By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Bob

Here is a list of all the postings Bob has made in our forums. Click on a thread name to jump to the thread.

<< First < Prev 1 2 3
Thread: CNC engraving
06/10/2009 17:25:45
Hi Ian
 
I think Paul is right about the spring loaded engraving tool. I think their main use is for manufacture of prototype PCBs from copper coated circuit board using island isolation milling to create the tracks. The material is very difficult to hold down flat and as the engraving is only about 10 thou deep the irregular surface results in erratic results if a normal engravint tool is used.
 
Bob
Thread: Howto operate the injector of a steam engine
29/09/2009 13:18:37
Hi Max
 
As a general guide turn on the water valve first and establish a steady flow of clean COLD water through the injector overflow. Then turn on the steam.
 
If the injector is working you will see the water stop flowing  or at least reduce to a drip from the overflow. At the same time you should hear the cold water being forced through the clack into the boiler. The injector has picked up. Watch the water level in the gauge glass and turn off the steam as soon as you are happy with the water level in your boiler. You may need to turn on the blower a bit to draw up the fire a bit as you have just injected a load of cold water into the boiler.
 
Common faults are sticking clacks, clacks not seating properly and injectors clogged up with limescale (especially in hardwater areas).
 
Injectors can be cleaned by soaking in vinegar or citric acid to remove the lime scale.
 
Bob
Thread: Small Milling Machine
28/09/2009 19:38:54
Might not be too helpful, but if you can find one the little BCA jig borer is a delightful machine for model engineering.
 
Bob
Thread: Engine building without power tools
07/09/2009 13:28:02
Posted by Philip Rowe on 07/09/2009 13:09:47:
Hi Mark,
Can't remember exactly when - 70's, 80's maybe there was a series in ME called "Handmaiden" by Tubal Cain I believe. This was a construction series on building a stationary engine using only hand tools.
I'm sure some of the more expert members here may be able to elaborate on this. I thought it may be of interest as there won't be the financial outlay on potentially expensive kits, only the purchase of stock size materials which will always be useful regardless.
 
Phil
 Hi Mark
 
I am sure Phil is right about Handmaiden. However, I don't think it was intended as a beginner's project, rather it was a 'proving it could be done' sort of exercise. I recall that Tubal Cain used a set of castings to make Handmaiden.
 
Bob
Thread: Choosing a lthe
07/08/2009 12:12:57
Hi Niloch
 
Had you considered a second hand industrial lathe rather than a new machine aimed at the hobbyist?
 
I have an old ML7 and more recently aquired an old Smart and Brown Model A toolroom lathe for £500. The S&B came equipped with a good range of chucks, about a dozen imperial collets, taper turning attachment, Norton gearbox etc. It takes up little more space than the Myford, but is much, much more solidly built. Parting off has become far easier and the general quality of work produced is much higher.
 
The downside was having to replace the three phase motor with a single phase motor but again no great problem as I happened to have a 2HP motor to hand.
 
I have been able to use the Myford vertical slide on the lathe cross slide so even the lack of a tee  slotted slide is not too great a problem.
 
Bob

Edited By Bob on 07/08/2009 12:16:29

Thread: Vulcan Beam Engine
03/08/2009 07:27:35
I am building the Vulcan Beam engine described by E T Westbury in Model Engineer Issue 2787, 2789, 2791, 2793, 2795, 2797, 2799 and 2801. I have the castings for the standards and the flywheel, but having to fabricate or mill from solid stock the remaining parts.
 
I would welcome comments from other builders of this engine and especially any variations from the drawings published in ME
 
Bob
 
Post script
 
Just found this video on You Tube of Alf Case's model in action at the Harrogate model exhibition in 2009 http://www.youtube.com/watch?v=2q7C_t_cyfM

Edited By Bob on 03/08/2009 07:55:42

Thread: Denford CNC milling
19/07/2009 08:53:48
Hi Mogens
 
We brought it through a school account, but I am sure Denford would be happy to supply an individual. I suspect the machines are aimed at the education market and the manufacturers may not warrent the use of the machine for more intensive production work. I know another manufacturer of CNC machines aimed at education refers to their machines as training machines to overcome any charges that their products are not up to production work.
 
My own experience of trying to machine stuff other than foam, Perspex, free cutting brass and aluminium alloy on a school CNC miller ( not, I hasten to add a Denford machine) has not been good. On the manufacturer's training course you are told not to try to machine tough stuff, because the machine is only a training machine.
 
Now I don't totally subscribe to this view because I cannot see that the machine is much lighter in construction than many millers marketed to model enginners and these will chomp away at chunks of cast iron and gun metal.
 
I would like to try setting the machine up to speeds and feeds appropriate to these tougher materials and give it a go. I tend to suspect that the feeds used in the supplied software are on the high side even for free-cutting metals.
 
Bob
18/07/2009 16:54:57
Hi Mogens
 
Its my guess that the good folks at Birds Royd would sell you one. You could probably save a good deal on delivery if you picked up the machine yourself. We brought a CNC router from them last year for making the F1 in Schools cars and I picked it up in my Suzuki Jimny, a tight fit but it just slipped into place. Its a good machine.
 
Bob
Thread: Milling on Myford
07/07/2009 13:41:41
Hi Ruaidhrí
 
Try this for starters,
 
Set the block of FCMS true across the lathe and approximately at centre height. Make sure all is secure. A strip of normal A4 typing paper between the vice and the work often improves grip on the work..
 
Set your 1/2" cutter in the collet. Make sure your drawbar is in place and that there is daylight between the backface of the closing nut and the body of the Autolock. Nip it up tight, but no need to flog it tight with a hammer!
 
Set the cross slide so the work is between you and the cutter, then advance the carriage until the cutter will take between 1/16" and 3/32" cut.
 
Now lock off the carriage. Disengage the leadscrew drive and engage the claspnut (If you have a handwheel on your leadscrew you can use the to apply subsequent cuts, very useful. Also use the nut that pinches down on the bed to lock things up while you are milling.
 
Set your lathe to bottom speed direct drive ( not backgear).
 
Put your safety glasses on, check the spindle is clear to revolve and start up the lathe.
 
Cautiously advance the work towards the revolving cutter. Listen and watch progress carefully. As long as the noise sounds ok and the swarf is coming off cleanly carry on until the entire cutter clears the work leaving a shallow slot in the steel.
 
The swarf should be bright and shiny, not blue. If the swarf is coming off blue then stop at once. You will neeed to reduce the speed of the cutter.
 
I am aware that these shallow cuts are unkind to the corners of the teeth on your cutter, but the poor rigidity of the set up means that you cannot drive the cutters hard. As others have pointed out, a small chamfer on the corners of your cutter will greatly increase its life especially if you are using it for facing work.
 
As you gain experience you can experiment with different speeds and feeds, but remember, the speeds and feeds quoted by cutter manufacturers are for industrial production on massively rigid machines and that these figures maximise the rate of metal removal at the expense of tool life (After all, they are trying to sell cutters!)
 
Your rippa should be OK for this job, but I would choose a four flute end mill as I don't need to plunge it into the work. You won't cut an accurate half inch slot this way. If you want to do this then start with a smaller diameter cutter in the middle of the slot. Then when the slot is almost to full depth machine first one side and then the other to dimension. Remember always to advance the work towards the cutter tooth.
 
You mention woodworking, just think about the rules for feeding a router around a piece of wood, its the same for milling. Trying things the other way (Climb milling) is not suitable for the type of setup you describe.
 
Bob
Thread: Bridgeport miller
19/06/2009 08:01:05
Thanks for the information.
 
I agree with the use of rollers to move machines. My drive is about 1 in 3 down hill and using a system of rollers, packing and wedges I was able to safely move my Smart and Brown Model A down the drive and into the workshop. The important thing was to position the wedges so that when the lathe started to roll it would run up the wedges, once wedged a second pair of wedges could be positioned a few inched down hill and then the lathe eased off the holding pair of wedges using a crowbar. No hairy moments and the lathe in place in an afternoon.
 
Bob
18/06/2009 13:14:09
Hi all
 
How much headroom in required to run a Bridgeport milling machine? I would like to put one in my garage workshop but am concerned there would not be enough clearance above the machine. I am especially worried about being able to remove the drawbar without having to dismantle the machine too much.
 
Bob
<< First < Prev 1 2 3
Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Shopping Partners
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate