Making "same length" pillars with no DRO?

[raynerd]

Hi, I`ve not been on for the last week or so much as I`ve been busy re-decorating. I have a long summer holiday coming up and my wife has started the "to-do" list early 

I know for most of you this is probably a very simple issue but the next step of my clock build requires me to make 2 pillars (actually four in total, 2 different sets) which hold a plate in which pivot holes are drilled to suspend a clock wheel arbour. The pillars need to be perfectly the same length or the pivot hole will be at an angle!

I tried this before when I made my skeleton clock for the frame pillars and despite my best efforts I didn`t do a great job and they were not spot on.

I`ve no DRO on my lathe. Has anyone got any suggestions on how to essentially part off or cut to size two perfectly equal lengths of bar stock?

I expect this has been covered in other build logs and so any links are welcome, my search didn`t bring up anything relevant.

All the best
Chris

[picclock]

Does the length need to be done on a lathe ?. Easy using a mill.

picclock

[BillTodd]

All you need is a depth stop for your lathe's spindle, then fix a dial gauge or a hard-stop to the bed and face the part to length.

Alternatively, if your parting off is  good enough for the job, is to use the tail-stock with centre as a length stop.

Bill

[krv3000]

HI well i had to nock up sum dawels all had to be spot on all i did was mack a snug fitting sleve to go over the stock in the lathe chuck and yoused  a center in the tale stock  then cut it off with patining tool the distence between the end of the sleeve to the center DONT for get to  add the thiknes of the parting off blade will be the lenth of the dawel or in your case pillers for your clock

[PekkaNF]

length/diameter/accuracy?

1) Goes trough lathe spindle, but freaking long: I would cut them approximately to correct length, Set facing off to shortest pilar and use any heavy object parked behind of the spindle to stabilize/set lengt. Feeler gauge is good idea between back stop and stock - it is removed before the cut of-course. Lock the cross slide and face both on same setting.

2) Does not go trough lathe spindle: Back stop inside the spindle. Steady rest. Same procedure than above.

3) As described before - in this thread. Parting off with a tail stock mandrel as a material stop.

Or is this something clock special again?

Pekka

[srm_92000]

Hi Chris,

What I normally do is face and turn the part, then part-off over length by .5mm or so.
Face the parted end to a nice finish remove and measure the length, noting down the amount still to remove.
Re-chuck with either end (depending on design).
With the compound set parallel to the ways, the compound dial zeroed with the handle turning clockwise and the part spinning, touch the tool tip onto the end of the work using the saddle, very lightly. I use a magnifying glass to help to see just when it touches.
Then just use the compound dial to advance in steps until the measured amount is removed.
I just did it this way with three bits of steel taking no particular care and they're all within .02mm
It's surprising how accurate you can get just touching on something by eye especially if you do it the same on both.


Cheers,
 
Steve

[raynerd]

Thanks for all the suggestions so far. I`ve just been googling like mad to find a post that i`m sure either Stew or John (Bogs) made regarding making a chuck backstop for the lathe?? I`m sure there is one out there!

I expect Steves reply is the easiest. Just parting off near to length, measuring and then taking off what is needed.

If anyone knows the link I`m after I`d be grateful. Thanks for all the suggestions

[John-Som]

Hi Chris

This might be what you are looking for http://start-model-engineering.co.uk/machines-and-tooling/minilathe/mini-lathe-mods/

(scan down the page till you find it)

John-Som

[Bogstandard]

http://madmodder.net/index.php?topic=1649.0

[raynerd]

FWIW - can I just say that I find madmodder search very strange at times - I searched, back stop, backstop and many other variations which got "hits" but never to that thread. That is the one I was looking for, thanks John.   That being said, John-Som, interesting link as well , thank you both.

Chris

[JimM]

I found the same Chris, after your initial post I tried a few searches on this site but Bogs thread never came up. Just tried again and there it was    It also threw up this thread which has a different design of backstop

http://madmodder.net/index.php?topic=1675.0

HTH

Jim

[raynerd]

John-som, yes sorry! that is the link just on a different site but yes Bogs design!

Chris

[doubleboost]

Hi
Chris
Just been making the colums for my marine engine
I just measure then use the compound scale (it is easy between centres as you can get the vernier on both ends)
John

[Anzaniste]

I have never tried this but the idea came to me as I was reading this thread. I assume that the actual length is not super critical just that all the pillars must be cock on the same length.
How about equalising the lenghts by screwing one  end on to a face plate. Fix all the pillars to the faceplate at the same time  and then face off the the ends simultaniously. They are bound to be all the same length then. The cut taken will depend on the diameter of the end of the pillar and the fixing screw size and the length of the pillar. I guess if the aspect ratio of the pillars was great you could arrange some sort of support between them to make the whole bag of mashings more ridgid.

Just a thought.

[loply]

If it's possible go chuck them both up at once in your 4 jaw chuck you can face them at the same time.

Depends on the dimensions etc though.

[Brass_Machine]

FWIW - can I just say that I find madmodder search very strange at times - I searched, back stop, backstop and many other variations which got "hits" but never to that thread. That is the one I was looking for, thanks John.   That being said, John-Som, interesting link as well , thank you both.

Chris

Depends on where you are in the board when you search... seems to me, and I need to verify this, that is I were to click 'search' while reading this post... I would only be searching 'How Do I??'

Now if I search from the main page, I search the whole forum. I need to verify this.

Eric

[doubletop]

This depends on your lathe; but I worked out this solution when I had a similar problem. My little lorch has a 10mm bore that takes collets similar to 4C(?) with a draw bar from the back. The chuck screws onto the nose and will go over a collet. Its as simple as installing the piece of round stock a collet, set it to some suitable length, and putting the chuck over the top. Once you've made the first item the you have the top slide vernier reading for the rest. I'd imagine if your lathe has collets in the nose and a screw on chuck it could work.

No pictures sorry

Pete