Member postings for Peter Krogh

You lucky stiff...

Pete

I quite like the type shown in your first picture. They are simple, rugged, straightforward tools. Nothing more than a rotary table set vertical with a sensitive bubble. Quite easy to check and, if needed, calibrate.

That's my vote. Now please send that one to me!

Pete

Congratulations! It's been a long haul and there have been times I wished I could just 'transport' to your shop and help with those never ending problems. I'm still very confused about why all the issues with the clack valves; new ones, old ones, first they seal then they don't...... aaarrrrgggghhhhh!!!

When you get the ones from Julian installed we do want to know the outcome!!

Happy steaming,

Pete

That sounds like old wrought iron. Pure iron with fine carbon that is mechanically included, not in chemical solution. I hard to find the stuff anymore! If you acid etch the rod, fairly heavily, and it shows a linear structure like lots of wires bundled, then you've got wrought iron.

Pete

Excellent work, Raymond! That is something I've been wanting to try so it's great to see that you've made it work so well. Very encouraging!

Pete

I've been using Imperial for 60+ years and additionally Metric for 40 of those years. Most every tool I have is Imperial.

But if I was starting out, or not very far into it yet, I'd go with metric. Base 10 is so easy to work with. I don't work with fractions unless forced to by circumstances and then I'm mentally swapping the fraction for a decimal value!

Go metric young man!!

Pete

Just ban ignorance!

Pete

Yes, the purists are agast at the use of a wood 'straight edge'. But let me share this; I needed to straighten out the tight and loose places in the X and Y of my little mill. I embarked upon making a cast iron 60* x 14" scraping master so I could do the job 'properly'.

Well, as usually happens around here I needed to use the mill NOW for a few simple jobs. A search of the wood stash yielded a piece of hard maple which I promptly turned into the required shape. Some sandpaper on the granite allowed me to make the needed two surfaces of the maple very straight followed by (!!) spot blueing and local sanding with 320 paper. The maple showed less than a half thou spotted on the granite.

Wrapped with some silicon carbide paper I used this block to sand away 90% of the tight and loose problem. And it was very fast. The next day I checked the block with the granite again and the block hadn't moved.

So I'll say that the use of a wood master, carefully made, can do a huge portion of slide way correction.

Or aluminum, or......

Pete

Thank you for the very good information. I was more concerned with the front to back clearance than the side to side, but I need to think about both.

Kozo, on his 7 1/2" 0-4-0 specifies .004" to .010" front to back for the driven axle box. I haven't looked at the coupling rod tolerances yet, nor have I examined the clearance for the front axle.

He is very specific about the tapers in the grooves for the axle boxes to allow for tilting.

This is very interesting, at least for a guy who has not spent any time thinking about the subject!!

Pete

I'm reading this with great interest as I have it in mind to build a 7 1/2" 0-4-0 starting in about a year. Need to clear up the current mess. And I've never built a loco, nor worked on one yet. I'll get there.....

Anyway, I'm really surprised at the tight clearances stated! How tight are the clearances of full size locos? Even multiplying those clearances by 8 doesn't leave much room.

I have Kozo's 0-4-0 switcher book by the way and am slowly 'absorbing' it.

Please educate this pilgrim!

Thanks,

Pete

Edited By Peter Krogh on 21/08/2016 05:20:20

OK, I'll throw a hand grenade in that foxhole....

Banning something is an admission of failure. Usually education.

There, take that...

Pete

I have a South Bend 10K lathe with bronze bearings in the head stock. About 40 years ago I had the opportunity to work in a shop that had similar machines that were used with side loaded knurling tools. One of the lathes was, at that time, set aside for that work as the head stock bearings were badly worn because of knurling. The other machines had been repaired recently to correct that issue. The shop foreman was adament that no knurling with side load tools would be done on any but the designated machine!!

I've purchased three scissor types in the last 20 years. None have been capable of doing the job without significant re-work. Of the three, only one will work truly properly. The other two are primarily for agricultural operations. These unitsare made to a price point that is way below the quality needed. They have way too much clearance in the parts and most all of the designs are wrong to start with.

Somewhere in the albums here are pictures of 'correct' designs that have big plates containing the arms on both sides. That concept, combined with big, tightly fitted pins and stout construction, is the way to go. Great care is needed when machining the parts to maintain true square and perpendicular parts and holes. The pin holes must be all parallel with each other or the wheels will walk all over during use. The arms must fit quite snugly between the plates which must be flat and parallel.

The junk tools are OK if you just want to make a rough spot so the hitch pin on the tractor is easier to grab. But to do quality work requires first class tools.

Off my box now,,,,

Pete

Here is one:

http://www.model-engineer.co.uk/albums/member_photo.asp?a=36958&p=635564

Edited By Peter Krogh on 18/08/2016 04:18:05

Edited By Peter Krogh on 18/08/2016 04:27:57

Excuse the **** outta me but if a rotary table is not intended to rotate a part while a cutter cuts the part, then what the **** is a rotary table for????? Rotating something so it may be admired??

I call BS on these excuses...

Pete

Jason, I've bookmarked the GHW site. My German is really weak but they seem to have some good stuff there. I'll go back later, with translator in hand....

Finding small fasteners with proper proportions is a real problem, especially Imperial sizes. Those metric fasteners at GHW are nice enough I just might have to start using metric. For model fasteners anyway....

I do use both systems but metric when the job, usually a repair, demands it.

Pete

Jason, thanks for the info on the source of those fasteners. The Polly page is the only place I've seen them. This has been a stressful week, which is probably why I 'spaced' your references and links.....

Pete

Edited By Peter Krogh on 15/08/2016 00:12:56

Polly Engineering have what look to be hex head screws with well proportioned heads. Mostly metric.

Pete

Aye, that's a proper ship she is!!

Pete

I'll guess it was the footman in the pantry with a knife.....

Pete

Really make one wonder, doesn't it?

Pete

Now this is the sort of thing I watch this space for. Every day!

Pete