Sir William

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Sir William

This topic has 17 replies, 8 voices, and was last updated 7 October 2011 at 21:53 by Sub Mandrel.

Viewing 18 posts - 1 through 18 (of 18 total)

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1 October 2011 at 20:48 #21943
Peter Wood 5
Participant
@peterwood5
Milling Steam Chest Ports
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1 October 2011 at 20:48 #75669
Peter Wood 5
Participant
@peterwood5
II
1 October 2011 at 20:59 #75670
Peter Wood 5
Participant
@peterwood5
I have just started on this project and having milled the steam chest from the integral cylinder casting I now have to mill the 2mm and 3mm steam inlet and outlets ports. My problem is that the steam chest is 11mm deep and the ports have to be milled a further 6mm deeper. My 2mm end mills only extend about 12 mm from the chuck and I have not found any long reach 2mm end mills .

Can I put a spacer in the screw thread of my collet chuck to extend the reach of the 2mm mill or could I get away with putting the mill in a normal drill chuck??
1 October 2011 at 22:05 #75672
Gray62
Participant
@gray62
If you are using a Clarkson type collet chuck, then NO, you cannot use a spacer. The collets in these chucks do not grip the cutter tighlty, their function is to provide accurate alignment. The cutter must be in firm contact with the taper at the rear of the chuck in order to lock the cutter in place.

Drill chucks are not designed for the forces placed on them by the action of milling, in addition, milling cutters are invariably hardened throughout, therefore a dril chuck will not be able to grip them adequately to prevent rotation/displacement of the cutter, in addition, you are likely to damage the chuck jaws.

Long series endmills and slotmills are available, try Tracey tools they have sets advertised on their website and will probably be able to supply individual cutters as well

regards

Graeme
2 October 2011 at 12:00 #75696
Peter Wood 5
Participant
@peterwood5
Thanks Graeme for the definitive answer. I will give Tracy Tools a call tomorrow.

Regards

Peter
3 October 2011 at 10:21 #75742
Peter Wood 5
Participant
@peterwood5
Well Tracy Tools don’t have long series 2mm or 3mm slot drills and I have drawn a blank on the internet. Does anyone know a source?

This may sound a daft question, but why are the inlet and outlet ports from the steam chest shown as slots when they connect to just two steam passages to the top and bottom of the cylinder. Would two drilled holes at each end of the slot locations, connecting with the longitudinal steam passages work just as well?

Any ideas?

Peter
3 October 2011 at 10:32 #75744
Keith Long
Participant
@keithlong89920
Putting in “long series slot drills” as a search term in Google turned up pages of potential suppliers. Tracy Tools have them listed but no details of stock but Cromwell Tools and Chronos come up as possibles as well.

Keith
3 October 2011 at 21:36 #75772
Peter Wood 5
Participant
@peterwood5
Thanks Keith. However I have tried all of them and none stock 2mm LS.

I can get 3mm from Chronos which will do the exhaust port.

For the present I have settled for 2 and 3mm drilled holes instead of the design slots.

Perhaps Anthony Mount will provide the answer when he gets around to the cylinders in the ME construction series.

Regards

Peter
3 October 2011 at 22:18 #75775
Roger Banks
Participant
@rogerbanks33631
Peter,

Try Cutwel Tools.

They sell long series end mills and slot drills with Weldon shanks. I’m not sure if they sell screwed shanks.

Roger
4 October 2011 at 01:40 #75781
David Littlewood
Participant
@davidlittlewood51847
Peter,

As Graeme said, drill chucks are quite unsuitable for holding milling cutters. however, ER series collets are quite suitable – I frequently use them for this. You should find this gives you a little extra reach with a standard length slot drill.

However, if that does not give you enough reach, you can get long series slot drills from J&L/MSC:

http://www.mscjlindustrial.co.uk/CGI/INPDFF?PMCTLG=00

Their prices are not the cheapest, but their speed of delivery is amazing. Also, look in their monthly sales flyer, you can often get what you need at a significant discount.

David
4 October 2011 at 11:21 #75796
Peter Wood 5
Participant
@peterwood5
Thanks for all the suggestions.

I have located LS 2mm & 3mm screw shank slot drills but at outrageously expensive prices – like £34 for one off each after P&P and VAT. Surprisingly Weldon shank can be obtained much cheaper.

I am now thinking that a cheap 6mm MT3 end mill holder from Arceurotrade and Weldon type slot drills might be the answer. Still expensive for six small slots.

Hey ho – you can’t take it with you!

Peter
4 October 2011 at 17:55 #75813
David Littlewood
Participant
@davidlittlewood51847
The J&L price for 2mm long series slot drills (with screw shank) is £10.55 + VAT and postage. Page 233 of the catalogue.

David
4 October 2011 at 18:04 #75815
JasonB
Moderator
@jasonb
Can’t you drill a bit of 1/2″ or 5/8″ rod 6mm and tap it for a grub screw then use one of the little FC-3 cutters in that, hold the whole thing in a milling chuck or even a MT collet.

Think thats what I used on my Fowler, valve chest is 11/16″ deep and then used an 1/8″ cutter on the ports

J

Edited By JasonB on 04/10/2011 18:26:01

Edited By JasonB on 04/10/2011 18:31:17
4 October 2011 at 22:59 #75836
Peter Wood 5
Participant
@peterwood5
David

I don’t want to appear ungrateful for your help but I just checked the J&L prices again.

2mm LS £10.55 3mm LS £11.93 Sub total £22.48

Shipping £4.95 (the cheapest option)

SalesTax £5.49

TOTAL £32.92

Hence my observation that it was expensive.

Peter
4 October 2011 at 23:32 #75838
David Littlewood
Participant
@davidlittlewood51847
Peter,

Like I said, look in the October monthly sales flyer for the best deals. 2 and 3 mm long-series slot drills (not screwed shank in this case) at £2.35 each:

http://www.mscjlindustrial.co.uk/CGI/INPDFF?PMCTLG=14

…and anyone who can’t find some other things to make the postage worthwhile has a *lot* more willpower than I do!

David
5 October 2011 at 09:03 #75845
Dusty
Participant
@dusty
Remember Peter, it’s not your money you are spending ‘it’s your kids inheritance’
5 October 2011 at 14:43 #75860
Peter Wood 5
Participant
@peterwood5
Well I solved the problem though I suspect some may not approve of my method!

I cut the threaded end off a broken mill which had a 6mm shank. After grinding the cut end flat I cut a slot in it to take a screwdriver. The ‘grub screw’was then fitted in the Posilok chuck collet adjusting it with the screwdriver until it was slightly proud of the screw hole. The slot drill was then inserted into the collet and the chuck tightened, firmly gripping the slot drill well enough to prevent any slippage. The reach was now extended by about 10mm

The method worked well enough to accurately mill the slots.

I cannot claim any credit as the method was suggested to me by a friend who had been an instrument maker for many years.

However thanks for all the suggestions and for the many new tool suppliers in my bookmarks.

Peter
7 October 2011 at 21:53 #75970
Sub Mandrel
Participant
@submandrel
Until I came to the last message I was going to suggest making a 2mm cutter on the end of a length of silver steel. I’m sure such a simple arranegment would work fine for cutting a small slot in good quality cast iron.

Neil
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