• Spring 2024 meetup in Calgary - tentative date Saturday, April 20/2024. Other regions are also discussing meet ups. If you want one in your area get going on organizing it! discussion
  • We are having email/registration problems again. Diagnosis is underway. New users sorry if you are having trouble getting registered. We are exploring different options to get registered. Contact the forum via another member or on facebook if you're stuck. Update -> we think it is fixed. Let us know if not.
  • Spring meet up in Ontario, April 6/2024. NEW LOCATION See Post #31 Discussion NEW LOCATION

Custom ATV Hubs

TimDubois

Member
Hello all, I'm new here.

I've been trying to get a quote from local machine shops to turn me some custom front hubs that I have designed for my custom Terra Jet.

I have CAD drawings in solid edge but none of the shops I have contacted are interested. I am about to bite the bullet and buy my own lathe and do them myself just like everything else that I need unless someone on here is looking for some work.

Max chucking diameter will be 6" and the longest piece is 4" long. If anyone is interested please let me know and I can send some jpegs of the CAD with dimensions.

I am in the Gatineau area but I don't mind having the parts shipped to me
 

TimDubois

Member
Hub 1(1).jpg
Hub 2(1).jpg
Spindle 1(1).jpg
Spindle 2(1).jpg
Here's some pictures to give you an idea of what I need. I've got plenty more details if anyone is interested.
 

DPittman

Ultra Member
Premium Member
Hi, I'll encourage you to go-ahead and buy yourself some machinery. It will never pay for itself but you will have fun making projects you dream up. You already have some design and computer drafting skills!

What material are you hubs to be made of?
 

Darren

Ultra Member
Premium Member
You will also need a mill for this job. With an indexing or rotary table, or DRO, to do the drilling/tapping.
 
Last edited:

Darren

Ultra Member
Premium Member
One area where you may have trouble finding a shop or machinist to make them, is that you don't specify tolerances and the material length is not there that i can see. What grade of steel? Do you have the bearings already?
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
I love your project, if we were neighbours I might invite you over to make them together. I'd never agree to do them for you because there is way too much chance of a misunderstanding. I want my neighbours and friends to have some of their own fat in the fire!

All in all I totally agree with others here. Buy the lathe and make them yourself. Reading between the lines I feel like that is what you really want to do anyway. The hubs are just your excuse to get one. That's not a criticism, it's just the way a lot of us (me included) are wired.

The milling can be farmed out to a friend or a local shop. But if you stretch your justification to the extreme limits, you might find a mill following you home too.

Do you have a CFO to answer to?
 

TimDubois

Member
Wife just gave me the go ahead on a lathe. I'm back and forth between the craftex cx708 and cx706. The 708 is $400 cheaper but it's a smaller machine and only comes with 1 chuck and no autofeed. But the 706 is variable speed which means when I'm turning large diameter at low rpm I will probably be short on power. The 708 being a gearhead would have all its power at each rpm setting.

Anyone have anything to say about these two lathes? I've been looking for weeks for a used proper lathe but they are all either 5k+ or won't do metric thread.
 

PeterT

Ultra Member
Premium Member
You might find some search hits on those lathe model numbers here on the forum, otherwise Google away. Parts support (or lack thereof) seems to be the sore point mentioned here & there. Another consideration using your part as example is, threading capability and metric threading. Some smaller lathes are a bit more rigmarole to set up threading although I'm not familiar with either lathe. For metric/module pitches its usually a matter of swapping in different gear combinations. But again, some machines have certain limits of what they can accommodate as a function of their gearing.
 

DPittman

Ultra Member
Premium Member
I have the older version(cx700) of the cx706 and despite often wanting bigger and more robust, I really quite like the lathe. I think the variable speed if a super good feature and not being a gear head lathe it is very quite and smooth running. I don't think the little bit of shorter bed length of th cx708 is likely to be significant when compared to the cx706. The cx706 list more threading capabilities than the the cx708, which may or may not be important to you. The power crossfeed of the the cx706 is also a nice feature.
Yes lack of power on large diameter material may be an issue with the cx706 but I'm not sure that would be that much worse than the cx708 which has a lower hp rated motor?
 

TimDubois

Member
My thinking is that the 3/4 hp motor on the 708 is gonna be giving 3/4hp (minus friction loss) at every rpm selected whereas the 706 will always be a percentage of the top speed depending on belt position. Even with the belt in the low speed position, 1000 or so rpm? Turning at 200 rpm would only get me 1/5 of a HP. It would be a different story if it had a brushless motor but alas it does not.

I'm a little torn as busy bee in ottawa has the 708 in stock but my gut is telling me the 706 is a more solid machine despite the power loss at low rpm.

For your cx700, do you have any issues threading at absolute minimum rpm? When threading to a shoulder I've always ran at min rpm to a groove and kicked out the half nut while the cutter is in the groove.
 

DPittman

Ultra Member
Premium Member
For your cx700, do you have any issues threading at absolute minimum rpm? When threading to a shoulder I've always ran at min rpm to a groove and kicked out the half nut while the cutter is in the groove.
Well I haven't threaded real large diameters but I can tell sometimes that the motor and controls are struggling to keep the speed constant. Although it has never limited me to getting a job done. One possible solution is to thread away from the headstock.
I think the cx706 has an upgraded motor to my cx700 but the printed specifications on my lathe are not consistent and there are discrepancies so I'm not really sure.
 

TimDubois

Member
One possible solution is to thread away from the headstock
You absolute madman! I don't know why they never mentioned that to us on my course. Probably because they taught us to feed the cutter in with the compound rest at 29⁰ and that would be tricky to do in the narrow space afforded by the groove.

I guess I'd have to flip the cutter over and run the spindle in the opposite direction. I'll be sure to give that a try. Thanks.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Probably because they taught us to feed the cutter in with the compound rest at 29⁰ and that would be tricky to do in the narrow space afforded by the groove.

I don't understand. What has the 29° (I use 29.5) have to do with the relief cut?

The 29 degree cut is only for the compound advancement. It is not for the main cut which is still done by the carriage cutting R to L for a normal outside thread.

The compound advancing at 30 or 29 or 29.5 for each pass merely keeps the cutting on one edge (instead of 2) to minimize the load. To be more precise, the idea of the 29 and 29.5 is to do a tiny skim cut on the second edge to keep the thread surface clean and smooth. Otherwise you could just do a 60 degree plunge cut using both edges.

There are other combinations, but for a RH outside thread like you describe, cutting in reverse allows you to cut on the front side with an upside down tool or on the backside of the lathe right side up but both from L to R.
 

TimDubois

Member
I was more getting at having the compound rest set at 29⁰ to the left side could cause interference with the stock whereas having it off to the right keeps the cradle and tool post away.

I don't have a lathe in front of me right now so I'm just going by what I remember everything looking and feeling like. Also stopping in the groove you can get away with a groove width as wide as your cutter plus whatever you need for reaction time. Starting in the groove you would need tool width plus however much the tool moves to the right to get your depth of cut.

Anyway, like I said I'll definately give it a try.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Also stopping in the groove you can get away with a groove width as wide as your cutter plus whatever you need for reaction time. Starting in the groove you would need tool width plus however much the tool moves to the right to get your depth of cut.

Ah, ok now I understand.

I prefer to cut on the backside instead. That way I don't have that problem.

I prolly should just keep my mouth shut, but now I don't understand what you mean about "starting in the groove you would need tool width plus however much the tool moves to the right to get your depth of cut."

If I do understand, you can cancel out the tool moving to the right by moving the compound first, then the carriage to center on the relief, and lastly the compound to reach into the relief groove before engaging the half nut. But more importantly, it's virtually nothing compared to my reaction time with the standard approach. In other words, small + small = small, but small plus huge = huge. LOL!
 

TimDubois

Member
I see what you're getting at now. Whenever I threaded I was always super paranoid. I would pull out of the groove, move the carriage back to zero on both the x and z axis, then go past zero on the z and bring it back to zero to minimize backlash. Then I would engage the half nut on exactly the same number on the dial even if the machine said I could use all odd or even numbers.

I do realize that none of that should matter (except for bringing the x axis back to zero of course) but once you ram that cutter between two threads on a part that's taken hours to make, you tend to get paranoid. That old clausing lathe we had would sometimes jump a half number on the feed dial.

I definately like the idea of cutting from the back side, especially if the compound rest cleared the stock and I could feed the insert in by backing out the compound.
 
Top