Here is a list of all the postings HOWARDT has made in our forums. Click on a thread name to jump to the thread.
|Thread: Jig borer|
As Clive said. A jig borer will have accurate table positioning, within 0.005mm/0.0002" is a manageable tolerance. The spindle will also be accurate in runout and z-axis, so precision bores can be produced using single point cutting as against a drill/ream hole. Machines are heavy compared to a mill of the same envelope and may use glass scales. To maintain accuracy the machine should be within a temperature controlled room.
|Thread: Help wanted solving groove for O ring cutting on lathe|
For those that can't see the pictures. I assume it is this way for most, they don't appear in email notifications, you have to use the forum (not necessary to log in).
|Thread: Apprentice Piece - Turning|
I spent my first year in employment in 1967 under the local engineering training group in a training workshop. Although I was employed as a draughtsman I had to learn by getting my hands dirty, enjoyed every (most) minutes of it. We had to do this for 10 months and 40 hours a week, plus travelling of an hour each way by train. I still have the riveted tool box with most of the pieces in, most entailed using different machines and hand finishing. I doubt you would get 30 sixteen year olds to do that these days, we had one lad drop out because he wanted to go into graphic design and got a job in that. How many of those worked in engineering all their lives, I have no idea, it would be interesting to find out. I have been lucky!!. Four redundancies, taken back once and finally contracting for the final 10 years. Contracting is were you see the lack of engineering skills both in other contractors and in the full time workforce. The amount of knowledge I have passed on over these last few years is ridiculous. Do others feel the same, as you get older you have to impart more to not only the young but also the not so young who didn't benefit by the apprentice schemes
A simple turning piece, as previous a centre punch or scriber, just make sure they know how to remove the chuck key and where the brake is.
|Thread: Thrust washer|
As Martin says no. Thrust washer can be of almost any material, PTFE to ceramic. But the material is chosen for the application, dose it run dry or in an oil bath, is the load low or high and a multitude of other design criteria. If you are replacing an existing washer ensure it is the same material and hardness. When you understand the design rules you may be able to substitute materials. Also ensure that the mating faces are as they should be, any wear on the mating faces may lead to premature failure when you fit a replacement.
A washer, a circular object with a hole in the centre and usually thin in relation to its diameter. A washer becomes a thrust washer when the thrust or load is placed on its face.
|Thread: 3D mouse|
When I first started using AutoCad back in 1988 I used an A3 tablet with a menu on it and a wired pen. As time moved on the tablet became out of date and we moved to a mouse and keyboard shortcuts. Then when Inventor came along I continued to use shortcuts. I did use a 3DConnexion space mouse, they used to sell it half price for home use, for some time but stil found myself going back to shortcuts. I now use Fusion360 at home and still prefer mouse and shortcuts.
|Thread: Air casters|
As Martin said the floor needs to flat and level. In the 70's I worked on a design for lifting and moving jet engines around the work floor, self contained hydraulic lift on four columns each with air skates. The floor was levelled and smoothed for it to work. I do believe I have seen a commercial system on the net in recent years, but can't remember where.
|Thread: what do you use when designing?|
Being a career machine tool designer I have always used Autodesk products from AutoCad v9 (1988) to Inventor 2014, then retired. I am now using Fusion 360 on a Mac. I was sceptical about 3D initially but after using it I became a convert. Since I was a professional user I had a long standing account with Autodesk which I log into, since retiring I can still log onto this account and used this to download Fusion which still allowed me to register it as a hobbyist.
Paper is still my way to get an idea fleshed out before woking out the sizes in 3D
|Thread: What Did You Do Today (2016)|
Just spent the last two weeks in New England, for the fall. Did a circular drive from Boston of 1300 miles. I can see how they can have such big workshops. When out of the cities houses each stand in a few acres. Sometimes the barn/garage is bigger than the house and often surrounded by rusting junk. No snow while I was there but was told it could be expected any time now, one petrol station I called into on the coast north of Boston actually had a guy pump gas for you, he said the norm was four/five feet there.
|Thread: Precision layout & machining?|
As others have said or alluded to, model engineering is about making some thing work not precision per se. When we worked as engineers precision depended on the trade and size of things. A micron for some was as near as ten millimetres for others. Mostly we are dealing in one offs as well. if the hole is a little undersize we can make the shaft a suitable fit ignoring the size. Also unless you are dealing with drawings from an engineering draughtsman I suspect it will have no tolerances on any way. You can of course go the precision machining route, but that would entail precision machines and measuring equipment to match. I for one cannot afford the precision route, i did buy a new slip gauge set for £100 noting that it wasn't in the same league as a precision set at £2000, but it is good enough for what I do.
|Thread: Evening Star 3 1/2 inch|
Bought all fasteners from PTS here in the UK. I know some may frown at the use of over scale looking fixings but they are cheap and easy to get. If it was a scale show piece then I would do things differently, but I want a working steam engine not a show piece and there are plenty of non scale parts on a model anyway.
Thanks all for the comments and links, always useful to find alternative sources.
Thanks John. I think it is the ideal size for the small home workshop, I wouldn't enjoy making anything bigger without full size machinery.
Have added a few photos to my album of bits in progress. Nothing to write home about but like to be complete as can be from a manufacture point of view, nothing worse than showing a complete assembly with no indication of the work that goes into it.
Seeing as people at the moment are discussing milling cutters, most of these parts have been produced with a two flute uncoated carbide 12mm slot drill, running at 2500rpm on my SX2P mill. It is a UK manufactured professional cutter that I found amongst my tools and seems to be a far denser carbide than the imports I have.
|Thread: MEX Photos for those that stayed home|
Visited MEX today, Sunday, 120 miles 2hours 10 minutes there, 2 hours 27 back. Interesting look round, never been to Brooklands before. MEX exhibition pieces were interesting, I am sure if I had another life time to dedicate to model engineering I might get close to the quality on display. As it is I will limit myself to what I can achieve without taking all of my final years trying to achieve the impossible, and be happy.
|Thread: How to align a V accurately with a slot?|
Create the vee first. Place a roller in the eve and measure off that to get centre for the slot.
|Thread: Evening Star 3 1/2 inch|
I have started to make Evening Star in 3 1/2 inch from LSBC plans from Reeves. This is my first build so though I would put it on here. I am sure many will find fault with the way I do things. the object is to get a reasonable model up and running in a reasonable time.
I intend to make as much as possible from scratch using my Sieg SX2P mill and C3 lathe. As I have no free source for materials, being retired, I have to purchase it all so tend to make things from what I have or what I can easily purchase locally. It is intended to use metric fasteners and fittings, I know they may look a little bulky but if it ever gets into steam and travels round a track no one will see them until is stops.
So far I have made a few parts for the frames and each of these has been modelled in Autodesk Fusion 360, so that I can have individual working drawings. When I can I will include photos of the progress. Perhaps this thread will help others in the future.
|Thread: Press fit bush|
Have a look at Oilite, Manganese Bronze. Although these are not re-machined after fitting, they achieve the correct bore after being press fitted into the correct hole.
|Thread: Weird lathe bed|
With a design like the Artisan the taper gib allows fine adjustment by using a screw on the end to push and pull it into place. Much easier to adjust clearances than fiddling with grub screws on the opposite dovetail as we have to now on the small imports.
|Thread: Sweating Plastic|
I had a Ford CMax, 54 plate until last year. Had the car for 8 years and for most of that time the heater dial knobs were sticky. Nothing I could do to the plastic could get rid of it. My guess was that something went wrong during manufacture.
Just had to re-activate PocketMags subscription. Copy of 4543 there but no 4542.
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