Here is a list of all the postings Clive Brown 1 has made in our forums. Click on a thread name to jump to the thread.
|Thread: Wanted ... design for snifting valve suitable for large boilered Tich.|
ME design for a 5" gauge version to illustrate features. The valve body is attached to the smokebox wall by the 3/8" thread using a suitable nut.The 5/16" thread is piped to the wet header. The valve allows air to be drawn into the header when the regulator is shut whilst the loco coasts. Steam shuts the valve when the regulator is opened.
Its positioning can be anywhere convenient.
Edited By Clive Brown 1 on 10/07/2019 15:21:11
Edited By Clive Brown 1 on 10/07/2019 15:23:12
|Thread: Hot water from the snifting valve,|
Don't know the Coumbia design, but does the ashpan have any damper arrangement that might be stifling the fire?
Or perhaps the builder hasn't provided sufficient air hole area past the ashpan. Have you seen this loco in steam?
The discharge from the snifting valve may well be because it needs pressure to keep it closed. The regulator might be leaking slightly, as many do, allowing this leakage past the valve.
|Thread: Internal collets|
Expanding mandrels are useful, but i'd think that accuracy could be an issue, With the ER system, the concentricity is maintained by the 16 deg. taper solidly mounted on the machine spindle. With the expanding system, keeping the taper concentric with the machine spindle would be more difficult.
Edited By Clive Brown 1 on 03/07/2019 11:47:32
|Thread: Using a Metal Cutting Disc on the SX2 Mill|
The method obviously works but, for myself, I'd not be too happy with a cutting disc in my mill. Also, at the low spindle speed, i'd expect disc wear to be fairly high giving lots of grit.
For such a job, I'd probably go for mounting the bar in a 4-jaw independant chuck in the lathe and parting off to just over the required length for subsequent facing off. No pricey slitting saw going dull and no grinding grit.
Tailstock support using a small centre hole in the r/h end of the bar might be helpful.
Just my two-penn'orth
|Thread: Warco WM16 machine vice|
I have a WM16B and the vice I mostly use is an equivalent to the Arc Versatile Milling Vice, 80mm jaw width. The swivel feture is hardly used although it can be handy on the rare occasions I want to mount the vice "lengthways" on the table.
I've also a 4" Abwood but that's a bit of a heavyweight for most of my work.
If the size suits your intended use, the Arc vice is good value imo and larger sizes are available
Can't suggest a particular table except to say that I wouldn't wish to have smaller than 5" or 6 "
hope that helps
Edited By Clive Brown 1 on 20/06/2019 09:46:01
Edited By Clive Brown 1 on 20/06/2019 09:54:11
|Thread: Making High Speed Steel Injector D Bits|
Laurie Lawence, in his fairly comprehensive series of articles in ME of 1986, suggested that making an LBSC injector that worked was mainly a matter of luck. He saw the design proportions as being satisfactory, but the simplified manufacturing description did not allow consistency.
The DAG Brown book builds on the Laurie Lawrence methods.
|Thread: Jones- Shipman tool spares supplier|
Rotagrip do some J&S tooling I think. Might be worth contacting them.
|Thread: Internal grooving help required.|
A couple of home-mades that can cut close to a blind end. One is made from 3/8" silver steel by offset turning in a 4-jaw independant chuck followed by filing and hardening. Silver steel nowadays seems a rather under-valued material for cutting tools but it's fine with proper use.
The other tool has a 3/16" dia toolbit. This is clamped by drilling the bar lengthways and inserting a clamping rod which is tightened by a grub-screw accessed from the mounting end of the bar. A G H Thomas design for his boring head IIRC.
Edited By Clive Brown 1 on 08/06/2019 15:50:24
Edited By Clive Brown 1 on 08/06/2019 15:52:04
Edited By Clive Brown 1 on 08/06/2019 15:52:28
|Thread: Problem with slitting saw arrangement...|
I don't think the L/H locking nut will make much difference. The 1" mandrel that I use on my small mill has a R/H thread. I would see a 3/32" saw into steel as being quite wide for a friction drive set-up.Try a washer as suggested but I'd replace the key and go carefully.
|Thread: allchin 1.5 scale o rings|
When the repeat construction series was published in ME, starting sometime around 1974, Hughes did provide some details for O-rings for piston and glands. AFAIK, the commercially available drawings are still in the original form however.
|Thread: 1" Minnie oil pump problem?|
Hi Terry; "cut-off " applies to the valve movement as adjusted by the reversing lever. Full movement gives steam admission for 100% of the piston stroke, (100% cut-off). Progressively less as the lever is moved towards mid-position. My point is that since the engine won't function at small cut-offs, say 25- 30% minimum, it doesn't need lubrication for that situation.
Dunno about the Minnie, but my Allchin water pump drive is off the crankshaft. The lubricator drive is off the valve spindle so the ratchet stroke is altered by the position of the reversing lever. If the stroke were to be too small, the drive wouldn't pick up a new tooth. I can't see that being an issue as the engine won't run with the valve gear in that position anyway. As long as the pump works with the cut-off at a working position., that's OK.
|Thread: Super 7 - Best way to use ER25 Collets|
The obvious difference between the two types is that the MT holder will not allow long lengths of bar to be held through the mandrel.
I wouldn't think that either one was inherently more accurate than the other.
|Thread: What are these change gears for?|
Similar to my Boxford ME10.
|Thread: Loco hand pump casting from Reeves|
The 3/4" dimension refers to the cylinder OD. Seemingly an extraordinary design. What's wrong wth increasing the bore to 5/8", which would have given plenty of capacity IMO?
|Thread: HSS or CS taps and dies|
IMHO both hss and cs tapsof good quality are suitable for the type of ME work that I do. I have both sorts, acquired as needed but mainly cs. I believe that hss taps are usually produced by thread grinding, whereas cs taps are cut threads. Grinding does, I understand, produce a thread-form to a tighter tolerance and possibly with better relief angles to the cutting edge, so is better for high class work.
I doubt whether the red hardness of hss is often called into play, certainly not in my workshop!
That's my tuppenceworth,
Edited By Clive Brown 1 on 20/05/2019 14:26:03
|Thread: Drilling cast iron - where did I go wrong?|
|Thread: fobco drill|
My Fobco Star is as others say. The Table is clamped by a through bolt and short ball handle. The slot is closed off at the bottom. I too use a piece of tubing to get more leverage. I put this need down to 50+ years of wear causing a slight increase in clearance on the column. In use I try to minimise the number of times I move the table with an array of wood packing kept by the machine.
The head is clamped by a two-piece clamp, also shown above. It's more effective than the split clamp but there is not enough metal in the table casting to modify it to that type.
Edited By Clive Brown 1 on 16/05/2019 08:39:22
Edited By Clive Brown 1 on 16/05/2019 08:40:31
|Thread: DIY Bed Gap|
The Saab discs that I skimmed did have a minimum specified thickness for such work.
I'm not a car enthusiast but I thought that the reduced life of brake discs since the "olden days" stemmed at least in part fom the change from asbestos based maerials for the pads. This forced a change in the material spec. for the discs to a softer value.
I once wanted to skim the brake discs from a Saab 99. These wouldn't quite fit on my Boxford ME10 so I put spacers under the headstock, which turned it into a ME10.5. Job went quite well as I remember with a carbide tiped tool.
Being a Saab, these discs were quirky in that they included a drum for the separate hand-brake shoes. The working surface of these drums corroded very badly, as they didn't ever do any real work,. I could skim them with the same set-up.
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