Member postings for Douglas Johnston

Hello Paul,

I have been fascinated with the idea of 3D printers for ages but have never done anything about it. Roughly how much do they cost to build and are the plastic consumables expensive to buy?

Doug

As an alternative to felt, I made some wipers from 1mm thick acetal sheet which I machined to an angled edge. With two layers of this it seems to be working fine and has been in place for about a year. Acetal or delrin is quite hard and slides over metal surfaces with very little friction. Mind you this stuff is'nt cheap either but you don't need much.

Doug

John S. - I have just fished out MEW 108 and the gear hobbing system looks very interesting, I must have flicked past it at the time without thinking too much about it.

I am interested in trying it out and was wondering if the layout for the PCB you mentioned is available, since I don't like veroboard. I could do my own layout but it would save me a lot of time if one was already available.

Doug

Welcome to the long running debate about oilers Chris. You have the Myford type of oil nipples and finding a suitable oiler that does not leak oil all over the place is not easy. The ones supplied by Myford when the company was still alive were prety poor and I suspect they were meant for grease.

It is possible to adapt a grease gun for use with oil (details on internet ) and I have been meaning to try this for ages, but might just give it a go now that you have indirectly reminded me.

Doug

Is loctite one of these products that are best stored in the fridge to extend shelf life?

Doug

I stand by my previous post, the accuracy of the collet or chuck is irrelevant if the tool is set up the way I mentioned.

Doug

I don't think these twin headed tramming devices rely on each indicator being perfectly matched. As I understand it, each indicator is set to zero on the same test block (without moving the block). This then sets the plane of the indicators at exactly 90 degrees to the spindle and eliminates any misalignment of the tool in the holding collet or chuck.

Doug

I use a piece of plate glass on the mill table when tramming the mill. I checked out the flatness and whether both faces were parallel before use and found they were spot on.

Doug

I did what you are doing about 5 years ago and you seem to have most points sorted so just a few pointers from my experience.

(1) Traditional roofing felt, as mentioned, is not a good long term idea, I used the newer adhesive backed polyester roofing "felt" after coating the wooden roof with bitumen primer. The polyester covering was then stuck to the roof,thus eliminating the need for roofing nails. After 5 years the roof is still perfect and should reach the expected life of 20 years.

(2) I used garage floor paint on flooring grade chipboard and the floor is still in good condition

(3) I made bench tops from 38mm kitchen worktop and they work very well.You can pick up slightly damaged ones very cheaply .

(4) I covered the inside of the glass windows with double walled polycarbonate sheets, sealed to the window frame. This served to improve the insulation and provided some security since they make seeing into the shed more difficult, while letting light in.

(5) Plenty of metal clad sockets-then add some more!

Doug

Ebay used to be very good for buying quality tips at a very good price, but I have noticed there are fewer bargains now. You also have to be very careful about tip size and tip radius to get what you need. I also have a few Glanze tools and they perform very well and are a lot cheaper than top brand names.It should also be said that tool holders are very easy to make yourself from decent quality steel and the torx screws are not that difficult to source.

Doug

Can I introduce a word of caution regarding charts. I have a whole collection of the cards provided by MEW in the past to form a workshop data book and I don't think many ever get read. By all means have a few charts, but stick to things that get a lot of use in the workshop and don't let the whole thing grow like topsy.

Doug

Thanks for the information Neil, I will take on board your ideas if I make other ER collet holders.

Doug

Ok Neil,

What form does your 8 degree "square" take and how do you use it? I have found getting the 8 degree taper a bit hit and miss and use a collet as my "square". Have you found a better way of doing it?

Doug

If your not in a hurry the soft start is a great way to operate the lathe/mill. My previous lathe had a rapid start which can't have been good for the drive mechanism of the lathe and it certainly was'nt good for my nerves. The soft start gives you a controlled start which can get you out of trouble if things go wrong at switch on since you can switch off before the motor is up to full speed.

Doug

What a brave chap you are John, 22V at 1A sounds a bit extreme for these panels but it does show they are very tolerant of over voltage. Can't imagine they would last long at that voltage but it will be interesting to see how you get on at 15V for soak test.

Doug

The type to get are the ones shown in the very first post which have 48 led's surface mounted on an area of about 5 by 4 cm. With a 12V led driver they are BRIGHT, I was going to fit two on my mill but might only need one.

Doug

Just bought an electronic LED driver for £4 on ebay (plenty people sell them around the same price) and it is perfect for running these panels. The unit is small and can supply up to 1A at 12V so could run a few panels. It also has the advantage of isolating the mains supply from the machine.

Doug

Some silly people get caught out by bidding stupid sums on an item at the last minute then find an under bidder has just bid a little less. When I was selling a cement mixer a while ago I looked at the going rate which was about £100. One mixer however sold for over £1000 because there were two inflated last minute bids for it. I often wonder if the person ever got the £1000.

Doug

I have just received one of these panels to try out (from UK source to get it quickly-although more expensive) and they are very nice indeed. At 10V they take about 150mA and at 12V the current is about double, although the change in light output is not great. The light output is pretty good, but it is the small size (6 by 4 cm) which makes them easy to mount on the mill, perhaps with a clear plastic cover to protect the led's. Conclusion- well worth buying-off now to buy some more from China.

Doug

I saw a website some time ago about making your own bellows, but can't remember the actual site. If you have some folding skills this may be a cheap way forward.

Doug