Here is a list of all the postings IanH has made in our forums. Click on a thread name to jump to the thread.
|Thread: Thread tool form|
A few years ago I started machining threads for crank pins and main shafts in JAP engines - these are fine threads subject to very high loadings - I took the plunge and invested in some throw away tip tooling which I would say has been one of the best tooling investments I have ever made. In particular I invested in Carmex miniature and sub miniature internal threading tools and these have been a Godsend.
I standardised on 20TPI (although metric pitch options can be cheaper) and bought full profile tools for that pitch, but supplement this with partial profile tools allowing me to machine any other pitch I need.
My advice would be to invest in some decent tooling - it is worth it.
|Thread: Sheared Drawbar|
Just picking up on the "damping ring" - in case you don't read my reply on the other thread - the damping ring makes a fine puller to pull the chuck out of the taper. Plenty of chucks do without them but having one makes your collet chuck superior in that if nothing else it provide a means for you to remove the chuck without beating your spindle to death again in the future.
|Thread: Centec with Clarkson Collet|
I had a Centec with a Clarkson Autolock chuck - if by the "damping ring" you mean the large diameter threaded collar on the collet chuck, that buts up against the bottom of the spindle then I recommend that you use this to extract the chuck from the spindle. My method was (first of all not to overtighten the thing in the first place!) - loosen off the draw bar by about 1/8" leaving it engaged in the chuck body. Now with a peg spanner on the damping ring and an open ended spanner on the flats on the spindle, use the "damping ring" to pull the collet chuck out of the taper. The damping ring has a fine thread so not much effort is required. When it frees, the chuck will drop but ony as far as the draw bar will let it. Put the spanners down and spin the draw bar free whilst you hold the chuck with the other hand.
|Thread: DIY Vacuum heat treatment oven|
Thanks very much for all this information - I don't live far from Stoke so I guess I have no excuse but to make some contacts and see what I can find out there, I will post progress as it happens.....
Just wondering idly over the Christmas break abou the practicality of making a DIY vacuum heat t reatment oven. I saw one recently in another workshop based on a gas cylinder lying on its side - the "top" of the cylinder had been removed and flanges welded on the cylinder body and on the remains of the top. It was hinged to form a door and although there was a clamping arrangement - the vacuum kept it shut and sealed - there was an O ring seal in the flange.
Inside there were refractory bricks and some electrical elements - and there was also a control system.
Anyone have any ideas - how many KW woud I need to heat treat steel - the actual chamber needs to be no bigger than a coupe of house bricks. Sources of heating elements and refractory bricks etc etc?
Edited By IanH on 26/12/2010 14:13:32
|Thread: Drilling of 34CrNiMo6 4340 817M40 En24?|
I have recently had a bit of fun recovering a job which involved drilling into hardened EN 36B - my normal Dormer HSS drills wouldn't touch it, it was like drilling glass. I bought a cheap solid carbide drill off Ebay (harryuk123 store) for just under £5.00 and it was a piece of cake. Don't be scared of solid carbide.
|Thread: Need for recomandations on cut off or parting tool|
I am not sure what a Sieg C6 lathe is but I can recommend the Q cut tool from Greenwood without reservation. I have two of these, one for my Myford 254 and one for my Colchester Student - I would not be without them.
They transform parting off from a tense operation at best to a complete no brainer. I have no qualms parting off alloy steels (EN16, EN24) and stainless steels at high speed (800 plus RPM).
Defintely worth the money! I have no connection with Greenwood tools by the way other than being a loyal customer - I generally stock up once a year at Harrogate 4 SCLCR tips and a couple of Q cut tips every other year (they last and last).
|Thread: CNC engraving|
Well, no good reason for not using doube sided tape really - I have used double sided tape in the dim and distant past on something or other but found it was less than happy with coolant around so I have not used it since. There was no coolant on this job of course but I didn't consider tape. I will remember this for next time.
Just looking back at this post I thought it would add interest if I added a photo of an engraving project. This is a reproduction dash board badge made on the Denford that now adorns my Morgan.
|Thread: Slotting Tool Design|
Cooking on gas now. Here is a photo of the tool.
Tool body maximum diameter to fit into the hole with just enough space for the cutter to project - tool body machined out of EN16 for toughness, bottom face and slot for tool steel angled at 8 degrees giving "top rake" with a chunky cap to hold it all together with 2 M5 cap heads. Easy to grind - just provide a bit of "front" clearance on the vertical face then off you go. FInal step was to tighten up the belt on the slotting head so all the power of the motor was available.
Just need to make another now for the 3/16" slot
Thanks for all the ideas
Thanks for this. On an earlier job I managed the keyways on the lathe racking the saddle back and forth with a home made tool holder with a piece of 1/4" sq HSS tool. This approach is just like the text books suggest.
I used this same tool in the slotting head and found that it tended to be pushed away from the cut until it finally bit, then at that point it dug in. I am now making a more robust version of the tool and if it works out I will post a picture here so you can see what it looks like.
Edited By IanH on 23/06/2010 17:52:08
Some few years ago I bought a slotting attachment to hang off the back of my Bridgeport. I now find myself wanting to create some 3/16" and 1/4" keyways in 1" and 1 1/4" bore holes in EN24 and am astruggling a bit with the design of the tool/tool holder. The slotting head has a 0.625" socket for the tool holder to sit in. Can anyone provide a sketch of something that will work?
I am anticipating using 1/4" square HSS tool bits for the 1/4" keyway and had thought of clamping it horizontally in the bottom of the tool holder. My first attempt has not been rigid enough allowing the tool to dig in and jam everything up. I can't find any pictures of commercial designs so thought I would turn to the forum.
Thanks in anticipation
|Thread: Roller bearing cages - full size|
Another attempt at the photo....
I think a final scheme is emerging. Moving up to a 40mm od crank pin and using a stock needle roller bearing get you up to 45mm od. If you then add in a hardened ring in the conrod eye you are looking at boring the conrod something like 0.15" over the iriginal dimension. At ths size the conrod is looking rather delicate and as this all started with a fork rod failure,,,,,
New conrods with a bigger "big end" would be required.
Plan B then is to go to a 35mm crank pin allowing me to use 42mm od needle roller bearings which can be accommodated by opening out the existing big end sleeve by only .030 on diameter. I am pretty sure the sleeve is hardened right through so this should be achievable. The od of the sleeve doesn't change so the original pattern conrods will do. If I stick with the bronze bush in the blade rod then it should be straighforward.
Thanks for all the information - I would love to see a sketch of the broach and die set up Ian is suggesting - any chance of this Ian?
I have sent a message to mgj to check out the woodruffe cutter proposal - I think we have different ideas of what a woodruffe cutter is although I suspect it is because the cage is relatively thick compared with its diameter rather than being a thin shell as he suggests.
At the Three Wheeler Opening run today concensus of opinion amongst the racing fraternity was to use an INA caged needle roller bearing running directly on the crank pin. The proposal for the crank pin is to go to a parallel pin with .004" interference and press it together in the hydraulic press - no tapers, no threads! I have to admit that this is tempting......
Question is whether the blade rod will be ok on its bronze bush or should this be sleeved and a crowded needle roller arrangement be put in place - it only rocks back and forth when all is said and done.
Thanks very much for this John,
This was the idea I had in mind talking about a two piece cage but I wasn't thinking of leaving the washer floating.
Reducing the inertia by going into a lighter material might be an idea?
What did you do in terms of clearance between the cage and the crank pin and the cage and the big end sleeve for both the cage and the floating washer? I am thinking of "Tuning for Speed" where there is discussion about the cage wearing the pin away,
What clearance did you use between each roller and its slot? I am thinking that using shaped slots like this you could keep the cage off the pin and sleeve, but the washer would be free to run on the crank pin.
What do you think of giving the washer a register to held it in position on the cage - the register would need to be deeper than the end float on the big end to keep it in place.?
Lots of questions I am sorry!
I am approaching a big end rebuild on my JAP LTOWZ engine (1000cc water cooled V Twin from the 30s). The original big end bearing was a crowded roller bearing (loads of rollers no cage) but I would like to modify this to add a light alloy cage.
The cage then is an annular ring with a series of rectangular slots to take the rollers.
Phil Irving in his seminal work "Tuning for Speed" recommends milling out the slots with a woodruffe cutter then filing the ends square but I am afraid I don't have it in me to do all that filing.
Do we have any alternative techniques for forming the cages without the filing? I have milling (manual and CNC) and turning of course.
I have wondered about making the cage in two pieces - a plain ring on one end to close off all the slots, but am not sure about how to secure it.
|Thread: CNC engraving|
Here is a vide of a commercial tool in action;
If you go to about 1.06 into the vide the operator moves the tool against the spring which gives me the impression that it is a pretty light spring.
Hi Paul and Bob,
Thanks for your thoughts. The thin brass I used for the dash board badge was clamped down onto a piece of wood which gave a somewhat eneven surface - I had three passes at engraving it getting down to about 10 thou in total from memory. The first pass was a bit hit and miss as the brass was not completely flat, partly as a result of the clamping method and partly as a result of it being cut out of a bigger sheet with snips. Note that this was with a tool in the normal spindle. Going to a spring loaded tool was hopefully going to allow me to get the engraving done in one pass.
Have a look here to see a commercial offering http://www.2linc.com/engraving.htm
I had a go with my spring loaded tool on the end of a reproduction Best and Lloyd oil pump plunger - the "happy man" logo has to go onto a domed knob. I was not confident enough to set the cut depth to .1" say and let the took find its own depth as it traversed across the domed surface.
Have you any feel for whether the spring should be "strong" or whether I should be able to lift the tool with one finger for example? Perhpas I have to just risk an engraving tool and "suck it and see".
I have been exploring CNC engraving on my Denford Easimill and have made myself a spring loaded tool holder. This is essentially a spring loaded mounting for the Axminster Power Tool centre heavy duty flexible drive which I found a recommendation for as a sounrce of a few tens of thousand rpm.
I am using 1/8" dia shank engraving tools sourced from Ebay and would like to get an idea of how strong the spring should be. I read the MEW article on a spring loaded tool holder for engraving but it did not give an indication of the strength of the spring.
Anyone got any ideas?
I will put anexample of some engraving in amongst my photos.....
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