Nu-Tool CH10 – Spares/Reworking

[Toby JonesParticipant @tobyjones79461]

Old Drill press Recon/Rebuild

[Toby JonesParticipant @tobyjones79461]

Hi all,

(Please be nice – this may look like a hack job – I am learning, but it is also because it is!!!)

I picked up a nutool ch10 Drill press the other day for £15, on the whim that if its truly knackered I will get it weighed in. I have gone done the rabbit hole… The motor runs well and after a new set of bearings its pretty quiet. Although the castings are pretty horrific. There is no flex in the table and seems to be a lot more substantial than the more modern cheap drill presses. This one has doncaster, england written on the side and was mfg in 1995 (although suspect it to be imported).

I have stripped the spindle and quill assembly, as the press was slipping. The spindle is still true but the teeth on the rack on the quill have failed. I attempted a repair by migging up the worn teeth as a super bodge and then grinding the tooth form with a dremel – to my surpise it worked a treat! as soon as it went under heavier load the unrepaired teeth failed!!! very surprised the welded ones held their own. Anyway, I digress… It appears the sealey SDM30 uses the same quill bore, which I have purchased new with a new press pinion for £15. Unfortunately the bore is too small for the new press handle… I am considering reworking the casting somehow to open it up, and then ream and install some bronze bushes on both the quill and press spindle, to make them a much better than factory fit. With a new chuck, bearings and reworked quill I think it could be quite a capable small drill!

I digress even more…. The latter requires access to all kinds of tooling which I do not have (yet!) so is likely a pipe dream/second iteration.

In the meantime, does anyone have one in pieces or spares in the shed that is going scrap? Hopefully I could combine both assemblies to get one working drill… I am reluctant to scrap it as I feel I am so close!!

Images below for open critique/mockery and viewing pleasure!

https://photos.app.goo.gl/cF7Pa7bFBVptQwcu7

Kind Regards,

Toby

[Clive FosterParticipant @clivefoster55965]

Nu-Tool products were generally at the upper end of "affordable" import machines in both quality and price. I think the company died because they were a bit to high end for a decent market size.

If bodgery becomes necessary the humble hole-saw can produce remarkably accurate results in cast iron when suitably guided.

Basic idea would be to replace the usual hole saw centre drill with a mandrel running nicely in the through bore for the press handle and open out one side. Then do a bigger mandrel to fit the opened out hole and enlarge the other side. Finish of with an expanding reamer if need be.

Basically same procedure as when using the Starrett "Oops" double hole-saw carrier to open up an undersize hole. This carries the correct size hole-saw concentric to a smaller one that fits in the undersize hole to act as a guide. If the two sides of the bore are different sizes its possible that an "Oops" will do the job if suitable saws can be found

I've done this sort of thing twice to resurrect SouthBend countershaft units with seriously worn plain bearing holes. First one with a hand held drill. Second one on a big drill press. Which was much, much easier. Finished off with a king-pin line reamer to get the right size and accurate alignment. 1 1/2" or so wide plain bearings perhaps 9" apart. Considering I started the first one by bushing the oval worn holes, over 1/8" wear on the worst one, with hammered in wood dowels drilled 1/4" for the initial start I was well chuffed with how well it worked out.

I imagine a RotaBroach would work even better and go direct to size. Big pillar drill or bolt the casting to a lathe cross slide I think. RotaBroach in a hand drill probably won't fly.

Clive

Edited By Clive Foster on 31/12/2020 12:58:44

[Henry BrownParticipant @henrybrown95529]

I've had a CH10 for some years I use for rough work, its all good except the quill has a fair bit of slop in it, it's on the round tuit job list to have a look at the quill bearings if it has any! If not I'll bore each end for a bronze bush.

Looks like you made a good job of those teeth, at least you have had some practice for the next batch…

[Michael GilliganParticipant @michaelgilligan61133]

Well done, Toby

…. I’m impressed

MichaelG.

[Toby JonesParticipant @tobyjones79461]

Useful to know that its somewhat worth saving – itll be the first piece of kit that I have outside the realm of "standard" diy power tools. There are bearings inside the quill for the spindle, but none in the drill head for the quill to ride in. I suspect the slop in mine has come from it riding against the relatively soft casting of the drill head for a good few years. I recon somebody previously had really cranked on it to muller the teeth, as it didnt look like wear as such, more sudden failure.

I like the idea of the starrett "oops" drill arbor – certainly on my list as something to have as I have previously just used a hand tapered reamer to try and remeder the issue – usually ending up with a slightly egg shaped hole! I think I will definitely give that a go if I cock up the rework on the now failed teeth, but would need to work out a jig for the pistol drill so I get it as square as possible. this may sound seriously daft, but what sort of pressing force should the teeth be able to take? I am predominantly from the shade tree mechanic/diy engineer background with some fortunate access to serious kit at uni, but no real "experience" of feel for a machine such as this.

I will keep the thread updated with the next attempt! Time to fire up the mightymig…

I appreciate the kind feedback too, certainly deterred me from throwing the towel in just yet!!

Kind Regards,

Toby

[Clive FosterParticipant @clivefoster55965]

Tony

In cast iron just enough pressure to keep the hole saw cutting is all you need. Don't try to force it and do pull out every tooth depth or so to clean out the dust. Seriously messy.

Trouble with the Starret Oops arbor for this job ( for folk who have never seen one **LINK**&nbsp is that its really intended for sheet metal work so the inner saw doesn't project as far as you'd like to be a really effective bore guide. A solid mandrel going right through to the other side is obviously going to be more stable.

Maybe the old shaft could be adapted?

When it comes to jigging for a straight push I've found that careful attention to the height and angle allowing you to push straight is frequently sufficient. Last time I needed to be super straight with a large, blacksmiths, drill I set the height such that I was able to push with my midriff in a manner similar to using a belly brace drill. Which seemed to work well.

One of the old fashioned "convert your pistol drill to a pillar drill" accessories might make a good basis for a drilling jig given some creative clamping. Lumps of wood, chipboard or whatever can be very useful for this sort of get it lined up once thing. Easily carved and joined with woodscrews.

Clive

[Toby JonesParticipant @tobyjones79461]

The diy gear cutting attempt 2 was short lived. Whilst I was able to make the tooth form quite nice and clean reworking a handful of them on the first attempt, the second time round has proved to be a nightmare as there isnt enough reference material on neighbouring teeth.I think if I were to carry on it would result in a very ill fitting and sloppy press mechanism, which would berate me every time I used it! Nonetheless, I have learned something so not a completely wasted exercise. That means…. plan 2!

I have the drill head on my desk, and am going to have a proper measure up best I can to work out that opening up the bore will definitely work and not cause any other issues. The other issue I have is the new pinion is just too short to on its shallower diameter, but think that could be rectified by turning down the bigger diameter to let it sit further in. Yet to work out how, but I have dropped odds and ends in to a local machine shop before who have been somewhat accomodating of my hair brained schemes for small cash jobs…

Clive – I like the idea of modifying the old shaft too as a bore guide, although am unsure how I would get it to engage on the drill. I have a standard drill arbor for hole cutting that I wonder if I drilled and tapped the end of the old shaft I could put a piece of studding into it and drop in the collet of the holesaw. Another possibly even more daft Idea is to 3d print a mandrel that I can make to a really close fit to guide it – the only concern being it failing during the drilling op…

The more tinkering I do the more I realise I need a lathe!!!! Its definitely on the list as my next item, but will lilkely be a while before I have the pennies saved! Is there such a thing as a "skills exchange" on the forums where people swap services? I am quite proficient in CAD and do a fair bit of 3D printing… Would happily exchange the latter via posting 3d printed parts/with the bits I need to rework somehow!

Kind Regards,

Toby

[Toby JonesParticipant @tobyjones79461]

A small update –

Before going full chop and cutting the casting, I have found some more suppliers with castings that look identical – I am convinced that the virgin castings at least still must originate from the same factory…. then it looks like some people just put in cheaper bearings or moving parts than others.

I contacted Warco, as their offering looks incredibly similar to my machine and despite my best efforts and stating that on my head be it they simply flat out refused to quote for just a quill and press gear, on the basis that it could work with a non warco machine.. – I almost felt like I had tripped on something I shouldnt!! the Warco mechanism from studying the photos online looks almost bang on identical, just with different handle knobs. I am tempted to contact them with another email address without the context of spares to see if they would be so kind enough to provide a drawing.

I also had an extensive look at adjustable hand reamers, the type which you can adjust with a nut each end to open a hole to an exact size. These look like a really useful piece of kit, and wonder if I could step them up to bore out the hole without even any drillings ops… Ive no experience with adjustable reamers so any input on them would be appreciated!

I have rebuilt the motor now, and it runs really smooth and quiet. I plan to modify a cheap bottle jack or make a screwjack with a fixture that bolts to the underside of the table to allow me to adjust the height with much greater ease. I won on eBay secondhand a machine vice that looks to be good quality (will see when it arrives) and have made my first step into tooling up with an RDG tools order of some essentials!

I hope everyone is keeping in good health – hopefully this is the last big lockdown and normality will start to creep in again in the summer!

Cheers!!

Toby

[Peter G. ShawParticipant @peterg-shaw75338]

Toby,

As a fellow CH10 owner who has done two relatively minor mods to this machine, I'd like to ask you to write up your modifications for MEW, including the problems and failures that have arisen, failures especially because then other users have an idea of where to be over cautious. I would certainly be interested, and I rather suspect that there will be others. Writing it up for MEW has the advantage that there is then a permanent record of the modifications – doing it on the forum runs the risk that the modifications get forgotten

Regards,

Peter G. Shaw

[Toby JonesParticipant @tobyjones79461]

Hi Peter

I certainly could if there is enough interest – although I am fortunate enough to still be working full time at the moment so may be as and when I get the chance!

I am still very new to the forums and how everything is set up, is that just a means of writing up and emailing off to someone?

Kind Regards,

Toby

[Peter G. ShawParticipant @peterg-shaw75338]

Toby,

Ideally, for publication you will need photos (taken as the project proceeds), drawings & text. Drawings & text can be done on completion although I have tended to do them as the project proceeds, but then I'm retired so plenty of time. Photos can be labelled up afterwards as required.

The whole lot should be sent to Neil Wyatt and the information of how to do that is knocking around somewhere. There are also some guidelines about, again knocking around somewhere.

Neil won't like this next bit, so sorry Neil, but if it could be done as a single article then that will go down well with Neil, but he will accept multi-part articles. Apparently, Neil has lots of multi-part articles & not enough single part articles.

Note as well that Neil & the rest of the editorial staff are quite capable of cleaning it up to publication standards.

Look forward to reading all about it at some future time.

Regards,

Peter G. Shaw

[Toby JonesParticipant @tobyjones79461]

Hi All,

As Peter suggested I compile this into a more comprehensive write up I shall update you all once I have it complete! Thank you peter for the relevant contacts – I shall get in touch with them once I have my act together!

For a brief update – a member on here very kindly posted me some old parts from a since gone CH10 drill. Unfortunately the quill teeth did not index on my press gear. Upon inspection it is identical in form to the Sealey quill and mates to the press gear of the one purchased from sealey on a whim. From inspecting various CH10 drills on ebay, it looks like anything PRE 95 has the early spindle and switch mounting, and post 95 has the later press gear and switch housing. It appears my 1995 model is a somewhat b*stard – taking the early spindle and later switch mounting and electronics – making it a unique challenge for parts!

I am pretty confident in stating anything nutool 95 or later is identical to current offerings by sealey, warco etc of the 5 speed drill variant – hopefully that helps anyone trying to get spares for their own machines!

I will continue to document what repairs or modifications to the drill press and likely take the very useful advice given by all in previous messages on this thread. I will post some photos how I get on! Hopefully I will get a chance this week at work to give a few things a try….

In the meantime I finally have built a substantial workbench – I may be without a drill press, but I now have a place to sufficiently hammer it to pieces until it works

Cheers!

Toby

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