To question the hive about change wheel fit
Bob Stevenson | 11/06/2017 23:18:27 |
579 forum posts 7 photos | Tonight I was investigating my change wheel set for Chinese mini-lathe. The machine is a Chester 'Conquest' and about 10 years old.....any thread cutting is usually done on my Colchester but for the first time it would be useful to be able to use the mini-lathe which lives in the house and can be easily moved etc, so I got out the black delrin change wheels and discovered that they don't fit the keyed studs on the lathe....in fact it's impossible to fit them by hand as they are far too tight. Removing the auto feed set up required a lot of levering with a screw driver and replacing them would seem to require difting back on with a hammer!
Does anyone have a 'Conquest' of other mini-lathe made by the 'Real Bull Factory' and have some previous with the change wheels please?
I'm about to use an expanding reamer to fit the change wheel bosses to the studs to good fit.........Good plan, or not? |
Michael Gilligan | 11/06/2017 23:36:13 |
![]() 23121 forum posts 1360 photos | Sounds like the material is significantly hygroscopic ... so it might be Nylon, not Delrin. MichaelG. |
Bill Pudney | 12/06/2017 01:06:04 |
622 forum posts 24 photos | I've had a Sieg C3 mini lathe (7" x 14" as the Yanks say) for about ten or twelve years. The changewheels have always been a snug fit, some have always required the application of a little force to remove. I have always understood that the material is acetal resin, a.k.a. Delrin. Being a BOF I would proceed VERY carefuly with an adjustable reamer, my preference would be to accurately measure the stud diameters and treat myself to a hand reamer of that size. Then rely on the low friction properties of the delrin. You don't want a sloppy fit on changewheels!! It may be a bit exciting, reaming a changewheel with a keyway anyway. best of luck!! cheers Bill |
Enough! | 12/06/2017 01:16:27 |
1719 forum posts 1 photos | Perhaps the bores have warped. Delrin is not particularly hygroscopic but it does benefit from being stress relieved prior to final machining. What are the chances that the Chinese manufacturers did that? |
I.M. OUTAHERE | 12/06/2017 04:58:04 |
1468 forum posts 3 photos | I found the problem with my mini lathe was the drive key was binding in the key slot in the gear. If the bosses are those horrible die cast ones that the key is integral with the boss you may need to fettle them as well , my other lathe has these and they were all different sizes by a couple of thou and one had a mushroomed end . You will find an expanding reamer will jam up in the bore because it has straight blades that will catch on the key slot , a spiral flut cutter will work better Ian. |
Neil Wyatt | 12/06/2017 09:07:15 |
![]() 19226 forum posts 749 photos 86 articles | My machine is a SIEG, and I can honestly say all the change wheels are the same push fit now as they were in 1999. Neil |
Bob Stevenson | 12/06/2017 11:12:20 |
579 forum posts 7 photos | ....Just a line to thank the responders very much!
I just looked at the other mini-lathe topic about fine feed and realised that the change wheel bore is supposed to be 12mm,..also backed up by Arceurotrade site.....my wheels are significantly under that at about 11.5mm and I will accurately measure later today....... |
john constable | 20/06/2018 00:24:27 |
![]() 80 forum posts 9 photos | I'm wanting to barley twists and spirals in wood stock up to about 2" x 8" max. Someone has explained to me I need a small metalworking lathe with change gears so I can radically speed up the saddle to spindle speed and turn the spindle slowly by hand.
I noticed you guys discussing small lathes and change wheels. Could you suggest any new or used mini lathes with change wheels that might fit the bill please? |
Hopper | 20/06/2018 00:50:30 |
![]() 7881 forum posts 397 photos | Posted by john constable on 20/06/2018 00:24:27:
I'm wanting to barley twists and spirals in wood stock up to about 2" x 8" max. Someone has explained to me I need a small metalworking lathe with change gears so I can radically speed up the saddle to spindle speed and turn the spindle slowly by hand.
I noticed you guys discussing small lathes and change wheels. Could you suggest any new or used mini lathes with change wheels that might fit the bill please? The Sieg C3 is very popular. |
john constable | 20/06/2018 01:08:57 |
![]() 80 forum posts 9 photos | That looks really good.Read other posts on it vs the SC2. Sadly a bit outside my budget. |
JasonB | 20/06/2018 07:18:20 |
![]() 25215 forum posts 3105 photos 1 articles | It is quite possible that you won't be able to do what you want with teh standard gears, you may need to buy more or even have to rig up your own Pulley/Gear arrangement. |
Thor 🇳🇴 | 20/06/2018 07:24:35 |
![]() 1766 forum posts 46 photos | Hi Bob, Wouldn't it be possible for you to bore out the changewheels from 11.5 to 12mm? From your first post it seems you have two lathes and I assume some way of holding the changewheels. I have made gearwheels in Delrin and used sharp tools made from silversteel, the gears turned out Ok. Thor |
Bob Stevenson | 20/06/2018 08:13:58 |
579 forum posts 7 photos | Thanks for continuing replies, however, this thread is a year old now and things have moved on.......
My Mini-Lathe (Chester Conquest) was made by Real Bull factory and the supplied change wheels were slightly different to the Sieg versions. I did aquire some extra wheels from ArcEuro and had to slightly adapt these to fit by modifying the bore and enlarging the keyway........
However, late last year I sold off my Mini-Lathe, on which I made most of my first clock, and aquired a WM180 lathe which is similar in size to a Mini-Lathe but has turned out to be much better engineered, designed and made. Although considerably heavier than Mini-Lathe the WM180 (made by another Chinese factory, Weiss) is still small enough to live in my conservatory being the same length as Mini-Lathe. It has steel change wheels which fitted properly from new and although a little more expensive than a Conquest is much better equipped with two chucks, rests etc and comes out at as very competitively priced. |
Niels Abildgaard | 20/06/2018 09:08:00 |
470 forum posts 177 photos | A source of WM180 lathe. I have a little bigger WM210 and gears run quite well.Not Swiss but nice. |
Howard Lewis | 21/06/2018 09:00:43 |
7227 forum posts 21 photos | I thought that the Chester Conquest was made by Seig. Mine has 3mm keys for the gears, whereas, I had been led to believe that Real Bull machines used 4mm keys. My gears are a snug fit on the studs. Made a pair of 100T gears, from "plastic", and reamed the bores 12mm, equally snug fit on the studs as the others (These gears brought about about other minor changes to the lathe to allow fitting of both; but that's another story not connected with bore sizes). May I suggest gentle application of a 12mm reamer? Howard |
Bob Stevenson | 21/06/2018 22:58:51 |
579 forum posts 7 photos | Howard,...My Conquest was definately made by the Real Bull factory and yes, it had 4mm keys....the cogs from ArcEuro were/are for Seig machines and need the keyway opening out in order to fit. The tight fit on the studs can be got over by (carefully!) heating the cog with a hot air gun which make forcing onto the stud a bit easier......I did try a reamer but in the end found it problematic to use mainly due to the keyway.
I actually liked my mini-lathe and although I viewed it as a bit of a toy initially I did go on to make some interesting items with it and then started making clocks so it was quite a successful machine especially since it was small enough to live in the house and was just the job for late night turning sessions with a mug of tea and Classic FM...a scenario which continues with the rather better WM180 which replaced it. |
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