help a little with this? I'll bring some with me and see..... Without looking at the whole ass'y it's hard to know if it'll work? .... But it might and that would be good   


We will see about it tomorrow





Ralph.

[Darren]

Ralph, the finish on the brass is exceptional, if I could do ally the same I would be very happy indeed...

[Divided he ad]

Well... I've since been to Darrens dungeon of cool stuff..... Oh yes, it's full of cool stuff     

I've seen that brass and the finish is truely exceptional.... It'd polish without flatting   

We had the aluminium coming out pretty darn good too 



I've got some bits n pieces from Darren to aid in my power feed, so I'll be posting the results here if that's ok? It'll keep it all together

I've got a lot of work to do, but it should be fun and will definately be worth it      




More on all this later



Ralph.

[Divided he ad]

Right, After a quick private natter to Darren we decided that keeping all the power feed mod's together sounds good.... That said......


I've been a little busy 


You've already seen the plate I started to make (if not... it's further back in this thread!)

Well here is the continuation of that....

Motor mounting, first the 11.5mm hole for the spigot shaft to enter through, then the 3 mounting holes ..... Yes I know I'm a bad lad for the Heath Robinson way of marking and eyeballing, but it works for me most of the time!! As it did here.  (I marked the hole points using the original motor mounting plate from the garage door op')







Then I robbed another part from the garage door op' the spigot drive doofor thingy (technically accurate I think you'll find!?) 



And two chain drive sprockets...




I cut the plate next to allow me to get the hand wheel on whilst I worked out the placement of the rest of the parts..
Hacksaw and drill.... Then clean up with the mill and finally a file to remove all 90degree edges.







I then turned my attention to the sprockets... Drilled out the centre of the smaller one and loctited a 10mm stainless bar into it, machined the end to accept the spigot drive doofor thingy and loctited that on to the end of the sprocket.



The larger sprocket was bored out to accept the handwheel hub.



and then the dial was re-sized to allow fitting of the whole ass'y.



This is what we're left with...



Then a bearing for the shart to allow pulling of the freely rotating shaft



And finally for last night...

Engaged...



Dis-engaged...




 


Bit of a monster post, but I had a lot to show 


Next time, a chain and a little release mechanism for the spigot drive doofor thingy!



Ralph.

[sbwhart]

Nice job Darren

 

I can see what you were explaining about the handle on your mill making things awkward.

On the face of it it will be easyer on my mill.

Stew

[sbwhart]

Her's a question

 

As my machine has an handle at one end and the facilties for a drive at the other would it harm if I had the motor permeantly engauged ?.

Stew

[Divided he ad]

Her's a question

 

As my machine has an handle at one end and the facilties for a drive at the other would it harm if I had the motor permeantly engauged ?.

Stew

Heavily geared motors Stew.... Most unlikely to work!  try turning it with a nut on the end of the shaft.... Should make it really clear!! 



Darren,

Much easier on your mill!

I'll get it done, even if I have to re-design the drive!! 



Ralph.

[Darren]

Stew, don't try to turn the shaft by hand, you might strip the teeth off the big gear.
Unlikely by hand, but you could probably do it with a hand wheel attached, like on the mill. 

Hence the disconnectin thingi bob wotsit

One gear is a worm wheel

[sbwhart]

OK Thanks for putting me straight Chaps

I'm not planning on doing anything just yet, Johns got some toothed belt drives for me to look at that may do the job.

Stew

[Bernd]

If they are permanent magnet motors you'll create a current trying to turn the shaft. Might not be good for your electronics. Could cause voltage spikes. Plus the faster you try to turn the motor the more resistance.

For an experiment take a DC permanent magnet motor and tie the two leads together. You'll feel the resistance of trying to generate a current.

Bernd

[Darren]

That's the back EMF I was talking about before.

I decided that it wouldn't be a problem in this situation for two reasons.

a: These types of motors stop dead when the power is switched off.

b: By using a center off switch we have disconnected them from the power supply completely when the switch is off.

Point to note about permanent magnet motors, they make very in-efficient generators, you really have to spin em fast to be of any use.
Better to use a field coil type motor I believe. 3 phase types can be very good.

[Divided he ad]

Well.... This should be interesting to some of you?

Since it was a bank holiday today I decided to have a go in the shop.... Not good weather and a day for free   


So we left it needing a bit of a lever for the engage/disengage.... Well here's what I've been upto...

Bore a short adapter for holding a flanged bearing.


Make a rear part to the bearing housing then cut a slot in it and cross drill, tap one half M5 and drill 5mm clearance through the oter half.



(plasticcy aluminium!!)



Cross drill then shape and size (to 12mm) a mild steel bar



Cut the 8mm slot in the bar (made over length since I was making this up as I went along!)


Narrow the bar for the slot on the bearing holder to fit.



Make the mounting for the lever..


Mount the lever pivot mounting


Cut and turn down the driveshaft to take the bearing (tapped M4 into the centre to hold the bearing on, not shown)




A quick and rough assembly of all parts... (Handle not cut to length and the allen bolts are to be replaced with purpose made 5mm bars threaded only where needed)





Finally a couple of short vid's. Using the CB power supply donated by Darren (not yet modified) just to check it all works....




Got to swap the split link round... it's too deep on one side and occasionally catches the post! (the other side is the same depth as the rest of the chain)



Hope that shows this will work 




Ralph   

[Brass_Machine]

Yup! I believe that shows it will work most definitely. Very good.

Eric

[Divided he ad]

Thank you Eric   


Just the electric trickery to figure out now..... I'm going back through the post to see what Darren wrote   






Ralph.