By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for macmarch

Here is a list of all the postings macmarch has made in our forums. Click on a thread name to jump to the thread.

<< First < Prev 1 2 3 4 5 6 7 8 Next > Last >>
Thread: Chronos silver steel, water or oil quench?
05/10/2010 09:44:28
The colour you temper to is determined by the use the tool is put to.
 
Assuming standard silver steel.  (should have "Stubbs" marked on one end.
   
                                     Oven Temp
Brass turning tools  180 C
Lathe tools                200 210 C      (and chisels)
Milling cutters           220 230 C
Scrapers                   190 200 C
Springs                      Flat out
 
By colour
Pale straw               190  200
straw                         210  220
dark straw                220 230
 
For things like cold chisels and screwdrivers  take them out of the oven and give a blast with a gas torch to get a little blue at the tip and plunge immediately.
 
I had a word with an old friend (85) and I quote,
" Quench in brine for a faster cool down. Quench in oil hardening oil but only if the silver steel is specifically an oil hardening type. The brine shoud be rock salt or other form not table salt as it has additives that can alter the material. Use a solution of about 10% salt. Don't forget that as you have cooled down a lump of overheated steel it will have all sorts of stresses in it so the slower and longer the heating and holding at the right temp during tempering the better."
 
HTH
 
PS If swimbo allows you can also use the chip fryer.  BUT MAKE SURE their is NO WATER on the parts.

As I was writing this I have been advised that Tubal Cain's book WPS1 covers this subject in great depth.
 
Edited By macmarch on 05/10/2010 09:46:37

Edited By macmarch on 05/10/2010 09:49:03

04/10/2010 20:06:42
When I was an apprentice, way back in 1900 and frozen to death, we were trained to water quench silver steel and gauge plate but oil quench tougher grades like EN24 and the like.  Perhaps someone has an ancient copy of Kemps or an old treatise on hardening circa 1950.  When I started to H & T at home there were times that cracking became apparent.  I have now changed my method of tempering and have not since had any problems that I am aware of.  After hardening and cleaning I temper in the electric oven. I find that a good half hour plus a minute per 10 thou of thickness does the trick . It is satisfying to see the required colour all over the part. It enables the grain structure to realign after the surface shock of quenching.  I have found that 'most' people heat to cherry red then quench when the cherry red stage should be held for some time to allow the grain to adjust all the way through before quenching and then the tempering temperature! held for the same reason.
 
Is there someone here that could give a simple explanation of the Iron/Carbon Diagram for the benefit of the newer members to the craft.
 
If you are a person that changes the own engine oil then keep some next time.  When a mild steel compenent has to used outside then heating to a dull red then dropping in the carbon rich oil won't harden it but it will give it long lasting protection against rust. Just don't try welding it after.
 
ray
Thread: Undersize Taps
24/08/2010 21:53:51
Hi Paul,
If you want the studs to 'lock' then use the taper tapt. The studs will then lock themselves in.  I wonder how you are measuring  the M8 taps. I have always repaired  Ali castings with 'helicoil' type inserts.
 
cheers
ray
Thread: ER25 Collet quality
16/08/2010 21:03:23
Hi Clive,
 Give Chronos a try.  Set ER25 2mm - 18mm £83/set
I have yet to have any problems with their gear.
 
usual disclaimer, just a satisfied customer.
 
Ray
Thread: Old Boiler New Regs
03/08/2010 21:25:09
Hi Philip,
 
Like you I started building a Caribou in 1977 then a change of job meant that it stood on the shelf for 25 years.  I had started the boiler.  My club boiler tester had a look at the drawings last year and only made one change.  The dwgs called for brass for the various bits and pieces to be attached. These had to be changed to lead free phos bronze, otherwise no problems. HTH
 
ray
Thread: Can you easly Silver solder to EN1A
04/07/2010 11:19:17
Silver soldering en1a will be fine, with the correct flux etc.  If you are going to weld then use EN3A. EN1A is for easy machining etc.  When welded the the interface will not neccessarily be homogenous.  There is a good chance of cracking.
 
Ray
Thread: mock up materials
22/06/2010 21:12:43
I cannot remember the name of it, but there is a material of a plastic nature that was used to prove the numbers when producing g code for cnc machines. It could even be screw threaded and tapped.
 
 
Thread: Which grade of steel required to make gears
15/06/2010 10:10:55
Julie,
 
I would be a little wary of using EN3A as a gear material. This is a general purpose steel that is readily machinable, bendable, (fabrication duties) and suitable for welding. It does not have any gut strength in a shear application.
as you say en5/6 upwards will be fine.
 ray
Thread: Valve gear - looking for a good introduction
07/06/2010 23:09:00
You could have a look at this site. Be warned LOTS of goodies to tempt you.

http://www.camdenmin.co.uk/
 
Ray
Thread: Turnbuckles
01/06/2010 22:26:27
Can't help with a specific supplier but you should be able to get these from any ship chandler.
 
Ray
Thread: Winding electrical coils
25/05/2010 09:34:40
This probably won't help much, but I'll throw it in anyway.  If you can find a 'mature' radio ham then try to locate a copy of Wireless World from the late 60's early 70's.  In one of those there is an article with drawings etc on building a coil winder. An old friend of mine built it and it would pile wind, wave wind and even wind the rotors on small motors. it was fully adjustable and quite simple to use. If you or anyone can find it I would be interested in it as well. My other hobby is Astronomy, Optical and Radio.  The receivers that I need to build use coils for the R.F. stages.
 
 
Ray
Thread: Joining a Society - contrasting experiences
24/05/2010 22:06:24
Over the last 50 years I have been a member of 6 different MES'S. (Due to moving about the country)  I believe that if you join a club and want to get help and be able to draw on the knowledge of those who have done it before etc then you should  put something in. In ALL cases I put in time and effort helping out on track days and the like. This was fine until I let it be known that I was building a non english Loco. (Caribou)  Boy did it get cold.  It seems to that 'Model Engineering Societies/Clubs' are only interested in puff puff's. As Chris says, its the cliques that create a problem.
Static steam, Traction engines, Steam vehicles etc are relegated to the few that huddle in the corner on club nights. This to me seems a shame as it will lead to the demise of clubs and the interest of up and coming model engineers.  As others have said, on this site you can 'meet' and discuss anything with the advantage that you can put in the most important thing of all, your own experience.  If its a not too emotional subject then perhaps it could be addressed in M.E.
 
cheers
Ray 
Thread: securing a facing cutter on an arbour
18/05/2010 10:16:35
I presume that your cutter is of the shelllmill type. Does it not have a keyway in the bore? For this size of cutter with the ability to remove large amounts of material at one pass it needs one. I would suggest that you fit a cap head onto the stub mandrel and cut a recess in the bore of the cutter to locate on the head. hth
 
ray
 
Thread: Boiler stays
01/05/2010 09:36:40
Jason, That's what I meant to say. Don't set a rivet when there is a gap;  only to hold parts together for SS.
 
Ray

Edited By macmarch on 01/05/2010 09:37:00

30/04/2010 19:50:05
You are using the rivets and stays to prevent the flat sections of the boiler from bowing and  blowing out.  So, yes set the rivets. Do not, however, rely on rivets to hold against pressure to compensate for bad fiiting of the plates.  Rivets should be used to hold while siver soldering.  There is no gap between the plates so silver solder cannot flow bvetween them.  The idea of using screwed stays is so that there is no  possibility of them popping out. They also hold the plates rigid to each other.
 
Ray
Thread: A beginners locomotive
27/04/2010 18:42:34
Hi Vincent and welcome to fold.  Have you considered yet as to which gauge you want to build?  As you are starting out I will assume that it will be 3 1/2".  From experience I can reccommend the Caribou. Not to dificult to build, Has outside gear (Baker so no fiddly bits.) As its Canadian It makes a large model for this gauge. I have seen it pulling 4 adults and 4 children.
 
Ray 
Thread: Do you get what you pay for ?.
25/04/2010 22:07:22
For those who are new to tapping may I suggest that spiral point taps are used, provided they are through holes or are deep enough to hold the swarf.  These taps eject forwards thus the body of the tap is thicker between cutting edges making them stronger and if you do break one it is a lot 'easier' to get it out. There is also the advantage that for some reason sp pt taps seem to drag themselves into the hole and stay perpendicular.  I find spiral flute taps very good for the soft metals.
 
Eric. I can reccommend Kirjeng.  You can choose to have used or new on most items he sells.
 
Thread: Cutting Bevel Gears
25/04/2010 18:36:27
Hi All,
 
Thankyou for the info.  Paul White 3 perhaps you can help, ccan you contact me? (my profile).
 
cheers all
 
Ray
24/04/2010 22:01:02
Out of interest, has anyone been able to get a copy of Haroaki's (not sure of the spelling) book on building Shay type loco's where he descibes how to cut spiral bevel gears on small home equipment?   I have tried the local library but to no avail. I would find £60 for the book for a few pages somewhat  excesssive.
 
24/04/2010 21:09:04
Hi Engine Builder,
 
Daval Gears will, if asked nicely send you a cat of "Metric Drive Components"
It contains all you could possibly wish to know about gears. They can be contacted on 01707 283131
 
<< First < Prev 1 2 3 4 5 6 7 8 Next > Last >>
Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Shopping Partners
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate