Finished Powered Drawbar for my mill...

[Barry_ward]

Bob,
Got any leads on HS spindle bearings and construction that I could use on the belt drive speeder?

I'd never seen "speeders" until you mentioned them. Cool, but expensive.

I'll be in China this coming week and will shop the machining district for a speeder. If I don't find anything I'll eventually build that belt drive....

Barry

[bill south]

Bob;
Where did you source the springs you added to the system and what are the specs. After a couple of weeks us, my system is starting to stick on the drawbar. I think springs would be the easiest fix.
Thx.
Bill from Spartanburg

[BobWarfield]

Bill, I just grabbed a couple of springs at the hardware store. They were big enough to fit the uprights and probably 2-3" long. The exact spec is not so critical because I use movable collars to adjust them for best performance.

Best,

BW

[wildcat]

Just curious - for those that have installed these on gear head mills - are you shifting the gear head to the lowest gear before activating the power drawbar? I wonder since the spindle rotates so easily when in the highest gear. Doesn't the power drawbar end up spinning the spindle a lot?

[locoind]

I'm not familiar with a lot of different types of mills, but we have 3 bridgeports, and 1 clausing where I work. We have kurt draw bars on all of them. They're pretty simple in action, but they utilize a piece of extruded aluminum that could be duplicated using pins. The basic idea is when the handle is pushed to the left, the butterfly is drawn down, and the correct side of the paddle is pushed in at the same time to unscrew/screw in. And the opposite for the other way. I can get some pics, and basci measurements, as long as no one has any worries about copyrighted.(even though reproducing the exact extrusion would be very hard.) Someone will have to guide me through the pic posting part.

[BobWarfield]

Originally Posted by wildcat Just curious - for those that have installed these on gear head mills - are you shifting the gear head to the lowest gear before activating the power drawbar? I wonder since the spindle rotates so easily when in the highest gear. Doesn't the power drawbar end up spinning the spindle a lot?

I've never yet had this problem, regardless of what gear I'm in. I do know of some folks who have made up spindle wrenches to hold the spindle and get things tight.

I also came across a swell idea on the HSM board. This fellow made a little spacer that sits under the drawbar and keeps it centered. Great idea:



I do find my drawbar is sometimes not quite centered and this would be very helpful. I've yet to make one up though.

Best,

BW

[wildcat]

Bob - The spacer is an absolutely fantastic find! I was planning on turning down the end of the drawbar but this will work a lot better. Got my weekend project now Thanks!

I have made some wrenches and they are a great improvement over having to shift gears. Maybe I'll start the power drawbar this weekend as well... So many projects

Originally Posted by BobWarfield I've never yet had this problem, regardless of what gear I'm in. I do know of some folks who have made up spindle wrenches to hold the spindle and get things tight. I also came across a swell idea on the HSM board. This fellow made a little spacer that sits under the drawbar and keeps it centered. Great idea:

[bill south]

Gents;
The drawbar on my lathemaster benchtop works great regardless of the headgear. The only problem I have is the socket missing the drawbar when it is not quite centered. I'm going to try the bushing idea and correct this (hopebully).
Question for Bob, what material was used for your model. I was kinda thinking aluminum since it would be easy to work with and would wear before the drawbar or spindle. I'd rather replace the bushing!!!
Thanks in advance.
Bill from Spartanburg.

[BobWarfield]

Originally Posted by bill south Gents; The drawbar on my lathemaster benchtop works great regardless of the headgear. The only problem I have is the socket missing the drawbar when it is not quite centered. I'm going to try the bushing idea and correct this (hopebully). Question for Bob, what material was used for your model. I was kinda thinking aluminum since it would be easy to work with and would wear before the drawbar or spindle. I'd rather replace the bushing!!! Thanks in advance. Bill from Spartanburg.

Bill, the picture is of someone else's spacer. I haven't gotten round to it yet. When I do, I plan to use 12L14 steel. It's pretty soft and I doubt there will be that much wear on the drawbar. It is super easy to machine. I guess I'd better get that spacer made tonight!

Best,

BW

[digits]

Originally Posted by BobWarfield I've never yet had this problem, regardless of what gear I'm in. I do know of some folks who have made up spindle wrenches to hold the spindle and get things tight. I also came across a swell idea on the HSM board. This fellow made a little spacer that sits under the drawbar and keeps it centered. Great idea: I do find my drawbar is sometimes not quite centered and this would be very helpful. I've yet to make one up though. Best, BW

Hi - I bought myself a set of those super-simple drawbar plans, but what I can't understand is whether or not you still need to use a (manual) spindle lock during tool changes. From what you've written above, it sounds like the impact wrench is undoing/retightening the drawbar even though the spindle is free to spin? Is the drag from the spindle motor and the inertia of the spindle enough to hold it steady?

[BobWarfield]

Originally Posted by digits Hi - I bought myself a set of those super-simple drawbar plans, but what I can't understand is whether or not you still need to use a (manual) spindle lock during tool changes. From what you've written above, it sounds like the impact wrench is undoing/retightening the drawbar even though the spindle is free to spin? Is the drag from the spindle motor and the inertia of the spindle enough to hold it steady?

Yes, it works fine without a spindle lock.

Best,

BW

[digits]

Originally Posted by BobWarfield Yes, it works fine without a spindle lock. Best, BW

Cheers - thanks for the info