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

Member postings for Jon Gibbs

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

Thread: RF-25 Belt-sizes and Table Stop Info Please
15/02/2016 08:44:38

Hi Howard,

Thanks very much for the suggestion - I'll have a quick look at the pulley alignment.

...but my machine is 20 years old and seems to have been well used. So, I suspect that if it was shredding belts, then that niggle might have been ironed out by now.

Thanks again

Jon

Thread: Cutting an external thread on the nose of a milling chuck
10/02/2016 11:31:51
Posted by Roderick Jenkins on 10/02/2016 11:19:52:

As has become usual on this forum, the answers to the OP's question (with the best of intentions) have become a bit like the the question "What's the best way to get to Limerick?" Answer: "I wouldn't start from here sir!"

It's a fair cop - I'm afraid you're right Rod. embarrassed

Jon

10/02/2016 10:54:27

Hi Adam,

Well if you only want to cut one thread you could just turn a parallel spigot (with flat) on the arbor and have a snug fitting bore on the "lump" with a set-screw as well as loctite. Provided the tightened set-screw is below the core of the thread on the "lump" it won't get in the way.

Alternatively you could mill some slots on the arbor and the threaded "lump" and screw on some small blocks to prevent rotation like this on my fly-cutter which is mounted on an arbor cannibalized from a face-mill.

HTH

Jon

10/02/2016 10:13:05

Hi Adam,

I think I'd be inclined to use an R8 blank-end arbor instead - you probably need to loctite a larger diameter lump on this one to get the size you need...

**LINK**

or try rethreading a dedicated boring head shank (6th one down) although this might be hard too.

 
HTH
Jon

Edited By Jon Gibbs on 10/02/2016 10:13:38

Thread: RF-25 Belt-sizes and Table Stop Info Please
09/02/2016 13:45:17

As a Post Script, here are the table stops I made. Decided to add a short spigot to engage with the outside of the dovetail slot to keep them central...

I also needed a replacement thumb-screw for the Y-axis scale...

So far my cheapy v-belts seem just fine but the size in the manual is wrong and the shorter one does appear to need to be an A30 rather than A31. Many thanks to Simon for his help with the belts and the stops.

As a primer I bought Harold Hall's Workshop Practice books on milling and made myself a set of clamps along with a rack...

I suspect it won't stay that tidy for long wink

Jon

Edited By Jon Gibbs on 09/02/2016 13:49:46

Edited By Jon Gibbs on 09/02/2016 13:50:47

Thread: Taper turning. (offset attachment)
05/02/2016 14:41:45

+1 for the Hemingway kits version which has a half-centre (dead of course).

I used mine, instead of setting over the tailstock, in order to be able to screwcut a taper between centres for a pigtail mandrel (that I could have bought for a few quid but I thought it'd be more fun to make one) which doesn't need a precise taper.

Even though I have it I don't use it for conventional tapers as it's quite tricky to set up precisely and the arms then need to stay horizontal and not move after the set-up. All my other tapers have been short enough to stay within the capabilities of the top-slide.

HTH

Jon

Thread: Colchester Student -ER40
03/02/2016 11:40:03

Hi Clogs,

Have you a 4-jaw chuck? If so then how about these instructions from HH...

**LINK**

The ER40 has the same internal bore angle as the ER32 and you can buy the spanners and closing nuts from Arc for a few quid.

I've made two ER chucks (ER20 and ER32) for my Myford based upon these instructions.

HTH

Jon

Thread: RF-25 Belt-sizes and Table Stop Info Please
23/01/2016 17:03:09

Hi Simon,

Thanks for the warning - I'll suck it and see.

Jon

23/01/2016 15:49:23

Simon,

Thank you for the pictures - very much appreciated.

Jon

23/01/2016 14:30:27

Thanks for the idea Simon.

I must admit I did wonder about the tensioning of the motor belt in a better way but I wondered whether the more critical belt would be that for the final drive using the middle wheel which will have the greatest torque when the lowest speeds are engaged?

I guess time and experience will tell.

Thanks again

Jon

23/01/2016 13:19:14
Posted by Ian S C on 23/01/2016 10:59:08:

I don't know how much movement there is with the pulleys for speed changing, I know that my Rexon mill has it's pulleys in line with each other, and there is not enough room to comfortably change speeds with a link belt, it takes a lot of heaving, and leavering with a large screw driver on my machine, and I had to enlarge the hole where the motor spindle comes through.

Ian S C

Hi Ian,

Well it was the inability to tighten the belts which made me think the current belts are too long but you are right that perhaps opening out the hole for the motor shaft would give enough adjustment. It might be that just fitting a shorter belt is just as good.

Amazon have belts for about £3 delivered so that's my starting point. At that price it's hardly worth leaving the chair, let alone finding a Halfords

Jon

23/01/2016 08:30:44

Hi All,

Thank you very much everyone.

I feel a bit stupid because I didn't realize that I had the sizes already - Dooh! The values A31 and A38 are given in the manual - but in case Simon's machine is more representative I also ordered an A30 one too.

The link belts look good but I'll try the cheap and cheerful continuous belts and if they are very noisy I'll consider upgrading to the link belts then.

I don't know if I'm looking in the wrong places but there seems to be an approximate 7-10x price hike for the link belts which seems a bit steep unless the benefits are worth having...

...but I'll certainly bear it in mind when my lathe belt needs replacing to save dismantling the headstock bearings.

Many thanks again

Jon

22/01/2016 20:18:22

I've just bought an old Rong-Fu RF-25 mill/drill which is in need of a bit of TLC.

It has what appears to be two new belts but they are too long to set the right tension on the pulleys without fouling the housing. Can anyone tell me the right sizes for these belts please so that I can fit the right ones?

The table stops are also missing completely and so there isn't one I can copy. Could someone kindly take a picture of one to set me on the right lines please, or if there are better designs point me to one I could copy please?

Very many thanks

Jon

Thread: Unkown thread.
14/01/2016 16:37:56

It looks so suspiciously close to M5 (Coarse) x 0.8 = 31.75 TPI I'd be tempted to try that to see whether it fits.

Jon

Thread: Views on warco Major Mill
13/01/2016 13:54:27

Many thanks Martin and David - the additional solutions are much appreciated.

I can see that it's something to be avoided if possible but not a show-stopper.

Thanks again

Jon

13/01/2016 11:43:53

Norman,

Thank you very much for the suggestions. The ideas give me hope that there are work-arounds out there. I'm hoping to pick up the drill/mill pretty cheaply. Your beefy drill comment is well made and this choice of mill was motivated at least in part by the desire to replace my cheapy pillar drill that has been resurrected more times than I care to remember.

I am pretty new to machining and so may have to be prepared to go through at least one upgrade iteration once I've cut my teeth and decided where my priorities lie.

As it happens I've been messing with low power laser indicators and this would be fairly easy to try I think and take advantage of the error multiplication effect over the length/width of the workshop.

Many thanks again

Jon

13/01/2016 09:07:37

With apologies to the OP because I'm not sure whether it's a hijack to this thread or not, but what are the work-arounds to the round column issues on these mills?

I'm in the process of considering a cheap RF25 and wondering whether I'm going to be buying a pup.

Many thanks

Jon

Thread: Propane bottle gauge.
08/01/2016 13:59:35

I've seen these temperature sensitive labels sold but I've no idea whether they work reliably or not.

**LINK**

I imagine that they rely on the liquid in the bottle being at a different temperature to the gas above it - but this might only work if there is gas flowing since there probably needs to be evaporation happening to achieve a cooling effect? You also need to stick them close to the top of the liquid.

May be snake oil but at £3 delivered it might be worth a punt.

HTH

Jon

Thread: Change Gears on Myford ML7R
08/01/2016 09:29:34

Hi Mike,

Have you a manual? You need to use configuration 1 on the diagram leading up to the chart which just calls for one of the studs to be on the banjo. On this stud is mounted the 70 tooth gear along with another one just to make up the thickness (any one will do). It's easier if you remove the other two studs from the banjo but you can sometimes move them to the ends of the banjo out of the way.

You need to put the leadscrew spacer outside the driving gear so that it can mesh on the same level with the driver and idler gear. With the banjo slack, position the 70 tooth idler so that it meshes with the leadscrew gear and tighten the nut on the stud and then position the banjo so that the idler meshes with the 20 tooth driver and tighten it down.

[Edit: When meshing the gears don't push them up tight but leave a small gap (say 20thou or 0.5mm) between the teeth to prevent wear. Oil the bushings as you assemble and keep them lubricated if you're running it for the first time or for extended periods. ]

HTH

Jon

Edited By Jon Gibbs on 08/01/2016 09:32:48

Thread: Brown Gunky Residue - Dormer Supercut or El-Cheapo ISO-32?
07/01/2016 15:58:05

I'm sure you're right that there's more than one way to skin that cat. It was 304 stainless I was machining.

Rightly or wrongly I've taken the plunge and order 5l of Lubetech's finest on Rod's suggestion.

At £4 per litre delivered it's about 1/6th of the cost of the Dormer stuff I think was gunging everything up and about 1/5th of the cost of the Arc's Maxcut.

Jon

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

Support Our Partners
ChesterUK
EngineDIY
cowells
Warco
emcomachinetools
Eccentric July 5 2018
Eccentric Engineering
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