7mm 'Denton Brook' an industrial whimsey

Jordan

Mid-Western Thunderer
'Like' - yet again, a woefully inadequate button. :rolleyes:

I was actually waiting for the lorry's suspension to sag as the cable drums were lowered onto the deck... :cool: :bowdown: ;) ...although the driver will be in big trouble for driving with an insecure load... :p :)

Anyway, to the matter in hand:- do I just give up modelling now, or go look for some knitting patterns first..?? :confused: :oops: :'(
 

DougT

Western Thunderer
Anyway, to the matter in hand:- do I just give up modelling now, or go look for some knitting patterns first..?? :confused: :oops: :'(

Well you can consider my gob well and truly smacked after that performance. Knitting it is...

... genuinely brilliant. :thumbs:
 

Giles

Western Thunderer
If been doing loads in order to get Denton Brook ready for Railex (still got a bit more to do...!)
After one false start, I've finally got the back cloth situation under control. The theme is 'it's about to belt down with rain in five minutes'.

I've also been laser cutting some more cable drums to supplement the resin cast ones from Skytrex

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Giles

Western Thunderer
I'm in the process of building a little radio controlled 0-14 Bagnall for the layout. Using an old Wrightlines body with a scratchbuilt chassis. All the chassis parts are milled from N/S.

Lasering with the Emblazer - an expansion link in .028" nickel-silver.

9D9C4ED7-0181-440B-AB22-EEA806A6267B_zpsjpe3ivwi.jpg

Well, almost..... a slight cheat....

I laser the expansion link in 2mm MDF twice full size as a template

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And then mill it out with my little Proxxon pantograph engraver, modified to light milling.

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Steph Dale

Western Thunderer
...mill it out with my little Proxxon pantograph engraver, modified to light milling.

Any chance of a review? Capabilities, accuracy, that sort of thing? I've got the MF70 mill and find I'm missing the capabilities of my Taylor Hobson...

And where do you get cutters from?

Steph
 

Giles

Western Thunderer
The machine is extremely good within its limitations - remembering that it is a small engraver, not a Miller.

First of all, the tables (and pantograph) are small, therefore limiting its capacity to something like 4mm scale frames, rather than decent sized O gauge frames. One would have to be very careful with positioning clamping bolts to maximise capacity, so they didn't interfere with the pantograph swing.

The pantograph also pivots up at the rear to give work clearance, rather that having a vertical parallel motion. This means you have to be careful setting the rear pivot height and the stylus height in order to get the pantograph action paralleled to the bed with the tool set at the correct height (which is random!). However, it doesn't take too long to adjust this correctly.

There is no noticeable play in the linkage, or in the tool support, which means that it reproduces accurately - indeed, the critical measurements I have taken have been within 0.1mm of my CAD drawings (via laser cutting MDF at 2x scale, and pantograph milling from the result.

I find it quite easy to break the 0.8mm D cutters if I'm not extremely careful but the slightly larger ones are much more resilient.

For me, it is a stunning compromise that gives me a very small machine, enabling very accurate production of parts which I would otherwise have to make by hand. A proper Taylor Hobsen would however be a much superior machine if one had the space.....

Being able to laser cut the templates is an incredible bonus to say the least.

The pantograph and drill come in at just under £250. D bits from EBay at a pound each
 

Steph Dale

Western Thunderer
Giles,

Many thanks, it's a shame the machine isn't available currently. I shall keep as eye out for a second-hand one.

Steph
 

Giles

Western Thunderer
Axminster tools still have a couple..... The GE20, and the IBS/E.
The price appears to have gone up since Christmas though!
 

daifly

Western Thunderer
Try Amazon.de - you can get the pages to translate to English automatically. Expect to pay around €240 instead of £250. A few € for delivery and you're done. Most of my purchases of e.g. Proxxon come via that source. Delivery in c5days. Big savings. What's not to like? I have the IBS/E on order at the mo. £75.19 delivered to the UK. Axminster £96 with free delivery.
Dave
 

Steph Dale

Western Thunderer
Aah - sorry guys, I've failed to communicate properly. My hope was to find the MF 70-based unit (GE 70), but find it's unavailable. You're right about the pricing of the GE 20 though and have found some good prices from German sources.

@Giles,
I enjoyed your video too - just two (maybe three!) points;
1. I wouldn't use my left hand in the way you do - other than to support the lifting of the pantograph
2. Depending on which way you run the stylus/cutter round the job you'll end up slightly over/under size; which can be handy.
3. I was interested to see the thumb nut at the back of the machine 'dancing' in response to the machine vibration; it looks like there's an extra nut, which I assume can be used to lock it off?

Steph
 
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daifly

Western Thunderer
Steph
There is so much commonality between the GE 20 and GE70 that I suspect that the GE20 will do what you may require of it when added to your MF-70. I think I might splash out and get one and see what it is capable of!
Dave
 

Brian McKenzie

Western Thunderer
A technique that users of pantographs in general may find helpful is to use a slightly oversize diameter tracing stylus pin or 'nib' first - for roughing out a part initially. Then for the finishing cut - change the stylus pin for one of the correct diameter relative to the diameter of the cutter (pin = cutter diameter x pantograph ratio).

Using Giles work as an example where he used a 0.8mm dia cutter:
First rough out part using a stylus pin of say 1.8mm diameter. At 2:1 pantograph ratio, this will leave 0.05mm along the edges of the work piece for then cleaning up with a finishing cut having by then changed to a 1.6mm dia stylus
pin. This method will help tidy those places where small cutters flex or where cutters tend to dig in, especially at internal corners.

I wouldn't use my left hand in the way you do. . .
Steph

Steph, you'll soon find yourself doing the same thing!! :) ;) !! Guiding a tracing stylus gently around a pattern whilst resisting the cutting forces, and ensuring that it doesn't race off and break the cutter, will give you many heart stopping moments. Enough to drive you to CNC. . . .

-Brian McK.
 

Steph Dale

Western Thunderer
Brian,
You underestimate me - just run the stylus round so that the cutter pushes into the working line. Trust me* ;)

Steph

*Yeah, well - I'd need some practice; the Taylor Hobson went over ten years ago now :(. Not that there's any way I could have kept it!
* Looking at Giles' video I reckon I keeps his hands steady with the intravenous Jameson that was lurking in the background.
 

Overseer

Western Thunderer
I bought a GE70 some years ago and wouldn't recommend it at all. In fact I would recommend not buying one even if you find one cheap. There is a problem with its design which results in too much slop for it to be useful for our purposes, but it just about works for making name badges. The problem is that it uses the ME70 mill, which is fixed in position, and moves the table under the cutter. Too much friction and slop in the linkages to allow accuracy.

The GE20 looks to be a better design, more similar to a real pantograph mill. Proxxon probably withdrew the GE70 because it didn't actually work.
 

Steph Dale

Western Thunderer
Fraser,

I appreciate you posting that. I found one a couple of hours ago and was at the 'hmm' stage. The GE 20 won't meet my needs from watching Giles' and Brian's videos; it's perfectly good as a profile cutter I can see, but not really as an engraver. The lack of measurable or repeatable cutting depth would irritate me in no time.

For the moment I'll stick with etching for any of that sort of work, but it might be time to start saving my pennies and looking for a Taylor Hobson Model A, I think...

Steph
 
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