Here is a list of all the postings Acrosticus has made in our forums. Click on a thread name to jump to the thread.
|Thread: Gear cutting calculation - 73 teeth|
Myford leadscrews were indeed rolled threads, I saw this done on a visit in around 1977. It used a very powerful press. ISTR the rationale was that the forming in this way led to a very strong product. The leadscrews for power crossfeed warped considerably when the keyway was cut and had to be straightened in Vee blocks.
|Thread: Funicular Railway "Fixed Points"|
P.S. There is a trailing cable running down beyond the carriage, but as you can see in the photo, this is much thinner than the one which carries the load.
It's a funicular: there are only two carriages. One goes up pulled by the cable, as the other comes down, in balance. They have double flanged wheels on the outer side of the loop, one carriage on the left, the other one on the right. They don't need to be turned, as they never come off the end of the cable The track is constructed to feed the cable around the correct side of the loop as the carriage comes down to it., as the photo shows.
This type of funicular carriage has double flanged wheels on the outside rail, and unflanged wheels on the inside, point-side, of the loop, and so are guided by the continuous outer rail of the loop. So, the two carriages are (obviously) mirror images in this respect.
|Thread: Club Night Speakers|
And if you use any, please tell the site owner (Me!)
No-one ever seems to
I'm thinking of taking this site down because no-one ever uses it, do they?
|Thread: A workshop idea for the short sighted|
You can get clip-ons that go on the top of specs. I bought these many years ago when I had trouble looking upwards to paint e.g. soffit boards on my house, and I couldn't see upwards properly as to what I was doing. They can be very handy. I think my optician supplied them.
Edited By Acrosticus on 12/02/2015 15:14:29
|Thread: Dickson parting blade holder problem|
I think you need a blade with a trapezium X-section, i.e. an opposite bevel along both edges.
The 1/2" blade in my Myford-Dickson holder has the bevel edges: the holder is made for that type, presumably the same though might be a different height blade
Parting blades with right angled edges are rare in my experience: However the tiny 5/16" blade in my special Dickson rear tool post holder is T-shaped with a very narrow top to the tee, to give side clearance when cutting, and has no bevels. (Blades of this type are very difficult to find)
|Thread: Ground level 5" gauge track|
You could have a look at the 3 part article I wrote in the "ME" Nos 4289,4291 and 4293 describing how I did it. You may find that helpful. I have found the system I used to create the track bed has worked well for me. I used PNP track components and have found them a very good system also (satisfied customer, usual disclaimer)
If you are building points, Doug Hewson's EIM article is very useful, but don't use brass screws to fasten check rails and frogs made in aluminium rail. Mild Steel is less likely to result in electrolytic corrosion than is brass and should be preferred. For points sleepers I used afrormosia
|Thread: Emma Victoria|
Looking at the drawings of the boiler, I see that no dimension is given for the vertical position of the support angles on the firebox sides.
Working back from the smokebox drawings in Issue 4467, the boiler centreline distance is 3" above the upper edge of the frame.
The height of the boiler centreline over the bottom of the firebox is 4.1/16" above the bottom of the fire box foundation ring, plus 3/16" projection of the inner wrapper below the ring, a total of 4.1/4". The bottom of the support angles should therefore be 1.1/4" above the bottom edge of the boiler as drawn ( i.e., 3" below the centreline)
|Thread: Pozilok chuck servicing|
Thanks Neil, I'll do that.
To remove it you need a tool like this special, which I made from a piece of 22mm dia bar about 60mm long.
The slot is a clearance 10 mm wide and the centre is recessed with a 10mm centre drill to clear the point inside the chuck. The two flats on the other end were gripped in the vice , with a spanner used on the flats of the chuck.
Hope this helps, anyway,
Well, no answers from here so far, so I took a chance on it, made the necessary special tool and successfully removed the centre point which was a lot more stuck than I had expected, So, point re-machined and chuck is back to normal again.( I wish the rest of what I did today had turned out as well as that!)
I've come to the conclusion that the allen screw is only there to stop the collet rotating, and not to hold the centre point.
How is the back centre (blunted on mine - by previous owner, not by me!) removed from the chuck body.
The allen grub screw which I assume is supposed to engage with one of the flats to hold it in place has not been engaged, so if screwed in it is now well jammed. I intend making a special spanner of 22mm dia steel bar with a 10mm wide slot in the end, in the hope of unscrewing it so that I can renovate the point, so would appreciate knowing that I am going in the right direction.
Thanks in anticipation!
|Thread: Emma Victoria|
|Thread: case hardening with sugar-question about terms used|
Tate may have given us the Tate Gallery, but Oliver Lyle gave us "The Efficient Use of Steam" one of the best and easiest to read textbooks I've ever read and a book I think I will buy if I ever see a copy. The style is inimitable and the book is famous for it. Lyle basically documented the practice of what T&L had achieved in their sugar refineries.
|Thread: Linked drive belts from RDG|
Fenner PowerTwist belts do have a definite right way round and there are arrows on the belt every tenth link to show this. (The PowerTwist type I bought from Chronos doesn't have any arrows so presumably it isn't Fenner's.) The tab-type tails underneath should, I understand, always be trailing, i.e. the opposite of the recommended way for Nu T-Link.
The latest Fenner Instructions for installing NuTLink belting say that the belt may be installed either way round
The old instructions of which I kept a copy say
DIRECTION OF TRAVEL
The belt will run equally well in either direction but preferably to run as illustrated with with tails leadin
The tails being the narrow part of the link underneath the belt
I fitted a Z-section Brammer belt (T-link) to my S7 motor drive and couldn't believe how much of the belt vibration disappeared when running at high speed! Wonderful!
Following this success I fitted a Fenner Nu-T-Link belt to my Startrite Super Mercury Bench Drill. The T-rivets initially fouled the head casting on the largest pulley so I had to machine a bit of the casting away, but when finished the reduction in vibration was significant.
Subsequently I fitted a Fenner Powertwist belt from Chronos to a slightly smaller bench drill and this again solved a major vibration problem: the standard V-belt slapped against the belt guard at high speed. If my S7 headstock belt wears out again (once in 25 years last time) I will have no hesitation in replacing it with a link belt either T-link or Powerplus.
Yes, I'm a convinced fan of link belts, expensive, but well worth it just to reduce vibration problems, never mind avoiding having to dismantle the headstock.
|Thread: Simpler the Better -what do you use?|
DraftSight is a free CAD package downloadable from Dassault Systemes
I have this and it looks useful, though I haven't done much with it yet.
It will load and save in DXF and DWG formats.
|Thread: Sealing a loco smoke box|
I was advised to use Holt's "Gun-Gum" (from auto accessory shops. It is sold for patching exhaust/silencer holes, and was still available four years ago), which I did and it has been entirely successful.
Yes the hole must be sealed up, or the smoke box vacuum will be defeated.
I have never seen it actually on drawings, but LBSC in his "words and music" says to use "asbestos string annointed with plumbers' jointing". Martin Evans advocated something similar in his "Manual" but things have moved on a bit from the 1960s!
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