Member postings for John Gray 7

/thank you Dalboy and all others. The video was useful. I’m reasonably sure now that the supply of inserts I’ve got on the draw will not need to be moved on and should fit the 10mm tooling for my new lathe. Should be able to just move on the 8mm holders.

Thanks JasonB I suspected that what you have suggested may be the case. I get easily confused looking at insert charts, and they serve more often to show up my ignorance!

Just a simple question (I think) but one that I don’t know the answer to. My current set up uses 8mm tooling. I use both HSS and insert, and I’m a great fan of the super sharp gt inserts often advertised as aluminium cutters. I’m thinking of changing to a slightly larger lathe, and this one uses 10 mm tooling. Now I know that I could still use my 8 mm stuff and shim up the bottom of the tool holders to achieve centre, but if I buy some 10mm tool holders, will my supply of inserts that fit my 8 mm tools fit the 10mm ones? My current inserts I think (I’m not at home at the moment) are 6mm edged. Does 10mm tooling use a larger insert?

The lowest speed on my micro sized mill (Proxxon BFW40/E) is 900rpm. I shall drill these small parts on my bench drill next time as I can operate this much slower than that. In fact I have an X-Y table on my bench drill so no drama at all if the coordinates are centre popped. I have not had any problems drilling with this mill/drill on other parts. The steam ports on the cylinder for instance were drilled on this device, but then that casting is indeed a much meatier piece than these small bits. In fact come to think of it, the steam inlet port was drilled and tapped on my mill/drill without any of this problem, but as has already been pointed out, this bit is on the centre of the cover, and it is the very edge of this piece that is causing me a problem. This has been a great learning curve for me.

Thank you JasonB, that is exactly the look my casting has. The surface is best described as “mottled”, in appearance , although the surface is flat. All surfaces of this casting were machined prior to this part of the task so there was not any scale remaining. Even the gland part was drilled and tapped with HSS without any drama, and also the 70 thou hole at the back that I had anticipated would be a problem, but in the event was not. Interestingly these of course were drilled at 90 deg to the problem surfaces. Don’t know if this is significant or not. I was struggling to understand why the iron was hard after it had been heated. Perhaps the answer is that it was hard before heating it! I shall talk to Stuart’s next week and have another go. Thank you again.
Howard, spark erosion is indeed a remarkable process, and one that I had never even heard of until you educated me. I have since watched several videos. It seems never a day goes past without I learn something new. If only I could prevent myself forgetting things I once knew, all would be well. Thank you for your contribution.

Some excellent advice here I think, and I thank you all. Certainly the casting was not heated to any amount that was any where near glowing. It is true I think that up to that point, all tooling was carbide, although I do use HSS s9metimes. I’m sure 5hat I have persisted too long with a blunt drill, and will be mindful of this on the future. The drills that broke were HSS offerings from Drills UK, but I also tried Presto bits in a different size without result. All bits were brand new at 5he time of use. In the future I shall stop immediately and check the end with a loupe. Seems so obvious now and I have learned from this journey. I shall talk to Stuart’s next week and get replacement parts ordered. Spark Erosion eh? I googled it. Never heard of such a process before, looks to be an offering from the Hogwarts school of clever things! Thank you to all.

Woodturner taking a sideways step into metalwork. I have started a Stuart S50 to enjoy the journey and hopefully learn along the way. I have watched all the YouTube stuff and read the Tubal Cain write ups and all was going swimmingly well, my piston moves as it should when I feed air from my airbrush compressor to each port. I completed the steam chest and the cover without too much drama and then had a think about the drilling and tapping of these two components. I found this fiddly and tried bolting the cover to the chest through the steam inlet hole in the cover so as to drill both cover and chest at the same time. This didn’t work out well, so tried using toolmaker vices to achieve the same, but didn’t like that either. In the end I used an angle plate and a height gauge to mark the centres for drilling on the cover, then centre popped where the lines crossed. I used loctite to stick the cover onto the chest and left it overnight. On my return I was not happy with the position of the cover, it seemed to have moved whilst the glue did it’s thing, and so I thought I would remove it, reposition and glue it again. I used a small jewellery type soldering flame to apply heat to the castings and eventually knocked them apart. I re glued them and returned to it again tonight. It was in the right position this time and so I started to drill the 4 7BA clearance holes in the corners. That is when I found that the castings had gone “glass hard” and a drill bit wouldn’t touch them! In desperation I used some all carbide tiny burrs normally used for artistic carving in hard wood, to see if I could break the surface before drilling further. This worked to get a start in the metal, but I still broke 2 drills inside the castings which are now to all intents ruined, and I shall have to reorder new ones and start again. The castings were not hard and machined well in both lathe and mill prior to me using heat to break the loctite. What has happened here, and how can I avoid it in the future. Assuming I have somehow heat treated it, can it be annealed? Can loctite be undone without heat? Sorry to ramble on but I’m a bit gutted as I had invested quite a bit of time in machining the steam chest and it is now ruined with broken drill bits embedded in it.

Thanks for the replies. Seems likely then that the S was more to do with the slide valve construction and not indicating a stationary engine. Interesting info on the link about the Stuart engines, and apologies to anyone offended by my spelling issues.

I’ve just started my first steam engine, a Stewart S50. Very early days yet, but it’s going well (I think). As with all new projects time at the lathe/mill is only a small percentage of the actual time spent….Thinking time, weighing up, call it what you like. I imagine this percentage changes with time and gained experience, il look forward to that. Anyway, one of my random thoughts the other day made me ponder where does the name come from? The Stewart 10V, I can see that the “V” would indicate that it’s a vertical build, and there were others, so probably the 10 was it’s time place so to speak. The S of S50 could indicate a stationary engine, but surely there aren’t 49 predecessor’s, are there?

Why thank you for your warm welcome gentlemen. I am located in the northwest, in Shaw, about halfway between Oldham and Rochdale. My workspace is at best considered chaotic, having more woodworking kit than should be allowed! Most things have to be moved to use then slotted back. For this reason my move into metalworking machines has resulted in me buying Proxxon 250e lathe and a small Proxxon BFW 40e mill system. These might appear almost toy like, but are very capable and accurate if used within their limitations. Indeed working within these limitations is a part of the learning journey. The super power of this kit is that it can be put away on top of my table saw when not in use. I may grow into an SC4 and a bigger mill which would probably be my choice, but that is just not possible without disposing of some other kit. I’m not ready to make those decisions yet, but hey ho you never know it may form part of my journey.

Just noticed this thread and should have posted here first before before adding to a thread bashing Proxxon kit. Sorry! Been Woodturning for more than 20 years, mainly interested in segmented and or sculptural work, and this is my first attempt at shaping metal. To me, crafting in wood or metal is all about the journey rather than the destination, and I’m enjoying learning. I’m hoping to combine the two materials on some useful and interesting way, but that’s some way off yet. I’m retired and I don’t have to produce anything to support myself, so there’s no time constraints, only the time left to me. I probably won’t be a big poster unless I get inspired, more likely to lurk and learn.

Just to put the record straight and to attempt to level the Proxxon a phobia let me speak up for Proxxon kit. In my opinion it is ludicrously expensive, usually under powered but reasonably well made. I have quite a bit of Proxxon kit and taken within the bounds that it is intended for, it performs extremely well. Taken outside it’s comfort zone into areas where it was never intended to go, it will not perform well. The main Proxxon kit I own that may be of interest to this forum and the OP in particular is the 250E lathe, and the BFW40e milling system. Used within the capacity of the lathe, I have not yet found a task that cannot be done. It would not suit many people. You won’t be making 100 thou cuts. You have to learn to work within its limitations. In a commercial environment it couldn’t cut it, as it would be too slow. Brass and aluminium is a breeze. Mild steel at least EN1 or 3 is also simple but a little slower. I have cut stainless steel and cast iron castings without issue, albeit in small model sized pieces. Much the same can be said of the mill system. I have only used the mill on metal. It’s first ever use was on a block of steel that I squared up and machined to size to replace my compound on the lathe and bring the tool post to size, as I don’t always use the compound, and can benefit from the increased rigidity. It coped perfectly well with this. Yesterday I machined some extra T-nuts from mild steel bar, again without problem. Come to think of it, I also drilled the 5mm holes in them using the drill function. I have many times on other occasions drilled 6mm holes in steel without issue.

The Superpower of this Proxxon kit is that when I’ve finished, I can, even at my age, pick it up and store it on my table saw. When I want to use my table saw I have to move it again. I would dearly like a Myford or a SC4 but I just have not the the space to commit to something that I cannot move. But the real point is that this small kit is very capable of machining metal albeit slowly. The flavour of the argument on this thread seems a bit like the owners of fast expensive exotic or luxury cars rubbishing the guy in the small family compact. They will both take you where you need to go, albeit at a slower pace. This is my first post. Please be gentle with me!