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Post by Oily Rag on Mar 31, 2022 0:54:10 GMT
I am enjoying reading your ME articles , however as we hang on upside down we wait for the 4 th part to arrive. For me I prefer magazines, books, paper compared to reading a screen. Take them camping, to the dunny, laying down on the couch, to the work shop, back to the dunny, in bed before going off to the land of ZZZZZZZZZZZZZZZZZ, my reading material gets an abused look to it very quickly . The best new thread in my ME world since DRO and PCB drills arrived into my world. Thanks Daz, I really appreciate that. However, I will forever associate the article with you reading it on the dunny... I promise you I keep the paper roll well stocked so I am never caught short :-)
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Post by Oily Rag on Mar 31, 2022 0:55:35 GMT
It is the reamer making that I need to get my head around.
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Post by Roger on Mar 31, 2022 6:22:26 GMT
It is the reamer making that need to get my head around. This is something that I might cover in a second article. However, a few comments here might prove useful. There are a few challenges with making these because they are long and slender. In my opinion, you need to grind them so that the cutting forces are as small as possible. If you turn them, it's inevitable that the smaller end will deflect more than the thicker end, and you won't get the taper you want. You have to be patient even when grinding them, for the same reason. So my preference is to use a HSS drill blank which can be bought from a reputable supplier such as Drill Service Horley, or alternatively from eBay. Once you've made the decision to grind them, HSS is the obvious choice. The angle isn't super critical from a thermodynamic point of view, but if you don't get it close, how are you going to set a collar to get the taper close to the drawing dimensions? I'm fortunate in having a Tool & Cutter Grinder that I've equipped with a scale for setting the angle. If you're using a Toolpost Grinder (with adequately covered slides to protect them!!) you can set the angle using a clock on compound slide against a parallel piece in the chuck. The idea is to move the Compound slide back and forth between two known positions, in my case 30mm. That forms the Hypotenuse of a right angled triangle. The Carriage remains still, but the Cross slide is moved to bring a DTI back to zero on the parallel piece in the chuck. Using trigonometry, you can work out the distance the Cross slide should move when the angle is right. You have to keep adjusting the angle until the Cross slide moves the right amount. Don't forget that the DRO or dial will be measuring the Diameter and not the Radius though! This method works really well. I use the parallel portion of the chuck as the reference. You can run the DTI along it with the Carriage to check it's truly parallel.
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Post by chris vine on Mar 31, 2022 7:54:53 GMT
Hi Roger,
In your cunning setting scheme above, I think the DTI is just measuring the movement of the cross slide and not the diameter. Unless the DTI has a hardened probe and the lathe is spinning while you are doing it!!!
Maybe you are referring to an unusual lathe where the cross slide is calibrated to show diameter cut, IE the dials show half the movement of the cross slide...
Chris.
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Post by Roger on Mar 31, 2022 8:05:33 GMT
Hi Roger, In your cunning setting scheme above, I think the DTI is just measuring the movement of the cross slide and not the diameter. Unless the DTI has a hardened probe and the lathe is spinning while you are doing it!!! Maybe you are referring to an unusual lathe where the cross slide is calibrated to show diameter cut, IE the dials show half the movement of the cross slide... Chris. Hi Chris, Yes, the cross slide moves in and out to measure the Opposite side of the right angled triangle. The only reason I mentioned the words Radius and Diameter is that the dial or DRO on the Lathe measure twice the actual movement so that they refer to a diameter when turning something. We need to know the actual movement of the Cross slide, hence using half the amount on the dial or DRO. The Lathe isn't turning when setting this up, it's a static measurement on either the side of the chuck or a parallel test piece.
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Post by chris vine on Mar 31, 2022 8:32:22 GMT
Ah yes, I see - A DRO will probably be set up to measure diameter. Myford dials on the cross slide show movement of the slide, IE radius, which is what you want for this.
Chris.
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Neale
Part of the e-furniture
5" Black 5 just started
Posts: 279
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Post by Neale on Mar 31, 2022 8:39:02 GMT
That confused me first time I moved from my Myford to my current ex-toolroom machine - I guess that Myford did it that way as it was intended to use for milling with a vertical slide. However, if you have a lathe DRO, it's probably worth checking if it has radius/diameter switching. Mine does but not sure how common it is.
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Post by Roger on Mar 31, 2022 10:14:12 GMT
Ah yes, I see - A DRO will probably be set up to measure diameter. Myford dials on the cross slide show movement of the slide, IE radius, which is what you want for this. Chris. I've never used a lathe that didn't have the graduations set for diameter. That must be a real pain since almost all of the times you use it are as a lathe. I have a spreadsheet that I just type the angle into, and it tells me the DRO reading I need.
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Post by Roger on Mar 31, 2022 10:16:07 GMT
That confused me first time I moved from my Myford to my current ex-toolroom machine - I guess that Myford did it that way as it was intended to use for milling with a vertical slide. However, if you have a lathe DRO, it's probably worth checking if it has radius/diameter switching. Mine does but not sure how common it is. Since this is something you do infrequently, it's no problem to have the measurement. As I said to Chris, I have a spreadsheet for different angles that give the DRO reading required.
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Post by Oily Rag on Mar 31, 2022 23:18:31 GMT
Hi Roger, In your cunning setting scheme above, I think the DTI is just measuring the movement of the cross slide and not the diameter. Unless the DTI has a hardened probe and the lathe is spinning while you are doing it!!! Maybe you are referring to an unusual lathe where the cross slide is calibrated to show diameter cut, IE the dials show half the movement of the cross slide... Chris. Chris. [/quote] My Myford 254S top slide is graduated for diameter. 0.05mm graduations for 0.25mm of tool movement. What is effing annoying is the long mark is on every 5 graduations. I consider this Numpty thinking as it seem they wanted to to be close to 0.001" to give it an Imperial feel to it My 40 YO Taiwanese lathe is radius, 0.02mm graduations and thus the long mark is on the 0.10 with every 5 th graduations. Which makes sense and is a joy for a metric user. It also has Imperial on the dials next to the metric but I never refer to this. I don't care if it is radius or diameter, but if I had the choice, diameter.
Any how I cope and counting grads with an automatic pencil and marking the dial from where and where to on odd occasions helps me to cope.
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Post by steamer5 on Apr 5, 2022 5:58:37 GMT
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Post by Cro on Apr 5, 2022 7:24:34 GMT
Anthony does amazing work with his Injectors!
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Post by steamer5 on Apr 5, 2022 7:42:04 GMT
Hi Adam, He sure does, I guess working in the 1.5" scale really helps..... if i heard it correctly 139 parts! Interesting to see the cross section he shows has the cones along the same design as Rogers
Cheers Kerrin
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Post by Roger on Apr 5, 2022 9:44:22 GMT
Hi Adam, He sure does, I guess working in the 1.5" scale really helps..... if i heard it correctly 139 parts! Interesting to see the cross section he shows has the cones along the same design as Rogers Cheers Kerrin Hi Kerrin, That's a beautiful Injector, and way more complicated than mine. It's using a moving cone that controls the overflow, rather than it all being in one piece like mine.
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Post by steamer5 on Apr 5, 2022 10:38:07 GMT
Hi Roger, Just had a look at the link to his site. The injector is 5" tall & a steal at $1895 US. Given the amount of work etc involved in the manufacturing to say nothing of how it looks probably not a bad price.
Cheers Kerrin
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Post by chris vine on Apr 5, 2022 15:58:48 GMT
Fabulous.
I don't understand his water valve. He says that when you move the lever for the first part that it opens the valve fully. Then as the lever lifts the water valve further it restricts the water flow. I can't see how the valve does that...
Chris.
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Post by Roger on Apr 5, 2022 16:38:31 GMT
Fabulous. I don't understand his water valve. He says that when you move the lever for the first part that it opens the valve fully. Then as the lever lifts the water valve further it restricts the water flow. I can't see how the valve does that... Chris. Hi Chris, If you look at the section view at the start of the video, you can see that there are two things moved by the lever. The one on the left is the Steam inlet, and the one on the right is the water valve. The first movement opens both of them together. However, when you move it far enough, the bottom part of the water valve has moved up enough to restrict the water flow. It does what while the Steam valve is fully on. This simulates what we often see done, ie the throttling of the water supply to make it pick up when it doesn't want to.
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Post by Cro on Apr 5, 2022 16:38:44 GMT
Fabulous. I don't understand his water valve. He says that when you move the lever for the first part that it opens the valve fully. Then as the lever lifts the water valve further it restricts the water flow. I can't see how the valve does that... Chris. Chris, The valve is like a cotton real (or dumbell) shape, the top part has o-ring seal which ultimately shuts the valve when down but as lifted opens up into the wasted section allowing water through and then when you carry on up the other end, larger dia, restricts the flow again but its not same size as bore so never closes just restricts. If you got to about 8:50 in the video he has a cut of the 3D model which helps explain that. Adam
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Post by chris vine on Apr 5, 2022 21:36:05 GMT
Thanks, both! I had not realised that the bottom part of the valve was moving up too. I had thought it was more like a needle valve with the central bit. All makes sense now.
What a wonderful piece of miniature engineering!!
Chris.
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Post by Roger on Jul 1, 2022 9:25:43 GMT
I just realised that I'd made an incorrect comment on the One Piece Cone drawing, so I've updated it to Issue 3 on the original post and here is it again here. I'd mentioned that you can use the same taper angle on both ends, but should have said that the 7 degree taper could be 9 degrees. You can't change the 9 degree Condensing Cone angle. Sorry for any confusion. One piece cone drawing Iss 3 by Timothy Froud, on Flickr
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