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Excello 602 Power Drawbar

bkahler

Member
Hi, just joined today and this is my first post. Hopefully I'm posting this in the correct forum.

I have an early XLO version that I've spent the last 10 to 12 years restoring/rebuilding, yes, I'm slow :) All work is being done in my spare time which I have very little of unfortunately.

One of the things that bothered me about the mill is that I'm short and the mill is tall. Accessing the top of the mill and holding the collet gets to be frustrating at times. Over the last few years, I've seen all of these Bridgeport owners add power drawbars to their machines. Unfortunately, there is a big difference between the top of an Excello mill and the top of a Bridgeport mill. A few weeks ago, I finally took the time to analyze just what needed to be done to fit a power drawbar and after some trial and error I came up with what I hope to be a workable solution.


20230729_122049.jpg


20230729_122122.jpg


I haven't actually tried using it yet because I have a few minor details I want to change. The four round spacers need to be larger in diameter, 1/2" instead of 3/8" and I want to drop the height of the platen down about 1/4" by shortening the spacers. Also, I need to lengthen the handle by about 3" to make it easier for me to manipulate.

The platen is about 2" taller than if it was mounted to a Bridgeport. Due to the variable speed pulley, there wasn't much of an option but to place it that high. The actual drawbar is one that I sourced off of eBay and is designed for Bridgeport and similar clones.

Anyway, I hope you find this interesting.

Thanks,

Brad
 
Nicely done. I'm assuming you have only R8 tooling? I like the small regulator filter assembly.
Welcome from Vancouver Island.
 
Thanks!

Yes, R8 tooling. I did purchase an ER32 setup a few weeks ago that I'm hoping will be worth using. I hope to give the drawbar a test this weekend, it would be nice to know whether or not I've wasted my money!
 
Thanks!

Yes, R8 tooling. I did purchase an ER32 setup a few weeks ago that I'm hoping will be worth using. I hope to give the drawbar a test this weekend, it would be nice to know whether or not I've wasted my money!
I doubt you have. Even my pneumatic version worked fine when I used it for R8 which requires a fair amount of draw bar turns to release it.
I was using a controller to blip it so I could also just turn two turns to release but not drop TTS holdes. That didn't work well so I've switched to a stepper motor and 25:1 reduction. Once it's safe to cast outside without worry about a spark lighting up the dry grass I'll remake the mounts for the motor based power draw bar.
I think I had a thread on building this on this forum but can't find it.
The controller has two buttons. Just tap it and the idea is two turns. Press and hold and it turns continuously. Pneumatic cylinder to push it down which had it's own share of issues jamming onto the draw bar nut.
InPosition.jpg


Here's the controller on a temporary panel for development purposes. The green and blue 3D printed bits are hall sensors to detect down position and turns of the draw bar.
DIM_on_Panel.jpg


And yes. If there's a hard and complicated way to do something I'll dive down that rabbit hole.
 
I bought a very similar looking one off ebay as well, and have been loving it. I think you'll find that the power draw bar is much quicker then swapping ER32 collets out, so if anything, you may feel you wasted money on the ER32 collets ;)

 
Nice job. While swapping the head on my own excello this weekend, I got brainstorming of way to make a power drawbar too. I want to make mine with an electric impact though, instead of pneumatic. I don't always run my compressor.
 
Very nice..... Welcome from Lillooet BC.
I love seeing old tools being brought back to life, and it looks like you are doing a great job on this one.
 
I doubt you have. Even my pneumatic version worked fine when I used it for R8 which requires a fair amount of draw bar turns to release it.
I was using a controller to blip it so I could also just turn two turns to release but not drop TTS holdes. That didn't work well so I've switched to a stepper motor and 25:1 reduction. Once it's safe to cast outside without worry about a spark lighting up the dry grass I'll remake the mounts for the motor based power draw bar.
I think I had a thread on building this on this forum but can't find it.
The controller has two buttons. Just tap it and the idea is two turns. Press and hold and it turns continuously. Pneumatic cylinder to push it down which had it's own share of issues jamming onto the draw bar nut.

I was wondering if a power down option would be a worthwhile addition. As I was setting mine up I noticed that socket engagement seemed to be somewhat hit and miss. However, I have yet to apply air to it so I wasn't sure if it was just me or something inherent in the design.

Maybe if the socket was rotating slowly while being driven down it would engage better. Is that something you've looked into?


Here's the controller on a temporary panel for development purposes. The green and blue 3D printed bits are hall sensors to detect down position and turns of the draw bar.
View attachment 37301

And yes. If there's a hard and complicated way to do something I'll dive down that rabbit hole.

Nothing wrong with going down a rabbit hole :cool:


What kind of control module is that?
 
I bought a very similar looking one off ebay as well, and have been loving it. I think you'll find that the power draw bar is much quicker then swapping ER32 collets out, so if anything, you may feel you wasted money on the ER32 collets ;)


It wouldn't be the first time I've wasted money on a project, probably won't be the last either! The good news is I also bought the ER32 chuck for my lathe so at least the collets won't go to waste.

Either that Bridgeport is really short, or you're really tall. I noticed you were pulling down on the top of the handle arm and not the knob. I can just reach the knob on mine.
 
Nice job. While swapping the head on my own excello this weekend, I got brainstorming of way to make a power drawbar too. I want to make mine with an electric impact though, instead of pneumatic. I don't always run my compressor.

I like the electric impact idea. Right now, I'm just going to use a 50' airline to get from my compressor to the mill. I wonder if they make an electric impact in the same form factor as the small air impacts.
 
I like the electric impact idea. Right now, I'm just going to use a 50' airline to get from my compressor to the mill. I wonder if they make an electric impact in the same form factor as the small air impacts.
I've never seen one similar to the butterfly pneumatic one, but most of the electric versions have a cast aluminum front gear case, that looks like it could be relatively easy to make a mount for. The big downside I see is losing the ability to dial down the ugga duggas with the air regulator though.

Once I get my mill up and running, I'd like to play around with some design ideas.
 
I've never seen one similar to the butterfly pneumatic one, but most of the electric versions have a cast aluminum front gear case, that looks like it could be relatively easy to make a mount for. The big downside I see is losing the ability to dial down the ugga duggas with the air regulator though.

Once I get my mill up and running, I'd like to play around with some design ideas.

They do make 12VDC electric impacts, so if you could replace the on/off switch with a variable speed switch from something like a battery powered drill that might give you what you're looking for.
 
They do make 12VDC electric impacts, so if you could replace the on/off switch with a variable speed switch from something like a battery powered drill that might give you what you're looking for.
I've thought about that too. I have a few spare makita 18v 1/4" hex drive impacts I will look at when the time comes. Even if I keep the battery power it would still be fine. I need to get the torque wrench out and measure drawbar tightening torque, and do some pondering to see where I stand. If it's not feasible, I'll make a pneumatic one like yours.

The other good thing about pneumatics is adding the air cylinder and valves to make it automatic and useable from a lower working height. No need to reach up to pull a lever, just push a button. That's why I want one, as My right shoulder is pretty messed up, from years of doing that, and other overhead work. I've finally rehabbed it back to the point I can throw a baseball normally again this year, but don't want to wreck it again.
 
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