A pleasure to watch and listen as always, an an opinion as always! Small items to be parted off, I was always taught; Face, rough od, rough bore, finish bore finish od, part off. Saves distortion of the oD and bore if the workpiece moves or the material is likely to change shape as it’s stress relived during machining (not likely with brass or aluminium) Always do all your roughing first, doesn’t matter how rough you are then! 👍 as for the chatter when grooving, you need to cut harder and keep the feed up, dwelling whilst grooving will cause chatter, same as when parting off
Great suggestions James - I must try to remember! I think I should try to bite the bullet and use the cross slide power feed when parting off - even though I feel I'm losing some sort of control. All the best. Andrew
Learning Turning Metal - by Andrew Whale to be honest Andrew I never use power feed when grooving or parting off, I find it’s always best to feel the machine cutting
Nice job Andrew. The little nick from the end mill does no harm and will never be seen. Great fit in the cylinder. Much better too tight than too loose at this stage. You should get good compression when the engine fires up. That is a tricky little piston head. They are so much simpler in steam engines.
Thank you again Andrew. Learning a lot from following you. Recently retired now so hopefully I can get out to the shop and try some newly learned skills and techniques. Thank you.
Hi John - I'm really glad you are learning too! I find it really enjoyable setting challenges. Just remember - some of my techniques might not be that great from an experienced machinists point of view. I get some great feedback though on how to improve. Have fun! Cheers Andrew
Hi Andrew, after watching this I'm now tempted to use an aluminium piston/nitrile 'O' ring in the Kerzel Hit & Miss. Its going to be less work than the cast iron piston with cast iron rings on the kerzel plans. Cheers Kevin
Hi Kevin - I think it must be an easier option and there is a massive range of Nitrile 'O' rings available. I'm looking forward to see which route you take. Cheers Andrew
Your vise will retain round parts better if you utilize the V-groves in the jaw. There are only two lines of contact when you rely on just the flat surfaces of the jaws with round parts. I prefer the use of V-blocks for these situations, but the V-groves may suffice.
Hi - when I reviewed the footage I couldn't believe that I hadn't utilised the v-groove in the jaw (I only have on in my vice). I could have kicked myself! I really like the idea of using V-blocks though. Many thanks for the suggestion. All the best. Andrew
Is it part of the original specification to use an o-ring as a piston ring? The instantaneous pressure and temperature is far higher than in a steam engine. Any leakage will sear its way through the rubber. Think head gasket failure or exhaust valve burn . But I'm thinking more than a few minutes of no-load running.
Hi Martin. Jerry Howell recommends an o-ring rather than a cast iron ring. He says "I can positively tell you that the o-ring is perfectly satisfactory in this engine. The engine only gets barely warm and with far less friction than cast iron rings it coasts much better between firing." He also recons that it will easily coast 20 to as many as 30 times between firing. Fingers crossed he is correct. Time will tell! Cheers Andrew
Hi Andrew. Great video thank you. I am building a Farm boy and I am a bit confused. I assume the ring in the plans 1" OD x 0.094 is a R-14 13/16 x 3/32 ring. The OD of the o-ring is exactly the same size as the bore and the slot is oversize in both dimensions compare to the ring section. This seems to imply the ring will be very loose in the bore with no wall pressure at all. Have I missed something or is that how it is meant to be? Thanks.
Hi. The o-ring should 'float' inside the groove. Some people think that the piston groove needs to pinch the o-ring in order to make the o-ring od fractionally larger than the id of the cylinder. Unfortunately this will cause increased friction between the o-ring and the cylinder which will result in the engine not freewheeling well between firing. It will also result in o-ring wear. I am no expert but as I understand it, the smaller od at the top of the piston allows air to pass by it. This, together with the larger groove, causes the o-ring to expand slightly and create a good seal. Jerry Howell was a great model engineer and if you stick to his dimensions you should end up with a really nice running engine. Hope that helps and good luck! Andrew
@@learningturningmetal Thanks Andrew. Yes, I think the reduced piston diameter above the ring is the clue that there is a bit of a trick going on. I will probably go with exact to drawing if I can and see how it goes. Your engine really freewheels nicely and I can see that any significant friction would really mess that up.
Nice work Andrew! Way beyond my skill and patience. At time 09:00. Use "Red Spirit" as lubricant! I have a pipett to give drops now and then. In the old days "White Spirit" was used. Are You a bit conservative when cross feeding? AT some 20:45. Why not use outside C clip rings(?) like in 50 cc mopeds to keep the bolt joining the piston and piston rod together?
Hi Stefan - I tend to use WD40 as a lubricant on aluminium - I've not come across Red Spirit though. Is that another name for paraffin? 'C' clip rings is a really good idea. I'm just following the drawings and I'm not great at thinking outside of the box. I don't think the grub screw method is a great idea as they could come loose and damage the cylinder. I think I will have to Loctite them in place. Cheers Andrew
@@learningturningmetal I see many Y-tubers using WD40 in quite different situations. I think the label says Awoid skin contact. Else it would probably work as suncream too. I'm joking. In Sweden the "old spirit" was called T-spirit and it was almost transparent. Now it is sold with other additives to be used in the petrol tank of cars in order to mix with eventual water in the fuel system. It probably cleans a bit of this and a bit of that on its way to the combustion chamber. Instead I have tried the available "Red Sprit". Technically more than the colour is changed. Before it got denaturated it worked fine as alcohol in drinks etc. The state lost taxmoney... It has a quite good cleaning effect on lightly sencitive surfaces. They both have been denaturated since very long. They prohibit the ALU from welding/gluing to the toolbit. Once owning a moped I got a cylinder that doubled the speed but it need new piston rings every 30 miles to bea at its top performace. Trying different pistons for more power was almost routine. Actually the C-spring was a special hard string being bent like a C, not the the usual C-, E- types etc. That gave the advantage that the piston rod only needed a precisely drilled hole, maybe having some bearing surface inside. You will need a piston rod being split to mount to that srew locked rod.
Hi Andrew, love your videos! I recently bought an sc4 lathe like yours and was wondering what speeds you use your carbide tooling at on the various materials
Thanks Tim. I am definitely no expert... I've never had great success with TiN coated carbide inserts. I probably don't drive them fast enough. I tend to use the silver coloured inserts for aluminium. They also work fine for me on cast iron, brass and mild steel. The speeds I use are closer to ones for HSS. I use the following formula: Rpm=100 x surfaceftm-of-metal / cutter-diam-MM The surfaceftm-for-metal is as follows: Carbon steel = 115 Brass = 180 Aluminium = 165 Cast iron = 90 I just created a spreadsheet so it's easy to get a ball park RPM. Example for 10mm dia brass is: 100 x 180 / 10 = 1800 Hope that helps. Like I say I am no expert! Cheers Andrew
Well done Constructive criticism time Keep a separate part off blade just for aluminium with about 15 degrees top rake on it flat front. Find a small soft plastic container and fill it with paraffin, Ebay blunt syringe affix to the lid spot on. Edge finder run faster more accurate ( about 5 to 6 hundred wont hert faster) Reamer slower take less of, flood with paraffin (reamers are funny critters the less they remove the more accurate they are )
Many thanks for the tips Jonathan - I've got a spare parting off blade, so I'll do that today and mark it up. I must admit - when I reviewed the footage I thought my reaming lacked lots of lubrication. I use WD40 - do you think that's close enough to paraffin? Cheers Andrew
NEVER use top rake on a parting tool, as soon as you try to go deeper than the length you have ground it will RUB and seize in the part and break. The reason is because the parting tool is tapered height wise, the instant you remove any material from the top face, it instantly becomes narrower than the rest of the blade. Take this as someone who knows from past experience, especially on aluminium.
True what you say, perhaps i should have been more clear. The problem with being a keyboard warrior is it is difficult to Show someone how it's done with a few lines on TH-cam. I have one I have used for years with no problem however once you grind It and put the correct clearance on they really don't wear cutting aly and I don't cut aluminium that often. The problem with aluminium is it doesn't like no top rake so you are stuck between a rock and a hard place. I find the same problem drilling holes in brass with positive rake twist drills. We were taught to grind them 0 degree top Rake to stop them dragging the drill onto the work. How do you compress five years learning with five minutes on a tablet basically as long as you keep your top face of the parting tool no more than two mm from the top face of the tool and grind a bit of side clearance further up the tool it works, when you reach two mm remove the hole front of the parting tool and start again. wd 40 is ok but a lot of goes airborne when you spray unlike flood coolant. thanks for pointing it out Regards
@@daveticehurst4191 i would disagree, always have top rake BUT do it by angling the blade not by ruining the blade with some silly grinding because as you quite correctly say it limits the possible depth of cut. An angled blade can be used on any material even ones traditionally thought to need zero rake like brass.
Andrew, is this engine water cooled ? Just wondering how well the Nitrile O ring will stand up to getting hot.I would have personally gone for a VITON ( fluorocarbon ) one, more cost though. Looking good again so far. If you can stand the smell I would just use plain Paraffin as it is cheaper thanWD 40. I put some in a small spray bottle and just give a light misting of the part.
Hi Dave. Yep it's watercooled. Jerry Howell says that it runs pretty cool and that Nitrile should be ok. Time will tell! I'll try to get hold of some paraffin and give it a bash. I've got about 1000 litres of heating oil (kerosine) in my oil tank but that probably isn't appropriate ☹️. Take care and all the best. Andrew
A pleasure to watch and listen as always, an an opinion as always!
Small items to be parted off, I was always taught;
Face, rough od, rough bore, finish bore finish od, part off. Saves distortion of the oD and bore if the workpiece moves or the material is likely to change shape as it’s stress relived during machining (not likely with brass or aluminium)
Always do all your roughing first, doesn’t matter how rough you are then! 👍 as for the chatter when grooving, you need to cut harder and keep the feed up, dwelling whilst grooving will cause chatter, same as when parting off
Great suggestions James - I must try to remember! I think I should try to bite the bullet and use the cross slide power feed when parting off - even though I feel I'm losing some sort of control.
All the best.
Andrew
Learning Turning Metal - by Andrew Whale to be honest Andrew I never use power feed when grooving or parting off, I find it’s always best to feel the machine cutting
Coming along nicely. Looking forward to it's first run. All the best from Somerset.
Thanks mate - slow progress but gradually getting there - I hope.
Cheers
Andrew
Nice job Andrew. The little nick from the end mill does no harm and will never be seen. Great fit in the cylinder. Much better too tight than too loose at this stage. You should get good compression when the engine fires up. That is a tricky little piston head. They are so much simpler in steam engines.
Thank you again Andrew. Learning a lot from following you. Recently retired now so hopefully I can get out to the shop and try some newly learned skills and techniques. Thank you.
Hi John - I'm really glad you are learning too! I find it really enjoyable setting challenges. Just remember - some of my techniques might not be that great from an experienced machinists point of view. I get some great feedback though on how to improve.
Have fun!
Cheers
Andrew
Great progress!
Thanks Tony!
All the best.
Andrew
when i do a piston fit i always use fine valve grinding paste to hone the piston to the cylinder works fine
Great work, all the best from Salisbury
Thanks Derek - all the best to you too from sunny North Yorkshire!
Cheers
Andrew
Hi Andrew, after watching this I'm now tempted to use an aluminium piston/nitrile 'O' ring in the Kerzel Hit & Miss. Its going to be less work than the cast iron piston with cast iron rings on the kerzel plans.
Cheers Kevin
Hi Kevin - I think it must be an easier option and there is a massive range of Nitrile 'O' rings available. I'm looking forward to see which route you take.
Cheers
Andrew
Your vise will retain round parts better if you utilize the V-groves in the jaw. There are only two lines of contact when you rely on just the flat surfaces of the jaws with round parts. I prefer the use of V-blocks for these situations, but the V-groves may suffice.
Hi - when I reviewed the footage I couldn't believe that I hadn't utilised the v-groove in the jaw (I only have on in my vice). I could have kicked myself! I really like the idea of using V-blocks though.
Many thanks for the suggestion.
All the best.
Andrew
Is it part of the original specification to use an o-ring as a piston ring? The instantaneous pressure and temperature is far higher than in a steam engine. Any leakage will sear its way through the rubber. Think head gasket failure or exhaust valve burn . But I'm thinking more than a few minutes of no-load running.
Hi Martin. Jerry Howell recommends an o-ring rather than a cast iron ring. He says "I can positively tell you that the o-ring is perfectly satisfactory in this engine. The engine only gets barely warm and with far less friction than cast iron rings it coasts much better between firing." He also recons that it will easily coast 20 to as many as 30 times between firing.
Fingers crossed he is correct. Time will tell!
Cheers
Andrew
Fair enough. Thank you for your reply.
Hi Andrew. Great video thank you. I am building a Farm boy and I am a bit confused. I assume the ring in the plans 1" OD x 0.094 is a R-14 13/16 x 3/32 ring. The OD of the o-ring is exactly the same size as the bore and the slot is oversize in both dimensions compare to the ring section. This seems to imply the ring will be very loose in the bore with no wall pressure at all. Have I missed something or is that how it is meant to be? Thanks.
Hi. The o-ring should 'float' inside the groove. Some people think that the piston groove needs to pinch the o-ring in order to make the o-ring od fractionally larger than the id of the cylinder. Unfortunately this will cause increased friction between the o-ring and the cylinder which will result in the engine not freewheeling well between firing. It will also result in o-ring wear. I am no expert but as I understand it, the smaller od at the top of the piston allows air to pass by it. This, together with the larger groove, causes the o-ring to expand slightly and create a good seal. Jerry Howell was a great model engineer and if you stick to his dimensions you should end up with a really nice running engine.
Hope that helps and good luck!
Andrew
@@learningturningmetal Thanks Andrew. Yes, I think the reduced piston diameter above the ring is the clue that there is a bit of a trick going on. I will probably go with exact to drawing if I can and see how it goes. Your engine really freewheels nicely and I can see that any significant friction would really mess that up.
Nice work Andrew! Way beyond my skill and patience.
At time 09:00. Use "Red Spirit" as lubricant! I have a pipett to give drops now and then. In the old days "White Spirit" was used. Are You a bit conservative when cross feeding?
AT some 20:45. Why not use outside C clip rings(?) like in 50 cc mopeds to keep the bolt joining the piston and piston rod together?
Hi Stefan - I tend to use WD40 as a lubricant on aluminium - I've not come across Red Spirit though. Is that another name for paraffin?
'C' clip rings is a really good idea. I'm just following the drawings and I'm not great at thinking outside of the box. I don't think the grub screw method is a great idea as they could come loose and damage the cylinder. I think I will have to Loctite them in place.
Cheers
Andrew
@@learningturningmetal I see many Y-tubers using WD40 in quite different situations. I think the label says Awoid skin contact. Else it would probably work as suncream too. I'm joking.
In Sweden the "old spirit" was called T-spirit and it was almost transparent. Now it is sold with other additives to be used in the petrol tank of cars in order to mix with eventual water in the fuel system. It probably cleans a bit of this and a bit of that on its way to the combustion chamber.
Instead I have tried the available "Red Sprit". Technically more than the colour is changed. Before it got denaturated it worked fine as alcohol in drinks etc. The state lost taxmoney...
It has a quite good cleaning effect on lightly sencitive surfaces. They both have been denaturated since very long. They prohibit the ALU from welding/gluing to the toolbit.
Once owning a moped I got a cylinder that doubled the speed but it need new piston rings every 30 miles to bea at its top performace. Trying different pistons for more power was almost routine. Actually the C-spring was a special hard string being bent like a C, not the the usual C-, E- types etc.
That gave the advantage that the piston rod only needed a precisely drilled hole, maybe having some bearing surface inside. You will need a piston rod being split to mount to that srew locked rod.
Is that like going swimming.
O my goodness. That chater. Is like going to the dentist.
Hi Andrew, love your videos! I recently bought an sc4 lathe like yours and was wondering what speeds you use your carbide tooling at on the various materials
Thanks Tim. I am definitely no expert... I've never had great success with TiN coated carbide inserts. I probably don't drive them fast enough. I tend to use the silver coloured inserts for aluminium. They also work fine for me on cast iron, brass and mild steel. The speeds I use are closer to ones for HSS.
I use the following formula:
Rpm=100 x surfaceftm-of-metal / cutter-diam-MM
The surfaceftm-for-metal is as follows:
Carbon steel = 115
Brass = 180
Aluminium = 165
Cast iron = 90
I just created a spreadsheet so it's easy to get a ball park RPM.
Example for 10mm dia brass is: 100 x 180 / 10 = 1800
Hope that helps. Like I say I am no expert!
Cheers
Andrew
Hi Tim
I've just been given a great tip. Try downloading FSWizard app onto your phone. It looks like a great app for calculating speeds.
Cheers
Andrew
Well done
Constructive criticism time
Keep a separate part off blade just for aluminium with about 15 degrees top rake on it flat front.
Find a small soft plastic container and fill it with paraffin, Ebay blunt syringe affix to the lid spot on.
Edge finder run faster more accurate ( about 5 to 6 hundred wont hert faster)
Reamer slower take less of, flood with paraffin (reamers are funny critters the less they remove the more accurate they are )
Many thanks for the tips Jonathan - I've got a spare parting off blade, so I'll do that today and mark it up.
I must admit - when I reviewed the footage I thought my reaming lacked lots of lubrication. I use WD40 - do you think that's close enough to paraffin?
Cheers
Andrew
NEVER use top rake on a parting tool, as soon as you try to go deeper than the length you have ground it will RUB and seize in the part and break. The reason is because the parting tool is tapered height wise, the instant you remove any material from the top face, it instantly becomes narrower than the rest of the blade. Take this as someone who knows from past experience, especially on aluminium.
True what you say, perhaps i should have been more clear.
The problem with being a keyboard warrior is it is difficult to
Show someone how it's done with a few lines on TH-cam.
I have one I have used for years with no problem however once you grind
It and put the correct clearance on they really don't wear cutting aly and I don't cut aluminium that often.
The problem with aluminium is it doesn't like no top rake so you are stuck between a rock and a hard place.
I find the same problem drilling holes in brass with positive rake twist drills. We were taught to grind them 0 degree top
Rake to stop them dragging the drill onto the work.
How do you compress five years learning with five minutes on a tablet
basically as long as you keep your top face of the parting tool no more than two mm from the top face of the tool and grind a bit of
side clearance further up the tool it works, when you reach two mm remove the hole front of the parting tool and start again.
wd 40 is ok but a lot of goes airborne when you spray unlike flood coolant.
thanks for pointing it out
Regards
@@daveticehurst4191 i would disagree, always have top rake BUT do it by angling the blade not by ruining the blade with some silly grinding because as you quite correctly say it limits the possible depth of cut.
An angled blade can be used on any material even ones traditionally thought to need zero rake like brass.
Another good idea just proofing there's more than one way to skin a cat my friend, can you suggest a source of
such a beast for the smaller lathe
Andrew, is this engine water cooled ? Just wondering how well the Nitrile O ring will stand up to getting hot.I would have personally gone for a VITON ( fluorocarbon ) one, more cost though. Looking good again so far. If you can stand the smell I would just use plain Paraffin as it is cheaper thanWD 40. I put some in a small spray bottle and just give a light misting of the part.
Hi Dave. Yep it's watercooled. Jerry Howell says that it runs pretty cool and that Nitrile should be ok. Time will tell! I'll try to get hold of some paraffin and give it a bash. I've got about 1000 litres of heating oil (kerosine) in my oil tank but that probably isn't appropriate ☹️.
Take care and all the best.
Andrew
Kerosene and paraffin are the same thing
are"not rings made of cast-iron if I remember right
Never stop machine with carbide in contact with part or you might chip carbide.
I'm thinking a thousand of a inch would not matter that much. M
But if your going to do it do it right ✅. M
51 please just say 50. M