Model Engine Maker

Supporting => Tooling & Machines => Topic started by: BillTodd on October 17, 2015, 06:24:24 PM

Title: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on October 17, 2015, 06:24:24 PM
Having finally persuaded Ryan to cut out my part on the works water jet (Lesson: never tell someone that you're in no hurry!) I have finally finished my Long radius attachment. I need the attachment to make some rollers for my Brother's Ranalah engish wheel (https://www.google.com/search?q=ranalah+english+wheel&safe=off&source=lnms&tbm=isch&sa=X&ved=0CAkQ_AUoA2oVChMI75brlP7JyAIVCzsaCh3UGgZS&biw=1131&bih=742)

The Hardinge cross-slide can be disconnected from the cross-slide nut by undoing a bolt on the cross-slide. The cross-slide is than moved by a slide that attached to the back of the cross-slide body

The LRA uses the Hardinge's taper attachment as a rear pivot point for a radius arm. The slide is now fitted with a locking screw to stop it moving. The radius arm is attached to a plate that is secured to the cross-slide. A sliding joint at the pivot and a long slot in the plate allows the radius to be adjusted from about 2" to just over 12" .

By presetting the radius using the plate (to 10 3/4") the cross-slide DRO can be set (to 21 1/2" 'cos it measures diameter) and then used  to accurately adjust the radius as required.
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on October 17, 2015, 06:48:43 PM
https://www.youtube.com/watch?v=0CuoGCDtnwI
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: Jo on October 17, 2015, 07:36:19 PM
Thanks Bill, That is giving me some new ideas for Mr Silky :whoohoo:

I don't have an original HLV-H taper turner for Mr Silky but it is on the list (as is a new design traveling steady  8))

Jo
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on October 17, 2015, 07:45:14 PM
My taper attachment is actually for a Harrison that someone adapted with a large block of ally to fit the hardinge , I bought it for £70 and it paid for itself with the first job I used it on :-)

This is my first attempt at a travelling steady:  I intend to modify it so that the support arm can be repositioned along a slide (mounted across onto the other side of the cross-slide)  ATM the support arm is too far forward of the tool


[edit] I've attached the DXF file of the LRA top plate
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: rhankey on October 17, 2015, 09:30:12 PM
That's a pretty nifty idea for using the Hardinge taper attachment to help make a radius attachment.  Your solution might also give you a bit more space to work closer to the chuck than the official Hardinge radius attachments does.  I tracked down a reasonably priced HLV-H radius attachment for my HLV.  I made a small adapter (spacer) so it would clamp to the narrower bed of the HLV without any modifications to the radius attachment.  I can put the adapter on the front or back side of the bed, which gives me much larger range of diameters than Hardinge envisioned.
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: Jo on October 18, 2015, 10:25:17 AM
:thinking: I reckon it would be equally easy to knock up a profiling tool along the same lines.

Jo
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on October 18, 2015, 09:46:19 PM
Quote
:thinking: I reckon it would be equally easy to knock up a profiling tool along the same lines.

You could certainly follow simple profiles, although the typical hydraulic profiler has its slide at 45 degrees to allow it to cut left hand faces as the carriage moves.

I was making some tear drop and tri-ball handles for my little Cadets, before I tried skiving  (http://www.practicalmachinist.com/vb/general/experimental-skiving-tool-283635/#post2274339)them, I looked at the possibility of making an electric profiler. 

I was thinking about using another top-slide (or adding a mod to the lathe's own) driven by a small motor and an amplifier feed back system using a cheap force sensing resistor.  The motor/amplifier would be set to drive forward at a fixed speed until a stylus (fixed to the slide) contacts the profile plate where it stops at a set force and will reverse if the stylus is forced back.  (ISTR something similar was produced by an American company in the 60's)

[edit] picture of the finished roller:  I was getting a bit of chatter and struggling to get a finish so  I had to polish it.
I was using the arbour from my mill, so perhaps I should have mounted the roller on a shorter mandrel. It has two 100mm radii with a central 6mm flat.

Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: stvy on October 30, 2015, 05:17:17 PM
Bill,

Very interesting. I don't suppose you know what the make and models of hydraulic profilers/copiers are that are suitable for a hlv-h?

Steve
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on October 31, 2015, 06:49:53 PM
Bill,

Very interesting. I don't suppose you know what the make and models of hydraulic profilers/copiers are that are suitable for a hlv-h?

Steve

Hi Steve, 

Not off the top of my head but, I can find out the type used at our press shop on their HC's  next week for you.

From memory they are no more than 18" long   (and are orange!)

Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: stvy on November 02, 2015, 09:38:37 PM
Thanks Bill. Please do let me know.

Find a picture of one attached. Not the interesting capstan tail stock as well. I've seen a few of those about and would very much like to source one.

Steve
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on November 02, 2015, 09:52:05 PM
One day......  when I find the time... 
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: stvy on November 02, 2015, 10:31:01 PM
Bill,

I'd be interested to discuss design ideas for this. I've been seriously thinking about making a pattern for a new casting but basing the internals on an existing design by Schaublin. For their "star wheel" tail stocks for the 125 or 135 lathes (and perhaps other models) they have 2 gear ratios. 3mm or 150mm per full turn. Other design goals I have is an to get around the stiction you can get after locking down the HLV-H tail stock. I had my bed plate reground and the tail stock has been scraped in and it can really stick in place after locking it. Of course the good part of that is its rock solid in use. I am worried as I get older it will be harder to move around than I'd like. For reaming, core drills etc I think a 3 MT spindle might be nice rather than the standard 2 MT and finally the casting should be designed to mount a DRO scale.

I thought about purchasing a "donor" Schaublin 135 2 speed star wheel tail stock. However the cheapest I've found available so far is more than what I paid for the HLV-H! Plus those have a 5 MT spindle which is a bit big.

Steve
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on November 02, 2015, 11:16:42 PM
Quote
basing the internals on an existing design by Schaublin.

you took the words right out of my mouth :-)

their two gear system is relatively easy to replicate (having previously studied the cazenueve design)

pm me with your email address and I'll pop some pics over to you.


HLV-H tailstock stick and shoulder ache :-*   I've picked up an extra lenght of hlv rack to go under the tail stock end with the idea of adding a rack gear to the TS... another project awaiting the round tuit.
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: stvy on November 02, 2015, 11:24:20 PM
Pm sent

Thanks
Steve
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on November 03, 2015, 03:44:45 PM
Some people here may be interested in the Schaublin two speed gear mechanism:

 The gear is fairly simple:

In low speed, it uses a small planetary gear (bottom left) which is fixed into the hub of the handle (large bits in the middle of photo). The planetary gear orbits a fixed spur gear  (lower-middle with three mounting holes) it also engages with the shaft gear (just to right of planet gear) which is cut to the same CP as the fixed gear but with one* more tooth. The net result is that as the hub is turned the shaft gear has to move one tooth further around to stay in sync with the fixed gear.

In high gear , the shaft gear is retracted away from the planet and into an internal gear (far right) which is fixed to the hub , so each turn of the handle is a turn of the shaft.


[edit] * just modelled it
Title: Re: Long Radius attachment for HLV-H (one for Jo)
Post by: BillTodd on November 04, 2015, 10:10:02 PM
Animation of the gear mechanism in slow mode
SimplePortal 2.3.5 © 2008-2012, SimplePortal