Hello from South West england

[Gavin Jones 1Participant @gavinjones1]

Introduction

[Gavin Jones 1Participant @gavinjones1]

Hi All, thank you for allowing me to join. I have been reading various posts for a while and find the threads very interesting.

I am a semi-retired time served engineer who enjoys working on old motorcycles and making/repairing parts with my Colchester Bantam 800 MK2.

I would like to buy a milling machine to supplement the latter's capabilities but I am short of workshop space – hence it will need to be a mini mill of some sort.

Best wishes, Gavin

[Mike HurleyParticipant @mikehurley60381]

Welcome to the forum Gavin – lots of friendly advice and useful info on here. Your mechanical engineering background and experience may well offer you opportunities to provide help to other members in the future.

All the best. Mike

[Gavin Jones 1Participant @gavinjones1]

Thank you very much Mike.

[Roger QuaintanceParticipant @rogerquaintance14196]

welcome aboard, where be you to?

[David George 1Participant @davidgeorge1]

Hi Gavin welcome to the forum. Also a retired toolmaker and ex biker. I wondered what sort of engineering you did as that can be useful to other members. I bought a bench top mill from Chester hobby store and that has been adequate for my use and space.

David

Edited By David George 1 on 01/04/2022 19:45:02

[Gavin Jones 1Participant @gavinjones1]

Hi Roger, thank you. I am in mid Cornwall. Where are you?

Hi David, thank you. I am a mechanical engineer by trade but my job involved some process, electrical and civil engineering. I am not so keen on eletrical/electronics engineering but love the other aspects.

I must take a look at the Chester products. So far I have been researching at Amadeal (Weiss) and Sieg.

[Howard LewisParticipant @howardlewis46836]

Welcome to the Forum

All sorts of expertise on here, should you need hel or advice.

Howard.

[Gavin Jones 1Participant @gavinjones1]

Many thanks Howard. I am sure I shall have some questions. Gavin

[Chris Evans 6Participant @chrisevans6]

Welcome along Gavin, from another retired toolmaker (mould and die) pre-war bikes are my passion.

[old martParticipant @oldmart]

Welcome to the forum, Gavin, I suggest that you check out the ARC link on this page, they give the footprint of their mills and have an excellent reputation for backup for their products.

[Gavin Jones 1Participant @gavinjones1]

Thank you Old Mart.

I have purchased a few tools from ARC and have been pleased. I understand they sell the Sieg range of milling machines. Their SX2.7 would suit my needs well. I have watched several videos of people setting up, measuring and reviewing their Sieg mills. I agree totally re vendor reputation. Many years ago I used to work in engineering purchasing and we used to say "the measure of a supplier is not so much when things are going well, but how they respond when things go wrong".

Thanks, Gavin

[old martParticipant @oldmart]

If you are buying new and have a choice between MT3 and R8 spindles, then go for the R8, it is a proper fitting designed for mills and far better than a Morse taper which was designed for drilling machines.

[Gavin Jones 1Participant @gavinjones1]

Thank you Old Mart. My lathe has MT3 in the tailstock and so does my pillar drill, but my heart is set on R8 for the mill as it will maximise the height available from the spindle nose to the table. Gavin

[old martParticipant @oldmart]

The main advantage of R8 over MT is the taper angle being much greater and therefore being easier to break, also you have to go to MT4 to get the same stiffness in the shanks. Mills with stuck Morse tapers are a perennial subject on this forum. I do not think that there will be a Z height advantage, rather the reverse. However, there are still a huge ammount of R8 fitting tooling available new or used on the market despite it being well out of date in industry.

Edited By old mart on 02/04/2022 17:49:17

[Gavin Jones 1Participant @gavinjones1]

Thank you again Old Mart. I will be sure to go for R8 in whichever mill I end up with. Gavin

[Gavin Jones 1Participant @gavinjones1]

Thank you Chris, seems there are several like minded people on this forum. I have not yet ventured into pre war bikes but find them fascinating. I do have chance to restore a very old Scott two stroke (not mine).

Gavin

[VicParticipant @vic]

Posted by old mart on 02/04/2022 16:07:17:

If you are buying new and have a choice between MT3 and R8 spindles, then go for the R8, it is a proper fitting designed for mills.

R8 seems to be very much a copy of the collets used on lathes at the time and is far inferior to later fittings designed specifically for milling machines. Once a mill is fitted with a milling chuck the taper in the quill isn’t of much consequence anyway. Having the ability to fit Morse taper drills directly in the quill is also very handy.

[old martParticipant @oldmart]

Posted by Vic on 02/04/2022 20:06:32:

Posted by old mart on 02/04/2022 16:07:17:

If you are buying new and have a choice between MT3 and R8 spindles, then go for the R8, it is a proper fitting designed for mills.

R8 seems to be very much a copy of the collets used on lathes at the time and is far inferior to later fittings designed specifically for milling machines. Once a mill is fitted with a milling chuck the taper in the quill isn’t of much consequence anyway. Having the ability to fit Morse taper drills directly in the quill is also very handy.

Vic, I did mention in an earlier post regarding R8 "despite it being well out of date in industry"

Also we have several sizes of drill chuck, 1/4",10mm, 13mm and 16mm, plus er25 collet, Osborn Titanic II threaded, and several shell mills in 40mm, 50mm, 63mm and 80mm, boring head, MT2 and R8 collets, so we are likely to change things often.

[Howard LewisParticipant @howardlewis46836]

If you dislike bashing spindles and their bearings to break Morse tapers, it should be possible (if the machine does not have a self releasing drawbar ) to make simple "pusher" for this purpose.

For my RF25, this involved removing the L H threaded nut above the spindle pulley and turning back , part way, the lower side of the nut. A matching plate was made up with two tappings (1/4 BSF, but M6 would do equally well )

Another plate with two clearance holes and a central tapping for a forcing screw (Again 1/4 BSF in my case)

When it is necessary to break the taper, two studs / setscrews are screwed into the plate beneath the nut, and the top plate fitted. Tightening the central forcing screw against the slightly slackened (!/2 turn or so ) drawbar will break the taper in most cases without the need to be brutal.

HTH

Howard

[Gavin Jones 1Participant @gavinjones1]

Good mod' Howard. I dislike bashing things. Gavin

[old martParticipant @oldmart]

Another plug for R8, Howard?

[Howard LewisParticipant @howardlewis46836]

Steeper tapers such as the INT Series and R8 are easier to separate than Morse tapers.

But those of us with older machines, using Morse tapers, have to find a less damaging method , to "break" a self holding taper, than plain brute force.

Admittedly, a suddenly applied force will have double the effect of a gradually applied one, but that effect may result in damage ball or roller bearings. So is best avoided. Hence my preference for an extractor, or self ejecting drawbars.

Particularly with Morse tapers the thing to avoid is to pull a cold Morse taper tool into a warm spindle. The spindle contracting as it cools onto the tool will make removal even more difficult.

Howard

[Gavin Jones 1Participant @gavinjones1]

Good points Howard. Currently, I have small machines from Seig, Optimum and Amadeal (Weiss) under review. Thanks, Gavin

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