# Sage DTP pump pressure control mod



## joey24dirt (Jan 28, 2017)

I had a seed planted firmly in my head recently about whether you could get some form of pressure profiling on the go with the DTP. It turns out you can so here's a quick write up of how I carried out my mod and how it performs.

First I wanted to install gauge so I could see what pressure I had going to the pf. This was a simple enough task and I just added a T piece to the line coming out of the pump.










The pipework is 4mm plastic. Parts are readily available to use push-fit fittings so that's what I did. I decided that to cause the least disruption I would use the tamper dock for my gauge.










The gauge is obviously upside down but it doesn't matter. It actually makes it easier to read rather than stooping down to look.










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Next I ordered up a voltage regulator from overseas










Simple enough to fit, just slip it in there before the pump and take control over the voltage going to it.

Location was decided by the space inside. Looking back if I were to do another, I would remove the adjusting pot and add some lengths of wire. That way the control dial could be mounted in other locations away from the main board.










First of all I did a dry run to check it worked. Once happy I started to chop up and drill my machine



















Controller in place it's now time for wiring.

***please ensure you have the machine isolated from the mains before starting any of this work. Probably should've mentioned this at the start***

Remove connections from pump and direct these into the controller. Then make up some more wiring to go from the controller into the pump.










You should be now in a position to test this now. Literally just run the machine and turn the dial. You should now be able to control the voltage going into the pump.

I can go into further details later, I just wanted to get the thread started off and then get into it properly. This opening post is long enough haha

Cheers


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## salty (Mar 7, 2017)

I don't have a DTP but I'm totally engrossed in the project and in awe of your technical skills, spirit of adventure and bravery when it comes to chopping up your pride and joy. And all while feeding your kids and making a nice flat white for Mrs Joey complete with latte art #whataguy


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## joey24dirt (Jan 28, 2017)

salty said:


> I don't have a DTP but I'm totally engrossed in the project and in awe of your technical skills, spirit of adventure and bravery when it comes to chopping up your pride and joy. And all while feeding your kids and making a nice flat white for Mrs Joey complete with latte art #whataguy


Very kind words indeed. I have this constant urge to fettle things and put to good use some bits I've learnt so far in life. I blame my grandad who passed when I was a lad. He's was the same from what I remember


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## joey24dirt (Jan 28, 2017)

The finished product is a nice looking little dial that is easy to get at 



















I've just took a quick video of it in operation so I'll get that uploaded. Just shows a basic adjustment (definitely not the best cameraman)

One thing I've found is that if you adjust the voltage down before the pre-infusion has finished, you get a temporary pump stall. It's a split second so hopefully won't cause any long term effects.


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## ajohn (Sep 23, 2017)

Me thinks that the "voltage regulator" is an scr dimmer such as

https://www.ebay.co.uk/itm/2000W-SCR-Voltage-Regulator-Light-Controller-Dimmer-For-Lamps-Water-Heater/261487473060?epid=754591643&hash=item3ce1de31a4:g:69IAAOxyaURTfrN9

This brings up loads of them

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR1.TRC0.A0.H0.Xscr+dimmer.TRS0&_nkw=scr+dimmer&_sacat=0

There are some 4000w 4 terminal ones about as well about.

John

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## joey24dirt (Jan 28, 2017)

ajohn said:


> Me thinks that the "voltage regulator" is an scr dimmer such as
> 
> https://www.ebay.co.uk/itm/2000W-SCR-Voltage-Regulator-Light-Controller-Dimmer-For-Lamps-Water-Heater/261487473060?epid=754591643&hash=item3ce1de31a4:g:69IAAOxyaURTfrN9
> 
> ...


That's them  like I say I think having the pot on a separate loom would be way easier. Chopping through that composite plastic shite was a nightmare that could've been avoided


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## joey24dirt (Jan 28, 2017)

I always forget to turn the phone on its side lol. Sorry for the rubbish video.


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## ashcroc (Oct 28, 2016)

joey24dirt said:


>


Great vid & mod. Can't wait for you to get bored & turn a new knob out of an old scateboard.


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## joey24dirt (Jan 28, 2017)

ashcroc said:


> Great vid & mod. Can't wait for you to get bored & turn a new knob out of an old scateboard.


Haha which one? The middle sage one?

I'm going to do a few for the aergrinds soon when I get chance so might pop a few on the forum if people are interested


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## Gaz| (Nov 29, 2017)

Great mod Joey! Are you guessing the dial before each shot or have you got a marker/line to square it up with? I see you then the dial back at the end, is this to put it back to full for the pre-infusion of the next cup? Cheers buddy


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## joey24dirt (Jan 28, 2017)

Gaz| said:


> Great mod Joey! Are you guessing the dial before each shot or have you got a marker/line to square it up with? I see you then the dial back at the end, is this to put it back to full for the pre-infusion of the next cup? Cheers buddy


Cheers mate. I haven't had much of a play with it so I'd need to figure out maybe marking it up like you say, so I can set it before starting.

I returned it back to normal at the end for steaming. I'm guessing it would need full pump voltage to keep the steam as it should be.

I need like a numbered disk don't I to stick behind the dial. Would look better than I marker pen haha


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## haz_pro (Apr 4, 2013)

Looks great.

Is there a way to turn the guilt in pre-infusion off? Feels like you'd have more control and repeatability if you could just start the process of brew with the voltage regulator turned down low, then slowly turn it up.

Either way, well done, makes me want to try the mod on my classic!


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## joey24dirt (Jan 28, 2017)

haz_pro said:


> Looks great.
> 
> Is there a way to turn the guilt in pre-infusion off? Feels like you'd have more control and repeatability if you could just start the process of brew with the voltage regulator turned down low, then slowly turn it up.
> 
> Either way, well done, makes me want to try the mod on my classic!


I'm not sure to be honest. There's a few circuit boards inside to control the pre-infusion. My guess is it's just on a timer but I'm not too sure if I would be brave enough to try and by-pass this.

I've I'd have bagged one of the £100 DTP's from Debenhams then it might have been a different story, at least I'd have had a spare haha


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## Gaz| (Nov 29, 2017)

Ahh yes steam! Lol have you tried out the minimum and maximum settings on it? Would be interesting to see the range in bar pressure these can do!

Was there a noticeable difference in taste at 4 bar?

And yeah a numbered dial would be perfect.. could even have it orientated to bar pressure as well!


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## joey24dirt (Jan 28, 2017)

Gaz| said:


> Ahh yes steam! Lol have you tried out the minimum and maximum settings on it? Would be interesting to see the range in bar pressure these can do!
> 
> Was there a noticeable difference in taste at 4 bar?
> 
> And yeah a numbered dial would be perfect.. could even have it orientated to bar pressure as well!


Who do we know on here who does laser etching??!! 

I'll have to have a look for a dial.

With regards to taste and texture, I definitely feel it's made a positive difference. It's probably opened a huge can of worms also haha!

I need to have a play about with it and try it at different pressures. I'm about to run out of the beans I'm using so I'll wait until I start my next bag to get right into it.

So far so good though


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## Gaz| (Nov 29, 2017)

joey24dirt said:


> Who do we know on here who does laser etching??!!
> 
> I'll have to have a look for a dial.
> 
> ...


Haha fantastic.. as long as you taste a difference for the better.. it's been worth it lol.

As for the dial, if you just made a template and scribed some lines on for different bar pressure, you could post it over and I could try knock you one up no problem.


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## joey24dirt (Jan 28, 2017)

Gaz| said:


> Haha fantastic.. as long as you taste a difference for the better.. it's been worth it lol.
> 
> As for the dial, if you just made a template and scribed some lines on for different bar pressure, you could post it over and I could try knock you one up no problem.


I'll see what I can do. We use dosing pumps at work that have dials on that are about that size so I may steal one of those haha.


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## ajohn (Sep 23, 2017)

The same part can be bought with the pot on flying leads

https://www.amazon.co.uk/gp/product/B075QFQN7S/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Or much cheaper from Hong Kong etc on ebay. I have one to fit to my popcorn machine for bean roasting. So far it's gained a switch to select blow and heat or just blow on it's own.

I wonder what happened to the OPV mod ? The dual boiler machine clearly uses 10 bar or more. Going on another thread the single basket on that holds well over 10g -







maybe dual boiler owners deserve stronger coffee 'cause they paid more. It sounds like the single on these is at least 12g. Now aint that weird. It's what I reckon I can't live without and adding a 14g as well would be even better.

From my experience on the BE an 8 1/2 bar setting would be a big help but based on an assumption that the ticks on the gauge are bar and the rate the drip tray fills up is due to the OPV opening. I can't help wondering why they have set it lower but it seems Gaggia do the same thing on their small model. I wondered if it was down to strength of the plastic grouphead but have my doubts. That could be beefed up anyway by adding the sort of wire or lightweight circlips cars use on rubber coolant pipes around the existing metal trim. They tend to offer more even pressure than the usual sort.








The BE uses a fixed 10 sec infusion.

I just ran a cleaning cycle on it. The fact that the tablet is in the central depression on the rubber disk does seem to initially allow it to generate higher pressure until it's washed away.

John

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## kennyboy993 (Jan 23, 2017)

joey24dirt said:


> Haha which one? The middle sage one?
> 
> I'm going to do a few for the aergrinds soon when I get chance so might pop a few on the forum if people are interested


Please put me on the list for an aergrind handle joey ;-)

Congratulations on the mod - amazing what you've done. I just hope breville/sage are watching.


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## joey24dirt (Jan 28, 2017)

kennyboy993 said:


> Please put me on the list for an aergrind handle joey ;-)
> 
> Congratulations on the mod - amazing what you've done. I just hope breville/sage are watching.


I've just bought myself some new wood chisels so when they arrive I'll knock some up


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## PPapa (Oct 24, 2015)

Awesome work Joe!


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## joey24dirt (Jan 28, 2017)

A thought just popped into my head. This works similar with my hot water in the house.

Because I'm slowing down the flow of water, I'm giving the water more time in the coil.

This will potentially give me an increase in temperature. Looks like I'll be adding a temp gauge to see


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## joey24dirt (Jan 28, 2017)

So after a few days of use I'm having mixed results. I've found my usual 1:2 ratio is leaving things a little sour, so I have increased this and now the shots are better. Last one I ran was 16g>42g and tried to sit at about 6 bar.

Didn't realise that the pressure would drop so much the further through the pull you went lol.

Every day is a school day.

Definitely need a victim who knows coffee to give them a try for me


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## hotmetal (Oct 31, 2013)

You are brave bud I'll give you that! Probably right about the temp on a thermo coil machine. You'd really need to measure temp in the basket though, so you'd need a thing like DavecUK knocked up that simulates a puck but has a thermocouple embedded in the centre.

Might also be tempted by a handle for my Aergrind as an ex-skater myself.


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## joey24dirt (Jan 28, 2017)

Well this post is mainly for my own benefit really so I can remember later.

Ran the machine at about 50% pump power from the start.

17.5g in of the django 38g in 40 seconds. Driest puck I've had for a while.

Delicious shot with lots of fruity notes. Very happy that the last shot of 2017 was one of my best.

Happy new year lol


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## joey24dirt (Jan 28, 2017)

As I couldn't drink last night and everyone was in bed, I thought I would tidy up the plumbing for the gauge.

I made up some new hoses (re-used original ends) and squared and secured it all up.










If anyone is thinking of doing this mod and needs hose then let me know. I have 30 meters of the stuff!


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## 9719 (Mar 29, 2015)

If anyone is thinking of doing this mod and needs hose then let me know. I have 30 meters of the stuff!

Judging by the rapidly increasing DTP membership lately, you'll soon need to be restocking that hose and other parts, in Joey's stores.


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## joey24dirt (Jan 28, 2017)

mines_abeer said:


> If anyone is thinking of doing this mod and needs hose then let me know. I have 30 meters of the stuff!
> 
> Judging by the rapidly increasing DTP membership lately, you'll soon need to be restocking that hose and other parts, in Joey's stores.


I should put a kit together


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## Rakesh (Jun 3, 2017)

This is seriously impressive, you've transformed your DTP, makes me miss mine!


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## Gaz| (Nov 29, 2017)

You could be right about the temp Joey.. And as you've found out the difference in tastes of shots could well be why the shots are tasting different if you've got an increase in temperature (I'm guessing increase as if you've slowed down the flow of water the longer the water has in the coil to heat up?)..

The only thing I can think of that would change this would be a built in thermostat by sage? If they have a temp set at say 93deg it shouldn't matter how long the water stays in there as it should still stay at 93? Thoughts?


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## -Tristan- (Jan 2, 2020)

joey24dirt said:


> I had a seed planted firmly in my head recently about whether you could get some form of pressure profiling on the go with the DTP. It turns out you can so here's a quick write up of how I carried out my mod and how it performs.
> 
> First I wanted to install gauge so I could see what pressure I had going to the pf. This was a simple enough task and I just added a T piece to the line coming out of the pump.
> 
> ...


 Just stumbled across this because I wanted to see what the inside looked like, then found this post. I'm also in awe of your ability, your grandfather sounds like he was very gifted indeed!


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## Border_all (Dec 19, 2019)

ashcroc said:


> Great vid & mod. Can't wait for you to get bored & turn a new knob out of an old scateboard.





> On 26/12/2017 at 23:41, joey24dirt said:


 That is seriously tricked ?


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## joey24dirt (Jan 28, 2017)

Border_all said:


> That is seriously tricked


Hopefully still is wherever it may be.

Sent from my iPhone using Tapatalk


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## Waveafter2 (Mar 13, 2021)

@joey24dirtSo I have done your modification to my machine, but I cannot seem to get the pressure gauge to read. Do you know if you used a special kind of gauge or something?


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## bunsofjam (Sep 13, 2021)

Hey Joey, don't know if I can loop back to this post, looks like last comment was about 4 years ago.

I'm curious if you need to add the voltage regulator in order to add the gauge, or if Its possible for me JUST to mod the gauge on to the machine. I really want to try and add the pressure gauge but don't know if I need/want to mess with the electronic side of my machine.

Cheers,

Benjamin.


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## El carajillo (Mar 16, 2013)

As Joey said, he just 'teed' of the flow from the pump, but without the electronics you will not be able to vary the pressure./flow.

The gauge will work but as above you will have a relatively stable pressure.


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## Ybo (Oct 14, 2021)

You can definitely put just the gauge and not the rest. However, all that will show is the pump pressure wich should be constant at 9 bars during extraction.

what Joey did is add a voltage regulator to control the pump and vary the pression over time. It's basically flow control...

Joey, if you read this, I think you should have tried to put the gauge between the heatin block and the group head. That way, you would read blockhead pressure ( which is what matters) and not just pump pressure. I agree that both are related but still...


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