Setting up a Hardness Tester

C

Chris Meyer

Joined
Aug 15, 2005
Messages
1,297
Greetings,

I recently picked up a Louis Small "All Scale" Rockwell Hardness tester, model 8-SSA, on eBay. It appears to be in excellent condition. I purchased a test block for the unit and tried it out. I discovered that the arrow for the minor load does not reach the proper mark. I'm assuming that the tester just needs to be adjusted to zero it out, but I have no idea how to do it. Is this something that I could do myself and, if so, how do I do it? Will I need to hire a professional to adjust it? I hate to pay someone if it's a simple operation, but I also don't want to screw the machine up. I would greatly appreciate imput from anyone with knowledge in these matters. Thanks. -Chris
 
Ask this question on the "Shop Talk" section . There are test blocks available to check and adjust the tester.
 
Moved from General Discussion since these guys are great and know what they are talking about.
 
you should be able to turn the dial by hand..............post a picture of it....
Brian
 
I bought a certified test block for the machine. It should give a reading of approx. 58.8 Rockwell C, but it doesn't. I'm assuming that this is because the tester needs to be adjusted. Does anyone know how this is done? I can turn the outside of the large dial so that I can zero that out, I just can't get the arrow for the minor load to reach the triangle mark. Once the arrow reaches that mark, that's when you zero out the major load dial (I think). :confused:

LouisSmallTester12.jpg


There is an adjusting screw inside the machine, but I don't know what it does, so I'm hesitant to move it.
LouisSmallTester4.jpg



Here are some overall pictures, in case they would help.
LouisSmallTester3.jpg


LouisSmallTester8.jpg
 
Michael, do I need to put the handle in the forward position before I bring the anvil up to set the minor load? I've tried it both ways, and it still didn't work. Since you have a similar machine, perhaps if you give me the steps you use to get a hardness reading, then I can figure out if I'm doing something wrong.
 
Chris Meyer said:
Michael, do I need to put the handle in the forward position before I bring the anvil up to set the minor load? I've tried it both ways, and it still didn't work. Since you have a similar machine, perhaps if you give me the steps you use to get a hardness reading, then I can figure out if I'm doing something wrong.
Click to expand...

with no load at all on the diamond, make sure the handle is in the forward position. Bring the screw up untill it touches the testblock. keep bringing it up untill the big needle turns about 3 times and the small needle is at the top position. turn the dial untill the big needle lines up with set. push the handle on the side forward, wait untill the needle stops and bring the handle forward.

Thats how it is supposed to work. The one i bought is a piece of crap and it needs major repairs before it is usable. I have a question for you. Could you please weigh the 3 weights on your machine and tell me what the weigh? Mine came without weights or an arm to put the weights on so I have to make them and I dont know how big to make them. Thanks for the help.

Michael
 
Michael,
Thanks for your response. My machine came with three weights that hang off of a metal rod. The weights weigh 60kg, 50kg, and 40kg, for a total of 150kg. According to some information of Kevin Cashen's web site, this is the proper weight for the major load. He briefly describes how to conduct the test, but makes no mention of having to initially turn a handle forward to get the minor load, like our machines apparently require. http://www.cashenblades.com/Info/Rockwell.html

The rod that holds the weights connects to a simple "T-shaped" bracket. The bracket has a hole on either side of the "T". The arm inside the machine has two strange looking bolts that are more like threaded rods, with nipple shaped ends. The nipple shaped ends point upward, and the holes in the "T" just slip over them. Hope this helps.
 
150 KG is approximatly 300 pounds. That weight is obtained through the use of a pivot or knife edge and lever.
I need the actual weight of the weights. You would have to take them off and weigh them seperatly. It might be a couple of pounds but i need that total so I can fab them out of brass bar or what ever i can find. I will fine tune it by drilling holes or adding washers but i want to at least get close to start with.

Could you call to discuss?
262-617-8043
 
Michael,
I'll take the weights off and weigh them. I think I'll have to use a bathroom scale, so I'm not sure how accurate that will be. I have to run out for a few minutes but I'll give you a call a little later with the weights.
 
Michael,
I got your voice mail when I called. The weights weigh a total of 11 1/2lbs. I couldn't weigh them individually because my digital bathroom scale wouldn't read them. I suspect it takes 10lbs to get the thing going.
 
Anyone have any ideas on the screw setting? Min slams pretty hard when i hit the paddle. I dont know if the cylinder is working on mine.
 
Did you ever get the hardness tester sorted out? If not, I may be able to help.
Regards,
Duhawki
 
If your asking me, no i didnt. IT seems to work when it feels like it so I cant rely on it. The readings are all over the place.
Of course I could say that my knives are heat treated to 52 to 77 rockwell.:jerkit:
 
I tried to phone adammichael at the 262-617-8043 number with no success. The diagnosis and correction of hardness tester problems is a complex topic best handled with two way communication. If you would like, phone me in the office at 937-498-3723. I'm a metallurgist and an old lab rat and happen to own a Louis Small All Scale which has been scattered all over my shop more than once.
 
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