Re: crooked core in cyl casting

[woffler]

Hello everyone , I am having a issue with a #1Pm research build ,the cyl. bore casting is way crooked before machining , it looks like a egg from left to right and the other end is not bad .
My concern when i bore this thing it will put all the mating parts ,cyl heads and everything else off of position and i not even how bad the bolt circles would be .
I went a head and bought another one and it is worse than the first one , any ideas for me to work this out ?

 

[larryg]

Ignoring the cored hole; how does the out side of the casting look? If the OD of the flanges are round then you may be able to locate off of the OD and then bore the the cylinder ID concentric from there. Hopefully the cored hole is not offset so far that you cannot get the bore cleaned up and remove all the rough cast hole. For me I would have to set that up on a surface plate and do some layout on the flange end with the worst off set and see if you can salvage the casting. You may have t o overbore and fit a piston to the new bore size.

I would also be on the phone to PMR and see if they can send a good casting. I've found they do answer the phone there.

lg
no neat sig line

 

[Charles Lamont]

Do you have enough material to bore it to the correct size, concentric with the exterior, especially in relation to surfaces that will not be machined? In other words, does the casting contain the correctly finished part, with at least some machining allowance, or not? If so it is OK, if not, keep sending them back till you get one that does.

 

[woffler]

I appreciate the replies Gentleman , i thought about offsetting the bore to the top ,i am going to make a bar to just fit the existing hole and see what i come up with ,it might be in there somewhere we will see .

The outside is petty good it may require a larger piston though and rings , I am going to wait and call them Monday and see what they have to say on the issue ,i am sure they have gotten this problem before if i have two of of these bad castings or they have a bad batch, I do not know much about the company .

 

[Richard Hed]

Hello everyone , I am having a issue with a #1Pm research build ,the cyl. bore casting is way crooked before machining , it looks like a egg from left to right and the other end is not bad .
My concern when i bore this thing it will put all the mating parts ,cyl heads and everything else off of position and i not even how bad the bolt circles would be .
I went a head and bought another one and it is worse than the first one , any ideas for me to work this out ?

You can't send them back for replacements for FREE? Stuart engines would neaver do that.

 

[johwen]

Hello Woffler,
If the OD of the casting is Ok Bore the cylinder oversize until it cleans up then sleeve it back to the correct bore size with a cast iron sleeve. That would be my trick to correct the problem. John

 

[Jasonb]

The core is really only there to save material and should not be used as any form of machining reference. Set the casting in the 4-jaw chuck and get the outer edge of the flange to run as true as possible then bore. Provided the core is not excessively off ctr the casting is perfectly OK.

Another option to set up cored castings is to plug the hole with a bit of wood or similar and then mark the ctr by scribing several arcs from the outer edge and then punch mark the average ctr. Set the punch mark to run true in the 4-jaw.

 

[Charles Lamont]

If the OD of the casting is Ok Bore the cylinder oversize until it cleans up then sleeve it back to the correct bore size with a cast iron sleeve. That would be my trick to correct the problem.

Woffler should not have to do that. Two castings of questionable quality have been supplied. A misplaced core is not a problem unless it is so far adrift that the part cannot be made to design. If careful measurement of the casting shows that it really can't, then it can be classed as scrap, and personally, I would send it back, so that the suppliers understand they are not going to get away with supplying substandard goods. I am not saying these parts are scrap. I don't know how they measure up.
On the other hand, I can well understand if Woffler does not want the hassle, and is prepared to go for a work-around. Castings that are marginal present an interesting challenge to our ability to make a satisfactory part out of them.

 

[davidyat]

I just went to the PM Research site and looked at the #1 engine. They show a picture of the cylinder casting with a rather good looking bore. Wonder how you got that mismatched one? One solution I thought of was to mic the outside of cylinder, subtract 1.000 inch (bore) and divide by 2. Then you know about what the distance SHOULD be from the edge of bore to the outside edge of the cylinder. Then mic the smallest distance as best you can from the edge of the unmachined bore to outside of the cylinder. If you have more, then I feel you can bore this casting. If not call PM Research.
Grasshopper

 

[Alec Ryals]

You can't send them back for replacements for FREE? Stuart engines would neaver do that.

I have !

 

[terryd]

Hi Woffler,

I'm not sure where you are based but the Consumer Contracts Regulations (replaced direct selling regulations in 2014) in Europe and the UK state your rights regarding faulty goods received after remote purchase. Basically you are within you rights to return the goods for replacement or refund and the sellers must bear the return costs. I cannot understand why so many people put up with faulty items and then moan about them when there is legal recourse.

You should not have needed to purchase a second cylinder when the first was faulty it should have been replaced by the company with a non faulty one. If however it is possible to bore out the cylinder to the original specification on the plans as JasonB suggests it is not faulty. If you could not machine it to the original specification you should not have to bore oversize or otherwise not follow the original specification it is faulty.

Anyone who sells remotely (by phone. letter online etc) should know the regs. or should know. I once had to gently remind a supplier of a faulty product that they had to bear the cost of return and after they initially refused I pointed them to the terms of the regulations and they then had to agree with me.

To quote Which (my underlining):

"If you receive faulty goods and wish to return them, the Regulations [CCR] are in addition to your other legal rights.

So, if your goods are faulty and don’t do what they're supposed to, or don’t match the description given, you have the same consumer rights under the Consumer Rights Act (which replaces the Sale of Goods Act from 1 October 2015) as you have when buying in store.

Any terms and conditions that say you must cover the cost of returning an item wouldn’t apply where the goods being returned are faulty."

As I said these are the regulations in the UK and Europe (even after Brexit) but I am sure that most other jut=risdictions will have similar so my advice is to research your rights.

TerryD

 

[MacKendrick]

Got a bad Casting from Stuart in England. Sent them an email with a picture and they sent a new casting. No problem. PMR is a good company they should do the same with those picture.

 

[davidyat]

Terry,
I've always been amazed these days at what people are accepting as acceptable work! I feel that the younger the person, the more they complain. Is it possible, at least here in the States, that the "participation trophy" and "me" crowd weren't taught how to work for what they get? A lot seems to be given to them, they don't have to work for it. But I always will remember what my late wife taught me, "There is no such thing as an absolute". I have come across some young people that are very hard workers.
Grasshopper

 

[Richard Hed]

Terry,
I've always been amazed these days at what people are accepting as acceptable work! I feel that the younger the person, the more they complain. Is it possible, at least here in the States, that the "participation trophy" and "me" crowd weren't taught how to work for what they get? A lot seems to be given to them, they don't have to work for it. But I always will remember what my late wife taught me, "There is no such thing as an absolute". I have come across some young people that are very hard workers.
Grasshopper

I must be VERY young as I complain a nd wine all day and night

 

[woffler]

Thank you all for helping ,what a response i am humbled , i would like to thank all who replied ,i spoke with Pm research they were very nice and asked me to send back the casting ,but in the same breath they told me they did not have a replacement as these engines are on backorder .

So i decided to make a line boring bar , just got the 3/16 square insert for the bar today and will make one up, i have a milling attachment for my lathe and the cylinder will fit into the saddle that will give me a up and down axis to align with .

I have .78 hole on one end and a .54 on the other ,yes nothing is very good about this casting ,it's kind of the perfect storm of defects .

At this point it's go big or stay home i guess ,this is the only thing i could think of to try and get a true bore thru this thing wish me luck and the Best to you and yours ,i will report back on the progress .
Thank You

 

[Jasonb]

I have .78 hole on one end and a .54 on the other ,yes nothing is very good about this casting ,it's kind of the perfect storm of defects .

Whether a parallel or tapered core is used is not a defect, neither as has been said is the position of the core PROVIDED you can get the desired central hole out of the part

Easiest way to tell if it is usable is to measure the OD of the cylinder ends in a few places and average out a size. Then subtract the finished bore from that size and divide by two. Now measure the casting where the core is closest to the edge and if that is less than the calculated wall thickness you will have problems, if not just get on and machine it.

 

[TubeTech]

I had to do the plug of wood technique on me Pmr cylinder Works perfectly well with no hassles.

 

[L98fiero]

I feel that the younger the person, the more they complain.

A while ago I heard someone else complain about the younger generation, the kids these days, so I looked for the earliest reference I could find, "Our Earth is degenerate in these later days; there are signs that the world is speedily coming to an end; bribery and corruption are common; children no longer obey their parents; every man wants to write a book and the end of the world is evidently approaching." from a Assyrian tablet, 28th century BCE - Smithsonianmag.com, Ten Notable Apocalypses That (Obviously) Didn’t Happen. As pointed out, after that complaint, the Assyrian Empire lasted another 1800 years.
Maybe it's not all the younger generation, just from where you're looking at it, I know some really great, super intelligent and smart younger generation people. The thing I've suggested to many of the complainers is that our generation taught them to be the way they are so I tend not to complain too much.

 

[terryd]

Whether a parallel or tapered core is used is not a defect, neither as has been said is the position of the core PROVIDED you can get the desired central hole out of the part

Easiest way to tell if it is usable is to measure the OD of the cylinder ends in a few places and average out a size. Then subtract the finished bore from that size and divide by two. Now measure the casting where the core is closest to the edge and if that is less than the calculated wall thickness you will have problems, if not just get on and machine it.

Hi Jason,

I'm not sure if you read my post but as I said then:

"If however it is possible to bore out the cylinder to the original specification on the plans as JasonB suggests it is not faulty. "

TerryD

 

[terryd]

A while ago I heard someone else complain about the younger generation, the kids these days, so I looked for the earliest reference I could find, "Our Earth is degenerate in these later days; there are signs that the world is speedily coming to an end; bribery and corruption are common; children no longer obey their parents; every man wants to write a book and the end of the world is evidently approaching." from a Assyrian tablet, 28th century BCE - Smithsonianmag.com, Ten Notable Apocalypses That (Obviously) Didn’t Happen. As pointed out, after that complaint, the Assyrian Empire lasted another 1800 years.
Maybe it's not all the younger generation, just from where you're looking at it, I know some really great, super intelligent and smart younger generation people. The thing I've suggested to many of the complainers is that our generation taught them to be the way they are so I tend not to complain too much.

Hi,

there are many similar quotation qoutations attributed to famous writers and teacher of the past such as:
Aristotle about 332 BCE

They [Young People] have exalted notions, because they have not been humbled by life or learned its necessary limitations; moreover, their hopeful disposition makes them think themselves equal to great things -- and that means having exalted notions. They would always rather do noble deeds than useful ones: Their lives are regulated more by moral feeling than by reasoning -- all their mistakes are in the direction of doing things excessively and vehemently. They overdo everything -- they love too much, hate too much, and the same with everything else.

Hesiod 800 BCE:

"I see no hope for the future of our people if they are dependent on frivolous youth of today, for certainly all youth are reckless beyond words... When I was young, we were taught to be discreet and respectful of elders, but the present youth are exceedingly wise [disrespectful] and impatient of restraint".

GK Chesterton (Writer) about 1920 attacks both aged and young:

"I believe what really happens in history is this: the old man is always wrong; and the young people are always wrong about what is wrong with him. The practical form it takes is this: that, while the old man may stand by some stupid custom, the young man always attacks it with some theory that turns out to be equally stupid."

There are many similar complaints about young people across the ages. As a teacher of 11 to 18 year olds for many years I actually found that the vast majority can be serious, intelligent and caring and funny, a bit thoughtless and self centred at times perhaps, but on the whole decent.

It was always thus.

Stay safe and healthy,

TerryD